Water Quality Information
Center of
the National Agricultural Library
Agricultural Research Service, U.S. Department of Agriculture
Simulation Models, GIS and Nonpoint-Source Pollution (III)
November, 1994-September, 1995
196 citations from AGRICOLA
by
Diane Doyle
Water Quality Information Center
**************************************************************
This electronic bibliography is intended primarily to provide
awareness of recent investigations and discussions of a topic and
is not intended to be in-depth and exhaustive. The inclusion or
omission of a particular publication or citation should not be
construed as endorsement or disapproval.
Send suggestions for electronic bibliographies related to water
resources and agriculture to wqic@nal.usda.gov
To locate a publication cited in this bibliography, please
contact your local, state, or university library. If you are
unable to locate a particular publication, your library can
contact the National Agricultural Library (please see "Document
Delivery Services" at
http://www.nal.usda.gov/ddsb).
************************************************************
SIMULATION MODELS, GIS AND NONPOINT-SOURCE POLLUTION (III)
1. Adaptive modified method of characteristics to solve the
one-dimensional solute transport equation.
Lui, H. H.; Dane, J. H.; Guven, O.
Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of
America. May/June 1995. v. 59 (3) p. 677-683.
Includes references.
Descriptors: solutes-; movement-in-soil; transport-processes;
dispersion-; equations-; mathematical-models; simulation-models;
advection-
Abstract: Simulation of advection-dominated solute transport in a
porous medium is complicated due to the inherent problems of
numerical dispersion and oscillation. We propose an adaptive
modified method of characteristics (AMMOC) to simulate
one-dimensional, advection-dominated solute transport problems,
which incorporates the advantage of a self-adaptive spatial grid
system with the computational power of the modified method of
characteristics (MMOC) to deal with numerical dispersion and
oscillation. The numerical simulations, including a pure
advection problem, show that the AMMOC is free of oscillation,
approximately global mass conservative, and exhibits
insignificant numerical dispersion. Related to this method, three
interpolation schemes to obtain the concentration of the
fictitious particle at the previous time step were also
evaluated. Our simulations show that the AMMOC, based on a
clipped quadratic interpolation schemes provides the most
accurate results.
NAL Call No.: 56.9-So3
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2. AGNPS tracks pollutants to their source.
Comis, D.
Agric-res v.43, p.22. (1995).
Descriptors: watersheds-; water-pollution; sources-;
computer-software; models-; pollutants-; tracking-
NAL Call No.: 1.98-Ag84
*****************************************************************
3. Alternative river management using a linked GIS-hydrology
model.
Rosenthal, W. D.; Srinivasan, R.; Arnold, J. G.
Trans-ASAE v.38, p.783-796. (1995).
Includes references.
Descriptors: rivers-; water-quality; simulation-models;
information-systems; hydrological-data; stream-flow; soil-;
land-use; weather-; texas-
Abstract: A geographic information system (GIS)-hydrologic model
link was used to aid in forming input files for the hydrologic
model, SWAT (Soil and Water Assessment Tool). The link and SWAT
prediction of streamflow volume were then tested for the Lower
Colorado River basin of Texas. With no calibration, simulated
monthly streamflow volume along the river was underestimated for
the extreme events, but the relationship was significant (R2 =
0.75). Model results also suggest that urbanization further
upstream can significantly affect streamflow downstream. The
system is general enough to be applicable to other river systems.
NAL Call No.: 290.9-Am32T
*****************************************************************
4. Analysis of nitrogen saturation potential in Rocky Mountain
tundra and
Baron, J. S.; Ojima, D. S.; Holland, E. A.; Parton, W. J.
Biogeochemistry v.27, p.61-82. (1994).
Includes references.
Descriptors: air-pollution; nitrogen-; deposition-;
nitrogen-cycle; nitrogen-metabolism; soil-flora;
biological-activity-in-soil; forest-soils; tundra-soils;
mountain-soils; subalpine-forests; leaching-; watersheds-;
lakes-; streams-; water-quality; simulation-models; colorado-
NAL Call No.: QH345.B564
*****************************************************************
5. Analytical modelling of pesticide transport from the soil
surface to a drinking water well.
Beltman, W. H. J.; Boesten, J. J. T. I.; Zee, S. E. A. T. M. v.
d.
J-hydrol v.169, p.209-228. (1995).
Includes references.
Descriptors: pesticides-; leaching-; water-flow; drinking-water;
wells-; water-quality; groundwater-pollution; mathematical-models
Abstract: Pesticide transport through the unsaturated zone was
modelled with an analytical solution of the convection-dispersion
equation assuming steady water flow, a linear sorption isotherm
and first-order transtormation kinetics. Pesticide behaviour in
the saturated zone was described with an analytical solution of
the mass balance equation for a cylindrical flow system assuming
steady flow, no dispersion, linear sorption and first-order
transformation. This simplified model for the
unsaturated-saturated soil system was developed to identify the
processes and parameters with the greatest impact on the fraction
of applied pesticide reaching a drinking water well. Leaching
from the unsaturated zone was highly sensitive to the parameters
describing travel time and transformation rate. Leaching
increased when heterogeneity of the soil was taken into account.
Pesticide arrival in the well was only moderately sensitive to
the characteristic travel time and transformation rate in the
aquifer. However, this sensitivity increases if zones without
pesticide application were introduced around the wells
(protection zones). For representative sandy soils under average
Dutch rainfall conditions, processes in the unsaturated zone had
a much larger impact on pesticide arrival in the wells than
processes in the saturated zone. Protection zones reduced
pesticide transport to wells substantially if their half-life was
much smaller than the characteristic travel time of the pesticide
in the aquifer.
NAL Call No.: 292.8-J82
*****************************************************************
6. An analytical solution for predicting solute transport during
ponded infiltration.
Huang, K.; Van Genuchten, M. T.
Soil-sci v.159, p.217-223. (1995).
Includes references.
Descriptors: solutes-; transport-processes; unsaturated-flow;
standing-water; infiltration-; mathematical-models
NAL Call No.: 56.8-So3
*****************************************************************
7. Analytical solutions for one-dimensional colloid transport in
saturated fractures.
Abdel Salam, A.; Chrysikopoulos, C. V.
Adv-water-resour v.17, p.283-296. (1994).
Includes references.
Descriptors: groundwater-flow; pollutants-; colloids-; rocks-;
fracture-; soil-parent-materials; transport-processes;
equations-; mathematical-models; simulation-models; rock-matrix
NAL Call No.: TD201.A4
*****************************************************************
8. Answers 2000: continuous simulation version.
Bouraoui, F.; Dillaha, T. A. I.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1994. (94-2120/94-2155) 28 p.
Paper presented at the 1994 International Summer Meeting,
sponsored by the ASAE, June 19-22, 1994, Kansas City, Missouri.
Descriptors: watersheds-; water-quality; water-pollution;
nitrogen-; phosphorus-; sediment-; losses-from-soil; runoff-;
erosion-; simulation-models
NAL Call No.: 290.9-Am32P
*****************************************************************
9. Application of GLEAMS to predict nutrient losses from land
application of poultry litter.
Yoon, K. S.; Yoo, K. H.; Wood, C. W.; Hall, B. M.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1993. (932080) 17 p.
Paper presented at the "1993 International Summer Meeting
sponsored by The American Society of Agricultural Engineers, and
The Canadian Society of Agricultural Engineering," June 20-23,
1993, Spokane, Washington.
Descriptors: poultry-manure; nutrients-; losses-;
application-to-land; water-quality; models-; computer-software
NAL Call No.: 290.9-Am32P
*****************************************************************
10. Application of the MAGIC model to the Glacier Lakes
catchments.
Reuss, J. O.
Res-pap-RM. [Fort Collins, Colo.] : Rocky Mountain Forest and
Range Experiment Station, Forest Service, U.S. Dept. of
Agriculture, 1978-. June 1994. (315) 19 p.
Includes references.
Descriptors: acid-rain; watersheds-; catchment-hydrology;
streams-; water-quality; simulation-models; national-forests;
wyoming-; medicine-bow-national-forest
NAL Call No.: A99.9-F7632U
*****************************************************************
11. Application of the precipitation-runoff modeling system model
to simulate dry season runoff for three watersheds in
south-central Guam. Application of the precipitation runoff
modeling system model to simulate dry season runoff for three
watersheds in south-central Guam.
Nakama, L. Y.; United States. Navy Dept.
Honolulu, Hawaii : U.S. Dept. of the Interior, U.S. Geological
Survey ; Denver, CO : Earth Science Information Center, Open-File
Reports Section [distributor], 1994. v, 38 p. : ill., maps.
Shipping list no.: 95-0091-P.
Descriptors: Precipitation-Meteorology-Guam; Runoff-Guam
NAL Call No.: GB701.W375--no.93-4116
*****************************************************************
12. Application to geostatistics for mapping nitrate contaminated
groundwater.
Dou, C.; Woldt, W. E.; Dahab, M. F.; Bogardi, I.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1994. (94-2091/94-2119) 15 p.
Paper presented at the "1994 International Summer Meeting
sponsored by the American Society of Agricultural Engineers,"
June 20-23, 1994, Kansas City, Missouri.
Descriptors: nitrate-nitrogen; groundwater-pollution; kriging-;
simulation-models
NAL Call No.: 290.9-Am32P
*****************************************************************
13. Assessing nonpoint-source pollution risk: a GIS application.
Lull, K. J.; Tindall, J. A.; Potts, D. F.
J-for v.93, p.35-40. (1995).
Includes references.
Descriptors: water-pollution; risk-;
geographical-information-systems; land-use; watersheds-;
montana-; risk-assessment
NAL Call No.: 99.8-F768
*****************************************************************
14. Assessment of in situ solvent extraction for remediation of
coal tar
Ali, M. A.; Dzombak, D. A.; Roy, S. B.
Water-environ-res v.67, p.16-24. (1995).
Includes references.
Descriptors: tars-; coal-; gasification-; industrial-sites;
groundwater-pollution; pollutants-; contaminants-; solvents-;
extraction-; simulation-models; wells-; power-industry;
manufactured-gas-plants; recovery-wells; injection-wells
NAL Call No.: TD419.R47
*****************************************************************
15. Assessment of in situ solvent extraction for remediation of
coal tar
Roy, S. B.; Dzombak, D. A.; Ali, M. A.
Water-environ-res v.67, p.4-15. (1995).
Includes references.
Descriptors: tars-; coal-; gasification-; industrial-sites;
groundwater-pollution; pollutants-; contaminants-; solvents-;
extraction-; equations-; mathematical-models; power-industry;
manufactured-gas-plants; nonqueous-phase-liquids
NAL Call No.: TD419.R47
*****************************************************************
16. Assessment of the fate of two herbicides in a Wyoming
rangeland soil: column studies.
Krzyszowska, A. J.; Allen, R. D.; Vance, G. F.
J-environ-qual v.23, p.1051-1058. (1994).
Includes references.
Descriptors: dicamba-; picloram-; leaching-; persistence-;
sorption-; soil-organic-matter; degradation-; rangeland-soils;
groundwater-pollution; simulation-models; LEACHP-model
Abstract: Extensive use of dicamba (2-methoxy-3,6-dichlorobenzoic
acid) and picloram (4-amino-3,5,6-trichloropicolinic acid) in
arid Wyoming, along with large volumes of irrigation water used
in some areas, has created a concern for the potential
contamination of surface and groundwaters by these herbicides.
Persistence and mobility of dicamba and picloram were
investigated in a Wyoming rangeland soil using batch adsorption
and soil column studies. The objectives of this study were to
characterize soil chemical and physical properties that affect
herbicide transport, examine herbicide sorption, model herbicide
movement, and estimate degradation rate constants. Essentially no
sorption of dicamba was detected; however, picloram sorption was
greatest in the highest organic C content horizon. Both saturated
(5.90, 2.96, and 0.82 kg ha-1 dicamba and 1.85, 0.97, and 0.47 kg
ha-1 picloram) and unsaturated (2.76 and 1.00 kg ha-1 for dicamba
and picloram, respectively) column experiments were conducted.
The herbicides and Br tracer (34, 38, 69, and 137 micrograms L-1)
were displaced through the soil columns using distilled water
that was added in daily increments (60 mL d-1). Degradation rate
constants were calculated using both simple recovery fraction
technique and by matching LEACHP-generated breakthrough curves to
experimental data. For the two columns receiving intermediate
application rates, anaerobic picloram dissipation was more rapid
(t1/2 = 19 d) than for aerobic conditions (t1/2 = 87 d). The rate
of dissipation of dicamba was approximately the same under
aerobic and anaerobic conditions (t1/2 = 15 and 17 d in the
saturated and unsaturated columns, respectively). Picloram and
dicamba dissipation was more rapid at. application rates, t1/2
of 23 and 17 d were measured for picloram and dicamba,
respectively. Both herbicides were found to be highly mobile,
with the mobility of picloram increasing at higher pore-water
velocities.
NAL Call No.: QH540.J6
*****************************************************************
17. Changes in acidification of lochs in Galloway, southwestern
Scotland,
Wright, R. F.; Cosby, B. J.; Ferrier, R. C.; Jenkins, A.; Bulger,
A. J.; Harriman, R.
J-hydrol v.161, p.257-285. (1994).
Includes references.
Descriptors: watersheds-; acid-deposition; ions-; acidification-;
soil-chemistry; water-quality; afforestation-; deforestation-;
fishes-; population-density; simulation-models; prediction-;
scotland-; water-chemistry; critical-load
Abstract: Decades of acid deposition in the Galloway area,
southwestern Scotland, have resulted in acidification of surface
waters and damage to fish. In the period since 1980, however,
acidic deposition has decreased substantially. A survey of 50
lochs conducted in 1979 and repeated in 1988 reveals major
changes in water chemistry over this 9 year period. Together
these two data sets separated in time by 9 years and covering a
period of relatively large and rapid change in acid deposition
offer a valuable basis for the evaluation of acidification
models. Concentrations of SO4 in the lochs were on the average
42% lower in 1988 relative to 1979. The decline is readily
explained by the large and rapid decline in sulphate
concentrations in precipitation in the area. Concentrations of
non-marine base cations decreased from 155 to 90 microequiv l-1
and acid neutralising capacity (ANC) increased. The change in ANC
was due mostly to decreased concentrations of Al. pH levels
showed no systematic change from 1979 to 1988. The regional
changes in water chemistry over the period 1979-1988 are
corroborated by regular measurements at several of these lochs
over this 9 year period. MAGIC (Model for Acidification of
Groundwater In Catchments) successfully reproduces the major
changes in water chemistry observed over the period 1979-1988.
Both calibration to the 1979 data with prediction of 1988, and
calibration to the 1988 with reconstruction of 1979 give close
fits to the observations. The model provides a means by which the
future impact of acidic deposition and afforestation can be
evaluated. A fish response function coupled to MAGIC provides the
basis for evaluation of past and future fish status in the
region. MAGIC. indicate that if acidic deposition is held
constant at 1988 levels, afforestation causes further
acidification of the lochs. Acidic deposition emerges as the
major cause of soil and water acidification in the Galloway
region, although forestry practices can exacerbate the effects.
NAL Call No.: 292.8-J82
*****************************************************************
18. CHEMFRANCE: a regional level III fugacity model applied to
France.
Devillers, J.; Bintein, S.; Karcher, W.
Chemosphere v.30, p.457-476. (1995).
Includes references.
Descriptors: air-pollution; soil-pollution; water-pollution;
groundwater-pollution; pollutants-; organic-compounds; movement-;
simulation-models; computer-simulation; france-;
environmental-fate
NAL Call No.: TD172.C54
*****************************************************************
19. Chemical leaching near the Waiawa Shaft, Oahu, Hawaii. 2.
Modeling results.
Loague, K.; Miyahira, R. N.; Green, R. E.; Oki, D. S.;
Giambelluca, T. W.; Schneider, R. C.
Ground-water. Dublin, Ohio : Ground Water Pub. Co. Jan/Feb 1995.
v. 33 (1) p. 124-138.
Includes references.
Descriptors: groundwater-pollution; chlorpyrifos-; diazinon-;
metribuzin-; nitrate-; leaching-; simulation-models;
mathematical-models; groundwater-recharge; hydrology-;
water-table; hawaii-; pesticide-root-zone-model
NAL Call No.: TD403.G7
*****************************************************************
20. Chemical processes controlling the mobility of waste material
contaminants in soils.
Wesselink, L. G.; Dekker, P. M.; Aalbers, T. G.
Stud-environ-sci. Amsterdam ; New York, Elsevier Scientific
Publishing Co. 1994. (60) p. 31-38.
In the series analytic: Environmental aspects of construction
with waste material / edited by J.J.J.M. Goumans, H.A. van der
Sloot and T.G. Aalbers. Implications of Construction Materials
and Technology Developments," held June 1-3, 1994, Maastricht,
The Netherlands.
Descriptors: slags-; building-materials; leaching-; percolation-;
leachates-; sandy-soils; soil-chemistry; chemical-speciation;
simulation-models; steel-slag; phosphorus-slag
NAL Call No.: QH540.S8
*****************************************************************
21. Climate, interseasonal storage of soil water, and the annual
water balance.
Milly, P. C. D.
Adv-water-resour v.17, p.19-24. (1994).
In the special issue: MIT Colloquium on Hydroclimatology and
Global Hydrology / edited by I. Rodriguez-Iturbe, D. Entekhabi
and R.L. Bras.
Descriptors: soil-water-balance; soil-water; seasonal-variation;
rain-; evaporation-; water-holding-capacity; climate-; runoff-;
simulation-; simulation-models; mathematical-models; equations-;
southern-states-of-usa; north-central-states-of-usa;
northeastern-states-of-usa
NAL Call No.: TD201.A4
*****************************************************************
22. Climatic variability of soil water in the American Midwest.
1. Hydrologic modeling.
Bae, D. H.; Georgakakos, K. P.
J-hydrol v.162, p.355-377. (1994).
Includes references.
Descriptors: soil-water; catchment-hydrology; stream-flow; rain-;
temperature-; evapotranspiration-; temporal-variation;
spatial-variation; hydrological-data; simulation-models; rivers-;
minnesota-; iowa-; rainfall-runoff-models;
des-moines-river-basin; mississippi-river-system
Abstract: A conceptual hydrologic rainfall-runoff model that is
an adaptation of the operational US National Weather Service
hydrologic model is used to simulate the hydrologic processes in
large basins of the US upper Mississippi region. In particular,
the conceptual rainfall-runoff model is used to produce daily
streamflow from daily rainfall, temperature and potential
evapotranspiration input over three neighboring headwater basins
that span 2 degrees longitude by 2 degrees latitude. When used
for simulation of historical flows, the model provides a means of
inference of the 40 year time series of unrecorded mesoscale soil
water and actual evapotranspiration for climate studies. In this
paper we discuss issues associated with parameter estimation, the
reliability and stability of parameter estimates, and the
interpretation of soil water estimates. It is concluded that the
conceptual hydrologic model may be used to estimate the
variability of aggregate soil water over large areas of the
Midwestern US provided that: (a) all significant basin inflows
and outflows are accounted for; (b) model verification yields
good agreement between observed and simulated flows on a daily
basis. Parameter sensitivity studies showed that estimating the
soil's capacity to hold water is most important for flood event
prediction and flow simulation, and, for such parameters,
underestimation is more critical than overestimation. Also,
uncertainty associated with the parametrization of
evapotranspiration may introduce local errors in the time series
of soil water estimates produced by the model. In a companion
paper we present a spatio-temporal analysis of the estimated time
series of soil water.
NAL Call No.: 292.8-J82
*****************************************************************
23. Combined use of watershed, aquifer and crop simulation models
to evaluate groundwater recharge through percolation ponds.
Selvarajan, M.; Bhattacharya, A. K.; Penning de Vries, F. W. T.
Agric-syst v.47, p.1-24. (1995).
Includes references.
Descriptors: groundwater-recharge; ponds-; aquifers-;
watersheds-; simulation-models; percolation-; irrigation-;
runoff-; evapotranspiration-; india-;
catchment,-pond-and-aquifer-simulation-model-capsim;
catchment-pond-simulation-model-capsim
NAL Call No.: HD1.A3
*****************************************************************
24. Commodity information and willingness-to-pay for groundwater
quality protection.
Bergstrom, J. C.; Dorfman, J. H.
Rev-agric-econ v.16, p.413-425. (1994).
Includes references.
Descriptors: groundwater-; water-quality; valuation-;
regional-surveys; consumer-attitudes; information-;
mathematical-models; georgia-; dougherty-county,-georgia
Abstract: The potential sensitivity of environmental resource
valuations to information concerning the resource is of interest
to researchers and decision-makers involved in estimating and
applying these numbers. An analysis of the impact of
characteristic and service information on the economic value of
groundwater quality is described. Characteristic information
details the objectively measurable traits of a resource, while
service information describes the consumption services provided
by the resource. The analysis provides insight into the impact of
information on environmental resource valuation decisions.
Hypothesis tests suggest that changes in the joint levels of
information may cause significant changes in groundwater quality
valuation behavior. More theoretical and empirical research is
required before firm conclusions can be drawn concerning the
effects of information on groundwater value estimates (e.g.,
estimated willingness-to-pay for groundwater protection).
NAL Call No.: HD1773.A3N6
*****************************************************************
25. A comparative study of policy measures for groundwater
pollution control.
Oh, S. I.
J-rural-dev v.16, p.257-275. (1993).
Includes references.
Descriptors: nitrates-; groundwater-pollution; pollution-control;
taxes-; externalities-; environmental-policy; farm-inputs;
mathematical-models; comparisons-; water-use; social-costs;
pigouvian-taxes; input-taxes
NAL Call No.: HD2095.5-.J8
*****************************************************************
26. Comparison of erosion predictions with GLEAMS, GLEAMS-WT, and
GLEAMS-SWAT models for alluvial soils.
Reyes, M. R.; Bengtson, R. L.; Fouss, J. L.; Carter, C. E.
Trans-ASAE v.38, p.791-796. (1995).
Includes references.
Descriptors: alluvial-soils; erosion-; runoff-; drainage-;
simulation-models; prediction-; performance-appraisals;
louisiana-
Abstract: Simulation performances of GLEAMS, GLEAMS-WT, and
GLEAMS-SWAT were evaluated by comparing their soil loss
predictions with measured data from two runoff-erosion-drainage
experimental plots at Baton Rouge, Louisiana. One of the
experimental plots was surface drained only, and the other was
both surface and subsurface drained. Although the hydrology
components of GLEAMS-WT and GLEAMS-SWAT predicted surface runoff
more accurately than the original GLEAMS, all three models
seriously underpredicted total soil losses over a seven-year
period (1981 to 1987). Transport capacity limited soil loss
prediction values in the models. Hence, we recommend that any
changes or modifications in the erosion submodel be focused on
improving transport capacity simulation; changes in the
detachment simulation routine may not be needed. A calibration
parameter was added to the erosion subroutine to adjust transport
capacity. However, even when the models were calibrated for a
specific site, there were still substantial annual and monthly
differences between predicted and observed soil losses.
NAL Call No.: 290.9-Am32T
*****************************************************************
27. A conceptual model for ecological risk assessment of
bottomland hardwood forests.
Vellidis, G.; Lowrance, R.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Winter 1993. (93-2574) 23 p.
Paper presented at the "1993 International Winter Meeting
sponsored by the American Society of Agricultural Engineers,"
December 14-17, Chicago, Illinois.
Descriptors: hardwoods-; bottomland-forests; forest-ecology;
risk-; assessment-; water-quality; models-; georgia-
NAL Call No.: 290.9-Am32P
*****************************************************************
28. A conceptual model of the Galveston Bay ecosystem.
McFarlane, R. W.; Galveston Bay National Estuary Program.
[Webster, Tex.] : Galveston Bay National Estuary Program, [1993]
xii, 81 p. : ill., maps.
"October 1993.".
Descriptors: Estuarine-ecology-Texas-Galveston-Bay;
Environmental-protection-Texas-Galveston-Bay;
Water-quality-management-Texas-Galveston-Bay;
Coastal-zone-management-Texas-Galveston-Bay;
Ecosystem-management-Texas-Galveston-Bay; Galveston-Bay-Tex
NAL Call No.: QH541.5.E8P83--no.42
*****************************************************************
29. Conservation tillage a sustainable agricultural practice.
Lakshminarayan, P. G.; Bouzaher, A.; Johnson, S. R.
Environmentally sound agriculture proceedings of the second
conference 20-22 April 1994 / p.139-146. (1994).
Includes references.
Descriptors: zea-mays; glycine-max; continuous-cropping;
rotations-; conservation-tillage; tillage-; environmental-impact;
sustainability-; erosion-; erosion-control; nitrate-nitrogen;
losses-from-soil; leaching-; runoff-; water-quality;
simulation-models; statistical-analysis; conventional-tillage;
metamodels-
NAL Call No.: S589.7.E57-1994
*****************************************************************
30. Consideration of spatial variability in nitrate contamination
to groundwater.
Goderya, F. S.; Dahab, M. F.; Woldt, W. E.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1994. (94-2091/94-2119) 11 p.
Paper presented at the "1994 International Summer Meeting
sponsored by the American Society of Agricultural Engineers,"
June 20-23, 1994, Kansas City, Missouri.
Descriptors: nitrate-nitrogen; spatial-variation;
groundwater-pollution; simulation-models
NAL Call No.: 290.9-Am32P
*****************************************************************
31. Convection, dipersion, and interfacial transport of
contaminants: homogeneous porous media.
Quintard, M.; Whitaker, S.
Adv-water-resour v.17, p.221-239. (1994).
Includes references.
Descriptors: groundwater-pollution; pollutants-; contaminants-;
dispersion-; convection-; mathematical-models; equations-;
aquifers-; groundwater-flow
NAL Call No.: TD201.A4
*****************************************************************
32. CREAMS/WEPP sediment deposition equation: a semitheoretical
evaluation.
Storm, D. E.; Barfield, B. J.; Altendorf, C. T.
Trans-ASAE v.37, p.1105-1108. (1994).
Includes references.
Descriptors: water-erosion; sediment-; deposition-;
mathematical-models; equations-; simulation-models;
sediment-yield; erosion-models
Abstract: A semitheoretical evaluation of the sediment deposition
equation used in the CREAMS and WEPP models is presented. The
original deposition relationship was presented in the CREAMS and
WEPP models without theoretical or conceptual justification. In
this article, the relationship is shown to be based conceptually
on four characteristics: 1) uniform velocity distribution; 2) no
lateral sediment inflow; 3) discrete particle settling; and 4) a
uniform sediment concentration--all of which are violated under
typical field conditions. Why then does the deposition equation
work? The deposition equation, as applied to a rill, approximates
the trapping that would occur in a fully-turbulent, rectangular
reservoir if a rill is discretized into a large number of
sections. When only one rill section is utilized, the equation
approximates a quiescent reservoir. Since most shallow rills are
typically discretized into a number of sections and experience a
combination of turbulent and quiescent flows, the deposition
equation should provide a first approximation of field
conditions.
NAL Call No.: 290.9-Am32T
*****************************************************************
33. Crop nitrogen utilization and soil nitrate loss in a lettuce
field.
Jackson, L. E.; Stivers, L. J.; Warden, B. T.; Tanji, K. K.
Fertil-res v.37, p.93-105. (1994).
Includes references.
Descriptors: lactuca-sativa; nutrient-availability; nitrogen-;
nutrient-uptake; nitrate-; losses-from-soil; denitrification-;
leaching-; -; transformation-; nitrification-; mineralization-;
seasonal-variation; rain-; irrigated-conditions; shoots-; roots-;
nutrient-content; growth-; simulation-models; california-;
nitrogen-pools; cropped-period; non-cropped-period;
nitrogen-dynamics; erosion; productivity-impact-calculator-epic
Abstract: Low N use efficiency and high nitrate (NO3-) pollution
potentials are problems in intensive vegetable production
systems. The purpose of this study was to quantify N utilization
by lettuce (Lactuca sativa L. cv Salinas), and identify periods
of NO3- loss in an on-farm study in the Salinas Valley in coastal
California. During autumn and winter, surface moisture remained
low, and NO3- concentrations increased, reflecting high net
mineralizable N, as determined by anaerobic incubation, and
nitrification potential, as determined by the chlorate inhibition
method. At the onset of a large winter storm, tracer levels of
15NO3- were injected in the top 5 mm of soil in 30 cm-deep
cylinders. After two weeks, most of the 15N was present as 15NO3-
at 10-30 cm depth. By difference, losses to denitrification
accounted for approximately 25% of the surface-applied 15N.
Leaching below 30 cm did not occur, since no 15N enrichment of
NO3-N was measured in anion-exchange resin membranes placed at
the base of each cylinder. During the crop period, NO3- losses
were most pronounced after irrigation events. Uptake of N by two
crops of lettuce (above- and belowground material) was
approximately equal to fertilizer inputs, yet simulation of N
fates by the Erosion/Productivity Impact Calculator (EPIC) model
indicated losses of 14.6 g-N m-2 by leaching and 2.5 g-N m-2 by
denitrification during the 6-month crop period. The large NO3-
losses can be attributed to accumulation of soil NO3- during
winter that was leached or denitrified during the irrigated crop
period.
NAL Call No.: S631.F422
*****************************************************************
34. Darcy-Weisbach roughness coefficients for surfaces with
residue and gravel cover.
Gilley, J. E.; Kottwitz, E. R.
Trans-ASAE v.38, p.539-544. (1995).
Includes references.
Descriptors: crop-residues; gravel-; covers-; upland-areas;
hydraulic-resistance; runoff-; roughness-; water-flow;
simulation-models
Abstract: Several types of hydraulic resistance factors may be
present on upland agricultural areas. It is not known whether
roughness contributions from individual elements are additive or
if interactions between resistance factors may occur. In this
study, Darcy-Weisbach roughness coefficients were measured on
surfaces containing corn-soybeans, sorghum-cotton, and
sunflower-wheat residue in addition to gravel cover. Varying
rates of flow were introduced into a flume in which residue and
gravel materials were securely attached. Roughness coefficients
were calculated from measurements of discharge rate and flow
velocity for Reynolds number values varying from approximately
1,200 to 13,000. The laboratory data were then used to identify
the contribution to total hydraulic resistance provided by the
different types of resistance elements. For most of the
experimental treatments, the addition of smaller diameter residue
materials (soybeans, cotton, or wheat) to surfaces containing
larger resistance elements (corn, sorghum, or sunflower) did not
significantly affect hydraulic resistance. However, smaller
diameter residue materials did influence hydraulic resistance
when they substantially increased the total volume of resistance
elements. Existing roughness coefficient values were not
significantly affected by the presence of gravel materials with
diameters similar to the larger residue materials. The
experimental results suggest that total hydraulic resistance
cannot be predicted by simply adding the contributions provided
by individual resistance elements. When estimating total
hydraulic resistance on upland agricultural areas, the relative
size, number, and volume of resistance elements must be
considered.
NAL Call No.: 290.9-Am32T
*****************************************************************
35. Description of simazine transport with rate-limited,
two-stage, linear and nonlinear sorption.
Streck, T.; Poletika, N. N.; Jury, W. A.; Farmer, W. J.
Water-resour-res v.31, p.811-822. (1995).
Includes references.
Descriptors: simazine-; transport-processes; sorption-;
sorption-isotherms; lysimeters-; models-; sorption-models;
transport-models
Abstract: This study was conducted to reconcile an apparent
inconsistency between the simazine laboratory sorption isotherm
data and the field lysimeter transport experiment reported by
Poletika et al. (this issue). In this investigation, linear and
nonlinear one- and two-stage simazine sorption models were fitted
to the sorption and desorption isotherm laboratory data to obtain
parameter estimates for use in the transport model. Once
obtained, the calibrated sorption model was combined with the
parameterized outflow concentration record from a mobile Br
tracer to represent rate-limited sorption and transport of the
simazine added simultaneously with the Br. The calibrated model
did an excellent job of representing the final simazine profile
in the soil, particularly with the nonlinear model. This is in
contrast to a single-stage adsorption model tested by Poletika et
al. (this issue), which reached poor agreement with the field
profile when laboratory-measured sorption parameters were used.
The results demonstrate the compatibility of field and laboratory
experiments on pesticide movement and also indicate that sorption
isotherms may require substantially longer to reach equilibrium
than is customarily allowed in current protocols.
NAL Call No.: 292.8-W295
*****************************************************************
36. Development of an in vitro model for investigating the
formation of the nuclear Ah receptor complex in mouse Hepa 1c1c7
cells.
Wang, X.; Safe, S.
Arch-biochem-biophys v.315, p.285-292. (1994).
Includes references.
Descriptors: aromatic-hydrocarbons; receptors-; nuclei-;
cytosol-; cell-lines; in-vitro; models-; transport-processes;
vanadium-; atp-; lectins-; dioxins-
Abstract: An in vitro assay for investigating factors which
modulate formation of the nuclear aryl hydrocarbon (Ah) receptor
complex was developed using 9S cytosolic Ah receptor isolated
from wild-type Hepa 1e1c7 cells treated with
2,3,7,8-[3H]tetrachlorodibenzo-p-dioxin (TCDD) at 4 degrees C and
nuclei from Ah-responsive and -nonresponsive wild-type and mutant
Hepa 1c1c7 cells. Incubation of the radiolabeled ([3H]TCDD) 9S
cytosolic Ah receptor with nuclei from untreated wild-type
Ah-responsive mouse Hepa 1e1c7 cells resulted in a time- and
temperature-dependent formation of the nuclear Ah receptor
complex as determined by either velocity sedimentation analysis
or gel mobility shift assays using a consensus 32P-labeled
dioxin-responsive element. Maximal levels of the nuclear Ah
receptor formed within 30 min at 37 degrees C and significantly
lower levels were observed after incubation at 4, 15, or 25
degrees C. Complementation studies using nuclei from untreated
wild-type and Ah-nonresponsive class II mutant
(translocation-deficient) cells and radiolabeled 9S cytosolic
receptor (bound with [3H]TCDD) from both wild-type and mutant
cell lines were also carried out. The results indicated that
nuclear translocation was primarily inhibited using cytosol from
mutant cells confirming the requirement for the aryl hydrocarbon
receptor nuclear translocator protein for formation of the
nuclear Ah receptor complex. The effects of a series of Ah
receptor antagonists, ATP, vanadate apyrase, phosphatases, and
lectin WGA, on formation of the nuclear Ah receptor complex were
also investigated in the in vitro model using radiolabeled
cytosolic Ah receptor and nuclei from untreated wild-type Hepa
1c1c7 cells. alpha-Naphthoflavone. apyrase inhibited and ATP
enhanced formation of the nuclear Ah receptor complex. The
results also show that TCDD-induced transformation of the Ah
receptor was inhibited by alpha-naphthoflavone but not by ATP,
lectin WGA, or apyrase. These data suggest that the cytosolic Ah
receptor is phosphorylated prior to ligad binding and ATP is
required for energy-dependent nuclear import of the Ah receptor.
NAL Call No.: 381-Ar2
*****************************************************************
37. Differences in contingent valuation estimates from referendum
and checklist questions.
Jordan, J. L.; Elnagheeb, A. H.
J-agric-resour-econ v.19, p.115-128. (1994).
Includes references.
Descriptors: groundwater-; water-quality; consumer-attitudes;
monte-carlo-method; consumer-surveys; probabilistic-models;
georgia-; willingness-to-pay-
NAL Call No.: HD1750.W4
*****************************************************************
38. Drainage reservoir systems for water quality control.
Melvin, S. W.; Wilcox, A.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1993. (932040) 9 p.
Paper presented at the "1993 International Summer Meeting
sponsored by The American Society of Agricultural Engineers, and
The Canadian Society of Agricultural Engineering," June 20-23,
1993, Spokane, Washington.
Descriptors: drainage-; reservoirs-; water-quality; models-;
irrigation-water
NAL Call No.: 290.9-Am32P
*****************************************************************
39. A dynamic analysis of the impact of water quality policies on
irrigation investment and crop choice decisions.
Wu, J. J.; Mapp, H. P.; Bernardo, D. J.
J-agric-appl-econ v.26, p.506-525. (1994).
Includes references.
Descriptors: maize-; sorghum-; wheat-; irrigation-water;
irrigated-farming; investment-; water-quality; farm-management;
decision-making; crop-enterprises; dynamic-models; cost-analysis;
soil-types; innovation-adoption; economic-impact;
irrigation-technology
Abstract: A dynamic model is developed to analyze farmers
irrigation investment and crop choice decisions under alternative
water quality protection policies. The model is applied to an
empirical example in the Oklahoma High Plains. The choices of
crops and irrigation systems and the resulting levels of
irrigation, income, and nitrogen runoff and percolation are
simulated over a ten-year period. An effluent tax on nitrogen
runoff and percolation is shown to be effective in reducing
nitrate pollution. The efficacy of cost sharing in adopting
modern irrigation technologies and restrictions on irrigation
water use depends on soil type. A tax on nitrogen use is shown to
be the least effective policy.
NAL Call No.: HD101.S6
*****************************************************************
40. Economic analysis of effluent control from catfish ponds.
Cerezo, G. A.; Clonts, H. A.
Bull-Agric-Exp-Sta,-Auburn-Univ. Auburn, Ala : Agricultural
Experiment Station, Auburn University, 1960-. May 1994. (621) 40
p.
Includes references.
Descriptors: fish-ponds; ictalurus-punctatus; fish-scrap;
water-quality; water-pollution; effluents-; water-reuse;
environmental-policy; fishery-management; water-systems;
watersheds-; costs-; taxes-; cost-benefit-analysis;
fish-stocking; linear-programming-model
NAL Call No.: 100-AL1S-1
*****************************************************************
41. Economics of screening for pesticides in ground water.
Natarajan, U.; Rajagopal, R.
Water-resour-bull v.30, p.579-588. (1994).
Includes references.
Descriptors: pesticides-; groundwater-; water-quality;
groundwater-pollution; screening-; monitoring-;
mathematical-models; cost-effectiveness-analysis; usa-;
sequential-analysis-screening; sample-compositing-screening
Abstract: In the United States, millions of dollars are currently
spent to monitor water quality for a whole suite of organic
compounds. However, results of several surveys conducted in the
past decade indicate that only a few pesticides occur in a small
proportion of wells. Screening methods based on historical
evidence of contamination patterns and knowledge of the locales
will have significant potential to reduce these costs and
effectively identify contamination problems. In this paper, the
economics of utilizing two screening methods, sequential analysis
and sample compositing, in the design of monitoring strategies is
captured in the form of mathematical models and illustrated for a
state-level monitoring program. When the two methods are adopted,
the total analytical cost to conclusively identify contaminated
wells in a network of 4,000 wells is shown to range from $12,500
to $1,575,000 depending on the extent of contamination. In
contrast, the total analytical cost of a conventional program
where all the wells in the network are sampled and tested for a
standard suite of pesticides at a cost of $250/sample is one
million dollars. Given such wide range in costs, it is prudent to
incorporate the screening concepts presented in this paper in the
development of cost-effective monitoring programs.
NAL Call No.: 292.9-Am34
*****************************************************************
42. The effect of farming practices on reducing excess nitrogen
fertilizer use.
Huang, W. Y.; Uri, N. D.
Water-air-soil-pollut v.77, p.79-95. (1994).
Includes references.
Descriptors: nitrogen-fertilizers; rotations-;
continuous-cropping; sole-cropping; zea-mays; glycine-max;
application-rates; low-input-agriculture; simulation-models;
farmland-; mathematical-models; leaching-; meadows-; farm-income
NAL Call No.: TD172.W36
*****************************************************************
43. Empirical analysis of slope and runoff for sediment delivery
from interril areas.
Huang, C. H.
Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of
America. July/Aug 1995. v. 59 (4) p. 982-990.
Includes references.
Descriptors: interrill-erosion; simulation-models; slope-;
gradients-; runoff-; sediment-; losses-from-soil; relationships-;
mathematics-
Abstract: Slope steepness (S) and runoff discharge (qw) are two
major factors in determining sediment delivery rates (qs) from
interrill areas. Under the current interrill erosion model
concept, these two factors are assumed to have independent
effects on qs; thus, each factor can be quantified individually
if the other factor is kept constant. This study was conducted to
show the effects of S and qw on qs and their interdependency.
Sediment discharge rates, measured under different rainfall
intensities and slope gradients, for eight soils from two
laboratory studies were analyzed empirically with curve-fitting
procedures. Results showed that there was a pair of empirical
equations for each soil: qs = A1 q2w + A2 qw + A3 and qs = B1 S2
+ B2 S + B3, where A1, A2, and A3 are functions of S and B1, B2,
and B3 are functions of qw. In other words, effects of slope
steepness and runoff on sediment delivery are dependent on each
other. When S and qw were combined together as stream power,
omega, and plotted against sediment concentration, qs/qw, a
unique nonlinear relationship existed for each soil: qs/qq = D1
omega 2 + D2 omega + D3, where D1, D2, and D3 are soil-dependent
coefficients. The stream power, which encompasses both slope and
runoff effects, may provide improved estimates for interrill
erosion. Although not based on theory, this result may be useful
in process-based erosion models.
NAL Call No.: 56.9-So3
*****************************************************************
44. EPIC simulation of water quality impact by land application
of poutry litter.
Yoon, K. S.; Yoo, K. H.; Wood, C. W.; Hall, B. M.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Winter 1993. (93-2531/93-2550) 16 p.
Paper presented at the "1993 International Winter Meeting
sponsored by the American Society of Agricultural Engineers,"
December 12-17, 1993, Chicago, Illinois.
Descriptors: poultry-manure; application-to-land;
environmental-impact; water-quality; simulation-models;
erosion-productivity-impact-calculator
NAL Call No.: 290.9-Am32P
*****************************************************************
45. Estimating snowmelt runoff erosion indices for Canada.
Hayhoe, H. N.; Pelletier, R. G.; Coote, D. R.
J-soil-water-conserv v.50, p.174-179. (1995).
Includes references.
Descriptors: meltwater-; water-erosion; runoff-; runoff-water;
rain-; simulation-models; computer-simulation; winter-;
erosivity-; canada-
NAL Call No.: 56.8-J822
*****************************************************************
46. Estimation of in situ unsaturated soil hydraulic functions
from scaled cumulative drainage data.
Eching, S. O.; Hopmans, J. W.; Wallender, W. W.
Water-resour-res v.30, p.2387-2394. (1994).
Includes references.
Descriptors: unsaturated-hydraulic-conductivity;
soil-water-retention; drainage-; water-flow; transport-processes;
simulation-; spatial-variation; mathematical-models; california-;
linear-variability-scaling-technique; inverse-solution-technique
Abstract: Simulation of water flow and transport processes in
soils rely on field representative soil hydraulic functions. The
linear variability concept in combination with the inverse
technique was used to estimate in situ soil hydraulic properties
in a 32-ha field. Measured cumulative drainage curves were scaled
yielding scaling factors. Subsequently, the drainage and moisture
content distribution of the scaled reference profile were input
to a numerical model to optimize the soil water retention and
hydraulic conductivity curves for the reference soil profile by
inverse solution of the scaled Richards equation. Field hydraulic
functions for each location were computed from the reference
curves and scaling factors. In addition, undisturbed soil cores
taken from 0.3-m and 0.6-m depths at 44 locations were used to
determine soil texture, and soil water retention and hydraulic
conductivity curves in the laboratory using the multistep outflow
technique. These hydraulic functions were scaled using the
simultaneous scaling technique. The reference field hydraulic
functions compared well with those determined from the soil cores
taken from the 0.6-m depth. In situ saturated hydraulic
conductivity variability was one order of magnitude less than
that of the soil cores.
NAL Call No.: 292.8-W295
*****************************************************************
47. Evaluation of LEACHM. I. Simulation drainage, bromide
leaching, and corn bromide uptake.
Jemison, J. M. Jr.; Jabro, J. D.; Fox, R. H.
Agron-j v.86, p.843-851. (1994).
Includes references.
Descriptors: zea-mays; bromide-; solutes-; ion-transport;
movement-in-soil; drainage-; leaching-; uptake-; prediction-;
mathematical-models; computer-simulation; simulation-models;
leaching-estimation-and-chemistry-model
Abstract: Use of mathematical models to predict solute transport
in soils, for research purposes, is increasing, but simpler
management-oriented models are needed that require less
field-specific data. Evaluation is needed to know which type of
model is appropriate. The input-intensive research and simpler
management options of the pesticide and tracer version of LEACHM
(LEACHMP) were evaluated to predict drainage in zero-tension pan
lysimeters, bromide (Br-) leaching, and corn (Zea mays L.) Br-
uptake from a 3-yr leaching experiment. Eighteen pan lysimeters
(0.465 m2) were installed 1.2 m below the soil surface to collect
gravitational water samples. In May 1988, a one-time application
of KBr was broadcast to all plots at 100 kg Br- ha-1. Corn Br-
uptake was evaluated by taking whole-plant samples at 2-wk
intervals in 1988 and 1989. The research model adequately
predicted drainage. Significant differences between predicted and
observed drainage were not found, and the correlations were
significant (0.73 to 0.83). The management model, however,
significantly underestimated cumulative drainage. The research
model overestimated Br- leaching, because the
convection-dispersion equation used in LEACHMP cannot model
dual-pore water flow and solute diffusion found in this soil. The
model generally underpredicted corn Br- uptake, which probably
contributed to the overpredicted Br- leaching. The research
version of LEACHMP adequately modeled drainage, but a more
sophisticated approach to solute transport and corn Br- uptake is
needed to adequately model Br- movement in this soil-plant-water
system. Management model results were generally less accurate
than the research model.
NAL Call No.: 4-AM34P
*****************************************************************
48. Evaluation of LEACHM. II. Simulation of nitrate leaching from
nitrogen-fertilized and manured corn.
Jemison, J. M. Jr.; Jabro, J. D.; Fox, R. H.
Agron-j v.86, p.852-859. (1994).
Includes references.
Descriptors: zea-mays; nitrate-nitrogen; leaching-; prediction-;
nitrogen-fertilizers; liquid-manures; cattle-manure;
mathematical-models; simulation-models; computer-simulation;
uptake-; calibration-; volatilization-; denitrification-;
nitrification-
Abstract: High NO3-N concentrations in groundwater resulting from
agricultural production have increased the need for mathematical
models to predict the concentration and mass of NO3-N leached
from agricultural soils. Study objectives included evaluating the
N version of LEACHM (LEACHMN) to predict mass of NO3-N leached
from nonmanured and manured corn (Zea mays L.), and to test two
methods of model validation. Four treatments (no manure with 0
and 200 kg N ha-1 and a manure treatment with 0 and 100 kg N
ha-1) from a NO3 leaching experiment were modeled for 1988, 1989,
and 1990. Model calibration involved adjusting nitrification,
denitrification, and volatilization rate constants to minimize
differences between predicted and observed data. When calibrated
for each year, LEACHMN produced reasonably accurate predictions
of NO3-N mass leached; however, LEACHMN tended to overestimate
summer and underestimate spring leaching losses. The lack of a
provision in LEACHM to allow solute diffusion out of water flow
channels, and underpredicted corn N uptake early in the season
probably created conditions conducive for high leaching losses
early; following harvest, insufficient NO3-N in the soil profile
resulted in the model underestimating leaching in the spring.
Validating LEACHMN using 1988 rate constants for the 1989 and
1990 years was unsuccessful. When 3-yr average rate constants
were used, simulation accuracy improved somewhat; most accurate
simulations were found if 3-yr average values were close to the
calibrated rate constant for that year. The model's predictive
capability would probably improve if it contained a more complex
corn N uptake routine and a dual-pore water flow component.
NAL Call No.: 4-AM34P
*****************************************************************
49. Evaluation of phosphorus loading models for south Florida.
Zhang, J.; Haan, C. T.; Tremwel, T. K.; Kiker, G. A.
Trans-ASAE v.38, p.767-773. (1995).
Includes references.
Descriptors: lakes-; phosphorus-; runoff-; water-pollution;
water-management; simulation-models; algorithms-; prediction-;
florida-
Abstract: Phosphorus enrichment poses a threat to the ecology of
Florida's Lake Okeechobee. As a part of a phosphorus management
program, the South Florida Water Management District evaluated
two nutrient loading models CREAMS-WT and FHANTM. Model
documentation and algorithms were reviewed Model simulations for
phosphorus loading were compared to measured data for three sites
for the period April 1989, through December 1991. Statistical
correlation of monthly and annual values was analyzed Based on
these analyses, recommendations concerning the models for
predicting phosphorus loading from Lake Okeechobee watersheds are
presented.
NAL Call No.: 290.9-Am32T
*****************************************************************
50. A farm scale water quality planning system for evaluating
best management practices.
Batchelor, W. D.; Dillaha, T. A. I.; Wolfe, M. L.; Heatwole, C.
D.; Mostaghimi, S.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1994. (94-2156/94-2185) 17 p.
Paper presented at the "1994 International Summer Meeting
sponsored by the American Society of Agricultural Engineers,"
June 19-22, 1994, Kansas City, Missouri.
Descriptors: water-pollution; water-quality; land-management;
simulation-models; pollution-control; non-point-source-pollution
NAL Call No.: 290.9-Am32P
*****************************************************************
51. Field and undisturbed-column measurements for predicting
transport in unsaturated layered soil.
Ward, A. L.; Kachanoski, R. G.; Bertoldi, A. P. v.; Elrick, D. E.
Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of
America. Jan/Feb 1995. v. 59 (1) p. 52-59.
Includes references.
Descriptors: layered-soils; solutes-; transport-processes;
soil-analysis; analytical-methods; soil-variability;
laboratory-methods; field-experimentation; models-;
stochastic-streamtube-models
Abstract: Transport properties vary considerably over small
distances in most soils. The stochastic streamtube model offers
one approach to incorporating heterogeneity into transport
predictions. This study tested the ability of the streamtube
concept to predict transport in heterogeneous fields using
measurements from undisturbed columns. Fifty undisturbed columns
(0.15-m diam. by 1.5 m deep) were taken every 0.4 m from a
20-m-long transect in 8 loamy sand soil with variable horizon
thickness. Each core was instrumented at 0.1-m intervals with
time domain reflectometry probes to measure resident fluid
concentrations of a conservative (Cl-) tracer under steady flow
conditions. Large-scale concentration curves of Cl- from solution
samplers and coring were obtained from field experiments
conducted on the same soil under similar boundary conditions.
Differences were observed in the solute spread and mass recovery,
but not in the centers of mass. Horizontal scale dependence of
transport was observed in the field but not in the columns. This
suggests that a higher dimensionality of transport, probably
along the horizon interfaces, may be responsible for the observed
scale dependence in the field. Although the stochastic streamtube
model gave good predictions of the center of mass, it does not
appear to be a realistic physical analogue for describing solute
dispersion in soils with spatially variable layer thickness.
NAL Call No.: 56.9-So3
*****************************************************************
52. Field validation and comparison of LEACHM and NCSWAP.
Jabro, J. D.; Jemison, J. M. Jr.; Lengnick, L. L.; Fox, R. H.;
Fritton, D. D.
Trans-ASAE v.36, p.1651-1657. (1993).
Includes references.
Descriptors: nitrate-; leaching-; simulation-models; prediction-;
silt-loam-soils; nitrogen-fertilizers; animal-manures;
computer-simulation
Abstract: The abilities of the LEACHM and NCSWAP models to
simulate nitrate leaching were compared using field data
collected from a three-year nitrate leaching experiment conducted
in central Pennsylvania on Hagerstown silt loam soil (fine,
mixed, mesic, Typic Hapludalf). Nitrate leaching losses below the
1.2-m depth from N-fertilized and manured corn were measured with
zero-tension pan lysimeters. Four nitrogen and manure treatments
were modeled for the growing seasons of 1988, 1989, and 1990
using the LEACHM and NCSWAP models. The cumulative simulations
were then compared with the cumulative pan efficiency corrected
measured data for these three years. Both models were calibrated
to the site conditions using the growing season data of 1989.
After the models were calibrated for the 1989 year, they were
evaluated using 1988 and 1990 nitrate leaching data. Simulated
results for the calibration year for both models were reasonably
accurate. Statistical criteria were established from the
calibration data set (1989) to evaluate the simulations from both
models for the two validation years (1988 and 1990). Based on
this statistical criteria, both models generally did not
successfully predict nitrate leaching below the 1.2-m depth for
most of the treatments for the validation years. Much of the
simulation error seemed to be related to the inability of both
models to simulate the macropore influenced waterflow in the
well-structured soil and/or the sub-model controlling soil
nitrogen rate constants. The overall performance of both models
was compared and it was concluded that the LEACHM model (Md =
0.38 kg ha-1) statistically performed better than the NCSWAP
model (Md = -3.44 kg ha-1) in simulating.
NAL Call No.: 290.9-Am32T
*****************************************************************
53. A forest site nitrogen dynamics model for land application of
sludge.
Crohn, D. M.; Haith, D. A.
Trans-ASAE v.37, p.1135-1144. (1994).
Includes references.
Descriptors: sewage-sludge; application-to-land; nitrogen-;
nitrate-; broadleaved-deciduous-forests; groundwater-; leaching-;
mathematical-models; computer-simulation; simulation-models;
nitrate-nitrogen; application-rates; forsento-
Abstract: The application of municipal sewage sludge to forests
may raise nitrate-nitrogen concentrations in percolating
groundwater. In agricultural systems, it is usually assumed that
the processes governing nitrogen concentrations in leachate are
relatively short-term, and that other contaminants, such as heavy
metals, limit long-term application rates. These assumptions may
not be appropriate for forests because the nitrogen levels in
these systems change over time and harvests in most forests are
relatively infrequent. We have modified a computer model from the
ecology literature to investigate the long-term impact of
nitrogen additions on groundwater quality in sludge amended
forests. The model is descended from previous models of forest
dynamics. It was tested with data from natural and sludge amended
northeastern forests, and was used to design long-term loading
rates for a northern hardwood forest in New Hampshire. Higher
loading rates are possible if applications are made at
multiple-year intervals as added nitrogen is immobilized in the
soil and in accumulated litter. If 4.5 Mg/ha (dry weight) of
anaerobically digested sludge (225 kg/ha total nitrogen) is
applied at three-year intervals to a 31-year-old site, the model
predicts that leaching nitrate-nitrogen concentrations will
respect the 10 mg/l drinking water standard for nitrogen-N in 99%
of all years.
NAL Call No.: 290.9-Am32T
*****************************************************************
54. A fugacity model of pesticide runoff to surface water:
development and validation.
Di Guardo, A.; Calamari, D.; Zanin, G.; Consalter, A.; Mackay, D.
Chemosphere v.28, p.511-531. (1994).
Includes references.
Descriptors: linuron-; metolachlor-; alachlor-; terbuthylazine-;
herbicide-residues; water-pollution; runoff-; runoff-water;
surface-water; simulation-models; fields-; computer-software;
veneto-
NAL Call No.: TD172.C54
*****************************************************************
55. GIS-based groundwater pollution hazard assessment: a critical
review of the DRASTIC model.
Merchant, J. W.
Photogramm-eng-remote-sensing v.60, p.1117-1127. (1994).
In the special issue: GIS / edited by G.A. Maclean and A.L.
Maclean.
Descriptors: groundwater-pollution;
geographical-information-systems; land-use; models-; aquifers-;
kansas-
NAL Call No.: 325.28-P56
*****************************************************************
56. A GIS data interface for water quality modeling.
Drungil, C. E. C.; Geter, W. F.; Wickey, K. J.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Winter 1993. (932565) 12 p.
Paper presented at the "1993 International Winter Meeting
sponsored by the American Society of Agricultural Engineers,"
December 14-17, Chicago, Illinois.
Descriptors: water-quality; geographical-information-systems;
watersheds-; catchment-hydrology; simulation-models
NAL Call No.: 290.9-Am32P
*****************************************************************
57. GIS interfaced with field & riparian zone models.
Tucker, M. A.; Thomas, D. L.; Altier, L. S.; Bosch, D. D.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1994. (94-2120/94-2155) 13 p.
Paper presented at the 1994 International Summer Meeting,
sponsored by the ASAE, June 19-22, 1994, Kansas City, Missouri.
Descriptors: water-quality; fields-; watersheds-;
riparian-forests; riparian-vegetation; information-systems;
pollutants-; computer-simulation; simulation-models
NAL Call No.: 290.9-Am32P
*****************************************************************
58. GLEAMS hydrology submodel modified for shallow water table
conditions.
Reyes, M. R.; Bengston, R. L.; Fouss, J. L.; Rogers, J. S.
Trans-ASAE v.36, p.1771-1778. (1993).
Includes references.
Descriptors: hydrology-; high-water-tables; simulation-models;
runoff-; percolation-; soil-water; evapotranspiration-;
louisiana-
Abstract: GLEAMS-Water Table (GLEAMS-WT) is a modified version of
GLEAMS that accounts for shallow water table fluctuations. The
modification was accomplished by replacing the evapotranspiration
and percolation algorithms in GLEAMS with evapotranspiration and
percolation routines that are affected by shallow water table.
Furthermore, routines to account for depression storage, steady
state upward flux from the water table, and water table depth
predictions were added. The simulation performances of GLEAMS and
GLEAMS-WT were evaluated by comparing their predictions with
seven years (1981 through 1987) of measured data from a
runoff-erosion-drainage experimental plot at Baton Rouge,
Louisiana. The GLEAMS-WT predictions of surface runoff volume
were very satisfactory. Total predicted surface runoff volume for
seven years was only 0.6 cm (0%) greater than the observed runoff
volume, a significant improvement from GLEAMS underprediction of
surface runoff volume by 54%. GLEAMS-WT predictions of water
table depth were satisfactory.
NAL Call No.: 290.9-Am32T
*****************************************************************
59. GLEAMS modeling of BMPs to reduce nitrate leaching in Middle
Suwannee River Area.
Reck, W. R.
Environmentally sound agriculture proceedings of the second
conference 20-22 April 1994 /. St. Joseph, Mich. : American
Society of Agricultural Engineers, c1994. 1994. 361-367.
Includes references.
Descriptors: groundwater-; water-quality; nitrate-nitrogen;
leaching-; farming-systems; farm-management; dairy-farming;
poultry-farming; monitoring-; models-; computer-techniques;
florida-;
groundwater-loading-effects-of-agricultural-management-systems;
best-management-practices
NAL Call No.: S589.7.E57-1994
*****************************************************************
60. GLEAMS-WT hydrology submodel modified to include subsurface
drainage.
Reyes, M. R.; Bengston, R. L.; Fouss, J. L.
Trans-ASAE v.37, p.1115-1120. (1994).
Includes references.
Descriptors: water-table; subsurface-drainage; hydrology-;
simulation-models; computer-simulation; runoff-;
surface-drainage; louisiana-
Abstract: The model GLEAMS-SWAT (GLEAMS with Subsurface drainage
and WAter Table) is a modified version of GLEAMS that accounts
for shallow water table fluctuations and subsurface drainage. The
modification was accomplished by incorporating a subsurface
drainage routine in GLEAMS-WT. Simulation performances of GLEAMS
and GLEAMS-SWAT were evaluated by comparing their predictions
with seven years (1981-1987) of measured data from a
runoff-erosion-drainage experimental plot at Baton Rouge,
Louisiana. Validations to test the accuracy of GLEAMS-SWAT
predictions of surface runoff volume, subsurface drainage volume,
total volume (surface runoff + subsurface drainage), and water
table depth were satisfactory. Total predicted surface runoff
volume for the seven-year period was 94% of the observed runoff
volume, an improvement from GLEAMS under prediction of surface
runoff volume which was 71% of the observed runoff Subsurface
drainage volume and total drainage (runoff + subsurface drainage)
volume predictions were, respectively, 99% and 96% of the
observed volumes. Water table depth prediction was deeper than
the observed depth, especially during the regrowing and growing
seasons.
NAL Call No.: 290.9-Am32T
*****************************************************************
61. GLEAMS-WT hydrology submodel modified to include subsurface
drainage.
Reyes, M. R.; Bengtson, R. L.; Fouss, J. L.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1993. (932122) 13 p.
Paper presented at the "1993 International Summer Meeting
sponsored by The American Society of Agricultural Engineers and
The Canadian Society of Agricultural Engineering," June 20-23,
1993, Spokane, Washington.
Descriptors: water-table; subsurface-drainage; subsurface-runoff;
hydrology-; simulation-models;
groundwater-loading-effects-of-agricultural-management-syste;
ms-water-table
NAL Call No.: 290.9-Am32P
*****************************************************************
62. Gleams-WT with pesticides.
Reyes, M. R.; Fouss, J. L.; Bengston, R. L.; Gayle, G. A.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Winter 1993. (932554) 10 p.
Paper presented at the "1993 International Winter Meeting
sponsored by the American Society of Agricultural Engineers,"
December 14-17, Chicago, Illinois.
Descriptors: water-table; pesticides-; runoff-;
simulation-models; ID:
groundwater-loading-effects-from-agricultural-management-systems-water-table-simulation-model
NAL Call No.: 290.9-Am32P
*****************************************************************
63. Gully erosion minimization on reclaimed surface mines using
SSAST computer model.
McKenney, R. A.; Gardner, T. W.
J-irrig-drain-eng v.120, p.910-924. (1994).
Includes references.
Descriptors: coal-mine-spoil; reclaimed-soils; gully-erosion;
runoff-; infiltration-; geological-sedimentation; hydrology-;
models-; pennsylvania-;
stable-slope-and-sediment-transport-model; postmine-hydrology
NAL Call No.: 290.9-AM3Ps-IR
*****************************************************************
64. Herbicide discovery and development: emphasis on groundwater
protection.
Lamoreaux, R. J.
Crop-prot v.13, p.483-487. (1994).
Includes references.
Descriptors: herbicides-; research-; groundwater-pollution;
screening-; simulation-models; lysimeters-
NAL Call No.: SB599.C8
*****************************************************************
65. Hierarchical approaches to the study of water quality in
rivers.
Hunsaker, C. T.; Levine, D. A.
Bioscience v.45, p.193-203. (1995).
Includes references.
Descriptors: rivers-; water-quality; land-use; watersheds-;
geographical-information-systems; simulation-models
NAL Call No.: 500-Am322A
*****************************************************************
66. Hydrologic modeling for riparian management.
Sheridan, J. M.; Williams, R. G.; Altier, L. S.; Lowrance, R. R.;
Mills, W. C.; Thomas, D. L.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Winter 1993. (932598) 18 p.
Paper presented at the "1993 International Winter Meeting of the
American Society of Agricultural Engineers," December 14-17,
1993, Chicago, Illinois.
Descriptors: water-quality; water-pollution; groundwater-
NAL Call No.: 290.9-Am32P
*****************************************************************
67. The impact of GIS-derived topographic attributes on the
simulation of erosion using AGNPS.
Srinivasan, R.; Engel, B. A.; Wright, J. R.; Lee, J. G.; Jones,
D. D.
Appl-eng-agric v.10, p.561-566. (1994).
Includes references.
Descriptors: erosion-; simulation-models; hydrology-;
geographical-information-systems; slope-; prediction-;
pollution-; point-sources;
agricultural-non-point-source-pollution-model
Abstract: Topographic attributes such as slope steepness and
slope length are important factors in predicting soil loss and
chemical movement using hydrologic simulation models. The
objective of this study was to examine the effects of various
slope prediction methods in providing input to the nonpoint
source (NPS) simulation model AGNPS. Four algorithms/techniques
(neighborhood, quadratic, best fit plane, and maximum slope
method) were used to estimate slope from elevation data sets. The
effect of each of these methods on slope percentages, slope
lengths, and erosion estimates using the grid-based GRASS
(Geographical Resources Analysis Support System) GIS and a
distributed parameter NPS pollution model AGNPS were
demonstrated. The four slope prediction methods were applied to a
124-ha (310-acre) watershed located in Waco County, Texas, using
the AGNPS model. Among the four slope prediction methods, notable
differences were found in their prediction of topographic
attributes and the use of these attributes to predict erosion at
the outlet of the watershed and within the watershed (spatial
distribution). Observed watershed data best matched simulated
watershed response using topographic inputs obtained from the
neighborhood method.
NAL Call No.: S671.A66
*****************************************************************
68. Implementation of a kinematic wave in the runoff block of
SWMM.
Ferguson, D.; Ball, J. E.
Manly Vale, N.S.W. : Water Research Laboratory, The University of
New South Wales, [1994] 1 v. (in various pagings) : ill..
At head of title: The University of New South Wales, Water
Research Laboratory.
Descriptors: Runoff-Mathematical-models;
Storm-sewers-Hydraulic-models
NAL Call No.: GB651.R47--no.183
*****************************************************************
69. Integration of a basin-scale water quality model with GIS.
Srinivasan, R.; Arnold, J. G.
Water-resour-bull v.30, p.453-462. (1994).
Includes references.
Descriptors: water-quality; watersheds-;
geographical-information-systems; simulation-models;
integrated-systems; texas-
Abstract: Geographic Information Systems (GIS) have been
successfully integrated with distributed parameter, single-event,
water quality models such as AGNPS (Agricultural Nonpoint Source)
and ANSWERS (Areal Nonpoint Source Watershed Environmental
Response Simulation). These linkages proved to be an effective
way to collect, manipulate, visualize, and analyze the input and
output date of water quality models. However, for
continuous-time, basin large-scale water quality models,
collecting and manipulating the input data are more
time-consuming and cumbersome due to the method of disaggregation
(subdivisions are based on topographic boundaries). SWAT (Soil
and Water Assessment Tool), a basin-scale water quality model,
was integrated with a GIS to extract input data for modeling a
basin. This paper discusses the detailed development of the
integration of the SWAT water quality model with GRASS
(Geographic Resources Analysis Support System) GIS, along with an
application and advantages. The integrated system was applied to
a simulated 114 sq. km upper portion of the Seco Creek Basin by
subdividing it into 37 subbasins. The average monthly predicted
streamflow is in agreement with measured monthly streamflow
values.
NAL Call No.: 292.9-Am34
*****************************************************************
70. Interceptor drains for lagoon seepage capture.
Huffman, R. L.; Feng, J. S.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1993. (934018) 8 p.
Paper presented at the "1993 International Summer Meeting
sponsored by The American Society of Agricultural Engineers," and
The Canadian Society of Agricultural Engineering," June 20-23,
1993, Spokane, Washington.
Descriptors: lagoons-; waste-disposal-sites; drainage-equipment;
simulation-models; groundwater-; seepage-; water-quality
NAL Call No.: 290.9-Am32P
*****************************************************************
71. Interpreting non-steady state tracer breakthrough experiments
in sand and clay soils using a dual-porosity model.
Saxena, R. K.; Jarvis, N. J.; Bergstrom, L.
J-hydrol v.162, p.279-298. (1994).
Includes references.
Descriptors: sandy-soils; clay-soils; macropore-flow; tracers-;
chlorine-; triticum-; leaching-; porosity-; solutes-;
transport-processes; simulation-models
Abstract: The effects of preferential flow on 36Cl transport in
undisturbed sand and clay soil monolith lysimeters were
quantified using a dual-porosity model (MACRO). A double tracer
test with 3H and 36Cl was performed simultaneously to check the
possible occurrence of sidewall flow in the lysimeters. In the
dual-porosity model MACRO, simulations can be performed in both
one and two flow domains. Run in one flow domain, the model
reduces to numerical solutions of Richards' equation and the
convection-dispersion equation. In the sandy soil, the occurrence
of preferential flow was tested by simulating in one domain,
assuming that a certain pore fraction takes no part in water flow
and solute transport. For the clay soil, the one domain case was
compared with two domain simulations accounting for macropore
flow. The double-tracer tests showed that sidewall flow did not
occur in either soil type. Simulations of water flow showed good
agreement with observed seepage until late autumn, but were less
good during winter because the model does not account for soil
freezing and snowpack/ snowmelt. Simulated water flows were
similar in one and two domain simulations, presumably because
water contents in the lysimeters were maintained close to field
capacity during the experiment. The simulations indicated that
preferential flow occurred in the sandy soil, with the observed
36Cl breakthrough curves, assuming an unwetted volumetric pore
fraction of 20%, reproduced reasonably well. The rate of 36Cl
leaching was consequently increased by c. 25% compared with the
simulation assuming no preferential flow. Macropore flow was
clearly demonstrated in the clay soil. The two domain simulation
matched the. soil water pressure head defining the boundary
between pore domains was set to -50cm. This implies that
preferential 36Cl transport was taking place in a wide range of
pore sizes, including smaller mesopores. The one domain
simulation failed to predict the pattern of breakthrough of 36Cl
in the clay soil, in that it seriously underestimate leaching at
early times and overestimated leaching towards the end of the
experiment. Accounting for preferential flow with the dual
porosity model resulted in significantly improved estimates of
solute transport, compared to the classical convective-dispersive
treatment, for both nonstructured sands and structured clay
soils.
NAL Call No.: 292.8-J82
*****************************************************************
72. Irrigation storage reservoirs as a water supply solution for
Upper Telogia Creek.
Reck, W. R.
Environmentally sound agriculture proceedings of the second
conference 20-22 April 1994 / p.176-183. (1994).
Includes references.
Descriptors: irrigation-water; water-supply; water-harvesting;
storage-; reservoirs-; runoff-irrigation; water-reuse;
environmental-impact; water-resources; computer-simulation;
simulation-models; florida-
NAL Call No.: S589.7.E57-1994
*****************************************************************
73. A knowledge-based system linked to AGNPS/GRASS interface.
Mohite, M.; Whittaker, A. D.; Srinivasan, R.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1993. (933041) 20 p.
Paper presented at the "1993 International Summer Meeting
sponsored by The American Society of Agricultural Engineers,"
June 20-23, 1993, Spokane, Washington.
Descriptors: erosion-; watersheds-; expert-systems
NAL Call No.: 290.9-Am32P
*****************************************************************
74. Leaching characteristics of banded and broadcast inorganic
tracers.
Dixon, K. L.; Smith, M. C.; Thomas, D. L.; Knisel, W. G.
Trans-ASAE v.36, p.1779-1788. (1993).
Includes references.
Descriptors: leaching-; bromide-; chloride-; tracers-;
broadcasting-; band-placement; downward-movement; diffusion-;
models-; groundwater-pollution; sandy-loam-soils
Abstract: A field study was conducted on an Ocilla loamy coarse
sand to determine the leaching characteristics of banded and
broadcast applications of bromide and chloride. Bromide and
chloride were applied in two treatments to eight plots absent of
any crop. One treatment consisted of banding one tracer while
broadcasting the other. For the second treatment, the banded and
broadcast chemicals were reversed. Lateral and vertical movement
was observed and comparisons were made between banded and
broadcast tracer applications. Results indicate soil variability,
dispersion, and diffusion negated potential banding effects on
the solute plume below the root zone.
NAL Call No.: 290.9-Am32T
*****************************************************************
75. Leaching potential of turf care pesticides: a case study of
Long Island golf courses.
Primi, P.; Surgan, M. H.; Urban, T.
Ground-water-monit-remediat. Dublin, OH : Ground Water Pub. Co.,
c1993-. Summer 1994. v. 14 (3) p. 129-138.
Includes references.
Descriptors: lawns-and-turf; golf-courses; pesticides-;
metabolites-; leaching-; sandy-soils; groundwater-;
groundwater-pollution; monitoring-; simulation-models;
analytical-methods; case-studies; new-york
Abstract: Pesticides used to maintain golf course turf can
threaten ground water. This concern is particularly important in
most of New York's Long Island, where generally sandy soils
overlie a sole source aquifer. This study uses two methods to
evaluate the potential for pesticides that are commonly used on
Long Island's golf courses to leach to ground water. Adapting the
Pesticide Root Zone Model (PRZM), Release 1, for dense turf and
applying site-specific soil data, certain pesticides, including
metalaxyl and trichlorfon, are identified as potential problem
leachers. PRZM simulations also identify the Long Island soils,
including the sandy Plymouth and Carver soils, which are most
vulnerable to leaching. When adequate input data for PRZM is
unavailable, the ground water ubiquity score (GUS) method may be
useful. GUS leachability classifications of pesticides commonly
applied on Long Island golf courses, and of pesticides actually
detected in ground water samples taken on Long Island, agree with
PRZM predictions and the field data. The GUS method is applied
to the evaluation of the leaching potential of pesticide
degradation products (DCPA, maneb, and mancozeb metabolites), and
the degradation products are shown to be a greater threat to
ground water than their parent compounds. These methods are
potentially useful in designing ground water monitoring programs
and for guiding the pesticide use and selection decisions of golf
course managers.
NAL Call No.: GB1001.G76
*****************************************************************
76. Long-term sulfate dynamics at Lange Bramke (Harz) used for
testing two acidification models.
Lange, H.; Hauhs, M.; Schmidt, S.
Water-air-soil-pollut v.79, p.339-351. (1995).
In the special issue: Biogeochemical monitoring in small
catchments / edited by J. Cerny, M. Novak, T. Paces and R.K.
Weider. Evaluation of Integrated Monitoring in Small
Catchments," held September 18-20, 1993, Prague, Czech Republic.
Descriptors: sulfate-; nitrate-; hydrogen-ions; soil-solution;
runoff-; acidification-; elements-; anions-; cations-;
mountains-; watersheds-; forest-soils; coniferous-forests;
picea-abies; lower-saxony; magic-model; bem-model
NAL Call No.: TD172.W36
*****************************************************************
77. A lumped parameter water balance of a semi-arid watershed.
Flerchinger, G. N.; Cooley, K. R.; Hanson, C. L.; Seyfried, M.
S.; Wight, J. R.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1994. (94-2120/94-2155) 17 p.
Paper presented at the 1994 International Summer Meeting,
sponsored by the ASAE, June 19-22, 1994, Kansas City, Missouri.
Descriptors: watersheds-; semiarid-zones; water-balance;
precipitation-; profiles-; soil-water; groundwater-; runoff-;
vegetation-; evapotranspiration-; simulation-models; idaho-
NAL Call No.: 290.9-Am32P
*****************************************************************
78. Managing agricultural pollution using a linked geographical
information system and non-point source pollution model.
Morse, G.; Eatherall, A.; Jenkins, A.
J-Inst-Water-Environ-Manag v.8, p.277-286. (1994).
Includes references.
Descriptors: pollution-; agriculture-; simulation-models;
geographical-information-systems; computer-software; prediction-
Abstract: This study documents the development of a link between
a geographical information system (GIS) and a non-point source
pollution model. The GIS ARC/INFO was linked to the agricultural
non-point source pollution model and ORACLE data sources.
Application of the system is demonstrated using the Bedford-Ouse
catchment as a suitable case study. Water quality impacts are
predicted from source data describing topography, soils, land use
and river network. The model results were in agreement with
observed nitrate concentrations at the catchment outlet, and more
appropriate data sources are considered to be the main priority
for improving model predictive ability. Management scenarios were
established to assess the impact of changing agricultural
management practices on predicted water quality. The approach has
significant potential for the management of agricultural
pollution in the UK.
NAL Call No.: TD420.W374
*****************************************************************
79. Managing underground storage tanks in urban environments: a
geographic information systems approach.
Hudak, P. F.; Speas, R. K.; Schoolmaster, F. A.
Water-resour-bull v.31, p.439-445. (1995).
Includes references.
Descriptors: soil-pollution; groundwater-pollution; fuel-tanks;
underground-storage; management-; urban-areas;
geographical-information-systems; databases-; texas-;
denton,-texas
Abstract: Fuels contained in underground storage tanks (USTs) are
a major source of soil and ground water contamination. Effective
management of the problem at the urban level is difficult due to
a large number of tanks and a vast array of factors (e.g., tank
characteristics, geology) that determine environmental hazards.
The problem is compounded by frequent abandonment and reuse of
service stations, which makes it difficult to track the status Of
underground tanks. Geographic information systems (GIS) are
ideally suited to organizing location and attribute data for
variables that are pertinent to the UST management problem. A
GIS-based UST management system was developed and applied to 136
current and former gasoline service stations in Denton, Texas.
The system is effective for tank inventory and can be applied in
a proactive fashion to identify potentially problematic
facilities. In the event of a leak or spill, the management
system can support the implementation of reactive measures to
mitigate subsurface contamination. Potential beneficiaries of
such a system include planning departments, environmental
regulatory agencies, emergency management officials, lending
institutions, gasoline distributors, and oil companies.
NAL Call No.: 292.9-Am34
*****************************************************************
80. Mass transfer in soils with local stratification of hydraulic
conductivity.
Li, L.; Barry, D. A.; Culligan Hensley, P. J.; Bajracharya, K.
Water-resour-res v.30, p.2891-2900. (1994).
Includes references.
Descriptors: soil-; transport-processes; hydraulic-conductivity;
solutes-; layered-soils; mass-transfer; mathematical-models;
stratified-soils
Abstract: The two-region model was developed originally to
describe nonsorbing chemical transport in soils with dead-end
pores based on the concept of mobile and immobile regions in the
soil. It has been shown that the model can simulate solute
transport in soils with local stratification, or inhomogeneity,
of hydraulic conductivity. However, the physical basis of the
model becomes questionable, since the mobile-immobile region
concept does not apply in stratified soils. In both soil types
the nonequilibrium effect is caused by an apparent mass transfer
process within the soil, as distinct from advection and
diffusion. Where there are immobile regions, the mass transfer is
due to solute interregion diffusion alone. In stratified soils
the nonequilibrium mass transfer process is affected also by
local flow variations. A conceptual model, numerical simulations,
and laboratory experiments are presented to analyze these
effects. For a given soil with fixed local stratification of
hydraulic conductivity, it is shown that in the low-velocity
range, the apparent mass transfer rate parameter, alpha, scales
as V2/D (V is pore water velocity in the two-region model and D
is the longitudinal dispersion coefficient), which implies that
the mass transfer process is predominantly affected by local flow
variations. When the velocity is relatively high, alpha varies
with DT/h2 (DT is the interregion diffusion coefficient and h is
the characteristic thickness of the stratified layers) and the
mass transfer process is dominated by interregion diffusion.
These scaling relations for alpha reflect the two mechanisms
controlling the mass transfer process in locally stratified
soils. They have implications. prototype soils. In particular,
the relationship alpha varies with V2/D leads to the conclusion
that exact physical modeling of nonsorbing chemical transport
coupled with apparent mass transfer in locally stratified soils
may be viable.
NAL Call No.: 292.8-W295
*****************************************************************
81. Measured and RZWQM predicted atrazine dissipation and
movement in a field soil.
Ma, Q. L.; Ahuja, L. R.; Rojas, K. W.; Ferreira, V. F.;
DeCoursey, D. G.
Trans-ASAE v.38, p.471-479. (1995).
Includes references.
Descriptors: agricultural-chemicals; environmental-impact;
surface-water; groundwater-; atrazine-; transformation-; runoff-;
simulation-models; distribution-; profiles-; sorption-;
performance-appraisals
Abstract: The ARS Root Zone Water Quality Model (RZWQM) was
developed recently to study the fate and behavior of
agrochemicals in the environment and the effects of agricultural
management on surface and groundwater quality. In this article,
model performance was tested by comparing three years of field
data for water and atrazine movement (runoff and concentration
profiles) and atrazine transformation obtained under different
management conditions with those simulated by RZWQM. Accuracy of
model simulation was quantified by standard linear regression
techniques. The regression correlation coefficients (R2) between
average measured and simulated data for water runoff, atrazine
runoff, atrazine persistence, and atrazine distribution in the
soil profile were 0.87, 0.92, 0.97, and 0.73, respectively.
Evaluation of the model, using best estimates for properties of
atrazine and hydrologic characteristics of the field soil and
limited calibration for water runoff, suggests that the model
effectively simulates the important processes operating on water
and chemicals.
NAL Call No.: 290.9-Am32T
*****************************************************************
82. A method for developing probability distributions for rill
flow and density.
Lewis, S. M.; Barfield, B. J.; Storm, D. E.
Trans-ASAE v.37, p.1879-1887. (1994).
Includes references.
Descriptors: rill-erosion; water-flow; overland-flow;
probability-; probability-analysis; imagery-; photographs-;
eroded-soils; runoff-; sediment-yield; digital-terrain-model;
probability-density-function
Abstract: Procedures are presented and evaluated for developing
probability distribution functions for rill numbers (density) and
rill flow rates that can be used to represent the stochasticity
of rill networks in recent erosion models such as PRORIL. Subsoil
and topsoil data sets, including photographs, collected at the
University of Kentucky were used in the evaluation. Photographic
images were corrected for optical distortion and visually
analyzed to develop the rill networks. A digital terrain model
(DTM) that allowed combining of channels, but not flow splitting,
was also utilized to develop a flow network and compared to the
photographically determined network. The DTM generated network
did not provide a good fit to the photographically determined
network, likely because of problems with interpolation and with
the inability to predict rill splitting. The DTM generated
networks were utilized to develop probability density functions
(PDFs) for rill numbers and conditional PDFs for rill flow rates
given a number of rills. The binomial distribution provided a
good fit to rill number distributions as defined by the
Kolmogorov-Smirnov test. The Weibull distribution provided the
best fit to the conditional PDF for flow rates, but the goodness
of fit was poor. This lack of fit, likely due to inadequacies of
the DTM, should improve with improved DTMs.
NAL Call No.: 290.9-Am32T
*****************************************************************
83. A method for simulating cadmium transport in soil: model
development and experimental evaluation.
Al Soufi, R. W.
J-hydrol v.163, p.233-247. (1994).
Includes references.
Descriptors: cadmium-; contaminants-; transport-processes;
polluted-soils; acid-soils; adsorption-; desorption-; soil-ph;
mathematical-models; simulation-; models-
Abstract: A model for simulating cadmium transport in soil is
presented. The calculation scheme is based on a three-dimensional
advection-dispersion model. The adsorption process is defined by
a lumped parameter mathematical model in which the amount of ions
that remains in solution is correlated with the amount that
originally exists in the input solution. Desorption is defined in
the same way by correlating the amount of ions desorbed with the
amount of ions held by the soil solid surface. Both relationships
incorporate the effect of soil solution pH which is defined by a
power equation that predicts the pH value at any time and at any
depth, from the pH of the input solution and elapsed time. Soil
column experiments were conducted to validate the performance of
the model. Also, batch tests were employed to determine the
essential adsorption-desorption parameters that are required to
operate the model. In light of the results, it was concluded that
the model satisfactorily forecasts cadmium concentration and the
pH of soil solution under varied acidic conditions. However,
values of model parameters are strictly empirical and need to be
determined for each soil type.
NAL Call No.: 292.8-J82
*****************************************************************
84. A methodology for the evaluation of global warming impact on
soil moisture and runoff.
Valdes, J. B.; Seoane, R. S.; North, G. R.
J-hydrol v.161, p.389-413. (1994).
Includes references.
Descriptors: global-warming; soil-water; variation-; runoff-;
precipitation-; temperature-; evapotranspiration-;
mathematical-models
Abstract: This paper presents a numerical evaluation of the
viability of soil moisture and direct surface runoff due to
global warming. An analytical model of the soil moisture balance
based on our previous work is used to evaluate the probability
distribution of the soil moisture concentration and resulting
surface runoff. The input of hydroclimatic values is based on the
approach suggested by C.W. Richardson in 1981. Our results show
that not only the mean of the distribution of both soil moisture
and runoff change, as expected, but that the variability of the
values around the means also changes. The results of our research
have immediate applications on the planning of reservoir
operation for irrigation demands and evaluation of the change in
surface runoff expected due to global warming.
NAL Call No.: 292.8-J82
*****************************************************************
85. Minimum leaching scheduling of nitrogen fertilization and
irrigation.
Falkovitz, M. S.; Feinerman, E.
Bull-math-biol v.56, p.665-686. (1994).
Includes references.
Descriptors: nitrogen-fertilizers; irrigation-;
mathematical-models; leaching-; optimization-
Abstract: This paper develops and applies dynamic mathematical
model for optimal scheduling of nitrogen fertilization and
irrigation that minimizes nitrogen leaching subject to a target
level of yield. The analysis assumes a single crop grown during
a single growing season of a given length. It is shown that
substitution of water for nitrogen along a given plant growth
path decreases nitrogen leaching and, therefore, groundwater
contamination. It is proved that a minimum leaching solution to
the optimization problem is obtained with a single nitrogen
application at the beginning of the season and irrigation
scheduling that maintains a wet soil throughout the growing
period. A numerical example utilizing experimental data for an
irrigated summer corn in Israel confirms and quantifies the
analytical findings.
NAL Call No.: 442.8-B872
*****************************************************************
86. Mn2+ as a contrast reagent for NMR studies of 35Cl- and 81Br-
transport through model biological membranes.
Riddell, F. G.; Zhou, Z.
J-inorg-biochem v.55, p.279-293. (1994).
Includes references.
Descriptors: membranes-; models-; transport-processes;
ion-transport; chloride-; bromide-; manganese-; spectral-data;
phosphatidylcholines-
Abstract: One major problem in using NMR to study halide ions in
biological and model biological systems has been to find a
contrast reagent to differentiate between halide ions in
different compartments. Mn2+ is shown to be a very efficient NMR
relaxation agent for the halide ions chloride and bromide and
preferable to Co2+ at high magnetic fields. Its use is
demonstrated in experiments in which halide ions are exchanged
across the membranes of egg yolk phosphatidylcholine vesicles by
the phase transfer catalysts tetrabutylammonium ion and
benzyltributylammonium ion. Benzyl-tributylammonium ion is shown
to be the more rapid anion transporter through the membrane.
Valinomycin is found to cotransport ammonium ions with chloride
as an ion pair at a faster rate than the phase transfer
catalysts.
NAL Call No.: QD415.B5
*****************************************************************
87. Model accuracy in snowmelt-runoff forecasts extending from 1
to 20 days.
Rango, A.; Martinec, J.
Water-resour-bull v.30, p.463-470. (1994).
Includes references.
Descriptors: meltwater-; runoff-; forecasts-; simulation-;
forecasting-; surface-water; hydrology-; models-; canada-;
hydrological-forecasting; surface-water-hydrology;
illecillewaet-basin
Abstract: This paper examines the performance of snowmelt-runoff
models in conditions approximating real-time forecast situations.
These tests are one part of an intercomparison of models recently
conducted by the World Meteorological Organization (WMO). Daily
runoff from the Canadian snowmelt basin Illecille-waet (1155 km2,
509-3150 m a.s.l.) was forecast for 1 to 20 days ahead. The
performance of models was better than in a previous WMO project,
which dealt with runoff simulations from historical data, for the
following reasons: (1) conditions for models were more favorable
than a real-time forecast situation because measured input data
and not meteorological forecast inputs were distributed to the
modelers; (2) the selected test basin was relatively easy to
handle and familiar from the previous WMO project; and (3) all
kinds of updating were allowed so that some models even improved
their accuracy towards longer forecast times. Based on this
experience, a more realistic follow-up project can be imagined
which would include temperature forecasts and quantitative
precipitation forecasts instead of measured data.
NAL Call No.: 292.9-Am34
*****************************************************************
88. A model for evaluating irrigation-induced water quality
problems in irrigation and drainage systems.
Manguerra, H. B.; Garcia, L. A.; Quinn, N.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1994. (94-2091/94-2119) 15 p.
Paper presented at the "1994 International Summer Meeting
sponsored by the American Society of Agricultural Engineers,"
June 20-23, 1994, Kansas City, Missouri.
Descriptors: irrigation-systems; drainage-systems; water-quality;
temporal-variation; models-
NAL Call No.: 290.9-Am32P
*****************************************************************
89. A model for sorption, flux and plant uptake of cadmium in a
soil
Palm, V.
Water-air-soil-pollut v.77, p.169-190. (1994).
Includes references.
Descriptors: cadmium-; metal-ions; sorption-; profiles-;
transport-processes; ion-uptake; plants-; mathematical-models;
simulation-models; algorithms-; hydrology-
NAL Call No.: TD172.W36
*****************************************************************
90. Model study on environmentally relevant information based on
agricultural statistics. Modellstudie zu umweltrelevanten
Informationen aus der Agrarstatistik.
Corell, G. 1.
Munster : Lit, [1994] xix, 198 p. : ill..
"August 1994.".
Descriptors: Agricultural-pollution; Agriculture-Statistics
NAL Call No.: TD195.A34M62--1994
*****************************************************************
91. Modeling and error analysis of kinematic-wave equations of
furrow irrigation.
Reddy, J. M.; Singh, V. P.
Irrig-sci v.15, p.113-121. (1994).
Includes references.
Descriptors: furrow-irrigation; mathematical-models;
infiltration-; runoff-; design-; errors-; analysis-; equations-
Abstract: A moving control volume approach was used to model the
advance phase of a furrow irrigation system whereas a fixed
control volume was used to model the nearly stationary phase and
the runoff rate. The resulting finite-difference equations of the
kinematic-wave model were linearized and explicit algebraic
expressions were obtained for computation of advance and runoff
rate. The solutions for the advance increment and the runoff rate
were compared with the nonlinear scheme, the zero-inertia model,
and a set of field data. A close agreement was found between the
models and the field data. Assuming a constant infiltration rate,
a differential equation was derived to estimate the error between
the kinematic-wave model and the zero-inertia model in predicting
the flow cross-sectional area along the field length. The
differential equation and two dimensionless terms were used to
define the limits for use of the kinematic-wave model in furrow
irrigation.
NAL Call No.: S612.I756
*****************************************************************
92. Modeling for optimal management of agricultural and domestic
wastewater loading to streams.
Ejaz, M. S.; Peralta, R. C.
Water-resour-res v.31, p.1087-1096. (1995).
Includes references.
Descriptors: streams-; water-pollution; water-quality;
waste-water; dairy-wastes; sewage-; waste-water-treatment;
overland-flow; simulation-models; optimization-; simulation;
optimization-models
Abstract: A simulation/optimization (S/O) model to aid managing
multiobjective wastewater loading to streams while maintaining
adequate downstream water quality is presented. The conflicting
objectives are to maximize the human and dairy cattle populations
from which treated wastewater can be discharged to the river
system. Nonindustrial municipal (domestic) wastewater undergoes
primary and secondary treatment by a sewage treatment plant (STP)
before entering as a steady point source. Dairy wastewater is
treated by overland flow (OLF) land treatment before entering the
stream as a controlled steady diffuse source. Maximum dual-source
loading strategies which do not degrade downstream water quality
beyond specified limits are developed. For each computed loading
strategy, an optimal OLF system design is also determined. The E
constraint method is used to obtain sets of noninferior
solutions. Sets of noninferior solutions are represented
graphically to show the trade-off between human and bovine
populations that can be maintained. Each set is computed for a
different upstream flow rate to illustrate sensitivity to
nondeterministic upstream flow rates. The nonlinear constraints
utilized restrict downstream concentrations of 5-day biochemical
oxygen demand, dissolved oxygen, nitrogen (organic, ammonia,
nitrite, and nitrate), organic and dissolved phosphorus, and
chlorophyll a. Concentrations are described via regression
equations. The new regression expressions, surrogates for the
complex advective-dispersive equation, permit rapid and feasible
solutions by this unique S/O model.
NAL Call No.: 292.8-W295
*****************************************************************
93. Modeling infiltration during complex rainfall sequences.
Corradini, C.; Melone, F.; Smith, R. E.
Water-resour-res v.30, p.2777-2784. (1994).
Includes references.
Descriptors: infiltration-; redistribution-; rain-; storms-;
soil-water-movement; ponding-; soil-water-content; runoff-;
simulation-models; surface-saturation
Abstract: An extension of the conceptual model earlier developed
by Smith et al. (1993) is presented. Their basic model considered
the problem of point infiltration during a storm consisting of
two parts separated by a rainfall hiatus, with surface saturation
and runoff occurring in each part. The model is here extended
toward further generality, including the representation of a
sequence of infiltration-redistribution cycles with situations
not leading to soil surface saturation, and rainfall periods of
intensity less than the soil infiltration capacity. The model
employs at most a two-part profile for simulating the actual one.
When the surface flux is not at capacity, it uses a slightly
modified version of the Parlange et al. (1985) model for
description of increases in the surface water content and the
Smith et al. (1993) redistribution equation for decreases.
Criteria for the development of compound profiles and for their
reduction to single profiles are also incorporated. The extended
model is tested by comparison with numerical solutions of
Richards's equation, carried out for a variety of experiments
upon two contrasting soils. The model applications yield very
accurate results and support its use as part of a watershed
hydrologic model.
NAL Call No.: 292.8-W295
*****************************************************************
94. Modeling multiple reactive solute transport with adsorption
under equilibrium and nonequilibrium conditions.
Marzal, P.; Seco, A.; Ferrer, J.; Gabaldon, C.
Adv-water-resour v.17, p.363-374. (1994).
Includes references.
Descriptors: groundwater-pollution; groundwater-flow;
pollutants-; solutes-; adsorption-; physicochemical-properties;
equations-; mathematical-models; equations-; transport-processes;
soil-physical-properties; soil-chemistry; soil-water-movement;
simulation-models; solute-transport-equations;
chemical-interaction-equations
NAL Call No.: TD201.A4
*****************************************************************
95. Modeling nutrient transport in vegetative filter strips.
Chaubey, I.; Edwards, D. R.; Daniel, T. C.; Moore, P. A. Jr.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1994. (94-2120/94-2155) 28 p.
Paper presented at the 1994 International Summer Meeting,
sponsored by the ASAE, June 19-22, 1994, Kansas City, Missouri.
Descriptors: water-; water-quality; grass-strips;
water-pollution; poultry-manure; runoff-; pollutants-;
infiltration-; mathematical-models; prediction-
NAL Call No.: 290.9-Am32P
*****************************************************************
96. Modeling of biologically mediated redox processes in the
subsurface.
Lensing, H. J.; Vogt, M.; Herrling, B.
J-hydrol v.159, p.125-143. (1994).
Special Issue: Field laboratory and modelling studies of flow and
transport processing / edited by H.S. Wheater, P.A.C. Raats, and
A.C. Armstrong. Sciences Programme Session HS1 of the XVII
General Assembly of the European Geophysical Society, April 6-10,
1992, Edinburgh.
Descriptors: groundwater-pollution; bacteria-; growth-rate;
metabolism-; redox-reactions; transport-processes; ions-;
monitoring-; simulation-models; bioremediation-
Abstract: To model bacterially catalyzed redox processes a
multicomponent transport reaction model is presented. The
transport part of the model solves the transient convection
dispersion differential equations. The pure chemical submodel is
conceptually similar to conventional thermodynamic equilibrium
models. The kinetic submodel describes the heterotrophic
metabolisms of several groups of microorganisms. To model a
complete redox sequence (aerobic carbonaceous oxidation,
denitrification, Fe(III)-reduction, Mn(IV)-reduction, and sulfate
reduction) four functional bacterial groups are defined. Their
growth and metabolisms are formulated in terms of Monod
equations. As in other biofilm models, diffusion-limited exchange
between the different phases (mobile pore water, biophase, and
aquifer material) is also considered in this approach. The
submodels are coupled by the equations of the microbially
mediated redox reactions. This numerical technique permits direct
mechanistic modeling of the influence of microbially catalyzed
redox reactions on the chemical milieu of an aquifer. A two-step
method is applied to solve the coupled transport and biochemical
reaction equations. The numerical model was applied to field data
of a natural subsurface flow path.
NAL Call No.: 292.8-J82
*****************************************************************
97. Modeling of intial discharges from hydraulic barriers
underlying solid and hazardous waste landfills.
Al Jobeh, Z. Y.
Proc-Ind-Waste-Conf. Chelsea, Mich. : Lewis Publishers. 1994. v.
48 p. 309-315.
Meeting held on May 10-12, 1993, West Lafayette, Indiana.
Descriptors: landfills-; landfill-leachates; soil-pollution;
polluted-soils; groundwater-pollution; mathematical-models
NAL Call No.: TP995.A1I5
*****************************************************************
98. Modeling perspective of the deforestation impact in stream
water quality of small preserved forested areas in the Amazonian
rainforest.
Forti, M. C.; Neal, C.; Jenkins, A.
Water-air-soil-pollut v.79, p.325-337. (1995).
In the special issue: Biogeochemical monitoring in small
catchments / edited by J. Cerny, M. Novak, T. Paces and R.K.
Weider. Evaluation of Integrated Monitoring in Small
Catchments," held September 18-20, 1993, Prague, Czech Republic.
Descriptors: tropical-rain-forests; logging-effects;
deforestation-; simulation-models; water-quality; streams-;
sulfate-; anions-; cations-; acidification-; soil-organic-matter;
organic-matter; reserved-forests; amazonas-; magic-model;
water-chemistry
NAL Call No.: TD172.W36
*****************************************************************
99. Modeling pesticide transport in subsurface drained soils.
Thooko, L. W.; Rudra, R. P.; Dickinson, W. T.; Patni, N. K.;
Wall, G. J.
Trans-ASAE v.37, p.1175-1181. (1994).
Includes references.
Descriptors: pesticides-; pesticide-residues; atrazine-;
herbicide-residues; leaching-; subsurface-drainage;
simulation-models; computer-simulation; zea-mays;
movement-in-soil; ontario-; drainmod-
Abstract: Transport of chemicals through the soil profile and
crop root zone, and the discharge from subsurface drainage lines
into surface water can be a significant source of water
pollution. This study measured and simulated subsurface drain
outflows and atrazine loads in the subsurface drains from a field
site in Ottawa, eastern Ontario, Canada, during 1988 and 1989.
Corn was grown for silage at the site, and an H-flume with an
automated water sampler was used to monitor temporal changes in
quantity and quality of subsurface drain outflows from a 14-ha
field site. A drainage simulation model, DRAINMOD, was combined
with a chemical transport model, GLEAMS, to simulate the chemical
transport of atrazine through the soil into the subsurface drain
outflow. The model was calibrated with 1989 field data and
compared to measured 1988 data. The calibrated DRAINMOD model
predicted subsurface drain outflows for 1988 with a coefficient
of determination of 0.40 and a standard error of the estimate,
S(y/x), of 0.09 mm. Measured Atrazine concentrations exceeded 6
micrograms/kg on one occasion, but simulated Atrazine
concentrations did not exceed 2.5 micrograms/kg. The model
underpredicted atrazine mass in the subsurface drain outflows.
Spring underpredictions of atrazine mass discharge was due to
underprediction of subsurface drain flows while fall
underpredictions were due to underpredictions of atrazine
concentrations. Effects of temperature on atrazine half life and
adsorption constant may be partially responsible for these
results. This integrated model of chemical transport with the
drainage simulation model provides a useful tool for studying
chemical transport through.
NAL Call No.: 290.9-Am32T
*****************************************************************
100. Modeling the effects of agricultural practices on nitrate
concentration of shallow ground water in the Coastal Plain.
Xie, M.; Huffman, R. L.; Jennings, G. D.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1994. (94-2091/94-2119) 16 p.
Paper presented at the "1994 International Summer Meeting
sponsored by the American Society of Agricultural Engineers,"
June 20-23, 1994, Kansas City, Missouri.
Descriptors: nitrate-nitrogen; wells-; monitoring-;
water-quality; groundwater-pollution; simulation-models;
prediction-
NAL Call No.: 290.9-Am32P
*****************************************************************
101. Modeling the water balance in cold regions.
McConkey, B. G.; Mulla, D. J.; McCool, D. K.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1993. (932141) 21 p.
Paper presented at the "1993 International Summer Meeting
sponsored by The American Society of Agricultural Engineers and
The Canadian Society of Agricultural Engineering," June 20-23,
1993, Spokane, Washington.
Descriptors: snow-; soil-; frost-; infiltration-; runoff-
NAL Call No.: 290.9-Am32P
*****************************************************************
102. Modeling tile drainage in an irregular network.
Waller, P. M.; Jaynes, D. B.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1993. (932125) 13 p.
Paper presented at the "1993 International Summer Meeting
sponsored by The American Society of Agricultural Engineers and
The Canadian Society of Agricultural Engineering," June 20-23,
1993, Spokane, Washington.
Descriptors: tile-drainage; water-quality;
finite-element-analysis; simulation-models
NAL Call No.: 290.9-Am32P
*****************************************************************
103. Modeling transport kinetics in clinoptilolite-phosphate rock
systems.
Allen, E. R.; Ming, D. W.; Hossner, L. R.; Henninger, D. L.
Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of
America. Jan/Feb 1995. v. 59 (1) p. 248-255.
Includes references.
Descriptors: clinoptilolite-; rock-phosphate; systems-;
nutrients-; ammonium-; phosphorus-; potassium-; release-;
transport-processes; kinetics-; mathematical-models
Abstract: Nutrient release in clinoptilolite-phosphate rock
(Cp-PR) systems occurs through dissolution and cation-exchange
reactions. Investigating the kinetics of these reactions expands
our understanding of nutrient release processes. Research was
conducted to model transport kinetics of nutrient release in
Cp-PR systems. The objectives were to identify empirical models
that best describe NH4, K, and P release and define
diffusion-controlling processes. Materials included a Texas
clinoptilolite (Cp) and North Carolina phosphate rock (PR). A
continuous-fiow thin-disk technique was used. Models evaluated
included zero order, first order, second order, parabolic
diffusion, simplified Elovich, Elovich, and power function. The
power-function, Elovich, and parabolic-diffusion models
adequately described NH4, K, and P release. The power-function
model was preferred because of its simplicity. Models indicated
nutrient release was diffusion controlled. Primary transport
processes controlling nutrient release for the time span observed
were probably the result of a combination of several interacting
transport mechanisms.
NAL Call No.: 56.9-So3
*****************************************************************
104. Modelling Ca-solubility in MSWI bottom ash leachates.
Comans, R. N. J.; Meima, J. A.
Stud-environ-sci. Amsterdam ; New York, Elsevier Scientific
Publishing Co. 1994. (60) p. 103-110.
In the series analytic: Environmental aspects of construction
with waste material / edited by J.J.J.M. Goumans, H.A. van der
Sloot and T.G. Aalbers. Implications of Construction Materials
and Technology Developments," held June 1-3, 1994, Maastricht,
The Netherlands.
Descriptors: solid-wastes; refuse-; ash-; building-materials;
calcium-; leaching-; solubility-; minerals-; ph-; leachates-;
chemical-speciation; simulation-models; equipment-;
municipal-solid-waste-incinerators; calcium-minerals;
incinerator-ash
NAL Call No.: QH540.S8
*****************************************************************
105. Modelling leaching and recharge in a bare transitional
red-brown earth ponded with low salinity water in summer.
Cai, L.; Prathapar, S. A.; Beecher, H. G.
Aust-j-exp-agric v.34, p.1085-1092. (1994).
Special Issue: Temperate Rice: Achievements and Potential.
Descriptors: red-soils; soil-water-content; ponding-;
saturated-hydraulic-conductivity; infiltration-; salts-;
leaching-; water-table; depth-; soil-depth; simulation-models;
summer-; winter-
NAL Call No.: 23-Au792
*****************************************************************
106. Modelling wash-off and leaching of pollutants by spring-time
flow.
Vasilyev, A.
J-hydrol v.159, p.215-222. (1994).
Special Issue: Field laboratory and modelling studies of flow and
transport processing / edited by H.S. Wheater, P.A.C. Raats, and
A.C. Armstrong. Sciences Programme Session HS1 of the XVII
General Assembly of the European Geophysical Society, April 6-10,
1992, Edinburgh.
Descriptors: pollutants-; agricultural-chemicals; phosphates-;
leaching-; runoff-; subsurface-runoff; water-quality;
water-pollution; watersheds-; models-; estonia-;
phosphate-phosphorus
Abstract: The quality of water in Estonian rivers in the spring
is influenced strongly by the conditions in the catchments, and
in particular by the amount of ice within the soil. After cold
winters, the soil is extensively frozen and surface runoff
predominates. After warmer winters, water flows through the soil
and leaches pollutants from the soil. Increased pollutant load to
Matsalu Bay has been identified by calibrating a water quality
model for the period 1959-1966 and then running the same model
for a test period (1977-1991). The observed concentrations during
the test period were higher than those predicted by the
calibrated model, indicating a real increase in pollutant load.
NAL Call No.: 292.8-J82
*****************************************************************
107. Models and modeling of hydrogeologic processes.
Narasimhan, T. N.
Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of
America. Mar/Apr 1995. v. 59 (2) p. 300-306.
Paper presented at the John Philip Symposium held at the 56th
annual meeting of the Soil Science Society of America, November
3, 1992, Minneapolis, MN.
Descriptors: soil-physics; hydrology-; soil-water-movement;
water-flow; subsurface-layers; transport-processes;
mathematical-models; computer-techniques
Abstract: J.R. Philip recently articulated a concern of many
earth scientists that computer-based mathematical models are
impacting soil science practice and soil science education in an
undesirable way. Unrealistic faith in the ability of these models
to predict the future has encouraged overzealous use of models at
the expense of the observational enterprise. These real concerns
draw attention to the fact that much needs to be learned about
the proper use of models in general and computer-based models in
particular in the earth sciences. I was impressed by Philip's
thoughts, and here reflect on the current status and the role of
models of hydrogeologic processes. While agreeing with Philip's
concerns about the improper use of models, I advance a
perspective that models (analytical or numerical) are tools with
inherent limitations. Despite their overenthusiastic use,
computer-based models are potentially capable of helping us
advance our knowledge of earth processes in unprecedented ways.
As we seek to exploit this tool to its full potential, we may be
challenged to reexamine and refine our conceptual foundations so
that hydrologic processes are described more precisely than has
hitherto been possible.
NAL Call No.: 56.9-So3
*****************************************************************
108. Modification of DRAINAGE model by using the nitrogen
component from the GLEAMS model.
Verma, A.; Kanwar, R. S.; Tim, U. S.
Trans-ASAE v.38, p.717-724. (1995).
Includes references.
Descriptors: groundwater-; drainage-; agricultural-chemicals;
leaching-; nitrogen-; nitrate-nitrogen; groundwater-; pollution-;
simulation-models
Abstract: The NITRO subroutine of the DRAINAGE model (Kanwar et
al., 1983) was modified using the nitrogen transformation
components of the GLEAMS (Leonard et al., 1987) model to predict
more accurately the leaching of NO3-N to subsurface drainage
water. Predicted values of tile flows and nitrate concentrations
in tile effluent have shown a good agreement with observed data
for the period from 1984 to 1992. There were some discrepancies
between the predicted and observed values in the beginning of the
simulation period resulting from lack of field data for
soil-profile initialization. Despite the assumed steady-state
condition within each time increment (one day) and the complexity
of the drainage system, the modified DRAINAGE model has shown the
capability to reasonably estimate long-term N loss with tile
effluent. Average deviation and standard error between the
predicted and observed NO3-N concentrations in the tile water
indicated that the modified DRAINAGE model developed in this
study resulted in better predictions of NO3-N concentrations in
the drainage water than the original DRAINAGE model.
NAL Call No.: 290.9-Am32T
*****************************************************************
109. Modification of RZWQM for simulating subsurface drainage by
adding a tile flow component.
Singh, P.; Kanwar, R. S.
Trans-ASAE v.38, p.489-498. (1995).
Includes references.
Descriptors: subsurface-drainage; water-quality; water-flow;
rain-; soil-properties; tillage-; simulation-models;
computer-simulation; performance-appraisals
Abstract: Fluctuating water table and subsurface drain flow
components were incorporated in the Root Zone Water Quality Model
(RZWQM) to enable the model to simulate subsurface drain flows.
Parameters in a modified model were calibrated using observed
subsurface drain flows for 1990. Model performance was evaluated
by predicting subsurface drain flows for 1991 and 1992 by using
the calibrated parameters and comparing the predicted drain flows
with observed subsurface drain flows for the same years. The
modified RZWQM model, in general, showed a good response to
rainfall in terms of time of peak flows. However, the modified
RZWQM model overpredicted total tile flows by an average of 13%,
and the magnitudes of peak tile flows were generally
underpredicted Selected soil properties (bulk density,
macroporosity, and residue content) in the surface horizon were
changed to investigate tillage effects on tile flows using the
modified RZWQM. Four different tillage systems, chisel plow (CP),
moldboard plow (MB), no-tillage (NT), and ridge-tillage (RT),
were considered. Predicted tillage effects on subsurface drain
flows were consistent with the observed effects (i.e., maximum
tile flow for NT and minimum tile flow for MB).
NAL Call No.: 290.9-Am32T
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110. Modification of the DRAINMOD-CREAMS model to incorporate a
nutrient submodel.
Saleh, A. R.; Bengtson, R. L.; Fouss, J. L.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1993. (932127) 23 p.
Paper presented at the "1993 International Summer Meeting
sponsored by The American Society of Agricultural Engineers and
The Canadian Society of Agricultural Engineering," June 20-23,
1993, Spokane, Washington.
Descriptors: subsurface-drainage; runoff-; nitrogen-; models-
NAL Call No.: 290.9-Am32P
*****************************************************************
111. Multidimensional infiltration: points, furrows, basins,
wells, and disk.
Clothier, B. E.; Green, S. R.; Katou, H.
Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of
America. Mar/Apr 1995. v. 59 (2) p. 286-292.
Paper presented at the John Philip Symposium held at the 56th
annual meeting of the Soil Science Society of America, November
3, 1992, Minneapolis, MN.
Descriptors: infiltration-; soil-water-movement; water-flow;
solutes-; transport-processes; theory-; mathematical-models;
sorption-; sorption-isotherms
Abstract: Multidimensional infiltration theory continues to be an
area of soil physics research dominated by the works of J.R.
Philip. The point source of these endeavors was his landmark
paper in 1966. Here in our contribution honoring John Philip, we
first discuss the multidimensional, similarity-solution
antecedents that were queried by him nearly 30 yr ago. We then
list the new theoretical developments contained in this
comprehensive treatise on multidimensional flow into unsaturated
soil. Next we comment on the three steady-state sequels derived
by J.R. Philip, P.A.C. Raats, and R.A. Wooding, especially in
relation to the experimental studies they spawned. Experiments
initially began with attempts to verify directly the various
multidimensional flow theories. But experimental procedures soon
came to use, in an inverse sense, these theories to permit
measurements of the hydraulic properties of field soil. The disk
permeameter, currently a widely used device, employs
multidimensional theory. In a variety of ways, disks are used to
infer the hydraulic properties of field soil in the pressure
potential range close to saturation. However, here we propose a
method by which the disk permeameter can be used to deduce in
situ the nonlinear adsorption isotherm that holds for the
transport of reactive chemicals through soil. We demonstrate this
proposal by using in the inverse sense of parameter
identification, not an analytical description, but rather a
two-dimensional numerical simulation of the flow of water and
transport of solute away from a surface disk maintained at a
given pressure potential, and some fixed concentration of
reactive solute.
NAL Call No.: 56.9-So3
*****************************************************************
112. Multigrid simulation of the transport of multicomponent
solute in groundwater.
Shen, H.; Yang, X.; Nikolaidis, N. P.
Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of
Agricultural Engineers,. Summer 1994. (94-2091/94-2119) 13 p.
Paper presented at the "1994 International Summer Meeting
sponsored by the American Society of Agricultural Engineers,"
June 20-23, 1994, Kansas City, Missouri.
Descriptors: solutes-; transport-processes; groundwater-;
simulation-models; mathematical-models
NAL Call No.: 290.9-Am32P
*****************************************************************
113. A multiple-pore-region concept to modeling mass transfer in
subsurface media.
Gwo, J. P.; Jardine, P. M.; Wilson, G. V.; Yeh, G. T.
J-hydrol v.164, p.217-237. (1995).
Includes references.
Descriptors: soil-pore-system; transport-processes;
saturated-conditions; mathematical-models
Abstract: Recent studies in soil science literature have strongly
indicated the need to incorporate pore structures in near-surface
mass transport modeling. There is increasing evidence suggesting
that pore structures. such as fractures and macropores,
facilitate the transport of water and solutes along a
preferential flow path while water and solutes are moved into
micropores and rock matrices concurrently. This study presents a
conceptual model a multiple-pore-region (or multi-region) concept
to account for pore structures as well as the resultant widely
distributed pore water velocities in macroporous media. Pore
regions can either be physically identified as discrete features.
such as fractures and rock matrices, or be experimentally
deterrnined by separation of water retention curves according to
pore classification schemes. A multi-region mechanism is proposed
to account for the effect of local-scale and field-scale
heterogeneities on mass transport under variably saturated
conditions. Two numerical codes for subsurface fluid flow and
solute transport have been developed with the multi-region
concept, in which a first-order mass exchange model is adopted to
simulate the redistribution of pressure heads and solute
concentrations among pore regions. The computer codes are used to
demonstrate the applicability of the concept to fractured porous
media, and to test a three-pore-region hypothesis using
laboratory soil column tracer injection data. Based upon the
parameters obtained from fitting multi-region