Water Quality Information
Center of
the National Agricultural Library
Agricultural Research Service, U.S. Department of Agriculture
Simulation Models, GIS and Nonpoint-Source Pollution (II)
January, 1994 - October, 1994
176 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
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construed as endorsement or disapproval.
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Delivery Services" at
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************************************************************
SIMULATION MODELS, GIS AND NONPOINT-SOURCE POLLUTION (II)
1. An agricultural chemical evaluation and management system.
Haan, C. T.; Nofziger, D. L.; Gregory, M.
J-agric-eng-res v.56, p.301-312. (1993).
Includes references.
Descriptors: agricultural-chemicals; movement-in-soil;
groundwater-pollution; simulation-models;
geographical-information-systems; evaluation-; management-;
systems-; oklahoma-
Abstract: An Agricultural Chemical Evaluation and Management
System (AGCHEMS), has been developed to investigate the impact of
various agricultural chemical management scenarios on the
movement of these chemicals toward groundwater. AGCHEMS was
developed by integrating a chemical transport model (CMLS), a
weather simulation model (WGEN), and a geographical information
system (GIS). AGCHEMS can evaluate the effect of chemical
application rate and timing, the particular chemical used, and
other management practices such as the amount and timing of
irrigation water. These factors affect the time and amount of
the chemical that will reach selected depths in the soil profile.
The GIS allows site specific soil information to be used in the
model. The GIS can also be used to prepare maps showing the
vulnerability of areas to exceed selected standards of chemical
movement. Uncertainty in the exact values of soil and chemical
properties and variability in weather sequences can also be
evaluated and maps generated showing the probability of exceeding
various amounts of chemical passing preselected depths in the
soil profile. The results obtained using possible and equally
likely weather sequences show considerable variability in
chemical movement due to weather alone. The implications of this
variability upon monitoring programmes, the interpretation of
model studies, and possible regulations on use of agricultural
chemicals are discussed.
NAL Call No.: 58.8-J82
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2. Alternating extraction/injection well interactions for in situ
bioremediation.
Shouche, M. S.; Petersen, J. N.; Skeen, R. S.; Hooker, B. S.
Appl-biochem-biotechnol. Totowa, N.J. : Humana Press. Spring
1994. v. 45/46 p. 775-785.
Paper presented at the "Fifteenth Symposium on Biotechnology for
Fuels and Chemicals," May 10-14, 1993, Colorado Springs,
Colorado.
Descriptors: bioremediation-; bacteria-; microbial-degradation;
carbon-tetrachloride; biomass-; spatial-distribution;
groundwater-flow; groundwater-pollution; wells-;
mathematical-models
NAL Call No.: QD415.A1J62
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3. Analyses of slope and runoff factors based on the WEPP erosion
model.
Huang, C.; Bradford, J. M.
Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of
America. Sept/Oct 1993. v. 57 (5) p. 1176-1183.
Includes references.
Descriptors: water-erosion; geological-sedimentation;
mathematical-models; equations-; mathematics-; slope-; runoff-;
sediment-; losses-from-soil; areas-;
water-erosion-prediction-process; rill-and-interrill-areas
Abstract: Under process-based erosion model development, the
source of sediment transported off a field isseparated into
that from interrill and rill areas, and separate detachment
equations are developed. Limitation of this spatial separation
is that, in many conditions, rill and interillareas are not
clearly defined a priori. We interpreted the erosion and
deposition equations usedin the current Water Erosion
Prediction Project (WEPP) in an alternative fashion such that
spatial separation of rill and interrill areas is no longer
required. Analytic solutions werederived for the WEPP erosion
and deposition equations under general conditions. Simplified
solutions for a specific case, uniform rain on uniform slope,
were examined closely for slope and runoff effects on sediment
delivery. Under both erosion and deposition conditions, analytic
solutions show a linear relationship between sediment yield, qs
and slope, S. The dependency of qson runoff, qw, is either
linear or quadratic depending on whether the system is dominated
by anerosion or deposition regime. These analytic findings
explain results obtained from laboratorystudies in which
sediment yield was collected under variable slope and rain
intensities.
NAL Call No.: 56.9-So3
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4. Analytical models of steady state organic species transport in
the vadose zone with kinetically controlled volatilization and
dissolution.
Zaidel, J.; Russo, D.
Water-resour-res v.29, p.3343-3356. (1993).
Includes references.
Descriptors: soil-pollution; volatile-compounds;
transport-processes; volatilization-; dissolving-; kinetics-;
mathematical-models; unsaturated-zone; steady-state-flow
Abstract: Kinetically controlled volatilization and dissolution
of nonaqueous phase liquids (NAPLs) may play an important role
in the transport of volatile compounds in the unsaturated
(vadose) zone. In this study, some one- and two-dimensional
steady state transport problems are solved analytically. The
one-dimensional case is pertinent to pollution by a relatively
long, mainly horizontally spreadleak of NAPL. The
two-dimensional case corresponds to situations in which the
pollution spreadsprimarily vertically, originating at the
ground surface and migrating to the top of the capillary
fringe, and in which the solution domain may be represented by a
cross-sectional model. Solutionsof the steady state transport
problems are used to investigate effects of several parameters,
characterizing the advective-dispersive and purely diffusive
transport regimes, on the NAPLconcentration distribution for
the one- and two-dimensional cases, respectively. Results of this
analysis indicate that the mass exchange between NAPL and other
phases may not reach equilibrium,even for relatively large
mass transfer rate coefficients and small water infiltration
rates, ifthis zone has relatively small vertical or horizontal
extent and is located close to the fullyopen ground surface.
Analysis of local volatilization and dissolution fluxes shows
that, underequilibrium conditions, the main losses of the
organic phase take place at the upper part of theNAPL zone.
NAL Call No.: 292.8-W295
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5. Analytical solutions for non-equilibrium solute transport in
three-dimensional porous media.
Leij, F. J.; Toride, N.; Van Genuchten, M. T. v.
J-hydrol v.151, p.193-228. (1993).
Includes references.
Descriptors: soil-water-movement; solutes-; transport-processes;
porous-media; flow-; mathematical-models; unidirectional-flow
Abstract: The movement of water and chemicals in soils is
generally better described with multidimensionalnonequilibrium
models than with more commonly used one-dimension and/or
equilibrium models. This paper presents analytical solutions for
non-equilibrium solute transport in semi-infinite porousmedia
during steady unidirectional flow. The solutions can be used to
model transport in porousmedia where the liquid phase consists
of a mobile and an immobile region (physicalnon-equilibrium)
or where solute sorption is governed by either an equilibrium or
a first-orderrate process (chemical non-equilibrium). The
transport equation incorporates terms accounting for advection,
dispersion, zero-order production, and first-order decay. General
solutions were derivedfor the boundary, initial, and
production value problems with the help of Laplace and Fourier
transforms. A comprehensive set of specific solutions is
presented using Dirac functions for theinput and initial
distribution, and/or Heaviside or exponential functions for the
input, initial,and production profiles. A rectangular or
circular inflow area was specified for the boundaryvalue
problem while for the initial and production value problems the
respective initial and production profiles were located in
parallelepipedal, cylindrical, or spherical regions of the
soil. Solutions are given for both the volume-averaged or
resident concentration as well as theflux-averaged or flowing
concentration. Examples of concentration profiles versus time
and. effects of non-equilibrium onthree-dimensional transport
are very similar to those for one-dimensional transport.
NAL Call No.: 292.8-J82
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6. Answer-2000: a model for agricultural pollution control
planning in the USA and the Ukraine.
Dillaha, T. A. I.; Bouraoui, F.; Kolpak, V. Z.; Beasley, D. B.;
Platonova, G. Y.
Proceedings of Industrial and Agricultural Impacts on the
Hydrologic Environment the Second USA/CIS Joint Conference on
Environmental Hydrology and Hydrogeology / USA/CIS Joint
Conference on Environmental Hydrology and Hydrogeology.
Alexandria, VA : Water Environment Federation, c1993.. v. 2 p.
165-178.
Title on cover : Environmental impact of agricultural practices
and agrichemicals / edited by Y. Eckstein and A. Zaporozec.
Descriptors: agricultural-production; pollution-; control-;
water-quality; planning-; models-; usa-; ukraine-
NAL Call No.: GB652.U82-1993
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7. Application of a GIS-based nonpoint source nutrient loading
model for assessment of land development scenarios and water
quality in Owasco Lake, New York.
Heidtke, T. M.
Water-sci-technol v.28, p.595-604. (1993).
Paper presented at the IAWQ First International Conference on
"Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact,
Abatement." September 19-24, 1993, Chicago, Illinois.
Descriptors: lakes-; water-quality; phosphorus-; loads-;
water-pollution; models-; geographical-information-systems;
land-use; new-york
NAL Call No.: TD420.A1P7
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8. The application of CREAMS model to forecasting the nitrate and
chloride leaching from grassland.
Sapek, B.; Sapek, A.
Water-sci-technol v.28, p.649-658. (1993).
Paper presented at the IAWQ First International Conference on
"Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact,
Abatement." September 19-24, 1993, Chicago, Illinois.
Descriptors: permanent-grasslands; groundwater-pollution;
nitrates-; chlorides-; leaching-; simulation-models;
forecasting-; poland-
NAL Call No.: TD420.A1P7
*****************************************************************
9. Application of geographic information systems in hydrology and
water resources management : proceedings of an international
conference held in Vienna, Austria, from 19 to 22 April 1993 :
this conference was jointly organized by the International
Commission on Groundwater of the International Association of
Hydrological Sciences (IAHS), the United Nations Educational,
Scientific and Cultural Organization (UNESCO) - as a contribution
to subprogramme M-2-3 of UNESCO's IHP-IV, Universitat fur
Bodenkultur, Vienna.
Kovar, K.; Nachtnebel, H. P.; International Association of
Hydrological Sciences.
Wallingford : International Association of Hydrological Sciences,
1993. xi, 693 p. : ill., maps.
Includes bibliographical references.
Descriptors: Geographic-information-systems-Congresses;
Hydrology-Data-processing-Congresses;
Water-resources-management-Data-processing-Congresses
NAL Call No.: G70.2.A77--1993
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10. 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.
Trans-ASAE v.37, p.453-459. (1994).
Includes references.
Descriptors: poultry-manure; runoff-; nitrogen-; phosphorus-;
water-quality; simulation-models; alabama-;
groundwater-loading-effects-of-agricul; -manage; -systems
Abstract: The GLEAMS (Groundwater Loading Effects of Agricultural
Management System) (version 2.1) water quality model was used to
predict nutrient (N and P) losses in surface and subsurface
runoff, and their concentrations in soil layers, following
application of two rates (9 and 18 t ha-1) of poultry litter and
a recommended rate of a commercial fertilizer on conventionally
tilled corn plots at the Tennessee Valley Substation of the
Alabama Agricultural Experiment Station. Model simulation results
were compared with field data. The experiment included four
replications for each of the three soil-amendment treatments. The
GLEAMS simulation of soluble and sediment P losses in surface
runoff and NO3-N concentrations in leachate and soil layers were
not consistent with field data. Simulation of N-transformation
effects on N losses in surface runoff did not agree with field
data. The model simulated higher NH4-N than NO3-N losses in
surface runoff, while field data showed the opposite. The model
simulated low concentrations of P in leachate at a 1.0 m depth,
while the observed data showed large variations.
NAL Call No.: 290.9-Am32T
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11. Assessing the movement of agricultural chemicals through the
soil profile at the Ohio management systems evaluation area.
Workman, S. R.; Ward, A. D.; Knisel, W. G.
Proceedings of Industrial and Agricultural Impacts on the
Hydrologic Environment the Second USA/CIS Joint Conference on
Environmental Hydrology and Hydrogeology / USA/CIS Joint
Conference on Environmental Hydrology and Hydrogeology.
Alexandria, VA : Water Environment Federation, c1993.. v. 2 p.
145-158.
Title on cover : Environmental impact of agricultural practices
and agrichemicals / edited by Y. Eckstein and A. Zaporozec.
Descriptors: zea-mays; glycine-max; triticum-aestivum;
vicia-villosa; atrazine-; alachlor-; metribuzin-;
movement-in-soil; prediction-; simulation-models; leaching-;
contamination-; ohio-
NAL Call No.: GB652.U82-1993
*****************************************************************
12. Assessment of pollution of groundwater by atrazine.
Kuhnt, G.; Franzle, O.
Land-degrad-rehabil v.4, p.245-251. (1993).
Special Issue on the June 1992 Conference of the Society for
Environmental Toxicology and Chemistry (SETAC) / edited by G.P.
Hekstra, E. Ivanova and J.H. Weverling.
Descriptors: atrazine-; groundwater-pollution; risk-;
monitoring-; soil-types; simulation-; models-; germany-
NAL Call No.: S622.L26
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13. Automated extraction of drainage network and watershed data
from digital elevation models.
Martz, L. W.; Garbrecht, J.
Water-resour-bull v.29, p.901-908. (1993).
Includes references.
Descriptors: drainage-; overland-flow; runoff-; watersheds-;
hydrological-data; algorithms-; computer-software;
geomorphology-; oklahoma-;
digital-elevation-drainage-network-model-dednm
Abstract: This paper discusses a computer program which extracts
a number of watershed and drainage network properties directly
from digital elevation models (DEM) to assist in the rapid
parameterization of hydrologic runoff models. The program
integrates new and established algorithms to address problems
inherent in the analysis low-relief terrain from raster DEMs
similar to those distributed by the U.S. Geological Survey for
7.5-minute quadrangles. The program delineates the drainage
network from a DEM, and determines the Strahler order, total and
direct drainage area, length, slope, and upstream and downstream
coordinates of each channel link. It also identifies the
subwatershed of each channel source and of the left and right
bank of each channel link, and assigns a unique number to each
network node. The node numbers are used to associate each
subwatershed with the channel link to which it drains, and can be
used to control flow routing in cascade hydrologic models.
Program output includes tabular data and raster maps of the
drainage network and subwatersheds. The raster maps are intended
for import to a Geographical Information System where they can be
registered to other data layers and used as templates to extract
additional network and subwatershed information.
NAL Call No.: 292.9-Am34
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14. Axisymmetric transport of water and solute underneath a disk
Quadri, M. B.; Clothier, B. E.; Angulo Jaramillo, R.; Vauclin,
M.; Green, S. R.
Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of
America. May/June 1994. v. 58 (3) p. 696-703.
Includes references.
Descriptors: water-flow; solutes-; movement-in-soil;
transport-processes; unsaturated-flow; permeability-
Abstract: No analytical solution exists for two-dimensional,
axisymmetric flow of both water and solute underneath a disk
permeameter. We developed a finite-difference numerical scheme
for such flows. Laboratory experiments were also conducted using
a box containing repacked sand. A 1/4-sector disk permeameter
was located on the surface in one corner. The disk, first
containing pure water, was placed on the soil for 200 s. It was
then removed, refilled with a KBr solution, and replaced at 225
s. Finally after 12.5 min the disk was removed and soil samples
extracted along three radial transects under the disk. In two
other experiments, the disk, containing only pure water, was left
on the soil surface and soil samples removed at the end i.e., 6
and 14 min. A tensiometer inserted through one face of the box
and located just 20 mm under the disk recorded the changing soil
water pressure head with time, h(t). Good predictions of both
the water content and Br(-) profiles were achieved with the
numerical model, and good renditions of h(t) and the transient
flow rate from the disk, q(t). Our results reinforce the need for
caution when determining the soil's sorptivity from observations
of q vs t(1/2). Care is required in deciding when q has indeed
become steady. Numerical models, such as this one might serve as
parameter-identification tools when using a tracer-filled disk
permeameter to infer the chemical transport properties of soil.
NAL Call No.: 56.9-So3
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15. Broiler litter application to land in an agricultural
watershed: A GIS approach.
Xu, F.; Prato, T.; Fulcher, C.
Water-sci-technol v.28, p.111-118. (1993).
Paper presented at the IAWQ First International Conference on
"Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact,
Abatement." September 19-24, 1993, Chicago, Illinois.
Descriptors: broilers-; poultry-manure; application-to-land;
agricultural-land; watersheds-; application-rates;
economic-evaluation; water-pollution; prediction-; optimization-;
models-; geographical-information-systems; missouri-
NAL Call No.: TD420.A1P7
*****************************************************************
16. Calculating critical loads for acidity with the simple mass
balance method.
Sverdrup, H.; Vries, W. de.
Water-air-soil-pollut v.72, p.143-162. (1994).
Includes references.
Descriptors: acid-deposition; forest-soils; polluted-soils;
groundwater-pollution; soil-pollution; water-pollution; acidity-;
soil-acidity; alkalinity-; soil-alkalinity; balance-studies;
mathematical-models; equations-; sweden-; netherlands-
NAL Call No.: TD172.W36
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17. CELMOD5--a semi-distributed cell model for conversion of
rainfall into runoff in semi-arid watersheds.
Karnieli, A. M.; Diskin, M. H.; Lane, L. J.
J-hydrol v.157, p.61-85. (1994).
Includes references.
Descriptors: watersheds-; rain-; storms-; runoff-;
catchment-hydrology; forecasting-; floods-; semiarid-climate;
simulation-models
Abstract: This paper introduces the general outline of CELMOD5, a
parametric, semi-distributed, quasi-linear model, for conversion
of rainfall into surface runoff. The model considers the
watershed as a series of interconnected cell units, each
representing a specific portion of the area of the watershed. In
contrast to grid models using a large number of rectangular
elements or cells, the number of cells in CELMOD is relatively
small and their boundaries are chosen according to the watershed
topography. For each cell, the program computes the surface
runoff hydrograph at the cell outlet, related to a specified
record of total rainfall data at a number of rain gages. If
measured surface runoff data are available for some locations in
the watersheds, the program can compare these data with computed
values of surface runoff at the corresponding points of the cell
model. Detailed descriptions are provided for the main model
procedures--computation of rainfall excess, conversion of
rainfall excess into surface outflow, routing the channel inflow
and subtraction of channel losses. Special attention is given in
this model to the specific conditions of arid or semi-arid
watersheds. This paper is also concerned with a technique for
calibrating and testing a forecasting model of storm hydrographs
with emphasis on two objective functions--runoff volume and peak
discharge. A method for evaluation procedure is presented based
on the following five steps: trial and error calibration:
sensitivity analysis; bilinear interpolation optimization,
testing the model on different storm events; testing the model on
a different watershed. Results are presented for all the larger
storm events with reliable. Experimental Watershed in
southeastern Arizona. The evaluation procedure is demonstrated
for one particular rainfall-runoff event.
NAL Call No.: 292.8-J82
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18. Chloride migration in heterogeneous soil. 2. Stochastic
modeling.
Destouni, G.; Sassner, M.; Jensen, K. H.
Water-resour-res v.30, p.747-758. (1994).
Includes references.
Descriptors: transport-processes; chloride-; prediction-;
stochastic-models
Abstract: The observed statistics of chloride breakthrough
presented by Sassner et al. (this issue) were compared with
predictions of a stochastic-advective modeling approach. The
stochastic-advective model based on the observed spatial
distribution of flow rates and on transport parameters consistent
with parameter values obtained from local breakthrough curves
(BTCs) agreed well with the observations. Alternative models that
agreed well with the local BTCs failed to predict the large-scale
BTC with realistic parameter values. The results support the
assumption that compared to advection variability, local
dispersion within the mobile water will often have a second-order
effect on field scale solute transport. The stochastic-advective
model is robust with regard to the rate of mass transfer between
mobile and immobile water zones. This robustness implies that
order of magnitude estimates may be sufficient for providing
useful predictions of both field scale solute transport and the
associated prediction uncertainty. In contrast, accurate
estimation of the statistics of solute advection at the scale of
interest for the transport problem is necessary.
NAL Call No.: 292.8-W295
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19. Climate change impact on distribution and abundance of
wildlife species: an analytical approach using GIS.
Aspinall, R.; Matthews, K.
Environ-pollut v.86, p.217-223. (1994).
Includes references.
Descriptors: climatic-change; wildlife-; habitats-;
geographical-distribution; climatic-factors;
geographical-information-systems; scotland-; species-distribution
NAL Call No.: QH545.A1E52
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20. Comments on "Boundry Conditions for Displacement Experiments
through Short Laboratory Soil Columns".
Shukla, B. S.
Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of
America. May/June 1994. v. 58 (3) p. 991-993.
Original article by M.T. van Genuchten and J.C. Parker published
in Soil Science Society of America Journal, 48(4), p. 703-708.
Reply by M.T. van Genuchten and J.C. Parker, p. 991-993.
Descriptors: solutes-; transport-processes; movement-in-soil;
mathematical-models; diffusion-
NAL Call No.: 56.9-So3
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21. Comparison of PRZM computer model predictions with field
lysimeter data for dichlorprop and bentazon leaching.
Mueller, T. C.
J-environ-sci-health,-Part-A,-Environ-sci-eng v.A29, p.1183-1195.
(1994).
Special Issue on the Evaluation and Comparison of Pesticide
Leaching.
Descriptors: dichlorprop-; bentazone-; leaching-;
simulation-models; prediction-; sandy-soils;
pesticide-root-zone-model
NAL Call No.: TD172.J6
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22. A comprehensive set of analytical solutions for
nonequilibrium solute transport with first-order and zero-order
production.
Toride, N.; Leij, F. J.; Van Genuchten, M. T.
Water-resour-res v.29, p.2167-2182. (1993).
Includes references.
Descriptors: transport-processes; solutes-; flow-; sorption-;
kinetics-; mathematical-models; subsurface-layers;
nonequilibrium-transport-models; semi-infinite-soil-systems
Abstract: Solute transport in the subsurface is often considered
to be a nonequilibrium process. Predictive models for
nonequilibrium transport may be based either on chemical
considerations by assuming the presence of a kinetic sorption
process, or on physical considerations by assuming two-region
(dual-porosity) type formulations which partition the liquid
phase into mobile and immobile regions. For certain simplifying
conditions, including steady state flow and linear sorption, the
chemical and physical nonequilibrium transport models can be cast
in the same dimensionless form. This paper presents a
comprehensive set of analytical solutions for one-dimensional
nonequilibrium solute transport through semi-infinite soil
systems. The models involve the one-site, two-site, and
two-region transport models, and include provisions for
first-order decay and zero-order production. General solutions
are derived for the volume-averaged (or resident) solute
concentration using Laplace transforms assuming both first- and
third-type inlet conditions, and arbitrary initial conditions,
input solute concentrations, and solute production profiles. The
solutions extend and generalize existing solutions for
equilibrium and nonequilibrium solute transport. The general
solutions are evaluated for some commonly used input and initial
conditions, and zero-order production profiles. Expressions for
the flux-averaged concentration are derived from the general and
specific solutions assuming a third-type inlet condition. Typical
examples of calculated concentration distributions resulting from
several sets of initial and input conditions and zero-order
production functions are also presented and briefly discussed.
NAL Call No.: 292.8-W295
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23. The conceptual framework for the National Pilot Project on
Livestock and the Environment. Livestock series report 2.
Bouzaher, A.; Johnson, S. R.; Neibergs, S.; Jones, R.; Beran, L.;
Frarey, L.; Hauck, L.
Staff-rep-Iowa-State-Univ,-Cent-Agric-Rural-Dev. Ames, Iowa :
Center for Agricultural and Rural Development, 1986-. Dec 1993.
(93-SR67) 34 p.
Includes references.
Descriptors: animal-feeding; livestock-;
environmental-assessment; pilot-projects; water-quality;
waste-disposal; models-; usa-; texas-; erath-county,-texas
NAL Call No.: HD1401.S75
*****************************************************************
24. A daily runoff simulation in semi-arid watersheds based on
soil water deficit calculations.
Karnieli, A.; Ben Asher, J.
J-hydrol v.149, p.9-25. (1993).
Includes references.
Descriptors: watersheds-; soil-water-content; water-deficit;
runoff-; storms-; semiarid-zones; simulation-models; arizona-
Abstract: Initial soil water content just before a rainfall event
is an input required for the calculation of a basin's water
balance including infiltration and runoff. However, for most
watersheds such information is not available because its
evaluation involves a large amount of labor. The objective of
this study is to describe a practical model with which to
estimate time-dependent changes of a basins soil water content.
It is further used for predicting runoff water yield when
rainfall depth is the only known component of the water balance
equation (WBE). Two distinct cases of the WBE are discussed: (1)
a runoff-producing storm; (2) a storm without runoff. Runoff
events from four watersheds in southern Arizona were measured
throughout 8 to 17 years and analyzed in this study.
Rainfall-runoff relationships are described in this model by an
empirical quadratic regression equation which includes four
parameters. They were estimated by an optimization subroutine
which was used to determine the minimum difference between
measured and modeled results. The optimized parameters enable
simulations of the continuous dynamic change of an index of the
soil water content as well as predictions of runoff depths. It
was found that the predicted runoff agrees reasonably well with
the observed runoff. The minimum coefficient of determination
(r2) between the computed and actual runoff for the multi-annual
data sets was 0.62 and the maximum 0.86. Runoff threshold value
was found to be a function of the basin average soil texture. The
lowest threshold was 4.6 mm for clay soil and the largest was 9.0
mm for sandy soil. Since direct soil water measurements were not
taken, we interpreted the acceptable agreement between measured
and predicted runoff as an indirect validation of the soil water
model. It is. simulated runoff on nearby ungaged watersheds in
semi-arid regions.
NAL Call No.: 292.8-J82
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25. Darcy-Weisbach roughness coefficients for selected crops.
Gilley, J. E.; Kottwitz, E. R.
Trans-ASAE v.37, p.467-471. (1994).
Includes references.
Descriptors: zea-mays; gossypium-hirsutum; hordeum-vulgare;
glycine-max; helianthus-annuus; triticum-aestivum; runoff-;
hydraulic-resistance; hydrology-; models-
Abstract: Total hydraulic resistance on an upland agricultural
site may be influenced by several factors including standing
vegetation. In this laboratory study, Darcy-Weisbach roughness
coefficients were measured for corn, cotton, sorghum, soybeans,
sunflower, and wheat vegetation. Experimental variables used in
this investigation in addition to crop type included plant
population, row spacing, row orientation, and flow rate. For some
of the experimental tests, a single row of vegetation was
oriented within a flume parallel to the principal flow direction.
For the remainder of the tests, rows of vegetation were placed
perpendicular to the flow using row spacings and plant
populations recommended by crop management specialists.
Measurements of discharge rate and flow velocity were used to
calculate roughness coefficients for Reynolds number values
ranging from approximately 550 to 22,000. Regression equations
which relate roughness coefficients to plant population, row
spacing, and Reynolds number were developed from the laboratory
data. With the exception of wheat placed perpendicular to flow,
roughness coefficients produced by standing vegetation were
negligible. On upland agricultural areas, total hydraulic
roughness will be influenced primarily by frictional drag over
the soil surface, and residue and ground cover.
NAL Call No.: 290.9-Am32T
*****************************************************************
26. A decision support system for evaluating the effects of
alternative farm management systems on water quality and
economics.
Yakowitz, D. S.; Stone, J. J.; Lane, L. J.; Heilman, P.;
Masterson, J.; Abolt, J.; Imam, B.
Water-sci-technol v.28, p.47-54. (1993).
Paper presented at the IAWQ First International Conference on
"Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact,
Abatement." September 19-24, 1993, Chicago, Illinois.
Descriptors: water-quality; farm-management; systems-;
decision-making; support-systems; farm-income; simulation-models;
arizona-
NAL Call No.: TD420.A1P7
*****************************************************************
27. Determination of traveltime in the Delaware River, Hancock,
New York, to the Delaware Water Gap by use of a conservative dye
tracer.
White, K. E.; Kratzer, T. W.; Delaware River Basin Commission.
Lemoyne, Pa. : U.S. Dept. of the Interior, U.S. Geological Survey
; Denver, Colo. : U.S. Geological Survey, Earth Science
Information Center, Open-File Reports Section [distributor],
1994. vi, 54 p. : ill., maps.
Shipping list no.: 94-0223-P.
Descriptors: Streamflow-Delaware-River-N; Y; -Del; -and-N; J;
-Mathematical-models; Water-quality-Delaware-River-N; Y; -Del;
-and-N; J; -Measurement
NAL Call No.: GB701.W375--no.93-4203
*****************************************************************
28. Determining off-site concentrations of volatile pesticides
using the trajectory-simulation model.
Yates, S. R.
J-environ-qual v.22, p.481-486. (1993).
Paper presented at the USDA-ARS Beltsville Agricultural Research
Center Symposium XVII, "Agricultural Water Quality Priorities, A
Team Approach to Conserving Natural Resources," May 4-8, 1992,
Beltsville, MD.
Descriptors: pesticides-; volatilization-; atmosphere-;
losses-from-soil; transport-processes; simulation-models;
environmental-fate-models
Abstract: An environmental transport model is described and
illustrated that will enable the prediction of the mass and/or
concentration of volatile pesticides at any depth in the soil
profile and at any height in the atmosphere relatively far
distanced downwind from agricultural fields. The theoretical
profile shape model is used to determine transport in the
atmosphere and is coupled to the behavior assessment model (BAM)
to describe transport in soils. The model outputs include the
soil-water concentrations, the surface volatilization rate, the
concentration of pesticides in the atmosphere above the field,
and the atmospheric concentration at specified distances downwind
from the field. The results from this approach can be used in
exposure assessment studies to determine the risk for individuals
living near agricultural fields.
NAL Call No.: QH540.J6
*****************************************************************
29. Determining parameter precision for modeling nitrate
leaching: inorganic fertilization in Nordic climates.
Larocque, M.; Banton, O.
Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of
America. Mar/Apr 1994. v. 58 (2) p. 396-400.
Includes references.
Descriptors: nitrate-; leaching-; deterministic-models;
fertilizers-; inorganic-compounds; movement-in-soil;
edaphic-factors; biological-activity-in-soil; cold-zones;
nitrogen-cycle
Abstract: Most NO3- leaching models require the quantification of
many parameters. Because the majority of these parameters are
difficult to estimate, it is important to know the impact of
parameter imprecision to make proper use of a model. A study was
performed to identify the relative influence of the parameters in
a deterministic NO3- leaching model (SOILN) used with inorganic
fertilization in nordic climates. A sensitivity analysis of the
model was performed using parameters related to the N cycle with
two reference systems for the parameters corresponding to field
sites located in Quebec and in southern Sweden. Results from both
sites showed that atmospheric deposits had little influence on
NO; leaching in agricultural areas in Quebec and Sweden; the
variation of parameters related to nitrification also had little
impact on NO3- leaching at the sites studied; parameters used for
mineralization, plant uptake, and denitrification had a
significant impact on NO3- leaching in the simulated conditions;
parameters related to abiotic factors had a variable influence,
depending mostly on soil water contents.
NAL Call No.: 56.9-So3
*****************************************************************
30. Determining the green-Ampt effective hydraulic conductivity
from rainfall-runoff data for the WEPP model.
Risse, L. M.; Nearing, M. A.; Savabi, M. R.
Trans-ASAE v.37, p.411-418. (1994).
Includes references.
Descriptors: rain-; runoff-; erosion-; hydraulic-conductivity;
hydrology-; models-; water-erosion-prediction-project
Abstract: The Green-Ampt infiltration equation is used in many
different hydrologic models. The effective hydraulic conductivity
parameter (Ke) within this equation is needed to obtain reliable
estimates of infiltration and runoff. In this study, a method was
developed for calibrating Ke for the Green-Ampt equation as
integrated with the WEPP continuous simulation model using a
series of rainfall-runoff events on natural runoff plots. Optimum
values of Ke were obtained at seven locations, and the average
Nash-Sutcliffe model efficiency for the Green-Ampt/Wepp
predictions of runoff on an event basis was 0.46 using these Ke
values. Green-Ampt/WEPP tended to overpredict runoff on the small
events and underpredict runoff on the larger events. This bias
could not be corrected through calibration and indicates a
structural flaw in the Green-Ampt equation, the WEPP model, or
the available data. Other estimates of effective hydraulic
conductivity were obtained from five different parameter
estimation methods based on relationships involving common soil
properties and were used in the Green-Ampt/Wepp model to predict
runoff at each of the locations. None of these methods of
estimating the effective hydraulic conductivity consistently
outperformed the others for all the data sets. The average
Nash-Sutcliffe model efficiency obtained using the best estimated
parameters was -0.16, indicating that considerable improvement
was obtained with calibration.
NAL Call No.: 290.9-Am32T
*****************************************************************
31. Development, description, and application of a geographic
information system data base for water resources in karst terrane
in Greene County, Missouri.
Waite, L. A.; Thomson, K. C.; Geological Survey (U.S.).
Rolla, Mo. : U.S. Geological Survey ; Denver, Colo. : Earth
Science Information Center, Open-File Reports Section
[distributor], 1993. vi, 31 p. : ill., maps (some col.).
Shipping list no.: 93-0640-P.
Descriptors: Geographic-information-systems;
Water-Pollution-Missouri-Greene-County-Data-bases;
Groundwater-Pollution-Missouri-Greene-County-Data-bases;
Karst-Missouri-Greene-County; Hydrogeology-Missouri-Greene-County
NAL Call No.: GB701.W375-no.93-4154
*****************************************************************
32. Development of a non-isothermal method for determination of
diffusional parameters.
Moreira, L. A.; Oliveira, F. A. R.; Silva, T. R.; Oliveira, J. C.
Int-j-food-sci-technol v.28, p.575-586. (1993).
Includes references.
Descriptors: turnips-; food-processing; acidification-;
blanching-; leaching-; diffusivity-; temperature-;
diffusion-models; mathematical-models; fick's-second-law
NAL Call No.: TP368.J6
*****************************************************************
33. Development of steady-state diffusion gradients for the
cultivation of degradative microbial consortia.
Wolfaardt, G. M.; Lawrence, J. R.; Hendry, M. J.; Robarts, R. D.;
Caldwell, D. E.
Appl-environ-microbiol v.59, p.2388-2391. (1993).
Includes references.
Descriptors: microorganisms-; groundwater-;
microbial-degradation; diclofop-; isolation-techniques;
cell-culture; gels-; bioreactors-; diffusion-; gradients-;
groundwater-pollution; simulation-models
Abstract: A diffusion gradient plate was constructed and
evaluated for its potential use in the isolation of degradative
microbial consortia from natural habitats. In this model, a
steady-state concentration gradient of diclofop methyl,
established by diffusion through an agarose gel, provided the
carbon for microbial growth. Colonization of the gel surface was
observed with epifluorescence and scanning confocal laser
microscopy to determine microbial responses to the diclofop
gradient. A detectable gradient developed over a narrow band (<10
mm). Consequently, quantitative analyses of the microbial
response to the gradient were difficult to obtain. A
two-dimensional, finite-element numerical transport model for
advective-diffusive transport was used to simulate concentration
and flux profiles in the physical model. The simulated profiles
were correlated with the measured concentration gradient (R2 =
0.89) and the cell numbers on the gel surface (R2 = 0.85). The
numerical model was subsequently used to redesign the physical
model. The detectable concentration gradient in the modified
physical model extended over the length of the gel (38 mm). The
simulated profile again showed a good correlation with the
measured profile (R2 = 0.96) and the microbial responses to the
concentration gradient (R2 = 0.99). It was concluded that these
gradients provide the steady-state environments needed to sustain
steady-state consortia. They also provide a physical pathway for
the development of degradative biofilms from low to high
concentrations of toxicants and simulate conditions under which
low concentrations of toxicant are supplied at a constant flux
over long periods of time, such as the conditions that could
occur in natural environments.
NAL Call No.: 448.3-Ap5
*****************************************************************
34. Digital data acquisition and development of geographic
information system coverages for use with the public water-supply
wells and springs in Tennessee.
Connell, J. F.; Barron, W. R.; Tennessee. Division of Water
Supply.
Nashville, Tenn. : U.S. Dept. of the Interior, U.S. Geological
Survey ; Denver, Colo. : U.S. Geological Survey Books and
Open-File Reports Section, distributor, 1993. iii, 28 p. : maps.
Shipping list no.: 93-0483-P.
Descriptors: Groundwater-Tennessee-Data-bases;
Hydrogeology-Tennessee-Data-bases; ¤
NAL Call No.: GB701.W375-no.92-4178
*****************************************************************
35. A distributed hydrology-vegetation model for complex terrain.
Wigmosta, M. S.; Vail, L. W.; Lettenmaier, D. P.
Water-resour-res v.30, p.1665-1679. (1994).
Includes references.
Descriptors: runoff-; catchment-hydrology; vegetation-;
simulation-models; canopy-penetration; evapotranspiration-;
snow-cover; meltwater-; topography-; mountain-areas;
spatial-distribution; montana-
Abstract: A distributed hydrology-vegetation model is described
that includes canopy interception, evaporation, transpiration,
and snow accumulation and melt, as well as runoff generation via
the saturation excess mechanisms. Digital elevation data are used
to model topographic controls on incoming solar radiation, air
temperature, precipitation, and downslope water movement. Canopy
evapotranspiration is represented via a two-layer Penman-Monteith
formulation that incorporates local net solar radiation, surface
meteorology, soil characteristics and moisture status, and
species-dependent leaf area index and stomatal resistance. Snow
accumulation and ablation are modeled using an energy balance
approach that includes the effects of local topography and
vegetation cover. Saturated subsurface flow is modeled using a
quasi three-dimensional routing scheme. The model was applied at
a 180-m scale to the Middle Fork Flathead River basin in
northwestern Montana. This 2900-km(2), snowmelt dominated
watershed ranges in elevation from 900 to over 3000 m. The model
was calibrated using 2 years of recorded precipitation and
streamflow. The model was verified against 2 additional years of
runoff and against advanced very high resolution radiometer based
spatial snow cover data at the 1-km(2) scale. Simulated
discharge showed acceptable agreement with observations. The
simulated areal patterns of snow cover were in general agreement
with the remote sensing observations, but were lagged slightly in
time.
NAL Call No.: 292.8-W295
*****************************************************************
36. The distributed modelling of agricultural nonpoint pollution
at basin
Preti, F.; Lubello, C.
Water-sci-technol v.28, p.669-674. (1993).
Paper presented at the IAWQ First International Conference on
"Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact,
Abatement." September 19-24, 1993, Chicago, Illinois.
Descriptors: agricultural-chemicals; application-; rivers-;
watersheds-; water-pollution; models-; italy-
NAL Call No.: TD420.A1P7
*****************************************************************
37. Dynamic simulation modelling for evaluating water quality
response to agricultural BMP implementation.
Cassell, E. A.; Clausen, J. C.
Water-sci-technol v.28, p.635-648. (1993).
Paper presented at the IAWQ First International Conference on
"Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact,
Abatement." September 19-24, 1993, Chicago, Illinois.
Descriptors: agricultural-land; phosphorus-;
input-output-analysis; movement-in-soil; groundwater-pollution;
surface-water; pollution-; sources-; dynamic-models;
simulation-models; vermont-; best-management-practices
NAL Call No.: TD420.A1P7
*****************************************************************
38. Economic and environmental impacts of water quality
protection policies. 2. Application to the Central High Plains.
Bernardo, D. J.; Mapp, H. P.; Sabbagh, G. J.; Geleta, S.;
Watkins, K. B.; Elliott, R. L.; Stone, J. F.
Water-resour-res v.29, p.3081-3091. (1993).
Includes references.
Descriptors: groundwater-pollution; groundwater-; water-quality;
water-policy; agricultural-chemicals; agricultural-production;
economic-impact; environmental-impact; mathematical-models;
programming-; simulation-models; models-; oklahoma-; kansas-;
texas-; new-mexico; colorado-; mathematical-programming-models;
transport-models
Abstract: A three-stage modeling framework is applied to evaluate
the potential economic and environmental impacts of agricultural
groundwater protection policies in the Central High Plains
Region. Three alternative policies (limitations on total nitrogen
applications, limitations on unit-area nitrogen applications, and
restrictions on the use of selected herbicides) are compared to a
baseline scenario that reflects the absence of any form of
groundwater quality protection measures. In general, nitrogen
restrictions are more effective in reducing nitrate loadings in
percolation water if implemented on a unit-area basis rather than
as a total (farm level) restriction. In contrast, the total
restriction is more effective in controlling runoff losses of
nitrogen. Both nitrogen restrictions have significant impacts on
crop production levels and regional agricultural income, while
the economic consequences of the pesticide restriction are much
less pronounced. The proposed regional modeling framework
provides critical information necessary to assess the economic
and environmental tradeoffs of policy alternatives aimed at
controlling agricultural nonpoint source pollution.
NAL Call No.: 292.8-W295
*****************************************************************
39. Economic and environmental impacts of water quality
protection policies. 1. Framework for regional analysis.
Bernardo, D. J.; Mapp, H. P.; Sabbagh, G. J.; Geleta, S.;
Watkins, K. B.; Elliott, R. L.; Stone, J. F.
Water-resour-res v.29, p.3069-3079. (1993).
Includes references.
Descriptors: groundwater-pollution; groundwater-; water-quality;
water-policy; agricultural-chemicals; agricultural-production;
economic-impact; environmental-impact; simulation-models;
mathematical-models; programming-; models-;
mathematical-programming-models; transport-models
Abstract: Agricultural production systems provide some unique
challenges for assessing the regional impacts of water quality
protection policies. A modeling framework is proposed for
assessing the environmental and economic consequences of
groundwater quality protection policies at the regional level.
The model consists of three components: (1) a crop
simulation/chemical transport model, (2) a regional economic
optimization model, and (3) an aquifer groundwater flow model.
The three submodels are linked and run recursively to simulate
producer response to alternative water quality policies over a
multiple-year time horizon. Model solutions provide projections
of production practices employed on various resource situations
across the region. Economic evaluation of alternative policies
may be based upon regional agricultural income, crop production
levels, input use, and changes in aquifer water levels over time.
Measures of agricultural nonpoint source pollution provided by
the model include nitrate, phosphorus and pesticide loadings in
deep percolation and runoff water, as well as sediment losses.
NAL Call No.: 292.8-W295
*****************************************************************
40. Economics of water resources : from regulation to
privatization.
Spulber, N.; Sabbaghi, A. 1.
Boston : Kluwer Academic Publishers, c1994. xxvi, 329 p. : ill..
Includes bibliographical references (p. 289-308) and index.
Descriptors: Water-resources-development;
Water-resources-development-Econometric-models;
Water-resources-development-Government-policy;
Water-quality-management
NAL Call No.: HD1691.S72--1994
*****************************************************************
41. Effect of depth of impervious layer and adsorption on solute
transport in tile-drained irrigated lands.
Kamra, S. K.; Singh, S. R.; Rao, K. V. G. K.
J-hydrol v.155, p.251-264. (1994).
Includes references.
Descriptors: solutes-; salinity-; transport-processes;
tile-drainage; irrigated-conditions; adsorption-; saturated-flow;
unsaturated-flow; groundwater-; effluents-; soil-depth;
desalinization-; soil-depth; simulation-models; impervious-layer
Abstract: A two-dimensional finite element model of solute
transport in a tile-drained soil-aquifer system was applied to
study the effect of the depth of impervious layer and adsorption
on salt distribution in the soil and groundwater, and the
salinity of drainage effluent. The model considers steady state
water flow in the unsaturated and saturated zones, and includes
the effect of convective transport, dispersion and linear
adsorption. The results indicate that though the depth of the
impervious layer has little effect on salt distribution in the
unsaturated zone, it significantly influences the quality of the
drainage effluent. Further, it was found that during the initial
years of reclamation of a highly saline soil with subsurface
drainage, the effect of adsorption is more pronounced in the
unsaturated zone than in the saturated zone and the movement of
adsorbing solute species is retarded for a longer time in the
groundwater than in the soil.
NAL Call No.: 292.8-J82
*****************************************************************
42. Effect of land surface representation on forest water and
carbon budgets.
Band, L. E.
J-hydrol v.150, p.749-772. (1993).
In the special issue: Water Issues in Forests Today / edited by
E.M. O'Loughlin and F.X. Dunin. November 22-26, 1992, Canberra,
Australia.
Descriptors: forests-; watersheds-; simulation-models;
evapotranspiration-; canopy-; photosynthesis-;
soil-water-content; runoff-; landforms-; topography-;
spatial-variation
Abstract: Forested landscapes often show very well-pronounced
heterogeneity in the factors that control evapotranspiration,
runoff production and carbon assimilation at a variety of length
scales. In hilly or mountainous environments, strong contrasts in
net radiation, available soil water, soil structure and stand
characteristics can produce a large variance in both the
meteorological drivers and surface resistance to carbon and water
exchange with the atmosphere over distances measured in tens of
metres. Because of the strong nonlinearities characterizing the
influence of the environmental variables on surface resistance
(particularly available soil water), the parametrization of
surface process models with mean values of the environmental
variables and no distribution often leads to significant bias in
areal average carbon and water flux. However, it is often not
feasible to incorporate directly the full distribution and
patterns of the landscape for regional-scale models. Continental-
and subcontinental-scale vegetation data sets currently being
collected by synoptic-level satellites (e.g. the Advanced Very
High Resolution Radiometer, AVHRR) do not capture the large
proportion of landscape variability that exists below the
resolution of the sensors. This paper explores the impacts of
various landscape representation schemes that retain a range of
detail in the description of land surface form and processes on
simulated areal average evapotranspiration, runoff production and
net carbon exchange with the atmosphere. Specific comparison is
made of schemes that attempt to incorporate the topographic
structure, soil and vegetation distributions of a region with
schemes that sample the surface at levels similar to current
coarse-resolution satellites. For strongly. variations in
available soil water can have significant effects on areal
averaged carbon and water flux rates, particularly under drying
conditions, whereas the spatial variations in radiation,
temperature and humidity over the terrain appear to have a lesser
ipact.
NAL Call No.: 292.8-J82
*****************************************************************
43. Effect of simulated climate change on snowmelt runoff
modeling in selected basins.
Katwijk, V. F. v.; Rango, A.; Childress, A. E.
Water-resour-bull v.29, p.755-766. (1993).
Includes references.
Descriptors: meltwater-; runoff-; climatic-change;
air-temperature; transpiration-; california-; colorado-
Abstract: The projected increase in the concentration of C02 and
other greenhouse gases in the atmosphere islikely to result in
a global temperature increase. This paper reports on the probable
effects of atemperature increase and changes in transpiration
on basin discharge in two different mountainsnowmelt regions
of the western United States. The hydrological effects of the
climate changes aremodeled with a relatively simple
conceptual, semi-distributed snowmelt runoff model. Based on the
model results, it may be concluded that increased air
temperatures will result in a shift ofsnowmelt runoff to
earlier in the snowmelt season. Furthermore, it is shown that it
is veryimportant to include the expected change in
climate-related basin conditions resulting from the modeled
temperature increase in the runoff simulation. The effect of
adapting the model parameters streamflow to April and an even
more significant decrease of snowmelt runoff in June and July. If
the air temperaturesincrease by approximately 5 degrees C and
precipitation and accumulated snow amounts remain aboutthe
same, runoff in April and May, averaged for the two basins, is
expected to increase by 185percent and 25 percent,
respectively. The runoff in June and July will decrease by about
60percent each month. Overall, the total seasonal runoff
decreases by about 6 percent. If increasedC02 concentrations
further change basin condition by reducing transpiration by the
maximum amounts. temperature increase, the April,May, June,
and July changes would average +230 percent, +40 percent, -55
percent, and -45 percent,respectively. The total seasonal
runoff change would be +11 percent.
NAL Call No.: 292.9-Am34
*****************************************************************
44. Effects of motility and adsorption rate coefficient on
transport of bacteria through saturated porous media.
Camper, A. K.; Hayes, J. T.; Sturman, P. J.; Jones, W. L.;
Cunningham, A. B.
Appl-environ-microbiol v.59, p.3455-3462. (1993).
Includes references.
Descriptors: pseudomonas-aeruginosa; adsorption-; motility-;
glass-; bioreactors-; transport-processes; pores-; porosity-;
models-; soil-pore-system; strain-differences; glass-beads
Abstract: Three strains of Pseudomonas fluorescens with different
motility rates and adsorption ratecoefficients were injected
into porous-medium reactors packed with 1-mm-diameter glass
spheres.Cell breakthrough, time to peak concentration,
tailing, and cell recovery were measured at threeinterstitial
pore velocities (higher than, lower than, and much lower than the
maximal bacterial motility rate). All experiments were done with
distilled water to reduce the effects of growth andchemotaxis.
Contrary to expectations, motility did not result in either early
breakthrough orearly time to peak concentration at flow
velocities below the motility rate. Bacterial size exclusion
effects were shown to affect breakthrough curve shape at the very
low flow velocity, butno such effect was seen at the higher
flow velocity. The tendency of bacteria to adsorb to
porous-medium surfaces, as measured by adsorption rate
coefficients, profoundly influencedtransport characteristics.
Cell recoveries were shown to be correlated with the ratio of
advectiveto adsorptive transport in the reactors. Adsorption
rate coefficients were found to be betterpredictors of
microbial transport phenomena than individual characteristics,
such as size,motility, or porous-medium hydrodynamics.
NAL Call No.: 448.3-Ap5
*****************************************************************
45. Environmental : hypermedia programs and water quality models.
Environmental hypermedia programs.
Center for Technology Transfer & Pollution Prevention.
West Lafayette, IN : Farm Building Plan Service, Purdue
University, [1994?] 1 computer laser optical disc 1 booklet.
Title from disc label.
Descriptors: Water-quality-Databases; Water-Pollution-Databases
NAL Call No.: TD370.E58--1994
*****************************************************************
46. Estimation of preferential movement of bromide tracer under
field conditions.
Jabro, J. D.; Lotse, E. G.; Fritton, D. D.; Baker, D. E.
J-hydrol v.156, p.61-71. (1994).
Includes references.
Descriptors: agricultural-chemicals; leaching-;
saturated-conditions; bromide-; tracers-; saturated-flow;
macropore-flow; infiltration-; soil-physical-properties;
saturated-hydraulic-conductivity; spatial-variation;
simulation-models; preferential-flow; leachm-simulation-model
Abstract: Leaching of agricultural chemicals from the root and
vadose zones into groundwater is an important environmental
concern. To procure a better understanding of the movement and
transport of agricultural chemicals through the soil profile, a
field research study was conducted to estimate bromide leaching
losses under saturated conditions where preferential flow is
occurring. The field data were then used to evaluate the LEACHM
model. Eighteen double-ring infiltrometers were used to apply a
pulse (100 mm depth) of bromide tracer on two previously
saturated soils located in a karst region of southeastern
Pennsylvania. Internal drainage over the next seven days resulted
in nearly 51% of the applied Br(-) being leached to a depth below
0.80 m. The LEACHM model was used to simulate the amount of
bromide leached in each infiltrometer. The model predicted,
accurately, an average of 46% of the applied Br(-) leached below
the 0.80 m depth. Mean values of bromide concentration in the
soil profile were predicted within two standard deviations of the
measured mean for all depths except for the 0.20-0.40 m depth
increment where the model overpredicted the bromide
concentration. The model predictions of Br(-) leached were tested
against field measurements using several statistical tests. The
LEACHM model performed adequately under preferential flow
conditions, perhaps because the infiltration rate at each site
was used as a model input. This, actually, is some measure of the
macropore flow process and suggests that simple models such as
LEACHM can be used in the field, as long as a distribution of
infiltration rates is used as an input.
NAL Call No.: 292.8-J82
*****************************************************************
47. Estimation of snowmelt runoff in the Peace River region using
a soil moisture budget.
Hayhoe, H. N.; Pelletier, R. G.; Van Vliet, L. J. P.
Can-j-soil-sci v.73, p.489-501. (1993).
Includes references.
Descriptors: meltwater-; runoff-; estimation-; prediction-;
equations-; algorithms-; mathematical-models; water-erosion;
losses-from-soil; water-budget; winter-; spring-; snow-; depth-;
frozen-conditions; freeze-thaw-cycles; british-columbia;
alberta-; frozen-soils
NAL Call No.: 56.8-C162
*****************************************************************
48. Evaluating agricultural nonpoint-source pollution using
integrated geographic information systems and hydrologic/water
quality model.
Tim, U. S.; Jolly, R.
J-environ-qual v.23, p.25-35. (1994).
Technical Reports from the Symposium, "Minimizing Agricultural
Nonpoint-Source Impacts", November 2, 1992, Minneapolis,
Minnesota.
Descriptors: water-pollution; agriculture-;
geographical-information-systems; simulation-models
Abstract: Considerable progress has been made in developing
physically based, distributed parameter, hydrologic/water quality
(H/WQ) models for planning and control of nonpoint-source
pollution. The widespread use of these models is often
constrained by the excessive and time-consuming input data
demands and the lack of computing efficiencies necessary for
iterative simulation of alternative management strategies. Recent
developments in geographic information systems (GIS) provide
techniques for handling large amounts of spatial data for
modeling nonpoint-source pollution problems. Because a GIS can be
used to combine information from several sources to form an array
of model input data and to examine any combinations of spatial
input/output data, it represents a highly effective tool for H/WQ
modeling. This paper describes the integration of a
distributed-parameter model (AGNPS) with a GIS (ARC/INFO) to
examine nonpoint sources of pollution in an agricultural
watershed. The ARC/INFO GIS provided the tools to generate and
spatially organize the disparate data to support modeling, while
the AGNPS model was used to predict several water quality
variables including soil erosion and sedimentation within a
watershed. The integrated system was used to evaluate the
effectiveness of several alternative management strategies in
reducing sediment pollution in a 417-ha watershed located in
southern Iowa. The implementation of vegetative filter strips
and contour buffer (grass) strips resulted in a 41 and 47%
reduction in sediment yield at the watershed outlet,
respectively. In addition, when the integrated system was used,
the combination of the above management strategies. demonstrated
the utility of integrating a simulation model with GIS for
nonpoint-source pollution control and planning. Such techniques
can help characterize the diffuse sources of pollution at the
landscape level.
NAL Call No.: QH540.J6
*****************************************************************
49. Evaluating and predicting the spatial and temporal
variability of storm runoff generation in watersheds of arid and
semi-arid regions.
Morin, J.; United States Israel Binational Agricultural Research
and Development Fund.
Bet Dagan, Israel : BARD, 1993. 306 p. : ill. (some col.), maps.
Final report.
Descriptors: Rain-and-rainfall-Mathematical-models;
Runoff-Mathematical-models
NAL Call No.: QC925.E93--1993
*****************************************************************
50. Evaluating the chemical movement in layered soil model as a
tool for assessing risk of pesticide leaching to groundwater.
Nofziger, D. L.; Chen, J. S.; Haan, C. T.
J-environ-sci-health,-Part-A,-Environ-sci-eng v.A29, p.1133-1155.
(1994).
Special Issue on the Evaluation and Comparison of Pesticide
Leaching.
Descriptors: pesticides-; leaching-; simulation-models;
soil-properties; groundwater-pollution; risk-; cmls-model
NAL Call No.: TD172.J6
*****************************************************************
51. Evaluation and comparison of pesticide leaching models for
registration purposes. Results of simulations performed with the
pesticide leaching model.
Klein, M.
J-environ-sci-health,-Part-A,-Environ-sci-eng v.A29, p.1197-1209.
(1994).
Special Issue on the Evaluation and Comparison of Pesticide
Leaching.
Descriptors: bentazone-; dichlorprop-; leaching-;
simulation-models; registration-; macropores-; prediction-;
pesticide-registration
NAL Call No.: TD172.J6
*****************************************************************
52. Evaluation and comparison of pesticide leaching models for
registration purposes.
Bergstrom, L. F.; Jarvis, N. J.
J-environ-sci-health,-Part-A,-Environ-sci-eng v.A29, p.1061-1072.
(1994).
Special Issue on the Evaluation and Comparison of Pesticide
Leaching.
Descriptors: pesticides-; leaching-; simulation-models;
registration-
NAL Call No.: TD172.J6
*****************************************************************
53. Evaluation of GLEAMS and PRZM for predicting pesticide
leaching under field conditions.
Zacharias, S.; Heatwole, C. D.
Trans-ASAE v.37, p.439-451. (1994).
Includes references.
Descriptors: zea-mays; no-tillage-; pesticides-; leaching-;
simulation-models; virginia-; groundwater-loading;
effects-of-agricultural-management-systems;
pesticide-rootzone-model; nonpoint-source-pollution
Abstract: Pesticide simulation models, GLEAMS and PRZM, were
evaluated for their ability to predict pesticide behavior using
field data from a plot under no-till corn in the Coastal Plain
region of Virginia. The models were evaluated in an uncalibrated
mode as well as with adjustment of important hydrology
parameters. The evaluation of model performance was based on
graphical displays and statistical measures. Difference in
evapotranspiration (ET) predictions by the two models caused the
simulated results from their hydrology components to vary. Runoff
and soil moisture measured in the field were predicted reasonably
well after adjusting important hydrology parameters. Except for
differences in magnitude, both models predicted the chemical
concentration profiles similarly. Overall, GLEAMS represented
pesticide behavior in soil better than PRZM. The models, GLEAMS
and PRZM, performed well in predicting pesticide mass in the root
zone, but were less reliable in predicting pesticide
concentration distributions in soil. Model predictions of
pesticide fate and transport were not greatly affected by changes
in curve number and the water holding capacity of the soil.
NAL Call No.: 290.9-Am32T
*****************************************************************
54. Evaluation of methods for determining soil-water retentivity
and unsaturated hydraulic conductivity.
Marion, J. M.; Or, D.; Rolston, D. E.; Kavvas, M. I.; Biggar, J.
W.
Soil-sci v.158, p.1-13. (1994).
Includes references.
Descriptors: soil-water-retention;
unsaturated-hydraulic-conductivity; determination-;
soil-analysis; analytical-methods; evaluation-;
soil-water-content; matric-potential; transport-processes;
mathematical-models
NAL Call No.: 56.8-So3
*****************************************************************
55. Evaluation of runoff and erosion models.
Wu, T. H.; Hall, J. A.; Bonta, J. V.
J-irrig-drain-eng v.119, p.364-382. (1993).
Includes references.
Descriptors: erosion-; runoff-; sediment-yield; measurement-;
simulation-models;
agricultural-non-point-source-pollution-model-agnps;
areal-non-point-source-watershed-environmental-response-simulation-model-answers;
chemicals-runoff-and-erosion-from-agricultural-management-systems-model-creams
NAL Call No.: 290.9-AM3Ps-IR
*****************************************************************
56. Evaluation of the GLEAMS model for pesticide leaching in
Sweden.
Shirmohammadi, A.; Knisel, W. G.
J-environ-sci-health,-Part-A,-Environ-sci-eng v.A29, p.1167-1182.
(1994).
Special Issue on the Evaluation and Comparison of Pesticide
Leaching.
Descriptors: dichlorprop-; bentazone-; leaching-; drainage-;
simulation-models;
groundwater-loading-effects-of-agricultural-management-systems
NAL Call No.: TD172.J6
*****************************************************************
57. Experimental approach and simulation of the retention
processes limiting orthophosphate transport in groundwater.
Isenbeck Schroter, M.; Doring, U.; Moller, A.; Schroter, J.;
Matthess, G.
J-contam-hydrol v.14, p.143-161. (1993).
Includes references.
Descriptors: groundwater-pollution; orthophosphates-;
simulation-models; sorption-; retention-
NAL Call No.: TD426.J68
*****************************************************************
58. An expert systems approach for assessing the potential for
pesticide contamination of ground water.
Crowe, A. S.; Mutch, J. P.
Ground-water. Dublin, Ohio : Ground Water Pub. Co. May/June 1994.
v. 32 (3) p. 487-498.
Includes references.
Descriptors: pesticides-; groundwater-pollution; expert-systems;
assessment-; models-
NAL Call No.: TD403.G7
*****************************************************************
59. An exploration of the economics of farm management
alternatives to improve water quality.
Heilman, P.; Yakowitz, D. S.; Stone, J. J.; Kramer, L. A.; Lane,
L. J.; Imam, B.
Application of advanced information technologies effective
management of natural resources proceedings of the 18-19 June
1993 Conference, Spokane, Washington /. St. Joseph, Mich. :
American Society of Agricultural Engineers, c1993.. p. 194-205.
Includes references.
Descriptors: water-quality; pollutants-; farm-management;
farm-income; decision-making; simulation-models; usda-; iowa-;
prototype-decision-support-system; agricultural-research-service
NAL Call No.: GE5.A66-1993
*****************************************************************
60. Farm-level evaluation of alternative policy approaches to
reduce nitrate leaching from midwest agriculture.
Swinton, S. M.; Clark, D. S.
Agric-resour-econ-rev v.23, p.66-74. (1994).
Includes references.
Descriptors: farming-; nitrate-nitrogen; leaching-;
pollution-control; economic-policy; economic-analysis;
federal-programs; models-
NAL Call No.: HD1773.A2N6
*****************************************************************
61. Fate of aldicarb in the vadose zone beneath a cotton field.
Cai, D.; Xiang, F.; Jiang, X.; Zhu, Z.; Hua, X.; Dai, Z.
J-contam-hydrol v.14, p.129-142. (1993).
Includes references.
Descriptors: soil-pollution; aldicarb-; pesticide-residues;
movement-in-soil; groundwater-pollution; cotton-; fields-;
simulation-models; jiangsu-
NAL Call No.: TD426.J68
*****************************************************************
62. A finite element model for simulating runoff and soil erosion
from mechanically treated agricultural lands. 2. Field validation
and applications.
Sharda, V. N.; Singh, S. R.; Sastry, G.; Dhruvanarayana, V. V.
Water-resour-res v.30, p.2299-2310. (1994).
Includes references.
Descriptors: agricultural-land; erosion-; runoff-;
soil-conservation; precipitation-; simulation-models
Abstract: The finite element model for simulation of runoff and
erosion as developed by Sharda and Singh (this issue) is
evaluated using data collected from agricultural land treated
with major mechanical soil and water conservation measures,
namely, contour bunding, graded bunding, bench terracing, and
conservation bench terracing. The simulated and experimentally
realized hydrographs and soil loss values are in reasonably good
agreement for various measures. Probable reasons for
discrepancies between the predicted and observed values are
discussed. The model has the potential of being used on a single
storm or a continuous basis provided the soil, crop, and climatic
parameters are precisely known or estimated for a given location
and for the period under consideration. The model logically
simulates the effects of flow, topographic, soil, and crop
parameters such as antecedent moisture level, roughness
coefficient, saturated hydraulic conductivity, slope, depth of
impoundment, size of outlet, longitudinal slope of the channel,
vertical interval, and cropping management factor. The model is
found to be quite sensitive to changes in roughness coefficient,
rainfall excess rate, and cover management factor, and hence
these parameters need to be assessed carefully in the field. The
general applicability of the model as a planning tool for soil
conservation measures and the scope for future development are
also discussed.
NAL Call No.: 292.8-W295
*****************************************************************
63. A finite element model for simulating runoff and soil erosion
from mechanically treated agricultural lands. 1. Governing
equations and solutions.
Sharda, V. N.; Singh, S. R.
Water-resour-res v.30, p.2287-2298. (1994).
Includes references.
Descriptors: agricultural-land; erosion-; runoff-; infiltration-;
soil-water-balance; geological-sedimentation; precipitation-;
soil-conservation; simulation-models; equations-
Abstract: A finite element model simulating runoff and soil
erosion from agricultural lands is developed. The computational
efficiency and stability of various numerical schemes used for
time integration are critically examined employing L2 and
Chebycheff (Chebyshev) norms. Predictor-corrector and fully
implicit schemes are found to give the least values of norms,
thereby permitting larger time steps. A finite element solution
of the one-dimensional Richards equation with a sink term
simulates rain infiltration and soil moisture balance in cropped
fields. A criterion to ensure stability and convergence of the
solution is suggested. A finite element solution of the sediment
continuity equation in conjunction with a fully implicit scheme
for time integration and Yalin's equation for sediment transport
capacity is developed to simulate soil erosion. The potential of
the model to reasonably simulate runoff and soil erosion is
demonstrated by comparing the finite element solutions with the
analytical solutions under simplified configurations and with
experimental data.
NAL Call No.: 292.8-W295
*****************************************************************
64. Flux-averaged concentrations for transport in soils having
nonuniform initial solute distributions.
Toride, N.; Leij, F. J.; Van Genuchen, M. T.
Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of
America. Nov/Dec 1993. v. 57 (6) p. 1406-1409.
Includes references.
Descriptors: soil-physics; solutes-; transport-processes;
movement-in-soil; mathematical-models
Abstract: The need to distinguish between volume-averaged or
resident concentrations [c(r)] and flux-averagedor flowing
concentrations [c(r)] is now widely accepted. Flux-averaged
concentrations associated with the convection-dispersion
equation (CDE) have been mostly used for solute transport
problemsinvolving uniform initial distributions. We present
flux-averaged concentrations for nonuniform initial
distributions using analytical solution methods for a
semi-infinite soil system andnumerical methods for a finite
system. Mathematically, c(r) is equivalent to c(r) associated
witha first-type inlet condition (rather than a third-type
condition) only for semi-infinite soil profiles having uniform
initial conditions. We show that, for a stepwise initial
distribution, c,can be both negative or much greater than the
initial concentration of c(r), especially during theearly
stages of solute displacement. This physically odd situation
results from the fact that c(r) represents a solute flux rather
than a directly measurable volumetric concentration.
Flux-averaged concentrations at the exit of a finite soil column
with a uniform initialdistribution are nearly identical to
c(r) for a semi-infinite system when the column Pecletnumber
is greater than approximately 5. However, if the initial
distribution involves a highgradient in c(r) near the exit,
c(r) values for finite and semi-infinite systems at the exit can
be very different, similarly as those for c(r) because of the
adoption of different outlet.
NAL Call No.: 56.9-So3
*****************************************************************
65. Gaining forests but losing ground: a GIS evaluation in a
Himalayan watershed.
Schreier, H.; Brown, S.; Schmidt, M.; Shah, P.; Shrestha, B.;
Nakarmi, G.; Subba, K.; Wymann, S.
Environ-manage. New York, Springer-Verlag. Jan/Feb 1994. v. 18
(1) p. 139-150.
includes references.
Descriptors: watersheds-; deforestation-;
geographical-information-systems; evaluation-; mountain-areas;
nepal-
NAL Call No.: HC79.E5E5
*****************************************************************
66. General stochastic unit hydrograph.
Hjelmfelt, A.; Wang, M.
J-irrig-drain-eng v.120, p.138-148. (1994).
Includes references.
Descriptors: watersheds-; runoff-water; rain-; stochastic-models;
missouri-
NAL Call No.: 290.9-AM3Ps-IR
*****************************************************************
67. GIS application to water quality management in the upper
Volga River
Belyaeva, T.; Higgins, J. M.; Kirpichnikova, N.; Lanzova, I.;
Hagerman, J. R.
Water-sci-technol v.28, p.119-127. (1993).
Paper presented at the IAWQ First International Conference on
"Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact,
Abatement." September 19-24, 1993, Chicago, Illinois.
Descriptors: water-resources; water-management;
geographical-information-systems; russia-; usa-;
tennessee-valley-authority
NAL Call No.: TD420.A1P7
*****************************************************************
68. GOSSYM/COMAX: a cotton crop management emphasizing irrigation
scheduling and water quality.
McKinion, J. M.; Boone, M. Y. L.; Porter, D. O.; Whisler, F. D.
Proceedings of Industrial and Agricultural Impacts on the
Hydrologic Environment the Second USA/CIS Joint Conference on
Environmental Hydrology and Hydrogeology / USA/CIS Joint
Conference on Environmental Hydrology and Hydrogeology.
Alexandria, VA : Water Environment Federation, c1993.. v. 2 p.
23-36.
Title on cover : Environmental impact of agricultural practices
and agrichemicals / edited by Y. Eckstein and A. Zaporozec.
Descriptors: gossypium-; irrigated-farming;
irrigation-scheduling; simulation-models; water-quality;
mississippi-
NAL Call No.: GB652.U82-1993
*****************************************************************
69. Groundwater contamination from agricultural sources in
Northern Italy: long-term monitoring and mathematical modelling.
Fortina, L.; Capodaglio, A. G.; Baldi, M.
Water-sci-technol v.28, p.369-377. (1993).
Paper presented at the IAWQ First International Conference on
"Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact,
Abatement." September 19-24, 1993, Chicago, Illinois.
Descriptors: groundwater-pollution; herbicides-;
mathematical-models; italy-
NAL Call No.: TD420.A1P7
*****************************************************************
70. Groundwater quality.
Mayer, A. S.; Imhoff, P. T.; Mitchell, R. J.; Rabideau, A. J.;
McBride, J. F.; Miller, C. T.
Water-environ-res v.66, p.532-585. (1994).
Includes references.
Descriptors: groundwater-pollution; pollutants-;
transport-processes; water-quality; monitoring-; biodegradation-;
movement-in-soil; groundwater-flow; sorption-; desorption-;
pesticides-; leaching-; models-; literature-reviews
NAL Call No.: TD419.R47
*****************************************************************
71. Groundwater quality management of a low inertia basin:
application to the San Mateo Basin, California.
Bagtzoglou, A. C.; Khan, M. N.; Guymon, G. L.
Water-resour-manag v.7, p.189-205. (1993).
Includes references.
Descriptors: groundwater-; water-quality; water-management;
watersheds-; groundwater-recharge; water-yield;
finite-element-analysis; models-; water-storage; california-;
nodal-domain-integration
Abstract: A two-dimensional finite element model is applied to
the San Mateo Basin, California in order toinvestigate
feasible and efficient management alternatives to enhance the
basin yield andpreserve the basin water quality. The model
utilizes lumped approximation methods for thedetermination of
its subsurface boundary conditions, and incorporates a variety of
hydrologicalprocesses. The model solves uncoupled flow and
transport equations using a nodal domainintegration technique
for the flow model and an integrated finite difference method for
thetransport model. The model incorporates the basin inputs
and outputs as ocean flux, well and phreatophyte extractions,
subsurface inflow, precipitation and streambed percolation.
Modelingresults indicate that the sustained yield may be
maximized by interception of ocean outflow fromthe basin. An
improvement of about four times of the historical sustained yield
was achieved.This strategy required relocation of existing
wastewater recharge ponds and increasing basinextractions. In
order to intercept most of the ocean outflow by increasing basin
extractions,simulated subsurface seawater intrusion was
observed. The water quality study indicated that thebasin
yield could be increased significantly by moderately relaxing the
water quality criterianear the ocean.
NAL Call No.: TC401.W27
*****************************************************************
72. Growing corn root effects on interrill soil erosion.
Bui, E. N.; Box, J. E. Jr.
Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of
America. July/Aug 1993. v. 57 (4) p. 1066-1070.
Includes references.
Descriptors: zea-mays; roots-; length-; density-;
soil-stabilization; interrill-erosion; erosion-control;
crop-growth-stage; runoff-; sediment-; losses-from-soil;
erodibility-; mathematical-models; georgia-;
water-erosion-prediction-project-model
Abstract: The relationship between plant roots and interrill soil
erosion is important in dynamic soil erosion predictions.
Rainstorm simulations of similar intensity (63.5 mm h-1) were
conducted in the summer of 1989 on 1 by 1 m field plots of Cecil
sandy loam (clayey, kaolinitic, thermic Typic Kanhapludult) to
study the effect of different root length densities, L(v) (cm
cm-3), of corn (Zea mays L.), during vegetative, preanthesis, and
anthesis plant developmental stages on interrill soil erosion.
Sediment loss and runoff data were assigned to treatments, L(va),
on the basis of L(v) range to reduce rooting variability
associated with plant developmental stage. To avoid confounding
by canopy cover, corn plants were cut at the stem base and
removed for the first four sets of simulations. A reference set
of simulations was performed on a fallow plot containing no
roots, L(va). Runoff and detached sediment were collected in
buckets from each plot during successive 5-min intervals over a
1-h period. Thirty cores, 5 cm in diam. and 5 cm deep, were taken
from each 1-m2 plot and roots were washed from the cores and
measured. Means for runoff and detached sediment were generally
not significantly different for the high L(v) or L(va), and
L(va0). When L(va) was < 1.5 cm cm-3, runoff and detached
sediment were significantly lower during the first 30 min of
simulated rainfall. High densities of live corn roots did not
reduce interrill soil erosion from a moldboard-plowed Cecil sandy
loam.
NAL Call No.: 56.9-So3
*****************************************************************
73. A hedonic analysis of herbicides: do user safety and water
quality matter.
Beach, E. D.; Carlson, G. A.
Am-j-agric-econ. Ames, Iowa : American Agricultural Economics
Association. Aug 1993. v. 75(3) p. 612-623.
Includes references.
Descriptors: herbicides-; weed-control; water-quality; safety-;
farmers'-attitudes; econometric-models; zea-mays; glycine-max;
decision-analysis; usa-; arkansas-; iowa-; north-carolina; ohio-;
broadleaf-weeds
Abstract: Farmers may value water quality and user safety
characteristics of herbicides as they select among products to
obtain weed control. Expenditures per application in the U.S.
corn and soybean herbicide markets are explained by several
safety characteristics in addition to market and weed control
characteristics. The explicit inclusion of safety characteristics
in the farm decision model indicates that not all safety aspects
of pesticide use are external to farmers. Leaching potential and
user toxicity are statistically significant, but their
elasticities are small relative to broadleaf and grass weed
control efficacy.
NAL Call No.: 280.8-J822
*****************************************************************
74. Human intestinal cell line Caco-2: a useful model for
studying cellular and molecular regulation of biotin uptake.
Ma, T. Y.; Dyer, D. L.; Said, H. M.
Biochim-biophys-acta v.1189, p.81-88. (1994).
Includes references.
Descriptors: biotin-; nutrient-uptake; regulation-;
transport-processes; intestines-; cell-lines
Abstract: The mechanisms of enterocyte and molecular regulation
of biotin uptake are poorly understood. An intestinal cell line
possessing the transport characteristics of native intestinal
cells is highly desirable to investigate the finer details of the
cellular processing and molecular regulation of biotin transport.
In the present study, we investigated the uptake of the
water-soluble vitamin biotin by a human intestinal cell line
Caco-2. Uptake of both low (4 nM) and high (20 micromolar)
concentrations of biotin by confluent monolayers of Caco-2 cells
was appreciable and linear for up to 10 min of incubation.
Replacement of Na+ in the incubation medium with other monovalent
cations -- K+, choline, Li+ and NH4+ -- caused a significant
inhibition of biotin uptake; a relatively lesser inhibition was
seen with Li+. Initial rate of uptake of biotin was
temperature-dependent and saturable as a function of
concentration at 37 degrees C but not at 4 degrees C. The Vmax
and apparent Km of the temperature-dependent saturable process
were 520 pmol/mg protein per min and 9.5 micromolars,
respectively. The addition of unlabeled biotin and the structural
analogue desthiobiotin to the incubation media caused a
significant inhibition of the uptake of [3H]biotin. The
inhibitory effect of desthiobiotin was competitive in nature with
an inhibition constant (Ki) of 41 micromolar. Biocytin, on the
other hand, was a weak inhibitor and biotin methyl ester and
diaminobiotin did not have any effect. Pretreatment of Caco-2
cells with the monovalent cation ionophore gramicidin and the
Na+, K+-ATPase inhibitor ouabain caused significant inhibition of
biotin uptake. Pretreatment with the K+ ionophore valinomycin did
not affect biotin. biotin- to Na+ coupling was found to be 1:1.
Growing confluent Caco-2 cells in a biotin-deficient environment
resulted in rapid up-regulation of biotin transport with a marked
increase (258%) in the Vmax of biotin uptake. These findings
demonstrate that biotin uptake by Caco-2 cells is via a
carrier-mediated systm. This system is temperature-dependent,
driven by Na+-gradient and is regulated by the substrate level.
These in-vitro findings are very similar to and further confirm
previous findings in human and animal studies and dispute other
findings previously reported for Caco-2 cells; the present study
also demonstrates the suitability of this system for further
characterization of the cellular and molecular regulation of
biotin uptake.
NAL Call No.: 381-B522
*****************************************************************
75. Hystem-EXTRAN: improvements to EPA-EXTRAN.
Fuchs, L.; Scheffer, C.
Water-sci-technol v.29, p.63-71. (1994).
Selected Proceedings of the 6th International Conference on Urban
Storm Drainage, September 12-17, 1993, Niagara Falls, Canada /
edited by J.C. Marsalek and H.C. Torno.
Descriptors: rain-; runoff-; hydrology-; water-management;
simulation-models
NAL Call No.: TD420.A1P7
*****************************************************************
76. Identification of road salt contamination using multiple
regression and GIS.
Mattson, M. D.; Godfrey, P. J.
Environ-manage. New York, Springer-Verlag. Sept/Oct 1994. v. 18
(5) p. 767-773.
Includes references.
Descriptors: streams-; salt-; sodium-chloride; water-pollution;
regression-analysis; geographical-information-systems;
massachusetts-
NAL Call No.: HC79.E5E5
*****************************************************************
77. The impact of changes in the runoff formulation of a general
circulation model on surface and near-surface parameters.
Viterbo, P.; Illari, L.
J-hydrol v.155, p.325-336. (1994).
Special Issue: Mesoscale Hydrology and General Circulation
Models.
Descriptors: soil-water; runoff-; simulation-models;
precipitation-; infiltration-; evapotranspiration-;
air-temperature; geographical-distribution; forecasting-
Abstract: The surface and near-surface properties of the European
Centre for Medium Range Weather Forecasting (ECMWF) general
circulation model are shown to be sensitive to the
parametrization of runoff. If a border subgrid-scale
distribution of precipitation is assumed when computing runoff,
the infiltration increases, more water becomes available for
evaporation and the model surface cools. The averaged Bowen
ratio over land is shown to decrease from 1.5 to 0.9 in a
Northern Hemisphere summer experiment. Possible implications for
the estimation of soil moisture and evapotranspiration using a
global data assimilation-forecasting system are discussed.
NAL Call No.: 292.8-J82
*****************************************************************
78. Impact of coal combustion waste on the microbiology of a
model aquifer.
Brunning, J. S.; Caldwell, D. E.; Lawrence, J. R.; Robarts, R. D.
Water-air-soil-pollut v.74, p.103-120. (1994).
Includes references.
Descriptors: aquifers-; groundwater-; pollution-;
fluidized-bed-wastes; coal-; combustion-; infiltration-;
leaching-; landfills-; landfill-leachates; groundwater-;
water-quality; alkalinity-; heterotrophic-microorganisms;
bacteria-; bacterial-count
NAL Call No.: TD172.W36
*****************************************************************
79. The impact of recession infiltration on runoff volume
computed by the kinematic wave model.
Stone, J. J.; Shirley, E. D.; Lane, L. J.
Trans-ASAE v.36, p.1353-1361. (1993).
Includes references.
Descriptors: runoff-water; infiltration-; rain-; kinematics-;
models-
Abstract: The effect of recession infiltration on runoff volume
is quantified using the kinematic wave modelfor the case of
lateral inflow made up of constant rainfall excess during the
period of rainfalland constant infiltration after rainfall
ends. A general solution is obtained using thefollowing
non-dimensional quantities; Q*=Q/R(e) (runoff volume divided by
rainfall excess volume),t* = t(e)/D (time to kinematic
equilibrium divided by the duration of rainfall excess), and f* =
f/r(e) (infiltration rate divided by rainfall excess rate).
Using these quantities, therelationship for the reduction of
runoff volume is Q* =1-m/(m+1) t* [f*/(f*+1)](l/m) when t* <
[(f*+])/f*]/(l/m) and Q* = 1/(m+1) t*1(-m) (f*+1)/f* when t* >
[(f*+1)/f*](l/m) where m is thekinematic wave depth-discharge
exponent. The first equation corresponds to the case when flow
ceases after the characteristic from distance and time zero,
C(0,0), reaches the end of the plane.The second equation
corresponds to the case when the flow ceases and C(0,0) does not
reach theend of the plane. These equations approximate the
reduction of runoff volume for the more generalcase of time
varying rainfall excess under constant and variable rainfall as
would be the casewhen the rainfall excess is generated using
the Green-Ampt infiltration equation.
NAL Call No.: 290.9-Am32T
*****************************************************************
80. Importance of soil and cropping systems in the development of
regional water quality policies.
Geleta, S.; Sabbagh, G. J.; Stone, J. F.; Elliott, R. L.; Mapp,
H. P.; Bernardo, D. J.; Watkins, K. B.
J-environ-qual v.23, p.36-42. (1994).
Technical Reports from the Symposium, "Minimizing Agricultural
Nonpoint-Source Impacts", November 2, 1992, Minneapolis,
Minnesota.
Descriptors: triticum-aestivum; sorghum-bicolor; zea-mays;
cropping-systems; soil-types; crop-yield; nitrate-nitrogen;
leaching-; water-quality; irrigation-; simulation-models;
geographical-information-systems; oklahoma-
Abstract: Targeting certain soils and cropping systems may be
necessary in consideration of regional water quality protection
policies. However, little information is available relating
soils and cropping practices to regional water quality problems.
This study evaluates crop yield and NO3-N movement to surface and
groundwater on four soils and nine principal cropping systems in
the High Plains region of Oklahoma. The cropping systems involve
wheat (Triticum aestivum L.), grain sorghum [Sorghum bicolor (L.)
Moench], and corn (Zea mays L.), and are part of a regional data
base also containing soils and chemical management information.
For each combination of crop, soil, cropping system, and chemical
alternative, a 20-yr simulation was made. The simulation was
based on a modeling system that includes EPIC-PST (crop
growth/chemical movement model) interfaced with a Geographic
Information System (GIS), Earthone. Results of each simulation
included crop yield and NO3-N movement in runoff and percolation.
Results show wide variations in NO3-N losses for different soils,
irrigation systems, and cropping systems. When compared with
continuous irrigated wheat and grain sorghum cropping systems,
double-cropped wheat-grain sorghum resulted in greater NO3-N loss
in percolation. Compared with sprinkler and LEPA (low energy
precision application) irrigation systems, furrow irrigation
resulted in high NO3-N loss on both fine-textured and
coarse-textured soils, with significantly greater loss on the
coarser-textured soils. The modeling framework can be used to
compare alternative water quality policies. Broad policies such
as a restriction on the amount of N that can be applied per
hectare can be compared with targeted. coarser soils or under
furrow irrigation.
NAL Call No.: QH540.J6
*****************************************************************
81. Infiltration and redistribution of organic liquids in layered
porous media.
Cary, J. W.; Simmons, C. S.; McBride, J. F.
Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of
America. May/June 1994. v. 58 (3) p. 704-711.
Includes references.
Descriptors: porous-media; oils-; transport-processes;
infiltration-; redistribution-; mathematical-models; vaclose-zone
Abstract: The remediation of many toxic waste sites throughout
the world requires a better understanding of the flow of organic
liquids in the vadose zone. The infiltration and redistribution
of three water-immiscible oils into columns filled with porous
material containing different textural layers are reported. In
some experiments, oil followed water into the columns and in
others, water followed oil. An explicit, one-dimensional,
multiphase flow code was used to model the results. The numerical
model contains elements of code that: (i) mimic the Haines jump
phenomenon in dry sand, (ii) account for oil entrapment when
water infiltrates, (iii) include forces on the oil phase caused
by surface-spreading pressures at the oil front in water-wetted
pores, (iv) include forces on the oil phase caused by water
intrusion into hydrophilic oil-saturated pores, and (v) generate
a factor that matches the water potentials of textural layers for
the initial boundary conditions. In general, the model did a
reasonable job of predicting the distribution of both water and
oil 8 h after infiltration was started, though some unresolved
problems persist. The liquid potential matching factor and the
hydrophobicity of the mineral particles induced by a transmission
oil have practical applications. The matching factor may be
easily adapted to all codes that model flow through layers. The
in situ creation of hydrophobic mineral particles may prove
useful for containing immiscible organic liquids that leak into
the vadose zone.
NAL Call No.: 56.9-So3
*****************************************************************
82. Influence of amount and method of irrigation water
application on leaching of atrazine.
Troiano, J.; Garretson, C.; Krauter, C.; Brownell, J.; Huston, J.
J-environ-qual v.22, p.290-298. (1993).
Includes references.
Descriptors: atrazine-; leaching-; percolation-; irrigation-;
soil-water-content; spatial-distribution; sandy-soils;
simulation-models; california-; leachm-model
Abstract: A study was conducted to relate leaching of an
herbicide, atrazine
[6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4,-di
amine], and inorganic water tracers, Br- and Cl-, to the amount
of deep-percolating water produced from irrigation. Soil at the
site was classified as a Dehli Loamy Sand (Mixed, Thermic, Tepic
Xeropsamment) which was an unstructured sandy soil that was low
in organic C content, conditions conducive to solute leaching.
The relationship between depth of solute movement and amount of
deep-percolating water was measured in sprinkler, basin, and
furrow irrigation methods. Soil distribution of inorganic tracers
indicated that graded levels of added water treatments, which
were based on reference evapotranspiration, produced
corresponding increases in the depth of percolated water.
Atrazine's soil distribution indicated greater downward movement
in response to increases in amount of deep-percolating water.
Magnitude of leaching differed between irrigation methods and
increased in the order: sprinkler < basin < furrow. Simulations
using the LEACHM model provided a physically based explanation
for the differences in water movement between sprinkler and basin
methods. The total amount of applied water was similar at each
level of percolation but sprinkler irrigations were more
frequent, resulting in more evaporation and, consequently, less
water available for deep percolation. Both amount and method of
water application are important factors that determine pesticide
movement and that, in irrigated agriculture, must be considered
as integral components of pesticide management.
NAL Call No.: QH540.J6
*****************************************************************
83. The influence of variable precipitation patterns on
simulations of pesticide mobility.
Roth, G.; Stahl, G.; Iwan, J.
Pestic-sci v.38, p.341-346. (1993).
Includes references.
Descriptors: pesticides-; leaching-; precipitation-; variation-;
temperature-; frequency-distribution; weather-data;
monte-carlo-method; simulation-models
Abstract: The behaviour of pesticides in the soil is governed by
a variety of complex processes including theclimatic
conditions. To investigate the influence of these specific
factors, a Monte-Carlo Methodwas used to generate sequences of
daily precipitation and temperature data representing natural
weather behaviour. Simulations of the leaching process were
performed for different compounds withthese sequences while
all other environmental parameters were held constant. The
results indicatedthat the use of stochastic variables yields
new insight into the leaching process. It is shownthat the
naturally occurring variability of the weather pattern has a
crucial influence on theleaching of pesticides.
NAL Call No.: SB951.P47
*****************************************************************
84. Integrated flux model for unsteady transport of trace organic
chemicals in soils.
Moldrup, P.; Poulsen, T. G.; Rolston, D. E.; Yamaguchi, T.;
Hansen, J. A.
Soil-sci v.157, p.137-152. (1994).
Includes references.
Descriptors: organic-compounds; transport-processes;
movement-in-soil; drained-conditions; deterministic-models;
unsaturated-soils; vadose-zone;
relative-impact-of-chemicals-at-transient-state-riocats
NAL Call No.: 56.8-So3
*****************************************************************
85. Integrating water quality modeling with ecological risk
assessment for nonpoint source pollution control: a conceptual
framework.
Chen, Y. D.; McCutcheon, S. C.; Rasmussen, T. C.; Nutter, W. L.;
Carsel, R. F.
Water-sci-technol v.28, p.431-440. (1993).
Paper presented at the IAWQ First International Conference on
"Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact,
Abatement." September 19-24, 1993, Chicago, Illinois.
Descriptors: water-quality; protection-; pollution-control;
ecology-; risk-; assessment-; models-; usa-;
best-management-practices
NAL Call No.: TD420.A1P7
*****************************************************************
86. Integration of geographic information systems and a computer
model to evaluate impacts of agricultural runoff on water
quality.
He, C.; Riggs, J. F.; Kang, Y. T.
Water-resour-bull v.29, p.891-900. (1993).
Includes references.
Descriptors: runoff-; river-water; water-pollution;
water-quality; nitrogen-; phosphorus-; simulation-models;
geographical-information-systems; michigan-;
geographic-resource-analysis-support-system-grass;
grass-waterworks;
agricultural-nonpoint-source-pollution-model-agnps; cass-river;
saginaw-bay; best-management-practices
Abstract: This study integrates an Agricultural Non-Point Source
Pollution Model (AGNPS), the Geographic Resource Analysis Support
System (GRASS) (U.S. Army Corps of Engineers, 1987), and GRASS
WATERWORKS (a hydrologic modeling tool box being developed at the
Michigan State University Center for Remote Sensing) to evaluate
the impact of agricultural runoff on water quality in the Cass
River, a subwatershed of Saginaw Bay. AGNPS is used to estimate
the amounts, origin, and distribution of sediment, nitrogen (N),
and phosphorus (P) in the watershed. GRASS and GRASS WATERWORKS
are used to generate parameters needed for AGNPS from digital
maps, which include soil association, land use, watershed
boundaries, water features, and digital elevation. Outputs of the
model include spatially distributed estimates of volume and peak
runoff, overland and channel erosion, sediment yields, and
concentrations of nitrogen and phosphorus. Management scenarios
are explored in the AGNPS model to minimize sedimentation and
nutrient loading. Scenarios evaluated include variations in crop
cover, tillage methods, and other agricultural management
practices. In addition, areas vulnerable to erosion are
identified for best management practices.
NAL Call No.: 292.9-Am34
*****************************************************************
87. Interfacial tension-induced transport of nonaqueous phase
liquids in model aquifer systems.
Anderson, M. A.
Water-air-soil-pollut v.75, p.51-60. (1994).
Includes references.
Descriptors: soil-pollution; groundwater-; pollution-; solvents-;
fuels-; transport-processes; immiscible-displacement;
surface-tension; toluene-; sand-
NAL Call No.: TD172.W36
*****************************************************************
88. Investigating prediction capability of HEC-1 and KINEROS
kinematic wave runoff models.
Obiukwu Duru, J.; Hjelmfelt, A. T. Jr.
J-hydrol v.157, p.87-103. (1994).
Includes references.
Descriptors: watersheds-; rain-; storms-; runoff-;
catchment-hydrology; prediction-; simulation-models
Abstract: In this study, two distributed parameter, physically
based, kinematic wave hydrologic models, HEC-1 and KINEROS, were
tested on a 30.4 ha watershed located near Treynor, Iowa. The
study had two objectives: (1) to determine the ability of the
models to predict runoff with very limited calibration: (2) to
determine how accurately the models can simulate runoff given
accurate model parameters. The results show that HEC-1 can
achieve good prediction of runoff with very limited calibration.
It was not, however, possible to achieve the same level of
prediction with the KINEROS model. Given good calibration, both
models can simulate the rainfall runoff process with great
accuracy.
NAL Call No.: 292.8-J82
*****************************************************************
89. Lake water quality modeling for projected future climate
scenarios.
Stefan, H. G.; Hondzo, M.; Fang, X.
J-environ-qual v.22, p.417-431. (1993).
Paper presented at the USDA-ARS Beltsville Agricultural Research
Center Symposium XVII, "Agricultural Water Quality Priorities, A
Team Approach to Conserving Natural Resources," May 4-8, 1992,
Beltsville, MD.
Descriptors: lakes-; water-reservoirs; global-warming;
carbon-dioxide; temperature-; dissolved-oxygen; size-; depth-;
turbidity-; phytoplankton-; seasonal-variation; water-quality;
simulation-models; water-temperature; trophic-status
Abstract: A deterministic, one-dimensional numerical simulation
model for water temperature and dissolved oxygen (DO) in lakes of
different size, depth, and trophic status has been formulated,
validated, and applied to lakes in the north central USA. The
standard error of predictions is on the order of 1 degree C for
temperature and 1.5 mg L(-1) for DO. The model is driven by
weather measurements at off-lake weather stations. Simulations
can be made for the open water season at daily timesteps and for
as many years as weather data are available without any parameter
adjustments. The model has been used to simulate the effect of
climate change due to a doubling of atmospheric CO2 on water
temperatures and DO in 27 lake classes in Minnesota. The lakes
have been differentiated by surface area, maximum depth, and
trophic status. Maximum water temperature near the surface is
projected to increase by no more than 2 degrees C in midsummer,
and DO will drop by less than 2 mg L(-1) in the surface waters
but will remain above 7 mg L(-1). In contrast, hypolimnetic water
temperature in midsummer may rise by as much as 4 degrees C or
may become colder by as much as 4 degrees C. Hypolimnetic DO will
be lower by as much as 8 mg L(-1) in midsummer and DO depletion
is projected to occur for a longer period of time in midsummer in
lakes with seasonal summer stratification. Changes will be
largest in spring and fall because the summer stratification
season will lengthen by 20 to 90 d for different lake types.
NAL Call No.: QH540.J6
*****************************************************************
90. Leachate geochemistry at a municipal landfill, Memphis,
Tennessee.
Mirecki, J. E.; Parks, W. S.
Ground-water. Dublin, Ohio : Ground Water Pub. Co. May/June 1994.
v. 32 (3) p. 390-398.
Includes references.
Descriptors: landfill-leachates; municipal-refuse-disposal;
wells-; groundwater-; samples-; chemical-composition;
concentration-; alluvium-; aquifers-; geochemistry-; models-;
groundwater-pollution; tennessee-
NAL Call No.: TD403.G7
*****************************************************************
91. Long-term (15 years) results of NPS controls in an
agricultural watershed upon a receiving lake's water quality.
Garrison, P. J.; Asplund, T. R.
Water-sci-technol v.28, p.441-449. (1993).
Paper presented at the IAWQ First International Conference on
"Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact,
Abatement." September 19-24, 1993, Chicago, Illinois.
Descriptors: watersheds-; agricultural-land; runoff-water;
sediment-; nutrients-; prediction-; models-; pollution-control;
phosphorus-; loads-; lakes-; water-quality; wisconsin-
NAL Call No.: TD420.A1P7
*****************************************************************
92. Measuring and modeling root water uptake based on 36chloride
discrimination in a silt loam soil affected by groundwater.
Schmidhalter, U.; Selim, H. M.; Oertli, J. J.
Soil-sci v.158, p.97-105. (1994).
Includes references.
Descriptors: daucus-carota; roots-; water-uptake; measurement-;
salinization-; groundwater-; saline-water; capillary-rise;
water-table; soil-depth; models-; solutes-; transport-processes;
chloride-; soil-water-content
NAL Call No.: 56.8-So3
*****************************************************************
93. Miscible displacement and theoretical techniques for
simultaneous study of pesticide sorption and degradation during
transport.
Gamerdinger, A. P.; Dowling, K. C.; Lemley, A. T.
SSSA-spec-publ p.115-123. (1993).
In the series analytic: Sorption and degradation of pesticides
and organic chemicals in soil / edited by D.M. Linn, T.H. Carski,
M.L. Brusseau and F.H. Chang. chemicals in soils," held on
October 30, 1991, Denver, Colorado.
Descriptors: pesticides-; transport-processes; models-;
transformation-; sorption-; estimation-; techniques-
NAL Call No.: S590.S62
*****************************************************************
94. Model farms results reviewed as project nears an end.
Carver, N.
Inside-edge v.3, p.1-2. (1993).
Descriptors: water-quality; farms-; models-; residues-;
project-appraisal; iowa-
NAL Call No.: S561.6.I8I572
*****************************************************************
95. Model of integrated effects of boron, inert salt, and water
flow on crop yield.
Shani, U.; Hanks, R. J.
Agron-j v.85, p.713-717. (1993).
Includes references.
Descriptors: hordeum-vulgare; zea-mays; growth-models;
mathematical-models; equations-; phytotoxicity-; boron-;
salts-in-soil; soil-salinity; soil-water; water-flow;
transport-processes; leaching-; available-water; crop-yield;
yield-losses; simulation-models; utah-
Abstract: High boron concentration in the soil causes yield
reduction. Recently, a piecewise linear response curve was
applied to describe yield response to B in near steady-state
conditions. However, application of similar curves to field
situations where water, B, and other ion contents are transient
and nonhomogeneous is limited. The objective of this study was to
develop a model for simulation of the integrated effects of B,
inert salt, and water on crop yield under field conditions. The
model computes water flow in response to irrigation, rain, or
evapotranspiration processes and subsequently computes inert salt
and B transport. Crop yield is related to soil matric and osmotic
potentials and B toxicity. Effects of B toxicity are considered
by adapting the steady-state approach to the transient situation.
Field experiments with barley (Hordeum vulgare L.) and corn (Zea
mays L.) were conducted on the Utah Power & Light Co. research
farm (Huntington, UT). Soil was Penoyer loam [coarse-silty, mixed
(calcareous), mesic Typic Torriorthent]. Line source irrigation
was used to obtain different irrigation levels. The effects of B,
Salt mixture of Na, Ca, Cl, and SO4), and B + Salt on yield were
studied in barley. The effect of B + Salt was studied also in
corn. Measurements and simulations were in close agreement for
both crops. Barley yield ranked B + Salt < B < Salt < control.
Corn yield ranked B + Salt < control. The B adsorption properties
result in less leaching than do those of an inert ion like Cl.
The effects of initial and boundary conditions together with the
B adsorption characteristics on B concentration in the soil
solution and the subsequent yield reduction are presented. This
model can serve for an analysis of the long-term effects of high
B and help in understanding the relative.
NAL Call No.: 4-AM34P
*****************************************************************
96. A model of nitrate leaching from agricultural systems in
Virginia's Northern Neck.
Johnson, T. G.; Parker, J. C.
Blacksburg : Virginia Water Resources Research Center, Virginia
Polytechnic Institute and State University, 1993. xviii, 308 p..
Includes bibliographical references (p. 125-137).
TD201.V57--no.179
*****************************************************************
97. Model simulations of dissolved oxygen characteristics of
Minnesota
Stefan, H. G.; Fang, X.
Environ-manage. New York, Springer-Verlag. Jan/Feb 1994. v. 18
(1) p. 73-92.
Includes references.
Descriptors: lakes-; water-quality; dissolved-oxygen;
simulation-models; climatic-change; minnesota-
NAL Call No.: HC79.E5E5
*****************************************************************
98. A modeling approach to evaluate best management practices.
Williams, R. D.; Nicks, A. D.
Water-sci-technol v.28, p.675-678. (1993).
Paper presented at the IAWQ First International Conference on
"Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact,
Abatement." September 19-24, 1993, Chicago, Illinois.
Descriptors: agricultural-land; crops-; river-water;
water-pollution; protection-; soil-management; water-quality;
improvement-; models-; usa-; vegetative-filter-strips
NAL Call No.: TD420.A1P7
*****************************************************************
99. Modeling mined land reclamation strategies in a GIS
environment.
Younos, T. M.; Yagow, E. R.; Zipper, C. E.; Diplas, P.
Appl-eng-agric v.9, p.61-68. (1993).
Includes references.
Descriptors: mined-land; reclamation-; computer-software;
models-; erosion-control; environmental-impact; virginia-
Abstract: The erosion potential from mined lands is considered a
major environmental threat. Mathematical models can be used to
predict and demonstrate the effectiveness of various reclamation
strategies for reducing erosion potential. The objective of this
project was to use the Universal Soil Loss Equation (USLE) with a
sediment yield component to evaluate the comparative effects of
alternative reclamation strategies in a Geographic Information
System (GIS) environment. The study site was an abandoned mined
land (AML) site located in southwest Virginia. Topographic and
landuse information for the site were obtained from topographic
maps, aerial photographs, and field observation. The GIS tools
were used to create digital data layers, store, analyze, and
display information. The USLE factors were spatially derived from
elevation, landuse, surface-water system, and watershed boundary
data layers. The basic and derived data layers were then used to
estimate the magnitude of soil loss and sediment yield. The
methodology was used to predict the soil loss and sediment yield
at the existing AML site, and to compare the effectiveness of
three reclamation options for reducing soil loss and sediment
yields. Results demonstrate the usefulness of the GIS tools for
planning land reclamation strategies.
NAL Call No.: S671.A66
*****************************************************************
100. Modeling mobility and effects of contaminants in wetlands.
Dixon, K. R.; Florian, J. D. Jr.
Environ-toxicol-chem v.12, p.2281-2292. (1993).
Annual Review Issue: Wetland Ecotoxicology and Chemistry.
Descriptors: wetlands-; simulation-models; contaminants-;
pollutants-; transport-processes; literature-reviews
NAL Call No.: QH545.A1E58
*****************************************************************
101. Modeling subsurface drainage and surface runoff with WEPP.
Savabi, M. R.
J-irrig-drain-eng v.119, p.801-813. (1993).
Includes references.
Descriptors: subsurface-drainage; surface-drainage; erosion-;
erosion-control; models-; water-erosion-prediction-project
NAL Call No.: 290.9-AM3Ps-IR
*****************************************************************
102. Modeling the effects of salt-water intrusion dynamics for a
coastal karstified block connected to a detrital aquifer.
Calvache, M. L.; Pulido Bosch, A.
Ground-water. Dublin, Ohio : Ground Water Pub. Co. Sept/Oct 1994.
v. 32 (5) p. 767-777.
Includes references.
Descriptors: aquifers-; coastal-areas; saline-water;
contamination-; groundwater-flow; landforms-; simulation-models;
mathematical-models; water-quality; salinization-;
groundwater-pollution; spain-
NAL Call No.: TD403.G7
*****************************************************************
103. Modeling the transport of solutes to groundwater using
transfer functions.
Roth, K.; Jury, W. A.
J-environ-qual v.22, p.487-493. (1993).
Paper presented at the USDA-ARS Beltsville Agricultural Research
Center Symposium XVII, "Agricultural Water Quality Priorities, A
Team Approach to Conserving Natural Resources," May 4-8, 1992,
Beltsville, MD.
Descriptors: solutes-; transport-processes; chemicals-;
unsaturated-flow; groundwater-; mathematical-models
Abstract: Transport of chemicals through the unsaturated zone
into groundwater is in general a highly nonlinear process with a
pronounced spatial structure of which only a very limited number
of measurements is economically and technically feasible. In most
applications, it is thus not practicable to model these processes
with high spatial and temporal resolutions. However, in an
agricultural environment chemicals are usually applied to large
areas, and we are generally interested in their long-term effects
on groundwater quality. With these restrictions, the transport
processes may be averaged in space and time over sufficiently
large regions such that it may be permissible to use a
stationary, linear approximation. An efficient way to study such
systems exploits that a stationary, linear system is completely
determined by its transfer function, that is, by its response to
a narrow pulse input. We use a general formalism to represent the
transport processes implicitly by the relation between the flux
and the resident concentration of a conservative chemical. To
model the transport of nonconservative chemicals, this
description is coupled, as it was done by (Villermaux, 1981),
with a model of the local interactions. We obtain an expression
for the transfer function of a linearly adsorbing chemical with
linear adsorption kinetics and first-order decay in the water and
in the adsorbed phase which is based on the measured transfer
function of a conservative tracer. This procedure has the major
advantage that parameter estimation and model validation tests
can be applied to the chemical reaction processes alone. KEEP.
NAL Call No.: QH540.J6
*****************************************************************
104. Movement of nitrogen through and agricultural riparian zone.
2. Distributed modeling.
Nikolaidis, N. P.; Shen, H.; Heng, H.; Hu, H. L.; Clausen, J. C.
Water-sci-technol v.28, p.613-623. (1993).
Paper presented at the IAWQ First International Conference on
"Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact,
Abatement." September 19-24, 1993, Chicago, Illinois.
Descriptors: riparian-forests; pollutants-; sources-; nitrogen-;
groundwater-pollution; surface-water; water-pollution;
movement-in-soil; mathematical-models; connecticut-
NAL Call No.: TD420.A1P7
*****************************************************************
105. New models for unsaturated soil hydraulic properties.
Zhang, R.; Genuchten, M. T. v.
Soil-sci v.158, p.77-85. (1994).
Includes references.
Descriptors: soil-water-retention;
unsaturated-hydraulic-conductivity; mathematical-models;
solutes-; transport-processes; water-flow
NAL Call No.: 56.8-So3
*****************************************************************
106. NLEAP simulation of residual soil nitrate for irrigated and
nonirrigated corn.
Follett, R. F.; Shaffer, M. J.; Brodahl, M. K.; Reichman, G. A.
J-soil-water-conserv v.49, p.375-382. (1994).
Commentary.
Descriptors: zea-mays; sandy-soils; irrigated-conditions;
soil-water-regimes; nitrogen-fertilizers; application-rates;
nitrate-; residues-; leaching-; nitrogen-; nutrient-uptake;
precipitation-; seasonal-variation; simulation-models;
crop-yield; nitrate-leaching-and-economic-analysis-package;
nutrient-management
NAL Call No.: 56.8-J822
*****************************************************************
107. Nondestructive determination of hydrogeometrical
characteristics of soil macropores.
Wang, D.; Norman, J. M.; Lowery, B.; McSweeney, K.
Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of
America. Mar/Apr 1994. v. 58 (2) p. 294-303.
Includes references.
Descriptors: macropores-; characterization-;
nondestructive-testing; dimensions-; water-flow; macropore-flow;
transport-processes; mathematical-models
Abstract: Hydrological and geometrical parameters of macropores
are essential for modeling water and solute transport through
soils containing macropores. This study was conducted to develop
a fast and nondestructive technique for determining the
hydrological and geometrical characteristics of soil macropores.
We measured the rate of water flowing into ant and earthworm
burrows with a macropore infiltrometer and estimated burrow
diameter, volume, and depth from the measured flow rate and a
water flow model. To evaluate the estimated burrow parameters, we
made castings of the ant and earthworm burrows with a dental
plaster. The burrows had similar diameters (2.1 mm for laminar
flow; 2.9 mm for turbulent flow) but different volumes and depths
[281-cm(3) volume and 0.60-m depth for ant burrows; 210-cm(3)
volume and 0.82-m depth for earthworm burrows]. This technique is
reasonable for ant burrows because the root mean square
difference (RMSD) between casting and infiltrometer-calculated
volumes is 17%; however, errors are larger for earthworm burrows
(RMSD is 73%). Saturated soil matrix hydraulic conductivity
[K(s)] estimated from the infiltrometer measurement of earthworm
burrows were comparable to matrix K(s) of the bulk silt loam. The
matrix K(s) values estimated for ant burrows were about eight
times smaller than matrix K(s) of the bulk sandy soil. Such large
decrease in K(s) is probably caused by infilling of burrow walls
by ants with fine materials. Combining the macropore
infiltrometer measurements with the model is a useful means of
estimating the hydrological and geometrical parameters of ant and
possibly earthworm burrows.
NAL Call No.: 56.9-So3
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108. Nonpoint source (NPS) pollution modeling using models
integrated with geographic information systems (GIS).
Engel, B. A.; Srinivasan, R.; Arnold, J.; Rewerts, C.; Brown, S.
J.
Water-sci-technol v.28, p.685-690. (1993).
Paper presented at the IAWQ First International Conference on
"Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact,
Abatement." September 19-24, 1993, Chicago, Illinois.
Descriptors: pollution-; sources-; watersheds-; rain-;
agricultural-chemicals; runoff-water; water-pollution;
water-erosion; geographical-information-systems; models-; usa-;
chemicals,-runoff,-and-erosion-from-agricultural-managementsystems
NAL Call No.: TD420.A1P7
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109. Nonpoint sources.
Line, D. E.; Osmond, D. L.; Coffey, S. W.; Arnold, J. A.; Gale,
J. A.; Spooner, J.; Jennings, G. D.
Water-environ-res v.66, p.585-601. (1994).
Includes references.
Descriptors: water-pollution; soil-pollution; water-quality;
water-resources; pollutants-; pesticides-; biodegradation-;
pollution-control; models-; monitoring-; literature-reviews
NAL Call No.: TD419.R47
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110. Numerical approach to the overland flow process in
vegetative filter strips.
Munoz Carpena, R.; Parsons, J. E.; Gilliam, J. W.
Trans-ASAE v.36, p.761-770. (1993).
Includes references.
Descriptors: erosion-control; overland-flow; pollution-control;
runoff-; sediment-; shelterbelts-; simulation-models;
water-pollution; mathematical-models; north-carolina
Abstract: Agricultural and other disturbed lands contribute to
non-point source pollution of water bodies (streams and lakes).
Vegetative filter strips (VFS) are often recommended to reduce
off-site impacts. Design guidelines to optimize performance of
VFS are not readily available. A process-based model is presented
to simulate the hydrology of a Vegetative Filter Strip for a
given event. The model consists of a quadratic finite element
overland flow submodel, based on the kinematic wave
approximation, coupled with an infiltration submodel based on a
modification of the Green-Ampt equation for unsteady rainfall.
The model is used to study the effect of soil type, stope,
surface roughness, buffer length, storm pattern and field inflow
on the VFS performance. Filter performance, i.e., reduction of
the runoff volume, velocity and peak, is higher for denser grass
cover, smaller slopes and soils with higher infiltration
capacity. Time to peak(s) depended mainly on the roughness-slope
combination.
NAL Call No.: 290.9-Am32T
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111. Observed and simulated transport of a conservative tracer
under line-source irrigation.
Comfort, S. D.; Inskeep, W. P.; Lockerman, R. H.
J-environ-qual v.22, p.554-561. (1993).
Paper presented at the USDA-ARS Beltsville Agricultural Research
Center Symposium XVII, "Agricultural Water Quality Priorities, A
Team Approach to Conserving Natural Resources," May 4-8, 1992,
Beltsville, MD.
Descriptors: solutes-; transport-processes; soil-water-regimes;
irrigation-; soil-depth; simulation-models;
agricultural-chemicals; silt-loam-soils; montana-; vadose-zone;
leachm-simulation-model
Abstract: Although a number of solute transport models are
currently available to predict the transport of agrichemicals in
the vadose zone, validation of these models under field
conditions has been limited. This study monitored the transport
of a conservative tracer (Br-) under three water regimes (high,
medium, and low) imposed by a line-source irrigation system and
tested the validity of the simulation model, LEACHM, to predict
Br- transport. In July 1990, RbBr was surface applied to 12
uncropped columns at 56 kg Br- ha(-1). Four columns (0.203-m
diam., 1.2-m length) were positioned in each water regime and
equipped with soil solution samplers at .36-, 0.66-, and 0.96-m
depths. Soil solution samples were taken 20 times over 80 d to
monitor Br- transport. Cumulative water applied to each water
regime, by irrigation and precipitation, ranged between 251 and
458 mm. Results indicated dramatic differences in Br- transport
among water regimes. Complete Br- breakthrough curves (with apex
concentrations of approximately 60 mg Br- L(-1) were observed
under high water regime at all depths whereas the majority of Br-
applied to the low water regime remained at or near the 0.36-m
depth. Inputs used to predict Br- transport in LEACHM simulations
were either measured directly or estimated from experimental
conditions. To simulate Br- transport for each water regime, we
used three LEACHM input files, which reflected the variability of
the soil profile water release retention coefficients. Results
indicated that LEACHM's predictions of Br- concentration (at all
depths and under all water regimes) differed from observed means
by an average (n = 180) of 9.0 to 9.4 mg Br- L(-1) (approximately
15-16% of the average apex concentrations). These results
indicate that under the experimental system studied, LEACHM.
vadose zone.
NAL Call No.: QH540.J6
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112. One-dimensional infiltration with moving finite elements and
improved soil water diffusivity.
Cox, C. L.; Jones, W. F.; Quisenberry, V. L.; Yo, F.
Water-resour-res v.30, p.1431-1438. (1994).
Includes references.
Descriptors: soil-water; solutes-; diffusivity-; infiltration-;
transport-processes; mathematical-models; transport-models
Abstract: A problem of significant interest to environmental
scientists is the flow of water and solutes through the vad