IMPACT OF WATER QUALITY ON THE FLUXES OF GREENHOUS GASES FOR REGULATED RIVERS

The major goal in this research is understanding the role of water quality in the Greenhouse Gas (GHG) emissions for regulated rivers. Since GHG emissions is a multi-factor problem, there will be simultaneous monitoring of GHG fluxes, water quality, meteorological conditions and sediment characterization in representative water columns. The following objectives are proposed. Objective 1: Conduct field data collection of sediments, water quality and GHGs emissions assisting in the identification of the forcing mechanisms explaining fluxes of GHGs. It implies identification of the variables, periodic sampling and continuous monitoring to get useful datasets for the relationship analyses with the aim to explain GHGs fluxes. It is planned that locations where observations will be conducted cover a variety of water quality and climate conditions in a regulated river to successfully explain GHG fluxes from representative water columns. It will require collaboration of the PI, co-PI's, students and a research technician during the first and second year.Objective 2: Analyze relationships of the variables related with water quality and fluxes of GHGs using frames of physical, chemical and biological processes. It is developing a process-based and data-driven analyses of datasets. The process-based approach will facilitate the analyses of phenomena associated with atmospheric conditions at the water-air interface such as water evaporation and flow regimes through a hydrologic-hydrodynamic model, whereas the data-driven will address the sediment-water interface in order to explain gas transfer and the role of water quality. Both approaches will establish relationships of the water column components at the site of study covering the CH4 and CO2 fluxes observed at the water-air interface, water quality conditions and sediment characterization. This stage will allow to explain GHGs fluxes subjected to a spatiotemporal variability, and will accomplished between the second and third year with the PI, a research technician and students.Objective 3: Identify key relationships between water quality and fluxes of GHGs and analyze their spatiotemporal variability. It will show the more important statistical relationships of the water column variables to know the role of water quality, atmospheric conditions and sediments characteristics on GHG fluxes. This approach will show alternatives to simplify the number of variables to monitor and the processes to observe in order to explain GHGs fluxes under limited instrumentation. Additionally, based on the spatiotemporal resolution of measurements of GHGs fluxes, it will be quantified the uncertainty of them. This work will be accomplished during the third year, participating PI, Co-PI's, a research technician and students.