Latif Kalin, a professor and hydrologist in Auburn University’s the School of Forestry and Wildlife Sciences, is the program director of an innovative environmental study that has received a $499,968 grant from the USDA National Institute of Food and Agriculture, or NIFA.
The research, “Coupling Swat and Wetqual for Improved N, P, and C Processing in Wetland Dominated Agricultural Watersheds,” aims to provide a major perspective shift on the ecological services that wetlands provide at the watershed scale, including their substantial impact on the processing of nitrogen, phosphorous and carbon.
This project will change the ways that crucial research is done in areas such as climate change and variability, land use and cover change and water quality and quantity.
Kalin and his fellow researchers emphasize that while an abundance of studies have demonstrated the ways that wetlands provide numerous ecological services at the local scale, there has been a dearth of research on the benefit of wetlands at the watershed scale, until now.
“Despite the importance of wetlands in watersheds, only a handful of watershed models consider wetlands in their computations,” Kalin said. “The overarching goal of this research is to create a model for improved representations of water quality processes in wetland-rich watersheds.
“If watershed models do not capture the wetland processes adequately, any ensuing modeling exercise to assess the effects and effectiveness of wetland conservation practices at the watershed scale will be limiting.”
Wetlands are low-lying, regularly inundated ecosystems recognized for their significant ecologic and economic value. Among other services, they provide water quality purification, material transformation, carbon sequestration, flood control, wildlife habitats and biodiversity at the ecosystem and watershed levels, Kalin noted.
Humans significantly influence the quality and quantity of these water resources in numerous ways. Along with natural pollutants, anthropogenic pollutants—those originating in human activity—cause nonpoint source pollution, a type of pollution that comes from many diffuse sources, including agricultural land, urban areas, construction sites and forested and pasture lands.
When wetlands flourish in watersheds, they have a strong cumulative effect on the spatial scale, magnitude, frequency and duration of biogeochemical fluxes, or transfer of water and materials to downstream aquatic systems.
“Constructed and restored wetlands—also known as green infrastructure—are among the most effective best management practices for trapping nutrients generated from agricultural fields,” Kalin said.
This pioneering project will fully couple one of the most widely used watershed models, the Soil and Water Assessment Tool, or SWAT+, with the wetland nutrient cycling model, or WetQual, to improve understanding of the nitrogen, phosphorous and carbon cycles in agricultural watersheds that have a significant wetland presence.
“The fully coupled SWAT+WetQual will provide an improved watershed scale hydrology and water quality model that can tackle any number of wetlands and more efficiently and accurately simulate the fate and transport of nutrients at the watershed level,” Kalin said.
The testing grounds for this coupled model will be the Tuckahoe Creek and Upper Choptank River watersheds in the Chesapeake Bay area of Maryland and the Fish River and Magnolia River watersheds in coastal Alabama. The study area in Maryland is rich in depressional wetlands, while the Alabama watersheds are dominated by headwater wetlands.
Haw Yen, an associate research scientist at Texas A&M University and a co-principal investigator, said the team was thrilled to receive the NIFA funding for this much-needed study.
“The proposed work will substantially improve the watershed-scale computational tool so that relevant conservation management scenarios can be conducted in a timely manner with scientifically credible solutions,” Yen said. “In case studies, two wetland dominant watersheds will be tested in changing land use and climate scenarios to further validate performance of the coupled model.”
Dean Janaki Alavalapati of Auburn’s School of Forestry and Wildlife Sciences said this innovative research is pivotal, as it couples two well-established research tools for the first time to uncover new solutions.
“The modeling system developed by Dr. Kalin and his team is filling a crucial research gap,” Alavalapati said. “By studying the role wetlands play within watershed areas, they will provide significant assistance to both the academic community and practitioners in better assessing water conservation efforts, best management practices allocations, land use and water quality and quantity in wetland-rich watersheds.”
In addition to Yen, co-principal investigators include Puneet Srivastava, professor and associate dean of the University of Maryland’s College of Agriculture and Natural Resources, and Jeffrey Arnold, agricultural engineer, Grassland, Soil and Water Research Laboratory at the USDA Agricultural Research Service in Temple, Texas.
(Written by Teri Greene)