Impacts of SWAT Modeling of Non-Point Source Pollution in Depression-Dominated Basins under Varying Hydroclimatic Conditions

By Jenna Peneueta-Snyder

A leading cause of water quality issues is nonpoint source pollution (NPS) caused by agricultural practices and run off. Current models may not be able to adequately analyze these areas because depression-dominated basin areas are most vulnerable to NPS pollution.

SWAT Modeling of Non-Point Source Pollution in Depression-Dominated Basins under Varying Hydroclimatic Conditions was published in November 2018 in the MDPI International Journal of Environmental Research and Public Health.

The team of authors for this project includes Mohsen Tahmasebi Nasab, Kendall Grimm, Mohammad Hadi Bazrkar, and Lan Zeng as well as Dr. Xuefeng Chu, Professor from the Department of Civil and Environmental Engineering at North Dakota State University; Dr. Jianglong Zhang, Professor in the Department of Atmospheric Sciences, and Afshin Shabani from the Earth System and Science Policy department, both from the University of North Dakota.

The project set out to hopefully “improve water quantity/quality modeling and its calibration for depression-dominated basins under wet and dry hydroclimatic conditions.”

“Climate and hydrologic models can be linked to predict the future of water resources under different scenarios,” said Nasab. “In one of our recent studies, we evaluated the impacts of temperature variations on macro-scale snowmelt simulations in the Missouri River Basin. We found that even sub-daily temperature fluctuations around the freezing temperature can significantly affect the generation of snowmelt.”

North Dakota State University, Mohsen Tahmasebi Nasab in his office. Photo taken from the North Dakota Water Resources Research Institute website.

“Hydrologic models are simplifications of the real-world water cycle systems and are being increasingly used to simulate different water-related processes or hydrologic processes such as snowmelt, surface runoff, and infiltration,” said Nasab. “Historically, water security or a reliable supply of water for agriculture, communities, and ecosystems has been one of the top priorities of humans.”

Prairie Pothole Region (PPR), Red River of the North Basin (RRB), Red River Valley (RRV), and four gauging stations in Doran, Fargo, Grand Forks, and Drayton. This study focuses on the U.S. part of the RRB. Taken from the journal paper SWAT Modeling of Non-Point Source Pollution in Depression-Dominated Basins under Varying Hydroclimatic Conditions.

In order to improve SWAT water quality and quantity modeling, wet and dry years must be taken into account as well as surface depression areas. Both of these factors can cause analytical readings of these basins to be off. For this reason, topographical depressions and varying hydroclimatic conditions must be taken into account.