Proceedings of the 2022 Mississippi Water Resources Conference

Year: 2022 Authors: Bhattarai S., Parajuli P., To F.

The unique interface of coastal waters lying between ocean and terrestrial land serves as a critical habitat to many shellfish species and it supports a wide range of human activities. This study evaluates the quantity and water quality of water runoff from the coastal watersheds in Southeastern Mississippi into the Bay of Saint Louis. A process-based river-basin scale Soil and Water Assessment Tool (SWAT) model is applied to integrate current scenarios of different management practices implemented into the upland watersheds which are predominated by forests. Two adjacent watersheds namely, Wolf River Watershed and Jourdan River Watershed are studied independently, the developed model is calibrated and validated for the flow, sediment, and nutrient yield using data collected from USGS 02481510 and USGS 02481660 stations for each watershed. Statistical analysis of the developed SWAT model includes coefficient of determination (R2) and Nash-Sutcliffe Efficiency (NSE), and the model's prediction was evaluated. Quantifying the amount of sediment yield and nutrient loss from small coastal watersheds flowing into St. Louis Bay will be insightful in assessing the impacts of water pollution in the bay ecosystem.