Development of a SWAT Model to Investigate the Impact of Hydroclimate and Land Uses on Water Quantity and Quality in the ‘Bangali’ River, Bangladesh.

Abstract

A hydrologic model was developed to investigate the effect on the "Bangali" River was looked into to find out the nitrogen load and surface-overflow runoff of the selected watershed zone. For the project's designated watershed region, we used ArcGIS and Arc SWAT modeling software to gather data on the nitrogen load as well as the existing and predicted surface- overflow burden. The spatial and temporal data were processed using ArcGIS-Arc SWAT. To compare real data with simulated data from software and produce graphs, MS Excel was employed. Manual calibration was performed by manually changing the curve number. A good calibration was found by comparing 2021 observed surface overflow data with 2021 simulated surface overflow data (R² = 0.677). By contrasting actual data for 2021–2022 with data from the model, validation (R² = 0.53) was achieved. A comparison chart was created to compare the data from the 2021 witnessed surface flood and the 2052 forecasted surface overflow. We implemented a vegetative strip in 2021 as a natural solution to reduce nitrogen burden. We were able to reduce nitrogen load by about 20% in August, the busiest month for agricultural. A significant decrease in surface overflow load is predicted to occur after 30 years according to the projection of future surface overflow runoff.