Development of a SWAT Model to Investigate the Impact of Climate Change and Land Uses on Water Bodies

Abstract

A project area of 27,690 acres, known as Lake Fork Reservoir was studied to calculate the surface-overflow runoff and nitrogen load of the selected watershed area. To get the data on present and future surface-overflow load and nitrogen load of the selected watershed area of the project, we used ArcGIS and ArcSWAT modeling software. The spatiotemporal data were processed in ArcGIS-ArcSWAT. The comparison of observed and simulated data from software and graph plotting was done by using MS Excel. Manual calibration was performed by changing curve number. Good calibration (R2 = 0.68) was found by comparing 2016-2020 simulated surface overflow data with 2016-2020 observed surface overflow data. The validation (R2 = 0.58) was done by comparing observed data of 2021 and model simulated data of 2021. A comparison chart was created comparing 2020 observed surface overflow with 2050 simulated surface overflow data. We applied vegetative strip as a nature-based solution to reduce nitrogen load for year 2020. After applying the vegetative filter strip, we were able to reduce nitrogen load by almost 65% in the peak farming month of June. The forecast of future surface overflow data also showed that in the future there will be a drastic increase in surface overflow load in winter.