Simulation of Runoff for Subarnarekha Catchment Using SWAT Model

Abstract

This paper is based on Soil and Water Assessment Tool (SWAT) which is a hydrological model that integrates the Geographic Information System (GIS) with the attribute database to simulate runoff. SWAT Model is basically executed in association with ArcGIS as ArcSWAT. The study area taken is Subarnarekha River which flows through the eastern part of India over the states of Jharkhand, West Bengal, and Odisha. In this paper, Digital Elevation Model (DEM) has been used for delineating the catchment area. Remote sensing data has been used as input in ArcSWAT for delineation of catchment area determination of drainage pattern, land use/land cover, slope, etc. To develop landuse/landcover map the satellite imagery from Landsat 8 was acquired and the soil map for the study area was obtained from Harmonized World Soil Database (HWSD) Raster world soil map. Hydrological Response Unit (HRU) analysis was performed which resulted in 25 subbasins and 194 HRUs. Then by using 11 years of daily rainfall data, SWAT simulation has been performed to estimate the monthly and yearly runoff for their respective rainfall. The annual rainfall-runoff of the Subarnarekha River from 2005 to 2015 has been plotted and found the maximum rainfall of 1811.62 mm and runoff of 595.65 mm is in the year 2007. The reliable accuracy of the model has been checked with the assessment of the model performance as with the rainfall-runoff correlation coefficient which was found to be 0.971.