Estimation of River Discharge in Mandovi Basin, Goa

Rivers are an important aspect of terrestrial hydrology. In fact, they are the reason for the interaction processes between land, ocean, and atmosphere. Most river discharge estimates are available at the gauging location, and scarce information is available on the discharge at the confluences. In this paper, studies are carried out to estimate discharge values for Mandovi River in Goa state. Ganjem watershed (599 km2 area) was modelled using the soil and water assessment tool) programme by USDA- ARS (Department of Agricultural-Agricultural Research sciences). Cartosat-1 DEM—Version-3R1 (Resolution 32 m), soil, land use/land cover, precipitation, and temperature data are used in this study. The model was simulated for five years (2010–2014), and discharge for each year is estimated. The model was calibrated using three years of data and validated for two years. SWAT analysis reveals that the model parameters CN2, GWDELAY, GWQMIN, SURLAG, and ALPHA_BF are sensitive for the Mandovi basin. The simulated and observed values are in good agreement. Statistical analysis showed that co-relation coefficient R2 and Nash–Sutcliffe efficiency (NSE) were 0.88 and 0.80, which indicate model results that are in good agreement with measurements.