Geomorphometric based catchment runoff characterization and assessment of temporal landuse change impact on runoff inflow to an ungauged reservoir under different climatic scenarios using geospatial techniques and SWAT model

Abstract

Abstract A morphometric analysis was carried out to study runoff characteristics of the Saleran reservoir catchment. Further, the impact of catchment landuse change on runoff generation and inflow to the Saleran reservoir has been assessed using geospatial techniques and SWAT. The geomorphometric analysis shows that the catchment is less elongated in shape, having fourth-order stream network, high stream frequency (9.36 no./km2), drainage density (4.55 km/km2) and high relief (220 m), which indicates that catchment would generate a moderate amount of runoff. The SWAT (ArcSWAT) model was used for the simulation of runoff and the average annual runoff inflow was simulated to be 14.2 mm (1995–1999), 13.2 mm (2000–2009) and 11.8 mm (2010–2019) per 100 mm of rainfall under the landuse 1999, 2009 and 2019, respectively. The results indicated that the temporal change in catchment landuse has significantly increased the runoff generation and its inflow to the reservoir but there is a decrease in the volume of runoff inflow which may be due to the decreasing trend in monsoon rainfall. Hence, an appropriate conservation strategy needs to be developed and adopted in the Shivalik foot-hills for managing the catchment landuse for sustainable water supply through reservoirs.