Comparison of Streamflow Simulations for Different DEMs

Hydrological modeling of the rainfall-runoff process is crucial not only for understanding the characteristics of a basin but also for sustainable planning and management of water resources. Most of the hydrologic models require digital elevation model (DEM) as the prime input, from which the basin and its stream network are delineated by using GIS tools. DEMs from various satellite imageries like Cartosat, SRTM, ASTER, IKONOS, and others have been widely used for such purposes. However, the primary challenge is the selection of an appropriate source of DEM, since the accuracy produced from satellite imageries varies. This study aims to compare the streamflow simulations in the Chaliyar basin using a HECHMS model developed from two different DEMs. The Cartosat-DEM and ASTER-DEM are considered for comparison. Results of the study show that Cartosat-DEM gives a clear watershed boundary and area of 2912 km2 which is very close to the India-WRIS data, whereas the ASTER-DEM gives slightly better results in simulating the streamflow based on performance measures of the model.