Hydrological Simulation using Process Based and Empirical Models for Flood Peak Estimation

Abstract

This study introduces about the parameterization of hydrological modelling for Asan and Song river basin the whole Doon Valley. SWAT an empirical hydrological model, VIC a physical hydrological model and HEC-HMS a semi distributed hydrological model are used for flood peak generation at predetermined locations. The land cover mapping of Doon Valley was attempted using remotely sensed images of Landsat and Google Earth imagery. The specific objectives are hydrological modelling for peak flow hydrograph generation, to observe LULC change scenarios between 1995, 2005 and 2014 year, comparison and validation of the simulated runoff using three different hydrological models (VIC, SWAT and HEC-HMS). The VIC model performance was found good and a close agreement between the observed and simulated values was obtained for 2014 LULC map. Model performance was also found good for other subbasins. The various input parameters are the meteorological data, discharge and sediment data were processed as per requirement of the SWAT model. The model was calibrated for the year 2006 to 2010. The Hydrological modeling indicates that the curve number is most influence parameter into the total discharge. Land use and vegetative cover play an important role in watershed runoff and stream flow discharge patterns over time, including peak flows. Increased human interventions have caused rapid transitions in land cover, adversely affecting the watershed processes and hydrological cycle in the long run. It may be concluded that the impact of land cover changes are most pronounced during low flows and that during high flows, role of land cover becomes comparatively less.