Snowmelt Runoff Simulation Using HEC-HMS in a Himalayan Watershed

The snowmelt-induced runoff makes the streamflow perennial that regulates streamflow during spring and summer. The Hydrologic Modeling System (HMS) of the Hydrologic Engineering Centre (HEC) has been adopted for simulating the snowmelt and rainfall runoff. This modeling system, abbreviated HEC-HMS, uses snow band methodology of US Corps of Engineers as used in Streamflow Synthesis and Reservoir Regulation (SSARR) model. In this paper reliability of the HEC-HMS snowmelt model is tested using a temperature index, spatiotemporal analysis of process parameters, and variables that characterize Beas sub-basin in the Pirpanjal range of the lower Himalayas above the Manali (1900 m of altitude). The daily and weekly simulations from simple temperature index method have been found satisfactory with R2 above 0.7. The results are presented through this paper. The model simulation reveals that ATI cold/melt rate functions are important to run, and the meteorological model index (mm) is important for model simulations.