Climate Change Impact on Snowmelt Runoff Modelling for Alaknanda River Basin

Abstract

Variable Infiltration Capacity hydrology model is a physically based, Semi-distributed macroscale hydrological model that represents surface and subsurface hydrologic processes on spatially distributed grid cell. In mountainous watersheds Snow melt can have a significant impact on the water balance and at certain times of the year it could be the most important contribution to runoff.

In this study the Variable Infiltration Capacity Hydrology model has been successfully applied for Alaknanda River Basin. As input to the model long-term(1999-2008) daily meteorological dataset such as temperature, precipitation, wind speed and geospatial dataset such as land cover data,  Elevation data , soil data were provided from multiple sources (NRSC,NBSS&LUP,NOAA and IMD). In addition, the spatial distribution of runoff, snow cover and snow depth were analyzed and compared with the monthly stream flow data obtained from rudraprayag (lat-30.285, lon-78.98), MODIS 8 day snow cover product (MOD10A2) and AMSRE snow depth product. The model runs resulted in an increase in Snowmelt Runoff for the period of record (2001–2006), as a result of decrease in Snow Cover and Snow Depth for the monsoon period. In this study Nash–Sutcliffe efficiency is 0.92 which indicate a good fit between observed and simulated runoff.

Keywords: VIC, Snow, Snow depth, Snow cover, GEFS, IMD, AMSRE, MOD10A2, Discharge