Hydrological Modeling and Streamflow Characterization of Gangotri Glacier

Abstract

High mountain basins provide high specific discharges to headwaters of major continental rivers. Glacierised catchments show a discharge regime that is strongly influenced by snow and glacier melt waters. Many of the major rivers in India originate from the Himalayas. These rivers have significant contribution from snow and ice which makes these rivers perennial. Himalayan region has high concentrations of mountain glaciers. Large extent of this region is covered by seasonal snow during winter. Runoff generates from melting of these snow and glaciers is one of the important sources of water for the Himalayan rivers. Glaciers and snowfields are distributed throughout the Himalayas and form a source of numerous streams. Considering this aspects, in this study a snowmelt runoff simulation model SNOWMOD suitable for Himalayan basins developed earlier has been modified and applied for simulation of flows from the Gangotri Glacier, the headwaters of River Bhagirathi in the Uttarakhand Himalayas. The flow data for the year 2010 has been considered for calibrating the model whereas the year 2011 and 2012 have been considered for validating the model for simulating the daily flows. The efficiency of the model has been computed based on the daily simulated and observed flow values for three years. The values of the model efficiencies are 86%, 87% and 90% respectively for the years 2010, 2011 and 2012.