The role of environmental parameter (degree day) of snowmelt runoff simulation

The upper Indus basin comprises the high mountains covered with snow and glaciers. So the major portion of flow from Indus basin is due to snow and glacier melt runoff. The terrain is difficult to measure the hydrological and hydraulics data. Most of the data is available at catchments outlets. Due to the data constraints Snowmelt Runoff Model (SRM) was used to estimate the snow melt runoff in Astor basin during, year 2000. The input data included daily temperature, precipitation and division of catchment in to different zones on the basis of elevation difference. The elevation zones were made from the Digital Elevation Model (DEM) of the area. The snow depletion curves were made by Landsat TM satellite data analysis on the monthly basis. The model output was discharge hydrograph. The model performance was tested by calculating the statistical parameters such as coefficient of efficiency (COE) and volume difference in percentage. The COE for simulation was 0.91 which illustr