APPLICATION OF SNOWMELT RUNOFF MODEL USING GIS AND REMOTE SENSING TECHNIQUES FOR THE UPPER KABUL RIVER BASIN

Abstract

The Snow which accumulates in the Upper Kabul Basin, is one of the great source of water for Kabul river, Afghanistan. The precise estimation of the volume of water stored in the snowpack and its release are essential for the efficient management of water resources. Generally, the accumulation of snow in snow-fed basins starts during winter season but its depletion starts during the spring and summer season. The extent or magnitude of the snow storage and it melting rate are based on climatic condition over the basin, once the melting era or period begin, the basin or catchment act like storage reservoir flow out continuously through the melt river or stream. The melted water routed through different stages, before reaching to the out-let of the basin. The melt water first percolates through the existing snowpack very slowly and reaches the ground surface. On the ground surface it travels as overland flow and then joins the melt stream. The present study has been carried out with the objectives of estimation of the snow cover area of the Upper-Kabul River basin, Computation of snowmelt runoff, Estimation of the flow for the Upper Kabul river basin using SRM Model.The Upper-Kabul River Basin selected for this study has an area of approx. 1654 sq. km, lies between (340 51’52.7” N) and (690 4’ 37.2” E). The elevation of the study area varies from 1822m to 4515m. The basin is located in the higher part of the Kabul river basin and has widely snow cover area during winter season. Information about snow cover area is essential for the observing or Monitoring of snowfall in the mountainous area. Consistent mapping and monitoring of snow cover by traditional means is difficult due to the less number of rain-gauges and inaccessible or remote terrain and high cost of the labor. Thus remote sensing techniques can be used to estimate the aerial extent of the snow cover in the basin. Furthermore, Digital elevation model (DEM) of the Upper- Kabul basin has been divided into 8 elevation zones with altitude variance of 322.22 m each zone. The temporal SCA for the period of 2015 to 2017 was derived from MODIS-8 days Images of snow cover data and SRTM DEM have been analyzed through GIS and ERDAS Imagine to obtain the Snow cover in different elevation zones. The daily SCA in each elevation zone has been calculated, snow cover depletion curves were derived and daily runoff was computed by SRM Model from snow cover area. In this study, 8-day snow cover products from MODIS and SRTM (DEM) of the basin with Geographic information system (GIS) and ERDAS IMAGINE and finally into the windows version of snowmelt runoff model (WinSRM or SRM) have been used.