Estimation of Snowmelt Runoff in the Poqueira River Basin (Province of Granada, Spain) Using SRM and MODIS Images

In mountain basins, where part of the precipitation is snowfall, snowmelt runoff can be a significant contribution to the total river discharge. This is the case of the Poqueira River, in Southern Spain, a tributary of the Guadalfeo river in the southwestern slope Sierra Nevada, where snowmelt is the main water supply of an ancient irrigation system. The Mediterranean climate of the Poqueira basin is influenced by the relief, elevation, and proximity to the sea. The relief affects the entry of the western winds, the main cyclone track, inducing a great variability in the precipitation. The elevation is responsible for the snow fall that occurs even in middle of the Spring when temperatures at the sea coast are very mild. The snow usually accumulates during late Fall, Winter and early Spring. Snowmelt starts in Spring lasting until early Summer. In this paper we present a snow water resources evaluation which applies to Poqueira River basin in order to quantify the water availability for irrigation. The evaluation is based on the simulation of the snow fusion using the snowmelt runoff model (SRM) and satellite data that provide the snow cover distribution (Rango, 2003).