Satellite driven modeling of snow runoff in a small semi-arid mountainous watershed in Morocco

The use of satellite data to monitor the snow contribution to runoff in a small semi-arid mountainous sub-watershed is explored. The Rehraya watershed, 228km/sup 2/ is located in the Atlas range. Its altitude range from 1068 to 4084m and its hydrological regime is characterized by an important snow contribution. The "soil and water assessment tool" has been selected to model the watershed's functioning and first results showed some limitations. To partly overcome the lack of climatic data over this area, we extract the snow extent from satellite images and we integrate this information in the model which should lead to better results.