干旱区生态环境知识资源中心

The Errachidia basin is located in the South Eastern part of Morocco and characterised by its typical arid climate. With an average rainfall of under 80 mm/year, the potential of water resources are very low in this part of the country. Because of its highly growing population, water is strongly required for agriculture (i.e. palms, vegetables...). Therefore, the management of water resources in the Errachidia basin takes priority.

The aim of the present work is investigating prospective groundwater reserves in the Cretaceous reservoir of Errachidia basin. The study uses Geographic Information System in combination with Geostatistics tools in order to produce a reliable map of potential groundwater resources.

Five basic spatial parameters in Raster and Vector format (Topography, Geology, Structures, Hydrogeology data and Hydrology) are used for this analysis. This spatial methodology required a probabilistic approach and the recourse to different statistical methods. The use of GIS for data preparation and interpretation combined with geostatistical tools is particularly useful in area where only few data have been collected.

The map of the potential groundwater resources generated through this model was verified with the yield data to ascertain the validity of the model. The verification showed that the groundwater potential zones predicted by the model are in agreement with the bore well yield data.

The present investigation demonstrates the capabilities of GIS in combination with geostatistical techniques in the demarcation of different potential groundwater zones. With appropriate adaptations, this method could be used in any other arid area.