Contribution of GIS for the Piezometric Monitoring of the Unconfined Water Table Aquifer of the Fez-Meknes Basin

The Fez-Meknes basin consists geomorphologically of the Meknes plateau to the west and the saïss plain to the east, separated by the Ain Taoujtat flexure. It is characterized by a semi-arid climate. Hydrogeologically, the basin contains two important aquifer reservoirs, a free and a captive water table. The first one circulates in the Plio-Villafranchian formations, while the second one is deep in the dolomitic limestone of the Lias. These two aquifers communicate with each other in some places, either directly through flexures and faults or indirectly through upward drainage. They are the main sources of drinking water and irrigation. These two aquifers have been overexploited due to successive years of drought and agricultural use. Thus, this work aims to monitor the piezometric level of the free water table through several field trips, technical data sheets of the drillings, geological and topographical maps. The analysis of rainfall data in the stations located around the piezometers in the study area allowed to distinguish a low water period (June, July, August and September) and a high-water period (March, April and May). The piezometric maps were made on the basis of the comparison between kriging and TIN during the low and high-water period. The TIN method has been recommended as the most reliable one.