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.
The present study aims at mapping areas vulnerable to water erosion based on the Priority Activity Program/Regional Activity Center (PAP/CAR) model guidelines, geomatics, remote sensing, and GIS in the Errachidia-Boudenib Cretaceous basin. This basin is located in south-eastern Morocco and covers an area of 13 000 km2, the basin is 320 km long and 75 km wide. The method of estimating water erosion is composed of three phases; a predictive phase consisting of a mapping of predisposing factors such as slope, substrate, and/or soils and vegetation cover, a descriptive phase based on the mapping of actual erosion, and an integration phase to arrive at the identification and evaluation of the erosion risk. The mapping of areas vulnerable to water erosion indicates that 70% of the studied basin has low erodibility and 22% is notable, while only 8% has high to very high erodibility. The areas most affected by degradation are located at the end of the basin and correspond to lands with steep slopes (>35%). Consequently, this study has allowed us to locate certain sectors and roads that may be affected by this type of erosion, namely the mountainous areas of the High Atlas and roads numbered R13, R601, R 703, and P7106.
In order to model the water flow of the free Quaternary aquifer of the Fez-Meknes basin, it is essential to determine the precise geometric limits of the aquifer. Indeed, the characterization and representation of the underground structure of the Miocene marl top which forms the aquiclude of the aquifer, constitutes the fundamental step to study and understand its influence on the groundwater flow. This study is facilitated by the available data, which allow to represent the underground formations on isohypses maps. The data base is formed by reconnaissance drillings, and the extraction of marl altitudes from previous geological works. During this work the generation of the marl top elevation map was based on the test of four interpolation methods, which correspond to : Kriging, IDW method, Natural Neighbors, and Topo to Raster, in order to choose the most reliable and best suited to the study area. On the one hand, the calculation of the conformity index between the values measured in the field and the estimated values for each method was successively (0.9796, 0.9848, 0.9814, 0.9842). On the other hand the values of the root mean square error (RMSE) were successively (13.59, 7.42, 21.27, 14.01). The comparison of these results allowed us to choose the IDW interpolation as the most reliable and suitable to interpolate the top of the aquiclude of the free water table of the Fez Meknes basin with a compliance index the highest and a RMSE the lowest compared to other methods.
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