Using GIS and remote sensing for the mapping of potential groundwater zones in fractured environments in the CHAOUIA-Morocco area

Abstract

The present study is a contribution to the effort of using new technologies (GIS and remote sensing) for the prospection of groundwater in fractured environments in the lower Chaouia region, which is characterized by the presence of nongeneralized water tables. Its main objective is to design a GIS prototype, coupled with the multi-criteria analysis AHP, as an efficient decision support tool for the mapping of potential groundwater zones and to define the most suitable sites for the implementation of future productive drilling. The combination of multi-source data (remote sensing, hydrographic, lithologic, fracturing, climatic, topographic, drilling, etc.) mainly obtained from new geomatics technologies has made it possible to set up a geo-spatial database. The most significant factors, namely, lithology, slope, lineaments, drainage density, land use, TWI and rainfall, were taken into account and assigned weights according to their relative importance in order to determine the potential groundwater areas. The combination of the different parameters conditioning the existence of reservoirs in fractured environments in a GIS facilitated the spatial analysis and cartographic restitution of zones with aquifer potential. The study area is dominated by the Very Weak and Weak classes (51%), followed by the Medium class (31%), and finally the Strong and Very Strong classes (18%). The validation of the obtained model was made on the basis of the superimposition of the exploitation flows of the existing boreholes and springs in the study area on the resulting thematic map, which reveals the reliability of the results and that the selected parameters that were highlighted to define the potential groundwater zones were satisfactory.