Evaluation of groundwater suitability for irrigation in the coastal aquifer of Mnasra (Gharb, Morocco)

Abstract

The coastal area of the Gharb plain constitutes the only hydric resource for region in terms of domestic consumption and agricultural demand which does not cease to increase. It is a very productive and easily accessible groundwater resource, used extensively for irrigation by own pumping. This study was performed to understand the impact of groundwater quality on the crop yields and its suitability for the irrigation for 63 wells and 7 boreholes. Groundwater quality in Mnasra was studied based on different indices for irrigation. The values of SAR, Na %, MAR, SSP, PI, RSC and TDS show that most of the samples fall under good to suitable category. Piper diagram reveals three facies: sodic, calcic and magnesic chlorinated. The results indicate that the order of cation dominance is Na > Ca > Mg > K, while anion dominance is in the order Cl > HCO3> SO4. Stuyfzand's classification indicates that most of the waters analyzed are fresh with moderate alkalinity. Richard Plot indicates that groundwater in the study area is within the low salinity to low sodium hazard and medium salinity to low sodium hazard class (C2S1 and C3S1). Wilcox Plot shows groundwater to be within excellent to a good class.