Evaluation of groundwater suitability for irrigation in the Skhirat region, Northwest of Morocco.

Abstract

Morocco has arid and semiarid climates. Irrigation is an imperative for agriculture. Skhirat region is known for the production of vegetables. Intensive peri-urban agriculture is associated with inconsiderate pumping of groundwater, and water becomes less abundant and of poor quality resulting in degradation of soil and water quality. Therefore, the objective of this research work was the assessment of the quality of irrigation water. The study site is located in a coastal area and dedicated to intensive land use for growing vegetables in a peri-urban agricultural zone. Monitoring of physicochemical parameters of water was carried out in 77 wells. Parameters like pH, electrical conductivity, and piezometric level were measured in situ while others like total dissolved solids and ionic balance were measured in laboratory whereas other parameters were calculated from those measured. Results showed that Na and Ca are predominant cations while Cl and SO4 are predominant anions. Piper diagram reveals two facies: sodic and calcic chlorinated. Regarding the permeability index, all wells are suitable for irrigation. The US Salinity Laboratory (USSL) diagram reveals that irrigation water has high salinization risk and low to medium alkalinization risk. The groundwater in the region is classified as very hard category; however, it does not present any risk of sodicity. These waters have a high risk of toxicity to chloride ions. In summary, although the groundwater in the Skhirat region presents a high risk of salinization, it is of good quality suitable for irrigation. Agricultural practices should be well managed to secure safe use of the water resource for a sustainable development of the agriculture in the region.