Groundwater quality in Zagora southeast of Morocco by using physicochemical analysis and geospatial techniques

Groundwater in Morocco is restricted because of the semiarid to arid climatic conditions; it is under threat from organic and inorganic pollution. Furthermore, it is considered the only source of potable water as well as having different usages, making its quantitative and qualitative protection an urgent priority. The present study focused mainly on the anthropogenic impact on the natural resources and groundwater quality around Zagora city. Fifteen samples were collected from wells during rainy and dry seasons in 2 years 2020-2021 and the analysis of the groundwater quality of studied stations. The suitability of the aquifer Fezouata was investigated using drinking and irrigation water quality indices. The results showed that sulfate and chloride are the dominant anions in the groundwater samples. While the mean abundance of major cations is Na +  > Mg²⁺  > Ca²⁺  > K⁺, the sodium ion is dominant and K + is the least abundant. The physicochemical parameters show that conductivity, nitrate, and sulfate exceed the limit fixed by WHO. Hydrogeochemical plots indicate that 93% of samples belong to Na-Cl facies and only 7% are mixt Cl-Mg-Ca in 2021, the results are similar except for two samples which are 13% belong Cl-Mg-Ca. The Water Quality Index suggests that 28.55% are good quality water, 23.90-47.55% are poor and very poor quality water, respectively, and 40.24% are unsuitable in 2020. Furthermore, the WQI of the 2021 campaign showed that only 17.48% were considered good quality water and 38.94% (43.58%) were poor or very poor quality water, respectively. However, 33.21% are unsuitable. Based on irrigation indices, the majority of groundwater samples can be used for agricultural purposes, notably those of the upstream part of the study area.