Quality assessment using water quality indicators with geospatial analysis of groundwater quality El-Oued region, Northern Sahara, Algeria

The present study was carried out to assess groundwater quality in two layers (Albian and complex terminal) intended for irrigation, to identify their original chemical composition and overall risk by different attack techniques in the province of El-Oued. Eleven physico-chemical parameters were measured at 16 locations. Emphasis was placed on the selection of irrigation water quality index (IWQI) inputs through the application of multivariate statistical analysis, the estimation of various classical irrigation indices, and the integration of geographic information systems. The results of the IWQI, sodium adsorption ratio, Kelly index, permeability index, residual sodium carbonate and magnesium hazard showed that the majority of groundwater samples were classified for irrigation purposes in the following categories: severely restricted (100%), low sodium and excellent (100%), good (93.75%), marginally safe (100%), good (100%) and suitable (81.25%), respectively. In addition, the majority of selected samples were classified as “good to eligible for irrigation” based on %Na as shown in the distribution map. Whereas the principal component analysis results show that the four factors together explain 72.74% of the total variance according to the Kaiser rule. Cluster analysis divides the parameters into three groups. In summary, the combination of the geographic system and irrigation quality indices is useful for identifying irrigation zones.