Several water sources which are utilized for irrigation purposes are dominant in the Wolaita and Kembata Zones of Southern Ethiopia. However, because of combined anthropogenic and natural factors, the water quality has impaired. The main objectives of the present study were to evaluate the suitability water resources (spring and river water) from Kembata and Wolaita Zone as well as to characterize the hydrochemistry of the water. Multiple irrigation water quality indices such as SAR, RSC, PS, MR, KI, PI, and Na% were used to ascertain the suitability of the water for irrigation use. Also, USSL and Wilcox diagrams were used to further investigate the suitability for irrigation use. Furthermore, geochemical modelling (PHREEQC) were used to assess and determine saturation indexes. Moreover, piper diagram, and Gibbs plots were used to determine ionic compositions of water and influencing factor. The findings show a considerable disparity in the quality of the water. Accordingly, very high salinity (EC up to 8.91 dS/m), high sodicity (SAR up to 22.92), residual sodium carbonate (RSC) (1.01–17.2), potential salinity (PS) (0.33–4.2385), magnesium ratio (MR) (9.83–70.39), Kelly index (0.86–16.32), permeability index (PI) (135.48–205.42), sodium percentage (Na %) (50.95–94.7%) were noted. Also, as per PHREEQC model, natural geochemical processes govern groundwater and surface waters more than anthropogenic pollution. Furthermore, piper diagram revealed a dominating sodium-bicarbonate (Na-HCO3) water type. Moreover, based on USSL and Wilcox diagram, water from Fulame and Hamido sampling sites were suitable for irrigation use. In order to guarantee sustained agricultural productivity in the area, our research offers a crucial basis for putting specific mitigation techniques into practice, such as mixing water and gypsum.
Habtewold et al. (Fri,) studied this question.