Impact of small dam's construction on groundwater quality and level using water quality index (WQI) and GIS: Nagarparkar area of Sindh, Pakistan

The study was conducted in Nagarparker area, Thar, Pakistan to assess the small dam's impact on groundwater quality for domestic use and water level variance in wells during pre and post-monsoon periods. The water samples collected from various locations of the study area were analyzed for twenty physicochemical parameters and their appropriateness was assessed using the water quality index (WQI) and geographicinformationsystem (GIS) techniques. The results revealed that groundwater level increased from 15-25 ft near the dams and 8-14 ft away from the dam after rainfall, a minor change was observed in the concentration of chemical and trace elements. Physico-chemical parameters analysis indicated that the concentrations of the 40% parameters (pH, SO4, Fe, CU, Mn, Zn, As and fluoride) were within the World Health Organization (WHO) guidelines, whereas 60% exceeded the thresholds. The WQI revealed that the quality of only 20% of the water samples was excellent, 25% good, 15% poor, 15% very poor and 25% unsuitable for drinking purposes. The spread of water related diseases in the area also indicated the groundwater contamination. Overall, the quality of water is poor to unsuitable for drinking purposes. Thus, such water should be treated properly before use to avoid toxic and hazardous effects on human health.