Quality of River Water for Irrigation and Drinking Uses and Sources of Contamination in Upper Catchment Areas

Aims: This study aimed to evaluate river water quality for any use depends on its level of quality, which can be influenced by several factors. Materials & Methods: This study was conducted in Dinavar River, upper Kaekheh Basin, Iran, to evaluate water quality and the factors affecting its uses for irrigation and drinking use during ۲۰۱۷-۲۰۱۹. Seven river sites were selected along the river catchment and subjected to field measurement and sampling. Vegetation cover and river degradation were assessed in the field. Water samples and fresh sediment were collected from the selected sites. Samples were analyzed for various physio-chemical parameters such as pH, electrical conductivity, total dissolved solids, total hardness, cation (Na+, K+, Ca۲+, Mg۲+), anions (Cl-, HCO۳-, SO۴۲-), and sodium absorption ratio. Findings: Water quality analysis showed that the water samples from five sites in plain areas were suitable for both drinking and irrigation purposes, while water quality at two upper catchment sites was significantly (p>۰.۰۵) affected by urban wastewater. Moreover, it was found that the Dinavar River's degradation factors increased riverbank erosion, while land use/cover change in river catchment with pollutant sources strongly affected water quality. The main pollutant sources were urban wastewater, improper agricultural activities, land use/cove change, animal manure, rural swage, and local tourism impacts. Conclusion: Since river water is of great importance for irrigation, drinking, and environmental applications in semi-arid regions, it is necessary to take measures against the pollutant sources.