assessment of the water quality of the kashkan river based on water quality indicators

River pollution is a critical issue with direct and indirect impacts on the health of humans, animals, and plants. in this study, arcgis software was used to delineate the kashkan river path, and its water quality was assessed using the irwqisc, nsfwqi, and wilcox indices in comparison with global standards. four sampling stations were established along the river, and water quality parameters were measured over one year, from autumn 2022 to summer 2023, using standard laboratory methods. the results revealed that water pollution increased from upstream to downstream, primarily due to agricultural drainage, industrial activities, and urban and rural sewage discharge. according to the irwqisc index, stations s1 and s2 were classified as moderate quality, while stations s3 and s4 were categorized as relatively poor quality. based on the nsfwqi index, all stations fell within the moderate quality category but did not meet the standards for drinking water. the wilcox index indicated that the river water remains suitable for agricultural use. the study identified urban and rural sewage, along with agricultural runoff near the kashkan river, as the main contributors to the decline in water quality. cluster analysis grouped the sampling stations into two major categories based on their water quality characteristics. therefore, it is recommended that environmental management strategies focus on continuous monitoring and identification of pollutants as a foundation for informed decision-making in this region.