Assessment of water quality compartments in Kor River, IRAN Vahideh Sheykhi & Nozar Samani Received: 14 May 2019 /Accepted: 28 June 2020 # Springer Nature Switzerland AG 2020 Abstract A comprehensive risk assessment tool may have advantages for investigating complex water quality data and for a better understanding of the ecological status of the studied systems including aquatic ecosys- tems. In this paper, the impact of agricultural, industrial, and domestic sources on the quality of the Kor River in Fars Province, Iran are investigated. The study devel- oped a procedure consists of pollution index (P i ), water quality index (WQI), and data grouping as a useful simple tool to assist water quality management. The pollution indicators used in the development of P i and WQI are 15 physical, chemical, and biological variables in the river water. According to the world guideline standards, an appropriate weight is assigned to each indicator, scores of P i are determined, a composite WQI is formulated, and a water quality grouping score is proposed. Pollution risk levels along the river are highlighted using the grouping score and dominant pol- lution sources are determined. Results revealed that pollution sources influence the water quality indicator content so that some sites are under the high influence of sewage disposal and industrial effluents and some others under the influence of agricultural runoff. Results also provide insight into the development of better pollution control strategies for the Kor River and other aquatic ecosystems affected by industrial, agricultural, and do- mestic pollution sources. Keywords Risk assessment . Pollution index . Water quality . Kor River . Iran Introduction Water is one of the most vital natural resources for the perpetuation of life on earth. In a natural condition, earth’s life forms live in equilibrium with their environ- ment. The aquatic environment with its water quality is considered the main factor controlling the state of health and disease in living organisms including humans. The accessibility and quality of water have always displayed a main component in determining not only where people can live, but also their quality of life (Agarkar and Thombre 2006; Veni and Mohanraj 2013). In the past century, the exponential development of anthropogenic influences has resulted in a severe impact on all envi- ronmental sections, including aquatic ecosystems (Iqbal et al. 2015). The aquatic ecosystems including the rivers are one of the most productive ecosystems and freshwa- ter resources in the world. River systems generally constitute areas with a high population density which are economically very important in fishing, agriculture, husbandry, and industry as well as ecologically signifi- cant due to the presence of many aquatic organisms, migratory and local birds, and scientific research. How- ever, rivers offer convenient alternative drainage for the discharge of surface water runoff, and industrial and domestic wastewater which results in a high risk to the environment. Therefore, the precise determinations of pollutants in river systems are of ultimate importance for Environ Monit Assess (2020) 192:532 https://doi.org/10.1007/s10661-020-08464-2 V. Sheykhi (*) : N. Samani Department of Earth Sciences, School of Sciences, Shiraz University, Shiraz 7146713565, Iran e-mail: vahidehsheykhi@gmail.com