Spatial and Temporal Evaluation of Water Quality in the Kashkan River

The Kashkan River basin is one of the most important watersheds in the west of Iran, where major urban, agricultural and livestock regions are located in its catchment area. The aim of the study reported here is to evaluate the spatial and long temporal variations of surface water quality in the Kashkan River by using Water Quality Index, which aggregates different parameters and their dimensions into a single score. This study was conducted by using the variations of concentration of nine physicochemical parameters which periodically were measured (from 1974 to 2009) at 10 sampling stations. Chemical data were analyzed using both the principal component analyses and cluster analyses, which quantify the relations between variables by computing the matrix of correlations and classifying the monitoring stations, respectively. The present study demonstrated the ability of Water Quality Index developed by Canadian Council of Ministers of Environment for interpretation of the historical water quality data in the Kashkan River, Iran. This study has also highlighted that among the 10 sub-basins in the watershed, Jelhool sub-basin has the worst water quality. Moreover, water quality in the Kashkan River has been slightly deteriorated since 2000. However, the Kashkan River water has had fair quality for general uses.