Gamasiab River Water Quality Assessment Using NAWQI and NIP Indexes

Due to the lake of water resources, rivers are known as the most important sources of water supply for various purposes. Gamasiab River is one of the largest sources of water supply for drinking, agriculture and industry in Kermanshah, Iran. The purpose of this study is to evaluate the water quality of Gamasiab River using different indicators. For this purpose 15 stations along the Gamasiab River in 2018 were selected. Different parameters of nitrate, sulfate, phosphate, potassium, sodium, electrical conductivity, pH and total dissolved solids were measured in spring and summer. The results of the WQI index were calculated using the WHO global standard. Due to the results, WQI index in the spring and summer have been estimated 9/16 and 3/16, which were less than WHO standard and placed in the highest category of drinking water quality. Assessing WAWQI index indicated high Quality of water in the spring season for drinking, irrigation and industry (21.29), Also, the results of the WAWQI index categorized Gamasiab River in good level for drinking, irrigation and industry (27.09). According to the results of the NPI index in the spring season with a value of -0.91 and in the summer season with a numerical value of -0.9, the water of the Gamasiab River is in the clean and unpolluted category in terms of nitrates. The results of Wilcox's classification for electrical conductivity in different stations showed that in spring and summer in all stations, water salinity is average and its quality is good.