Ali Ranjbar - Tarbiat Modares

Different regions of the world are faced with different types of problems associated with the occurrence, use and control of water resources, which may endanger the sustainable development of these resources. The quality of surface waters is a very sensitive issue. The restoration of the river water quality has been a major challenge to the environmental managers. Due to rapid population growth and consequently the development of urban and industrial centers around the Kashafrood River, pollution in the river bed is occurred and human health and other creatures are threatening. Hence In the present paper, NSFWQI was used to evaluate the River Zayanderoud water quality and Pearson's correlation test was done for identifying the correlation rate between NSFWQI and measured parameters and which parameters has the most effect on NSFWQI measured in each season. in autumn, DO )r = 0.247, p-value = 0.278(, In winter, the parameters of temperature )r = 0.301 , p-value = 0.253(, DO )r = 0.621 , p-value = 0. 0.05 at 0.05 level( and total phosphorus )r = 0.644 , p-value = 0.042 at the 0.01 level( , respectively, In spring, the parameters of DO )r = 0.906, p-value = 0.01 at the 0.01 level( and turbidity )r = - 0.281 , p-value = 0.025(, respectively, in summer, only parameter of DO have the maximum directly correlation with NSFWQI )r = 0.246 , p-value = 0.557(.The study also identifies the critical pollutants affecting the river water quality during its course through the city. With comparing the obtained results of NSFWQI for sampling stations can conclude that only stations one and two in autumn and winter seasons have medium quality and in spring and summer seasons have bad quality and another stations in all seasons have bad quality. The highest NSFWQI was 54 which is related to station 1 in autumn season and the lowest NSFWQI was 42 for station 8 in summer season. However, there is need for routine monitoring of the various human activities within the basin especially at the downstream to check the occurrence of high nitrate and fecal coli form.

Watershed pollution; NSFWQI; Kashafrood River