پهنه بندی کیفیت آب رودخانه هراز بر اساس شاخص NSFWQI

Background and purpose: In order to identify the impact of aquaculture effluents systems, industrial, agricultural and residential centers, between the output of water from Lar dam up the water input to the Caspian Sea in 7 different stations, river water quality parameters from October 1388 to September 1389 was studied and evaluated with water quality index. Materials and methods: This experimental study was conducted on Haraz river. In order to identify the impact of aquaculture effluents, industrial, agricultural and residential centers, between the output of water from Lar dam up the water input to the Caspian Sea in 7 different stations, river water quality parameters from October 1388 to September 1389 studied and evaluated. Sampling, sample preparation and analysis, according to standard methods (1998) were done. Results: Results of statistical analysis data indicate that the parameters of BOD, TS, EC, turbidity, nitrate, phosphate, and fecal coliform in the effluent entering the river to the plains and the confluence with agricultural and residential centers based on indicators of water quality NSFWQI class average was 70-50 with a range of indicators, while the downstream station (station Sorkhrood) of these indicators in the months except January, June and July reduced to below 50 and as a region with poor water quality (pollution) were identified. Conclusion: Haraz river water at 6 stations (output from Lar dam until Karesang station) based on NSFWQI water quality index evaluated. The range of average quality index was 70-50, while in the downstream stations (station Sorkhrood), the value of these indicators, reduced to below 50, except for the months January, June and July. The station Sorkhrood was identified as an area with poor water quality (pollution).