Study on Water Quality in the Ghohrood River of Kashan using National Sanitation Foundation Water Quality Index (NSFWQI) and its Zoning using Geographic Information System (GIS)

摘要

Background: Zoning of the water quality based on NSFWQI index is used more than other indices. The purpose of this study to evaluate the water quality of Kashan's Ghohrood River, using National Sanitation Water Quality Index (NSFWQI) and its zoning with Geographic information system (GIS).Materials and Methods: In this study, water quality parameters of Ghohrood River are studied monthly in five different stations from October 2014 to September 2015 during 12 months in Kahsan central of Iran. Also, these data were analyzed with NSFWQI index, and finally route of river was zoned using GIS software.Results: Among the studied stations, station A had the highest and best rate of water quality by 86.87% in March. Water quality index was 60.93% in station E in August. Average studied index in stations A, B, and C in all of the months was 72-80 and in stations D and E average index was 67-69. Average index of NSFWQI had a downward slope in the warm months; so that, in the summer, the index was lower than other seasons in each station.Conclusion: Results showed that water pollution increases by increasing the distance between source of the river and station. Since the area is considered as a recreational resort especially in the spring season and the fact that around the river is used as pastures, water quality deterioration especially in D and E stations is a very important issue.