Water Quality Assessment Based on Nsfwqi Index by Using GIS Software: Babolrood River (Iran)
Babolrood river is emanated from the south of Babol city and is poured into the Caspian sea in the north of Babolsar city after passing the 67 km. Emission of some pollutants into the river affects on the river water quality. This cross-sectional study aimed to evaluate the quality of the Babolrood river during of low and high rainfall periods. Initially, ten sampling stations (s1-s10) were selected in the sensitive locations of this river when the nine important parameters such as physical, chemical and biological parameters were measured. The obtained data were analysed by NSFWQI, and then the riverís path was zoned by using GIS software. The results showed that the important parameters including BOD, fecal coliform, nitrate, phosphate, TS and turbidity from s1 to s10 were increased when the DO was reduced. Based on NSFWQI, the best situation was related to the low rainfall period in s2 (79, good quality) and the worst situation was related to the high water period in s10 (41, bad quality). The quality of river during high water period was changed from good in s1to bad in s10 and during the low water period was changed from good in s1to medium in s10. These cases could be due to the direct discharge of urban, rural and agricultural wastewater into the river. Also, discharging and piling of solid wastes alongside the river could be noted as another cause of river pollution.
Index terms- Water quality assessment, NSFWQI, Babolrood river