Investigation and Analysis of the Impact of Urban Area (Amol City) on Water Quality of the Haraz River Based on Qualitative Standard Indicators

Water resources and its health is one of the main foundamentals of sustainable development. In this study, the effect of the presence of an urban area in a section of Haraz River located in an urban area was investigated by analyzing 17 physicochemical and biological parameters. Sampling was done at two sections of entrance and exit of the urban area. Sampling time were also determined both before and after rainfalls on the basis of the forecast of specialized meteorological sites about rainfall that caused significant runoff at the city area. Also, three qualitative water Indices, including the U.S. National Sanitation Foundation Water Quality Index (NSFWQI), the Oregon Water Quality Index (OWQI) and the Wilcox agricultural index were determined. The U.S. NSFWQI for the Haraz River was in the mid-range class (50-70), indicating that the river is moderately good in terms of quality. According to the OWQI, Haraz River was mostly in the weak and medium range and needs drastic management changes. According to the Wilcox index, the river's water was placed in C2S1 classification. The amount of lead in the samples was 0-1.2 µg/lit, which in all cases was lower than standard. The results of analysis of variance using SAS showed that the effect of cross section and sampling time on lead and water quality indices were not significant at 5% level. Also, according to the results, the presence of the urban area of Amol city did not have a significant effect on the water quality of Haraz River.