Quality assessment of Takab Sarugh river right branch by Wilcox index and its zoning using geographical information system, 2011

Using Water Quality Indices are necessary for monitoring the
quality of water in various applications, including agriculture. This study aimed to assess the quality of
Takab Sarugh river right branch by WILCOX index.
Materials and methods: In this cross sectional study some quality parameters including water
temperature, sodium, calcium, magnesium, total hardness, pH, electrical conductivity, sodium adsorption
rate, total dissolved solids were measured monthly in five stations located along the river during spring
and summer 2011. EC and SAR levels changes toward river discharge were determined for each station.
Also, quality of water in each station was determined using WILCOX diagram and geographical
information system.
Results: The maximum SAR and EC values (1.3 and 1368 s/cmμ, respectively) were found in
station C in September, while the lowest values were seen in station A in May. Results showed that the
concentration of parameters decreased when the river flow increased. Based on SAR index the quality of
water was in class S1 (low alkaline risk) and the EC was fluctuating between C1, C2, C3 classes (salinity
risk: low, medium, and high, respectively).
Conclusion: The results showed that quality class of river water in low water season decreased
into moderate class from good and excellent classes. Probably sedimentary rocks, limestone springs and
effluent of a gold extraction factory located in the studied area resulted in declining quality of water