The investigation of land use change trends and its impact on water quality of Zarrinehroud (West Azarbaijan)

Land use is referred to the use of land in existing condition that includes all uses in different parts. Land use change is affected by several factors. In this research, land use Changes in the Zarrinehroud watershed and its effect on water quality were investigated in three periods (1987, 2004 and 2013) using Landsat satellite TM and OLI sensors. The results indicate that land use changes in the watershed is going to reduce of pasture and increasing of agriculture. Wilcox and Schuler diagrams were used to evaluate the chemical quality of agricultural water, and drinking water, respectively. Based on the Wilcox diagram, only year 2004 (dry period) was on the C3-S1 class and the remaining years were on the C2-S1 class. Based on the Schuler diagram, the year 2004 (dry period) is considered acceptable in the drinking category and the remaining years are in good drinking category and have no restrictions on drinking. Water quality assessment of the Zarrinehroud watershed shows a decrease in water quality, as a result of increasing the EC, TDS and SAR characteristics in year 2004 that indicates a decrease in river water quality due to land use change and accordance with the occurrence of droughts in the year 2003-2004.