Study of land use change and its effect on erosion in Nir city using GIS and RS (Case study: Nir county)

Due to human activities and natural phenomena, the face of the earth is always undergoing change. Therefore, for the optimal management of the natural areas, awareness of the land use ratio is a necessity. Soil erosion is one of the environmental disasters that annihilates thousands of soil, crops each year, and land use change is one of the important factors in erosion. Therefore, the present study was conducted to investigate the land use change trend in Nair, Ardabil province, and its effect on erosion using GIS and RS in order to carry out the research, images from 2000 and 2016, OLI and TIRS sensors, Landsat 8 were used and land use map was prepared using a controlled classification method. The erosion zonation map was performed using landuse maps and factors such as slope, lithology, distance from the road, distance from the waterway, precipitation and soil using Critical Weighing and Weighted Linear Combination (WLC). The results showed that the highest amount of area in 2000 was related to dry land farming with 442.38 km2 and semi-condensing pastures with an area of 347.39 km2. In 2016, the highest area of use of rangelands density, and then the use of semi-metamorphic rangelands are 478.76 and 458.5 km2, respectively. According to the erosion zoning plan of 2000, 17.25% and 25.55%, respectively, according to the 2016 erosion zonation, 12.44% and 26.51% of the city area are located in two high risk and high risk categories. Mostly, high risk and high-risk areas are located in both dry land and aquaculture fields at both time periods.