(تحلیل خصوصیات هیدروژئومورفیک زیرحوضهها در حساسیت فرسایشپذیری خاک (مطالعه موردی: حوضه آبریز الندچای، شمال غرب ایران.

The main purpose of the present study is to investigate and analysis the role of hydrogeomorphic indicators in the sensitivity to erodibility of the sub-basins of the Aland Chai basin located in Khoy County. To achieve this aim, first the Aland Chai basin was divided into 15 sub-basins based on the characteristics of drainage network and topography and using a digital elevation model (DEM) with 12.5m spatial resolution. In the next step, 12 hydrogeomorphic parameters were evaluated to investigate the erodibility of sub-basins. The studied parameters were: Drainage density, Stream frequency, Bifurcation ratio, Drainage texture, Texture ratio, Infiltration Number, Compactness coefficient, Elongation ratio, Circulatory ratio, Form factor, Relief, and Gradient. In the following, a geomorphometric ranking method was used in order to rank the parameters. The results of the research showed that sub-basins 1, 3 and 4 had the highest score in terms of the studied parameters, which indicates the high erodibility of these sub-basins. These sub-basins, with an area of 257 Km2, include 22% of the total area of the basin area. In the next step, Landsat satellite images were used to study land use changes in the area and its relationship with the erodibility of the sub-basins. Supervised classification methods and maximum likelihood algorithm were used to extract the land uses of the area. Examining the prepared land use maps showed that the class of built-up areas (urban-rural) has increased during the statistical period studied, so that it has reached 3393 hectares in 2020 from 1028 hectares in 1985. The study of the relationship between land use changes in each sub-basin and their erodibility showed that in the sub-basins upstream of Aland Chai basin, land use change (an increase of agricultural lands) or inappropriate and excessive use of area capacity, It is effective in intensifying erodibility of sub-basins. [ABSTRACT FROM AUTHOR]