University of Tabriz , s.hejazi@tabrizu.ac.ir
Abstract: (18 Views)
This study aimed to evaluate the effect of land-use change on soil erosion in the Ahar Chay watershed, East Azerbaijan Province, using the RUSLE model. The model estimates annual soil erosion based on five factors: rainfall erosivity (R), soil erodibility (K), slope length and steepness (LS), vegetation cover (C), and conservation management (P). To improve accuracy, the Buris, Maidment, USDA, and Vanoni models were used to derive physiographic, land-cover, soil, hydrological, and management parameters in the study area. Topographic data were obtained from a 30-m ASTER digital elevation model; land-use data from Sentinel-2 imagery and classification; soil texture from sand, silt, and clay percentages; rainfall from maximum precipitation data from ERA5-Land; and vegetation cover from the normalized difference vegetation index derived from Sentinel-2 imagery. The novelty was applying bivariate spatial relationship analysis to examine spatial associations between the erosion map and influential factors. Bivariate Pearson correlation was also used for quantitative analysis and validation. Results showed that land-use changes, particularly conversion of natural covers, including rangelands and barren lands,to agricultural and built-up areas, increased soil erosion. The highest erosion occurred in rangelands, accounting for 62.98% (1336.798 km²), while the lowest occurred in barren lands, accounting for 0.155% (2.492 km²). Pearson correlations showed significant positive relationships (p < 0.01) between erosion intensity and slope (0.93), slope length (0.79), and rainfall (R) (0.37), whereas vegetation cover (C) showed a weak negative relationship (0.09-). RUSLE estimated a mean annual soil erosion rate of approximately 20 t ha⁻¹ yr⁻¹, with about 514.424 km², equivalent to 20% of the watershed, exposed to erosion. Overall, soil texture can affect runoff and erosion within the watershed, but its influence depends on local conditions and other factors. Land-use management, vegetation protection and restoration, prevention of rangeland degradation, and sustainable agricultural management can reduce runoff and control soil erosion.
Keywords: RUSLE Model, Spatial Correlation Analysis, Pearson’s Test, Vegetation, Rainfall Erosivity Cover, Ahar Chay
Type of Study: Research |
Received: 2026/02/14
Received: 2026/02/14
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