Spatial modelling of soil erosion potential in a mountainous watershed of South-eastern Serbia

This work aims at the assessment of soil erosion rate and its spatial distribution in hilly mountainous Nisava River Basin (South-eastern Serbia) with a surface area of approximately 2,848 km². The study was conducted using Universal Soil Loss Equation (USLE) model due to its modest data demand and easy comprehensible structure. The erosion factors of USLE were collected and processed through a GIS-based approach. Landsat 7 Enhanced Thematic Mapper (ETM+) image and normalized difference vegetation index (NDVI) were used for the determination of crop management factor. The average annual soil loss was estimated at 27.0 t ha⁻¹ year⁻¹ classifying Nisava River Basin under very high erosion rate category. About 39.0 % of the watershed area was characterized by slight erosion rate (<5 t ha⁻¹ year⁻¹), 7.7 % of the area was found to be under moderate erosion rate (5–10 t ha⁻¹), 13.8 % of the area is under high erosion rate (10–20 t ha⁻¹), while around 17.5 % of the area was under very high erosion rate (20–40 t ha⁻¹ year⁻¹). Severe erosion rate (40–80 t ha⁻¹ year⁻¹) was observed at 14.2 % of the study area, whereas very severe erosion rate (>80 t ha⁻¹ year⁻¹) described about 7.8 % of the watershed. The results of this work are in agreement with the soil erosion map of Serbia, the sediment yield measurements in the basin and with other, more detailed, studies in the watershed. Therefore, the presented methodology could be applied as a framework for the evaluation of erosion factors on soil resources in South-eastern Serbia when limited data are available. The outputs of these studies can be used for the identification of vulnerable areas on a cell basis and for planning of conservation practices.