What are the impacts of land use change and cover-management factors on soil erosion modelling studies?

Abstract

Soil erosion is a major environmental problem with significant impacts on land degradation. This study’s main objective was to determine the effect of different cover-management factor (C-factor) values on soil erosion estimates with varying proportions of land use types. This effect was demonstrated in a mountain catchment, located in the Polish Carpathians, over two time periods (1977 and 2019), reflecting differing land use and land cover (LULC) influenced by political and socioeconomic changes, particularly after the collapse of communism. The LULC changes in the studied catchment, including an increase in forest area and a decrease in cultivated land, represent broader regional trends within the Carpathian Mountains. The Revised Universal Soil Erosion Equation was used to estimate soil erosion. The model was validated using 30 years of stationary measurements from experimental plots on Carpathian slopes. This study investigated four different C-factor variants, including values derived from previous remote sensing-based European studies and local long-term field data, to comprehensively assess their impact on soil erosion estimates. This study’s results show how the proportion of each LULC type changes the estimated soil erosion values at different C-factors. The average differences in soil erosion between the four C-factor variants were up to 41 % in 1977 and over 96 % in 2019. These contrasts are due to significant differences in the C-factor in all variants, especially for grassland, forests and cultivated land, the areas of which changed significantly over the studied period. The results of this comparison should be considered in soil erosion analyses and guide the selection of appropriate C-factor values, especially in areas where detailed data are unavailable. Overall, this analysis showed that C-factor selection is crucial for determining soil erosion values and that land use structure plays an important role in soil erosion dynamics and sustainable development. Based on this study’s results, specific recommendations for land use management and conservation strategies are proposed. To mitigate soil erosion, afforestation efforts should be prioritised on steeper slopes, while permanent grassland cover should be maintained in areas prone to surface runoff.