Insights into Land-Use and Demographical Changes: Runoff and Erosion Modifications in the Highlands of Serbia

This research investigates the effects of land use/land cover (LULC) and demographical changes on runoff and erosion processes in the watersheds of border highlands in Serbia. It provides an interdisciplinary approach, linking demography (human geography) with physical geography (hydrology and geomorphology). (A) A predominant decrease in curve number (CN), a key hydrological indicator, is recorded in more than 20 watersheds in Eastern and Southeastern Serbia, largely due to continuous depopulation and abandonment of arable land over recent decades. In contrast, minor CN changes are dominant in over 10 watersheds in Western and Southwestern Serbia. (B) Through cluster analysis, four regions are spatially delineated by changes in four key indicators: runoff, soil erosion, agricultural land use, and rural population. Soil erosion change is correlated with the deagrarianisation and depopulation processes at a significance of p < 0.0001 with r = 0.580 and r = 0.629, respectively. The border watersheds are being studied for the first time using a complex approach that analyses the relationships between changes in demography, land use, surface runoff, and soil erosion. The study results contribute to a better understanding of sustainable land management and risk management in the hilly and mountainous border regions, which are particularly vulnerable to torrential flooding and soil erosion.