GIS-based assessment of soil erosion risk in a post-nuclear landscape: A morphometric approach using ALOS PALSAR DEM

Morphometric analysis of terrain is widely recognized as one of the most effective approaches to investigating soil erosion processes. This study examines the relationship between terrain morphometry and soil erosion susceptibility within the Semipalatinsk Test Site (STS), Kazakhstan, using the ALOS PALSAR digital elevation model (DEM) at 12.5 m spatial resolution processed within ArcGIS 10.4. A series of thematic morphometric maps – including hypsometric, slope gradient, and slope aspect layers – were generated and used to develop a three-level hierarchical classification of theResults indicate that flat and very gentle terrain (slopes below 6°) accounts for approximately 51% of the STS territory; gentle to moderate slopes (6° – 25°) cover 44%; and steep slopes (above 25°) occupy only approximately 5% of the total area, concentrated within the Degelen Mountain Range. The dominant slope aspect is north-facing, contributing to pronounced microclimatic asymmetry. Integration of GIS-based morphometric parameters with land cover and soil data revealed distinct erosion-prone zones correlated with slope steepness and relative relief. The findings confirm that high-resolution DEM-based morphometric analysis is a reliable and efficient tool for landscape assessment, soil erosion monitoring, and sustainable land management planning in semi-arid regions with complex topography.