Modelling Water Erosion and Mass Movements (Wet) by Using GIS-Based Multi-Hazard Susceptibility Assessment Approaches: A Case Study—Kratovska Reka Catchment (North Macedonia)

Abstract: Kratovska Reka is a short (17.3 km) left tributary of Kriva Reka, whose watershed (68.5 km2)
is located on the northwestern slopes of the Osogovo Mountains (North Macedonia). Due to the
favorable natural conditions and anthropogenic factors, the Kratovska Reka catchment is under a
high risk of natural hazards, especially water erosion and landslide occurrences. For this reason, the
paper presents an approach of modelling of potential erosion and areas susceptible to the abovementioned
hydro-meteorological hazards in the Kratovska River catchment. Firstly, this study
analyzed the main geographical features that contribute to intensive erosion processes in the area.
Then, using the Gavrilovi´c EPM erosion potential method, an average value of 0.56 was obtained for
the erosion coefficient Z, indicating areas prone to high erosion risk. Furthermore, by using landslide
susceptibility analysis (LSA), terrains susceptible to landslides were identified. The results shows
that 1/3 of the catchment is very susceptible to mass movements in wet conditions (landslides).
According to the combined multi-hazard model, 3.13% of the total area of the Kratovska River
catchment is both at high risk of landslides and under severe erosion. The Kratovska River catchment
is significantly endangered by the excessive water erosion processes (39.86%), especially on the
steep valley sides, i.e., terrains that are completely exposed, under sparse vegetation, and open to
the effects of distribution/concentration of the rainfall amounts throughout the year. Identifying
locations with the highest erosion risk serves as the initial step in defining and implementing
appropriate mitigation measures across local and regional scales, thus enhancing overall resilience to
environmental challenges.