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 above-mentioned 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 Gavrilović 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.

Preliminary Assessment of Geohazards’ Impacts on Geodiversity in the Kratovska Reka Catchment (North Macedonia)

“…Due to the heightened global risk of geohazards, novel methods are emerging for approaching and zoning threatened areas, particularly with regard to landslides, floods, and excessive erosion. Based on the findings from [2], the erosion coefficient Z within the catchment averages 0.56. Furthermore, a considerable portion (approximately 17.35%) of the Kratovska Reka catchment is classified as being at a very high risk of erosion, exceeding 2000 m 3 /km 2 /year, which equates to soil loss of 2 mm per year-an alarming rate.…”

“…Multi-hazard techniques thus play a crucial role in the analysis of hazard events [2,[11][12][13][14][15][16][17][18][19][20], and an alternative approach involves applying probability and deterministic stochastic processes [21]. Consequently, there is a need to develop models for the assessment of potential erosion, landslide-prone areas, and flash flood-prone areas in the Kratovska Reka catchment (North Macedonia).…”

“…However, despite these features, there is currently no designated geosite in this region recognized and protected as valuable geoheritage, even though numerous proposals have been put forth [8]. Situated on the northwestern slopes of the Osogovo Mountains in North Macedonia [2], the Kratovska Reka catchment is encompassed by the Kratovo-Zletovo paleovolcanic area, covering 48.4 km 2 or 70.7% of the total area, making the paleovolcanic relief the dominant feature (see Figure 1). According to [9], the Kratovo-Zletovo volcanic area stands as the largest extinct volcanic region in North Macedonia, dating back to the Oligocene period (32-29 million years ago).…”

“…Geodiversity, encompassing a variety of geological features, processes, and landscapes, plays a pivotal role in shaping our environment [1]. As humanity continues to expand and interact with geological settings, the assessment of geodiversity's impact gains increasing importance, particularly concerning the identification of geohazards [2]. As pointed out by Aleksova et al [2], geohazards refer to phenomena or events that have the potential to degrade environmental quality and pose risks to people, infrastructure, and ecosystem services.…”

“…As humanity continues to expand and interact with geological settings, the assessment of geodiversity's impact gains increasing importance, particularly concerning the identification of geohazards [2]. As pointed out by Aleksova et al [2], geohazards refer to phenomena or events that have the potential to degrade environmental quality and pose risks to people, infrastructure, and ecosystem services. Understanding the intricate relationship between geodiversity and geohazards is crucial for effective risk assessments, hazard mitigation, and sustainable development.…”