Land Degradation Processes in Mountainous Landscapes in Türkiye: Preliminary Results

Mountainous landscapes face numerous threats stemming from population growth, economic development, and climate change. The unique and fragile climatic conditions in mountain areas are susceptible to all changes that may occur due to anthropogenic activities (i.e., overgrazing, agricultural intensification, deforestation, land abandonment, infrastructure and construction activities, and unplanned settlement), exacerbated by extreme weather events like intensified rainfall, causing soil erosion, and prolonged drought. Land degradation occurs through the interaction of multiple processes in different regions and areas, and these processes are particularly complex and susceptible to accelerating factors in mountainous regions. Given Türkiye's topography, 58% of the land cover consists of mountainous areas; the land degradation processes in these areas, which constitute an essential segment of the Alpine–Himalayan orogenic system, remain poorly understood.    

Therefore, this study aims to develop a land degradation map in mountainous areas in Türkiye. In this regard, we compiled primary land degradation indicators for mountainous landscapes, including the normalized difference vegetation index, bare soil fraction, soil moisture, grassland, human footprint, and aridity data, at a 1km resolution for the year 2000. Here, we combine Mann-Kendall trend analyses and overlay analyses in selected mountainous areas, which comprise 5% of the total study area, to evaluate our approach for testing mapping capabilities. 

Our initial results indicated that NDVI was a decreasing indicator for land degradation. Localized degradation hotspots were identified specifically; 21% of the total area showed degradation over the last 23 years. Another important aspect we observe is a statistically significant negative trend in the grassland across 3.18% of the total study area. Whereas the human footprint exhibits varying trends that are not readily associated with land degradation. Taking all these preliminary findings into account, this study will provide the first "Land Degradation Map of Mountainous Landscapes in Türkiye" upon the completion of the land degradation assessment approach.