Determining the current erosion risk status in Artvin's Hopa stream catchment with the help of the ICONA model and relating to the general morphological characteristics of the catchment

In this research, the hydromorphological characteristics of the Hopa Stream Catchment (HSC), located in the Hopa district of Artvin province, were determined using Geographic Information Systems (GIS), and the current erosion risk status of the catchment was assessed using the ICONA model. The primary objective of the study was to reveal the cause-and-effect relationship between morphological structure and erosion risk, and to map the catchment's physical characteristics and erosion-prone areas. A Digital Elevation Model (DEM) was obtained from the Earth Explorer platform of the United States Geological Survey (USGS) for the morphological analysis of the catchment. Using this model, basic morphological attributes such as catchment boundaries, water flow direction and accumulation, aspect, slope classes, and drainage network were analyzed in a GIS environment, and the relevant thematic maps were produced. As part of the erosion risk analysis, parameters such as slope, geological structure, soil protection status, land cover, and land use were integrated into the ICONA model. Land cover data were obtained from stand maps of the Artvin Regional Directorate of Forestry, and land use data from CORINE 2018. By overlaying these layers, a potential soil erosion risk map for the catchment was created. According to the analysis results, it was determined that the catchment reaches an altitude of approximately 1858 meters above sea level, the dominant aspect is facing north (35%), the areas above 20% slope constitute 87.5% of the catchment and the main drainage branch, Hopa Creek, flows in the east-west direction. The erosion risk map derived from the ICONA model shows that catchment is predominantly in the "medium" and "high" erosion risk classes. Overlaying the resulting erosion risk map with land use data revealed that areas with high erosion potential are mostly located on steep slopes and high altitudes, and these areas overlap with areas where forest cover has been converted to tea cultivation.