Evaluation of Soil Erosion Potential in the Firouzabadchay Catchment Area using Geomorphic Indicators and Fuzzy Logic

Soil erosion is one of the most important geomorphological processes on the earth's surface, which has accelerated due to human intervention. This process causes many damages such as loss of fertile soils, destruction of infrastructure and filling of dams. In the assessment of soil erosion, several factors should be used in a combined and integrated manner. In this regard, in basins without data or with limited data, a set of geomorphological indicators can be used in combination with other indicators and the erosion potential can be evaluated. In the current research, the erosion potential of Firouzabadchay catchment area located in Ardabil province has been evaluated. In this regard, 13 indicators, mainly geomorphological, were used. In order to combine and overlapped the layers, fuzzy logic was used in the context of the geographic information system (GIS). The results show the high potential of soil erosion in the surface of the Firozabad catchment area. Several factors are effective in the erodibility of the basin's soils, which in this context can be the wide outcrop of Quaternary alluvial formations, gypsum marls, lahar and volcanic ash, weak vegetation, predominance of steep slopes, high drainage density, existence of numerous streams, high values of roughness number and long slopes. In zones of the study basin where several factors affecting erosion have favorable conditions, the rate of erosion has intensified. In this regard, we can mention the central sub-basins of the study basin, which are among the critical areas of the basin due to the presence of alluvial and marl formations, weak vegetation, high slope, high drainage density and several other factors.