DETERMINATION OF THE IMPACT OF FOREST FIRES ON SOIL EROSION RISK BY USING THE ICONA MODEL: A CASE STUDY OF AYVALI DAM WATERSHED

Abstract

Soil erosion in dam watersheds is a crucial phenomenon since dams have become a critical component of economic development for many countries. Therefore, the expected increase in both forest fires and heavy rains in the Mediterranean region poses a threat to the dam watersheds. The increase of these two phenomena will cause a serious increase in soil erosion after forest fires in dam watersheds. Therefore, revealing the possible effects of forest fires on soil erosion risk will be extremely beneficial for taking proactive measures in the management of dam watersheds. So, the goal of this study is to reveal the soil erosion risk and to determine the effect of possible forest fires on the soil erosion risk in the Ayvalı dam watershed. The ICONA model was used to reveal the soil erosion risk in the study area. The effect of forest fires was determined by scenario analysis. In the forest fire scenario, it is assumed that all forests in the study area are burned. Considering this scenario, a new soil erosion risk map was produced with the model. Then these two maps were compared. The results showed that 70.33% of the study area faced very high erosion risk, while 21.65%, 7.19%, 0.77%, and 0.05% of it had high, medium, low, and very low erosion risk, respectively. This potentially very high risk results from the steep slopes, high soil erodibility, and sparse vegetation density in the study area. As a result of the fire scenario, it was determined that while the areas with the very high risk increased by 18.11%, areas with high, medium, low, and very low risk decreased by 48.55%, 26.36%, 35.43%, and 100%, respectively. The findings can be a guide for decision-makers to prioritize necessary precautions depending on the soil erosion potential before and after forest fires.