Climate change effect on soil erosion using different erosion models: A case study in the Naip Dam basin, T?rkiye

Abstract

Soil erosion, expected to increase with the potential effects of climate change, is the main problem that reduces the useful storage capacity of river dam reservoirs. This problem threatens the safety and sustainability of water and food resources. Over the last few years, a large number of numerical models have been developed and used to predict the current, and future state of soil erosion with Geographic Information Systems (GIS) based erosion models. This study aims to estimate the annual average amount of soil loss in the Naip dam basin in Turkiye Thrace by using GIS-based Revised Universal Soil Loss Equation (RUSLE) and Modified Universal Soil Loss Equation (MUSLE) erosion models and analyze the forecast outputs verified by the reservoir sedimentation results within the framework of the effects of climate change. Thus, the effects of future climate change on the spatiotemporal change of erosion rate and reservoir sedimentation were tried to be explored. Study data were organized using the ArcGIS Soil Erosion Tool, and annual average soil loss was calculated based on the dam basin's RUSLE and MUSLE erosion models. Accordingly, it was understood that the average annual soil loss in the basin area was between 0.31 t ha-1 yr-1 (RUSLE) and 0.36 t ha-1 yr-1 (MUSLE). These results were checked by the results of reservoir sedimentation determined by the volume changes of the Naip dam. RUSLE and reservoir sedimentation results were found to be compatible with each other. Therefore, the RUSLE erosion model was rerun with climate change data for 9-year periods between 2021 and 2050. Because of the predicted effects of climate change, it is understood that erosion will increase more in this area in the future. Thus, helpful and guiding information was provided to the decision makers for the dam reservoir sedimentation management, the dam's sustainability, and the extension of the reservoir life. In terms of adaptation to climate change, it is recommended to take measures to reduce or prevent erosion in the basin area.