Abstract:

The present study aims to estimate soil loss due to sheet and gully erosion in the Jeyhoon watershed of Bandar Khamir County. To estimate sheet erosion, the WaTEM/SEDEM and RUSLE models were utilized. For assessing gully erosion, UAV (Unmanned Aerial Vehicle) imaging was conducted over the gullies in the area, achieving a Ground Sample Distance (GSD) of 3 cm, from which a gully expansion map was generated. Subsequently, the morphometric characteristics of the gullies were measured to estimate the amount of soil loss caused by gully erosion. The results indicated that the average soil erosion due to sheet erosion in the study area is approximately 40.3 tons per hectare per year. The total soil loss due to gully erosion was estimated to be around 52,000 tons per year. Accordingly, the 56-year average (1967-2023) of soil loss from gully erosion was calculated to be approximately 12 tons per hectare per year. Ultimately, the total annual soil loss from all types of erosion in the Jeyhoon watershed was estimated to be approximately 15.4 tons per hectare per year.