Soil erosion is a serious and continuous environmental problem in Ethiopia. Lack of land use planning, environmental protection, over-cultivation, and overgrazing are prominent causes of erosion and sedimentation. This study is conducted in Anjeb watershed located in the Upper Blue Nile Basin, Ethiopia. In this study, the quantity and distribution of soil erosion, sediment delivery ratio (SDR), and sediment yield of the watershed were assessed by employing remote sensing, geographic information system (GIS), and revised universal soil loss equation analysis capabilities. Important data sets of topography, soil, conservations practices, cover management, and rainfall factors were processed and superimposed in GIS analysis, and soil loss rate, SDR, and sediment yield of the watershed were derived. Based on the result found, the watershed was categorized into six classes of erosion: slight (0–5), moderate (5–10), high (10–15), very high (15–30), severe (30–50), and very severe (> 50) t ha−1 yr−1. The estimated average annual soil loss was 17.3 t ha−1 yr−1. The soil loss rate is higher in the steeper and topographically dissected part of the watershed. The average sediment delivery capacity was about 0.122. The result showed that the average sediment yield in the watershed was grouped into classes of low (< 2.5), moderate (2.5–7.5), high (7.5–12.5), very high (12.5–22.5), severe (22.5–40), and very severe (> 40) t ha−1 yr−1. It is found that from a total of 20,125.5 t yr−1 eroded soil over the whole watershed 2254.5 t yr−1 of sediment has been brought and deposited to the channels. Sediment accumulation from the watershed threatens the storage capacity and life span of Anjeb reservoir which is the source of irrigation water downstream. The study provides an insight to planners and resource managers to design and implement practices of watershed management to reduce erosion and enhance land productivity and to minimize the reservoir sediment accumulation.

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The goal of this study was to examine how land use/land cover (LULC) changes affected the hydrology of the Upper Gilgel Abay watershed which is located in the Upper Blue Nile Basin. Landsat pictures (Landsat 5 TM 1986, Landsat ETM + 2003, and Landsat 8 OLI-TIRS 2021) were categorized into LULC classes using a technique of supervised classification, and the Soil and Water Assessment Tool (SWAT) was used to estimate the hydrological implications of LULC changes. During the 1986–2003, the result showed an increase in cultivated land (11.7%) and a decrease in forest (39.6%), shrubland (17.5%), grassland (5.6%), and water bodies. While cultivated land, grassland, and water bodies were decreased woodland and shrubland were grew up between 2003 and 2021. While surface runoff (6%) and water yield (1.8%) were increased groundwater flow (37.9), lateral flow (4.1), soil water (1.85), and evapotranspiration (2.2%) were decreased at a watershed-scale as result of the LULC changes between 1986 and 2003. In contrast, between 2003 and 2021, the average watershed surface runoff and water yield decreased, while lateral flow, groundwater flow, soil water, and evapotranspiration increased, owing to the growth of forest and shrubland and the decline of cultivated land. However, at the sub-watershed scale the impacts of spatio-temporal LULC variations on the investigated hydrological parameters throughout the 1986–2003 and 2003–2021 periods were not in the same direction. The findings point to increase plant cover in the study watershed, as well as the Ethiopian Highlands, as a way to reduce surface runoff and boost groundwater flow and soil water.