Background Soil erosion in Ethiopian highlands is highly consistent with land use/land cover(LULC)changes that are associated with deforestation and a decline in biodiversity.However,identifying soil erosion-prone are...Background Soil erosion in Ethiopian highlands is highly consistent with land use/land cover(LULC)changes that are associated with deforestation and a decline in biodiversity.However,identifying soil erosion-prone areas and quantifying soil loss in rugged terrains and various agroecologies due to LULC changes have not been dedicated to scientific studies.Therefore,we quantified the impacts of spatiotemporal LULC changes on soil loss across agroecologies and slope categories using GIS and RUSLE model from 1985 to 2021 in Zoa watershed,southwest Ethiopia.Moreover,prioritizing erosion severity risks at sub-watersheds and quantifying temporal sediment yield is essential for better conservation planning.Landsat images,rainfall,Digital Elevation Model,and soil data were obtained from field observations and secondary sources.Results Bareland and farmland have been expanding at the expense of other land use types.The annual soil loss in the watershed ranged from 0 to 113.21 t ha^(-1) year^(-1),0 to 163.16 t ha^(-1) year^(-1),and 0 to 194.58 t ha^(-1) year^(-1)with a mean annual soil loss of 21.07,29.35 and 40.93 t ha^(-1) year^(-1) in 1985,2000,and 2021,respectively.Among LULC classes,the highest soil loss was generated from bareland(31.73 t ha^(-1) year^(-1))and farmland(27.08 t ha^(-1) year^(-1))in 1985 later upsurged to 35.52 t ha^(-1) year^(-1)and 59.91 t ha^(-1) year^(-1) in 2021,respectively,due to the maximum susceptibility of soil erosion risks from unprotected surfaces.The results also revealed that the lowland agroecology generated the highest mean soil loss of 24.05 t ha^(-1) year^(-1)in 1985,39.74 t ha^(-1) year^(-1) in 2000,and increased to 57.55 t ha^(-1) year^(-1)in 2021.Considering the slope categories,the highest and most excruciating soil loss was engendered from steep(35.55–60.78 t ha–1 year–1)and very steep(52.48–72.69 t ha^(-1) year^(-1))slope terrains during 1985–2021.The northwestern part of the watershed is the most erosion-prone area which is now expanding to the central and western parts of the watershed.The sediment yield increased at the fastest rate at the watershed outlet,from 39.3%in 1985 to 94.26%in 2021.Conclusions The results of this study indicated that the conversion of other LULC categories into farmland was the most detrimental to a watershed in terms of soil loss,which necessitates the implementation of appropriate soil and water conservation measures with effective design by considering spatial variability to reduce soil erosion hazards.展开更多
Albania results are a country with high quantitative level of soil erosion in Europe and elsewhere based on different studies. The amount of soil eroded from the surface water erosion is from 20-40 t/ha/year and in ex...Albania results are a country with high quantitative level of soil erosion in Europe and elsewhere based on different studies. The amount of soil eroded from the surface water erosion is from 20-40 t/ha/year and in extreme cases results up to 100 t/ha/year from the deepest erosion. This preliminary study will identify the more specific places in order to do more details analyses in the future to take protection measures in highly sensitive places with high erosion risk. This will be a quantitative assessment of places with different level of erosion risks. Further on these results will be generalized at the level of main water basins of Albania. The following main elements of soil erosion assessment are evaluated in this study which include the land cover, slope and density of the hydrologic net.展开更多
Land erosion is an increasing problem that is seriously affecting our country in recent years. In many areas of our country, mountainous and hilly territories suffer major erosion in both surface and depth, where the ...Land erosion is an increasing problem that is seriously affecting our country in recent years. In many areas of our country, mountainous and hilly territories suffer major erosion in both surface and depth, where the solids are deposited in the flat parts of the country, thus leading to a higher content of gravel in agricultural land and filling of the sewage networks. The phenomenon of erosion is greater in the vicinity of residential areas where damages are larger and more sensitive. One of the most vulnerable in our country in terms of soil erosion is the district of Tirana. This study had the main goal to define and categorise of erosion rates in natural environments of the forest economies of the Tirana, the rate of recovery of vegetation, slope and rainfall index, which will serve as information and guidance on the land use by farmers, communes and the state regulatory officials, depending on the ownership of these woodland surfaces.展开更多
文摘Background Soil erosion in Ethiopian highlands is highly consistent with land use/land cover(LULC)changes that are associated with deforestation and a decline in biodiversity.However,identifying soil erosion-prone areas and quantifying soil loss in rugged terrains and various agroecologies due to LULC changes have not been dedicated to scientific studies.Therefore,we quantified the impacts of spatiotemporal LULC changes on soil loss across agroecologies and slope categories using GIS and RUSLE model from 1985 to 2021 in Zoa watershed,southwest Ethiopia.Moreover,prioritizing erosion severity risks at sub-watersheds and quantifying temporal sediment yield is essential for better conservation planning.Landsat images,rainfall,Digital Elevation Model,and soil data were obtained from field observations and secondary sources.Results Bareland and farmland have been expanding at the expense of other land use types.The annual soil loss in the watershed ranged from 0 to 113.21 t ha^(-1) year^(-1),0 to 163.16 t ha^(-1) year^(-1),and 0 to 194.58 t ha^(-1) year^(-1)with a mean annual soil loss of 21.07,29.35 and 40.93 t ha^(-1) year^(-1) in 1985,2000,and 2021,respectively.Among LULC classes,the highest soil loss was generated from bareland(31.73 t ha^(-1) year^(-1))and farmland(27.08 t ha^(-1) year^(-1))in 1985 later upsurged to 35.52 t ha^(-1) year^(-1)and 59.91 t ha^(-1) year^(-1) in 2021,respectively,due to the maximum susceptibility of soil erosion risks from unprotected surfaces.The results also revealed that the lowland agroecology generated the highest mean soil loss of 24.05 t ha^(-1) year^(-1)in 1985,39.74 t ha^(-1) year^(-1) in 2000,and increased to 57.55 t ha^(-1) year^(-1)in 2021.Considering the slope categories,the highest and most excruciating soil loss was engendered from steep(35.55–60.78 t ha–1 year–1)and very steep(52.48–72.69 t ha^(-1) year^(-1))slope terrains during 1985–2021.The northwestern part of the watershed is the most erosion-prone area which is now expanding to the central and western parts of the watershed.The sediment yield increased at the fastest rate at the watershed outlet,from 39.3%in 1985 to 94.26%in 2021.Conclusions The results of this study indicated that the conversion of other LULC categories into farmland was the most detrimental to a watershed in terms of soil loss,which necessitates the implementation of appropriate soil and water conservation measures with effective design by considering spatial variability to reduce soil erosion hazards.
文摘Albania results are a country with high quantitative level of soil erosion in Europe and elsewhere based on different studies. The amount of soil eroded from the surface water erosion is from 20-40 t/ha/year and in extreme cases results up to 100 t/ha/year from the deepest erosion. This preliminary study will identify the more specific places in order to do more details analyses in the future to take protection measures in highly sensitive places with high erosion risk. This will be a quantitative assessment of places with different level of erosion risks. Further on these results will be generalized at the level of main water basins of Albania. The following main elements of soil erosion assessment are evaluated in this study which include the land cover, slope and density of the hydrologic net.
文摘Land erosion is an increasing problem that is seriously affecting our country in recent years. In many areas of our country, mountainous and hilly territories suffer major erosion in both surface and depth, where the solids are deposited in the flat parts of the country, thus leading to a higher content of gravel in agricultural land and filling of the sewage networks. The phenomenon of erosion is greater in the vicinity of residential areas where damages are larger and more sensitive. One of the most vulnerable in our country in terms of soil erosion is the district of Tirana. This study had the main goal to define and categorise of erosion rates in natural environments of the forest economies of the Tirana, the rate of recovery of vegetation, slope and rainfall index, which will serve as information and guidance on the land use by farmers, communes and the state regulatory officials, depending on the ownership of these woodland surfaces.
