Impact Of Land Use Change On Reservoir Sedimentation (case Study Of Karadobi)

The Blue Nile Basin is one of the most affected areas by soil erosion, sediment transport andrnland degradation. The land and water resources of the basin and the ecosystem are in danger duernto the rapid growth of population, deforestation, overgrazing, soil erosion, sediment deposition,rnstorage capacity reduction, drainage and water logging, flooding, pollutant transport, populationrnpressure and over-exploitation of specific fish species.rnThe lack of decision support tools and limitation of data concerning weather, hydrological,rntopographic, soil and land use; are factors that significantly hinder research and development inrnthe area. There is a need for hydrological and sediment transport research of the Blue Nile Basinrnthat can improve catchment’s management programs. Appropriate decision support tools arernneeded for better assessment of the hydrology and soil erosion processes for planning andrnimplementations of soil and water conservation measures. The tools concern variousrnhydrological and soil erosion models as well as geographical information system (GIS).rnThe modelling tools will finally help to save the physical quality of the land. In this paper therninfluence of land use changes on catchment’s hydrology is observed particularly on sedimentrnyield. To carry out this SWAT MODEL was used for simulation. The delineated watershed wasrndivides into 75 sub basins and 293 HRUs by the model. Model calibration and validation wasrndone at Kessie. In addition to this the model efficiency was checked at this station. Based on thisrnvalues for coefficient of determination (r²) and Nash–Sutcliffe model efficiency (ENS) werernfound to be in the acceptable range i.e. (0.80 to 0.95 for r² and 0.70 to 0.92 for ENS ).The annualrnsediment load at Karadobi is found to be 855 ton per square kilometre. And in 50 years 7.84% ofrnthe active storage will be depleted due to sediment accumulation. Four scenarios are developedrnto observe the impact of land use changes. Based on this a 10 and 20% of change in agropastoralrnland to agricultural land has resulted in 12% and 61% increase in sediment load. Butrn60% and 90% change of pasture and forest lands have resulted in a sediment increment by lessrnthan 0.5%.

Get Full Work

Report copyright infringement or plagiarism