Estimating Landscape Vulnerability to Soil Erosion by RUSLE Model Using GIS and Remote Sensing: A Case of Zariema watershed, Northern Ethiopia
Background:Zariema watershed located in the Tekeze basin Northern highlands of Ethiopia has been a subject to serious problem of soil erosion. Soil degradation due to soil erosion is one of the key environmental and socioeconomic case which threats soil nutrient depletion and food security in northern Ethiopian highlands. This study was conducted to estimate the soil loss rate and identify hotspot areas using RUSLE model in the Zariema watershed, Tekeze basin, Ethiopia.Methods:The rainfall –
... off erosivity(R) factor was determined from mean annual rainfall, soil erodibility(K) factor from soil map, Topographic factor (Ls) were generated from DEM, Crop management factor (C) and Conservation support practice factor(P) obtained from land use/land cover map. Finally, the factors were integrated with Arc GIS 10.3 tools to estimate soil loss rates and landscape vulnerability to soil erosion of the study watershed. Results:Annual Soil losses rates were estimated to be between 0 ton ha-1 year-1 in plain areas and 989 ton ha-1 year-1 in steep slope areas of the study watershed. The total annual soil loss from the entire watershed area of 2239.33Sq. Km was about 3,603,895.23 tons. About 31.41% of the study areas were affected through the soil loss hazard which is above acceptable soil loss rate 11 ton ha-1 year-1. The spatial hazard classification rate was 68.59% of the watershed area categorized as slight (0 – 11 ton ha-1 year-1), 8.03% moderate (12 – 18 ton ha-1 year-1), 7.64% high (19 – 30 ton ha-1 year-1), 6.65% very high (31 – 50 ton ha-1 year-1) and 9.09% severe (>51 ton ha-1 year-1). Conclusion:As a result, In the cultivation land around steep slope the soil loss rate was in sever condition. To mitigate the severity of the soil erosion in the identified prone area which accounts for about 31.41% of the total watershed area immediate action of soil and water conservation required.