Impact of Land Use Land Cover Changes on Soil Erosion in the Upper Guder River Catchment: Upper Blue Nile Basin of Central Ethiopia

Abstract

Evaluating the impacts of Land Use Land Cover/LULC changes on soil erosion is one of the challenges which strongly influence the process of agricultural development and food security situation in Ethiopia in general and in the upper Guder River catchment in particular. The main objective of this study was to evaluate the impact of LULC change on soil erosion in the upper Guder River Catchment of Blue Nile Basin in Ethiopia. Landsat imageries of the year 1986, 2002 and 2020 were used to map the LULC spatial distribution of the area during the study periods. ERDAS Imagine15, ArcGIS10.4.1 and RUSLE model were employed for analysis. Data on the proximate and underlying drivers of LULC changes were gathered through interview purposively. The results imply that in the previous 34 years between 1986 and 2020 the shrub land which covers 28.60% of the total area in1986 dropped down to 6.61% in 2020 at degraded rate of 949.8ha/yr. Forest land at the classification base year (1986) had a cover of 13.60 % left only 11.24%ha in 2020, while grass land was also dropped from 4.66% to 2.98%. In contrary, cultivation land and settlement area showed an increment from 51.89% and 0.23% to 78.40%ha and 0.59%ha in 2020 respectively. This study revealed that demographic factor (population growth), expansion of cultivated land, increase demand for firewood and construction, introduction of new development projects (roads) and absence of policy and institutional framework towards sustainable use of resources within the catchment were making the major drivers of LULC changes. The LULC changes had leaded to increase the mean annual soil erosion rate from 107.63t to 144.16t and 172.91t in 1986, in 2002 and in 2020 respectively. The LULC change and associated problem observed in the area had several environmental implications at local, regional, national and international levels, because the consequences of the degradation had no boundaries. Significant expansions of cultivated land at the expense of shrub land, forest and grasslands had occurred during the time serious of 1986 -2020. The change in soil erosion rate was a direct result of significant modifications and changes of cover in the catchment. Management interventions were necessary to improve the status and utilization of catchment resources by applying sustainable land management practices for sustainable livelihood of the local people.