The Spatio- Temporal dynamics of Land Use Land Cover Change and its
Impact on Soil Erosion in Tagaw Watershed, Blue Nile, Ethiopia
Abstract
Blue Nile basin is one of the hotspots of soil erosion areas in
Ethiopia. However, there impact of land use changes on soil erosion is
poorly understood in the Tagaw areas. Hence, the objective of the study
was to assess the impact of land use land cover changes on soil erosion
over the last 31 years. Rainfall, soil, satellite images and topographic
data were acquired from field survey and secondary sources. Land use
change analysis was conducted using supervised classification based on
four different satellite images. In addition, Revised Universal Soil
Loss model was used to estimate soil erosion. The study shows the
watershed was predominantly covered by farm land (22%), bare land
(17.8%), built up (22%), grassland (9.7%), marshland (8.8%), shrub
land (12.4%) and forest (6.7%) in 2016. Moreover, the mean annual soil
losses of the watershed were 19.3, 22.93 and 26 tons/ha/yr for the 1995,
2006 and 2016 respectively. The total soil losses varied from
0.06-503.56, 0.11-516.67, and0.00-543.5 tons/ha/yr. for the year 1995,
2006 and 2016 respectively. The highest soil loss was found for bare
land. The RUSLE model further showed that the highest soil erosion
occurred in 2016 whereas the lowest soil erosion was occurred in 1995.
Most of the land use changes (36%) occurred on farmland (36.1%), shrub
land (-52.4%), built up (50.9%), and bare land areas (31.6%) due to
rapid population growth and inappropriate farming practices. To
conclude, there is a significant impact of land use land cover change on
soil erosion in Tagaw watershed.