Implication of long-term watershed development on land use/land cover change and sediment loss in Maybar Sub-Watershed, South Wello Zone, Ethiopia
Tilahun Taye, Awdenegest Moges
Abstract
Long-term-watershed management in Ethiopia has been assessed in different locations since the 1980s, but there are no adequate studies of its effect on the aspects of natural resources. A boundary map of geographical coordination and Google Earth imagery was created from the ground base survey. This study was conducted to investigate the implications of long-term watershed management on the land use/land cover change and trend of runoff-sediment loss. Data for this study were obtained from- Time-series satellite Landsat images of the years 1986, 1997, 2008, and 2019, and runoff, and sediment load and discharge data from the Maybar watershed station dataset. Analyses of these data show, from 1986 to 2019, forest and settlement land area coverage had been increased from 20.9% to 39.2% and from 9.2% to 22.6%, respectively. In contrast, cultivation land, open woodland, and grassland coverage was reduced from 26.7% to 18.4%, from 32.7% to18.9%, and from 10.6% to 1.1%, respectively. The discharge–runoff and runoff–sediment load processes were affected by the watershed development activity which the trend of annual sediment loss and runoff generation slightly reduced through time. Therefore, the long-term growth of watersheds has a beneficial effect on changes in on-site natural resources, such as improving vegetation coverage and reducing the generation of runoff.