Maejo International Journal of Science and Technology (Sep 2011)
Impact assessment of soil and water conservation measures at Medego watershed in Tigray, northern Ethiopia
Abstract
The aim of this study is to assess the impact of various physical and biological soil and water conservation (SWC) measures implemented during the past 2_3 decades in combating land degradation caused by soil erosion in the Medego watershed, northern Ethiopia. Such evaluation is essential to understanding the success or failure of previous conservation measures and readjusting accordingly in the future planning. Data collected through semi-structured interviews, transect walks, field observation and field measurements demonstrated that terraces and check dams were filled with soil up to 1.5 m deep, gullies started to stabilise, irrigation and other water supplies increased many folds, the seedling survival rate rose to over 45%, and the vegetation composition and coverage density improved by more than 30%. Water levels increased in hand-dug wells by up to 2 m, and in a number of springs and shallow wells by more than 100 times as a result of the positive impact of SWC measures implemented in this watershed. Existing SWC measures should be improved for continued maintenance and also expanded further to restore critically degraded areas to their full potential through integrated intervention.