Call edition 2012
A new edition of the Prize of the Belgian Development Cooperation has been launched. This call is open until March 31st, 2011. You can read in the regulations whether you comply with the criteria for participation.
Land degradation in the Ethiopian Highlands is caused by erosive rainfall, steep slopes, deforestation and fallow agricultural land, which results in the formation of gullies and increased surface runoff, which in turn further erodes the fertile soil. The depressing end result is the impoverishment of the population due to lower crop yields. Lien Terryn’s thesis addresses the question of how to interrupt this vicious downward spiral.
For the last couple of years exclosure has been used as one measure against land degradation; this allows vegetation, biodiversity and infiltration capacity to recover and sediment that has been washed away to be stabilized. By means of field experiments and modelling Lien Terryn examined whether and how the infiltration and stabilization of sediment can be optimized by diverting gully water into an exclosure area. She quantified the difference in water availability in an exclosure area with and without the extra gulley water. It was shown that the greater availability of water during a longer season led to a higher biomass production and sediment stabilization as well as a rise in the groundwater supply. The latter phenomenon causes the groundwater level to rise and new springs to be created which can provide water for drinking or irrigation. She thus demonstrated that gulley water diversion stimulates sustainable development in the Ethiopian Highlands by the rebuilding of the fertile soil layer and the greater availability of groundwater. Exclosure areas can thus recover more quickly and become available again for agriculture and cattle breeding, and with this the downward spiral is interrupted. A very positive aspect is that these are small-scale measures taken at local level, which can be carried out by the local population with limited means and which produce visible results within a short space of time.
Report: Dr O. Batelaan, Department of Hydrology and Hydraulics, Vrije Universiteit Brussel, Belgium