International Symposium on
Drylands Ecology and Human Security
Hydrologic Impacts of Contour Ridges in Tunisian Semi-arid Regions
Nasri Slah1, Baccari Noamene2, Jean Marie Lamachère3, Mohamed Rached Boussema2
1 Institut National de Recherche en Génie Rural, Eaux et Forêts (INRGREF), Tunisia
During the three last decades, about one million hectares of hill slopes field lands were arranged by earth contour ridges (or earth benches) in Tunisian semi-arid regions. These water harvesting techniques allow to reduce soil water runoff erosion and support the infiltration of surface waters on the space between two successive contour ridges. Authors of this work studied the hydrologic impact and the efficiency of these techniques on an elementary scale and on catchment scale, and also their impact on the reduction of water runoff and silting up towards a hill reservoir existing downstream these contour ridges.
Keywords: water runoff, contour ridges, effectiveness, hill reservoir, erosion, semi-arid, Tunisia