干旱区生态环境知识资源中心

Observations on the present demonstrations of the erosion and signs of desertification in the Meknassy basin (central Tunisia). -The Meknassy basin knows a proliferation, sometimes spectacular, of water erosion demonstrations. Often, dense gullies networks, reaching, in some cases, the stage of badlands, provoked the sterilization of extended surfaces. In the same way, wind erosion, affecting constantly ploughed and loosen lands by mechanical engines, caused the appearance of a real desertification in the major part of the basin. Belonging, in the origin, to the upper arid domain with steppe vegetation, the survey region is affected today by eolians shapes typical of desert environments. The analysis of the main land use parameters in the area revealed an excessive recourse to the dry framing mode in arboriculture, notably for olive trees. These practices are chiefly responsible for desertification phenomena. The deterioration of the natural vegetation under inappropriate land developments and the existence of a large livestock seem also to be behind of this environmental imbalance that knows the region.