Science et changements planétaires / Sécheresse


Proposals for development works in the wadi Fergoug micro watershed (Algeria) weakened by drought episodes and water erosion Volume 17, issue 3, Juillet-Août-Septembre 2006


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Institut agronomique méditerranéen de Montpellier (Iamm), 3191, route de Mende, 34093 Montpellier cedex 5 France

Located in Northwest Algeria, the wadi Fergoug micro watershed is an ecosystem weakened by drought episodes and strongly sensitive to water erosion, in particular linear. The consequences of this ecological phenomenon are disastrous: silting of the wadi Fergoug dam, loss of fertility of the soils. Localising the gullied zones and specifying the climatic and hydric characteristics of the study zone are prerequisites to the development of any sustainable erosion control strategy. This preliminary phase shows that the erosive phenomenon is the result of a combination of several factors: aggressiveness of the rains; erodibility of the soils; stiffness of the relief, weakness of the vegetal cover. The overlaying of a series of thematic maps has led to the design of a map localising the gullied zones in the micro watershed requiring restoration works, first and foremost. The antierosive operations suggested include technical measures (torrential corrections) as well as biological measures (reforestation, fruit plantations, and pasture improvements). Such erosion control measures should however be integrated into a program whose main objectives should be a better management of water and soil resources taking into account the expectations and needs of the rural population, the primary stakeholder involved in this weakened ecosystem.