THE SILTING UP OF VEGETABLE CROP AREA IN GANDIOLAIS (NORTHERN COAST OF SENEGAL)

The Gandiolais is part of the large "Nia yes" ecosystem in the Saint Louis region. It is bordered by active dunes from the recent Quaternary delimiting interdune depressions in which the sub-surface water table has favored the practice of vegetable crops. These vegetable cropping areas are production systems that are now facing silting up. Our results show that this silting is due to deflation and/or mass movement of dune soils. These two phenomena are generated by the sensitivity of dune soils to deflation by trade winds and drought. The resulting negative consequences include, among others, the abandonment of vegetable cropping activities by farmers. Solutions to reduce trade wind speeds and improve the cohesion and structuring of dune soils are proposed. In particular, we recommend the creation of windbreaks and the reconstitution of sufficient plant cover.