Homes, which will soon be totally covered by shifting sand. - - Sand Dune Fixation. Mauritania, one of the countries most vulnerable to sand silting and dune movement, is ecologically predisposed to Aeolian erosion. Long drought periods have undermined the rural society (traditionally nomadic), which is now condemned to a sedentary life in urban shantytowns or at water-supply points. Immediate results are decreasing agricultural production and breakdown of supply lines to the interior. FAO consultants carried out technical studies on the process of silting up. The Government (assisted by UNDP with FAO as executing agency) has now launched a 7-year project, which, initially, will train technicians, nursery gardeners and forest guards and alert populations to the problems and the need for dune anchorage. Techniques being introduced include anchorage by vegetation (a nursery has been set up where seedlings of autochthones plants are grown), building embankments for wattle palisades and making hurdles from palm-tree leaves.