Geohazards (floods and landslides) in the Ndop Plain, Cameroon Volcanic Line

International audienceThe Ndop Plain, located along the Cameroon Volcanic Line (CVL), is a volcano-tectonic plain, formed by a series of tectonic movements, volcanic eruptions and sedimentation phases. Floods (annually) and landslides (occasionally) occur with devastating environmental effects. However, this plain attracts a lot of inhabitants owing to its fertile alluvial soils. With demographic explosion in the plain, the inhabitants (143,000 people) tend to farm and inhabit new zones which are prone to these geohazards. In this paper, we use field observations, laboratory analyses, satellite imagery and complementary methods using appropriate software to establish hazard (flood and landslide) maps of the Ndop Plain. Natural factors as well as anthropogenic factors are considered. The hazard maps revealed that 25% of the area is exposed to flood hazard (13% exposed to high flood hazard, 12% to moderate) and 5% of the area is exposed to landslide hazard (2% exposed to high landslide hazard, 3% to moderate). Some mitigation measures for floods (building of artificial levees, raising foundations of buildings and the meticulous regulation of the flood guards at Bamendjing Dam) and landslides (slope terracing, planting of trees, and building retaining walls) are proposed