Vulnerability to Land Slides in Bafoussam I Council (West Region-Cameroun): Multi-Factor, Cartographic and Geographic Information System Analytical Approach

Populations and their property are becoming increasingly vulnerable to landslide hazards. High demographic and land use pressure in tropical countries increase the chances of natural hazards such as landslides. With increasing vulnerability to landslides, populations and their property are exposed to hazards. The population of Bafoussam I doubled within a period of 15 years increasing household numbers and anthropogenic activities. These rapid increases coupled with anarchical land occupation even in risk zones aggravate vulnerability to landslides in Bafoussam I Council area. This study seeks to assess the level of vulnerability of Bafoussam I to landslides using multi-factor analysis from GIS processed data, oral histories and field observation. Response scores of 80-100% indicate that the level of susceptibility of sites exposed to landslides in Bafoussam I is in relation to predisposing factors such as texture, structure and geology that increase soil water retention capacity, accentuated relief, and population pressure, land use (farming, houses/roads construction), climate (heavy rainfall) and hydrology. By modeling these predisposing factors, we were able to generate a map with five levels of landslide susceptibility (very low, low, moderate, high and very high) to which the population is vulnerable. In addition, a criticality grid enabled us distinguished three categories of landslide risk zones, to wit: high vulnerability, moderate vulnerability and low vulnerability in Bafoussam I. Based on a critical assessment of these three categories of landslide risk zones, the paper suggests management strategies for a reduction of population's vulnerability to landslide risk in Bafoussam I.