Forensic investigation of the Gouache landslide disaster, Western Region, Cameroon

Abstract

This study made use of a disaster forensic approach to investigate the root causes of the landslide disaster which occurred in Gouache, West Region, Cameroon on 29th of October, 2019 that registered 49 to 60 deaths. The aims of the study were to;1) identify the natural and man-made causes of the landslide; 2) determine household vulnerability factors; and 3) identify the administrative weaknesses that led to the disaster. To achieve this, geological data was collected from field observations; rainfall data for a period of 30 years (1988 to 2018) with additional monthly data (January to December) for 2019 was obtained from the National observatory on Climate change (ONACC), Yaounde; satellite imagery from Landsat ETM+ and 8 (2001 and 2020) and SRTM DEM were used to assess land use/ landcover changes and slope respectively; questionnaire administration, household and key informant interviews were used as primary data collection tools. Findings revealed that the root causes were: heavy rainfall that occurred prior to and during this event; the presence of weathered granitic rocks on steep slopes, and springs that increased landslide susceptibility. Susceptibility to landslides was fostered by human activities such as: significant reduction of the savannah vegetation and cutting of the slope for house construction. Household vulnerability factors were lack of awareness of landslide hazards and large household sizes (4-6 persons). Over 70 % of the landowners constructed without a building permit and had no land certificate. The administrative authorities acknowledged that Gouache was officially recognized as a landslide susceptible zone. The findings generated in this study would be useful for the government to strengthen or re-adjust existing policies or strategies of disaster risk reduction in the area.