GIS-based landslide susceptibility assessment in Eyinoke Hilly Area of Okeigbo, SW, Nigeria

Many areas are exposed to different types of natural hazards including landslides, which can lead to loss of lives, injury to people, damage to property and disruption of economic activities. This paper assessed the landslide susceptibility and quantifies the hazard and risk related to landslides in Okeigbo, southwest, Nigeria using remote sensing imageries, geographic information system (GIS) and logistic regression model. The result revealed that slope, elevation, aspect, profile curvature, distance from road and land use influence landslide susceptibility. Current landslide and the most susceptible areas to landslides were within the areas with high slopes especially at slope angles of landslide occurred on slopes between 14 % and 25 % in the upper, steep and narrow ridge with elevation of between 413 m and 459 m. The landslide occurred northwest aspect class where there is increased land use activities characterized by deforestation and improper agricultural practices. It was further revealed that the landslide occurred about 200 m close to the road and potential areas were landslides can occur in the future are closely located within the 100-300 m buffer zones. Generally, Slopes have more influence than land cover for the susceptibility map. Although a smaller portion of the study area is presently located in the high hazard zone, intensive land use activities on the steep slope could expose the land to other triggering factors such as rainfall. A landslide susceptibility assessment and monitoring will assist in prediction, management future occurrences and general developmental planning in the area.

Keywords
Landslide hazard; Vulnerability; Geographical information system; remotely sensed data