Geospatial Assessment Of Landslide Vulnerability Mapping Using Remote Sensing And Fuzzy-Ahp In Urban And Rural Regions Of Orumba North, Southeastern Nigeria

Landslides present a significant geohazard in Orumba North, southeastern Nigeria, with varying impacts on urban and rural regions. This study aims to assess and compare the vulnerability of both regions to landslides using a combination of remote sensing, (GIS), and the fuzzy analytical hierarchy process (Fuzzy AHP). The integration of these methodologies allows for a precise spatial delineation of landslide-prone zones based on the factors contributing to the differential susceptibility of urban and rural landscape. These conditioning factors include; slope, rainfall, elevation, curvature, land use and land cover, normalized difference vegetation index, and proximity to streams and roads, which were used for the assessment. Through fuzzy-AHP, these factors were assigned weighted importance based on expert judgement and environmental conditions, the defuzzification process converted the fuzzy weights into crisp value for precise evaluation these crisp values was used to rank the factors based on their relative importance. Using the defuzzified weights, a landslide vulnerable map was generated, classifying the study area into four susceptibility levels; low, moderate, high, very high. The result highlight that the urban areas such as Oko, Nanka, and Ajalli exhibit higher vulnerability to landslide due to intense human activities, including construction, deforestation, and poor drainage management that exacerbate slope instability. In contrast rural area like Ufuma and Omogho are largely affected by natural factors including steep slope, agricultural practices, leading to significant but less human induced susceptibility. Statistically, the affected urban area covers about 78% of the study area, while the rural area cover about 22%. This geospatial assessment offers valuable knowledge for local planner and decision markers, as the generated susceptibility map can serve as a guide for hazard mitigation strategies, By identifying high risk area, particularly those in urban centres with higher development pressure, targeted efforted can be made to improve land use planning, drainage system and slope stabilization. The study findings are crucial for formulating policies that address both human and natural factors contributing to landslides, ultimately aiding in disaster risk reduction in the urban and rural area of Orumba North region.