Analysis of Areas Susceptible to Gullies in Ideato South Local Government Area of Nigeria Using Geographic Information System and Remote Sensing Technology

Abstract

Gully erosion is a critical environmental hazard in Southeastern Nigeria, threatening agricultural productivity, infrastructure, and communal safety. This study provides a spatially explicit assessment of gully erosion susceptibility in Ideato South Local Government Area (LGA), Imo State, using an integrated Geographic Information System (GIS) and Remote Sensing framework. The methodology employed a multi-criteria decision-making approach, utilizing the Analytical Hierarchy Process (AHP) to weight thirteen geo-environmental conditioning factors, including topography, hydrology, rainfall, soil properties, and Land Use/Land Cover (LULC). These factors were standardized and integrated through a weighted overlay technique to produce a Gully Erosion Susceptibility Map (GESM). The results demonstrate that LULC (19%) and soil properties (15%) are the most significant drivers of erosion in the region. Spatial analysis reveals a landscape highly predisposed to degradation: Approximately 57% (34.33 km²) of the LGA is classified as having "Slight" to "Very High" susceptibility. Notably, 12% (7.25 km²) and 0.17% (0.10 km²) of the land area are categorized as "High" and "Extremely" susceptible, respectively. These high-risk zones are primarily concentrated in areas characterized by steep slopes, high flow accumulation, and intense anthropogenic disturbance. The findings provide a robust evidence-based framework for environmental planners to implement targeted soil conservation measures and sustainable land-management policies in Ideato South.