Abstract

Gully erosion contributes to land degradation and destruction of physical infrastructures and properties as well as retarding the socio-economic growth and development of the inhabitants of a community. This research investigated the geo-environmental factors influencing the occurrence of gully erosion in Uyo, Akwa Ibom State, Nigeria. Ten gully sites in the study area were purposively selected with training datasets of 80% and validation dataset of 20% were used in the study. Nine gully-related geo-environmental factors namely slope, aspect, curvature, rainfall, distance from stream, topographic wetness index, lithology, distance from road and NDVI were identified from literature and examined. The Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) 2022 with a spatial resolution of 30m and Advanced Spaceborne Thermal Emission and Reflection (ASTER) Digital Elevation Model (DEM) 2004-2022 with a spatial resolution of 30m were used to extract the topographic features. Data were analysed using ARCGIS 10.7 with Frequency Ratio (FR) as the main statistical tool. The results indicated that all the geo-environmental factors examined in the study were positively associated with gully erosion, with rainfall (FR= 3.26), distance from road (FR = 2.71), NDVI (FR= 2.59) and distance from stream (FR = 2.34) being the most significant geo-environmental factors influencing gully occurrence. It was concluded that a wide range of geo-environmental factors contributed to gully expansion at different susceptible rates. Proper land management practices is recommended. It is also recommended that government should regulate land use and urban development in its effort to control gully formation.