ABSTRACT
The unattended and devastating effects of the Ibore gully erosion development has unarguably led to damage of properties and untold hardship to the inhabitants of the Ibore community and its environs. The aim of this project is to identify the mechanics and factors responsible for the gully erosion at Ibore, Esan Central Local Government Area, of Edo State, with a view to prescribing appropriate measures and control against subsequent expansion, loss and destruction of lives and properties.
The research was carried out by first conducting a detailed topographical survey using the Total Station Instrument. Bench marker were transferred to the site from a nearby established station. The gully cross sections were taken at intervals, while the bed profile level was also taken. This gave input for creating the cross-sectional and gully bed profile drawings and study the extent of gully formation. Geotechnical investigation was undertaken to study the engineering characterization of the gully soils and its environs. Soil samples were retrieved using hand auger at various locations with coordinate and carried to the laboratory for analysis. Some test analysis includes, sieve analysis, particle distribution test, Atterberg limit test, compaction test, share box test. The final step was to carry out slope stabilization. Slope stabilization was carried out for various cross sections along the longitudinal axis of the gully. The wall slopes and corresponding soil properties were extrapolated for the corresponding cross section and the slope stability were computed for both wet and dry conditions.
From the study, it was deduced that the gully at Ibore community was caused from poor termination of drain section which is backed up by other environmental factors such as the topography of the area, rainfall intensity, the contributing flow catchment. The volume of soil loss from the site was computed as 538181m3. All slopes were computed to be stable ranging from 1.553 to 1.892 for the left gully slope and 1.576 to 1.857 for the right gully slope.
