An Assessment and Mapping of Gully Erosion Hazards in Abia State: A GIS Approach

Abstract

The issue of gully erosion is of major concern in the south-eastern part of Nigeria. This study adopts Geographic Information Systems (GIS) as a tool to identify and study gully erosion hazards in Abia state. 171 gully erosion sites were coordinated using GPS receivers and overlaid on the soil and geological maps of the study area. Spatial database for erosion sites was created using relational database model. Additional 35 gully erosion sites were identified from the processed digital elevation model (DEM) and ground verification carried out. Result shows that gUlly erosion sites were well dispersed around false bedded sand stone geological formation. The slope characteristic was ascertained to be greater than l5°which encourages gully erosion activities. An erosion hazard map was produced showing risk and vulnerability of settlements and infrastructure. This study shows that GIS is an efficient and effective tool in the study and mapping of gully erosions. [ABSTRACT FROM AUTHOR]