地理情報学と地球統計学: 概要

Mapping Potential Soil Erosion Risk Areas in Abia State, Nigeria Using Geographic Information System (GIS) and Remote Sensing (RS)

Okoro BC and Uche OO

Mapping Potential Soil Erosion Risk Areas in Abia State, Nigeria Using Geographic Information System (GIS) and Remote Sensing (RS)

The study used Geographic Information System (GIS) to integrate data from Remote Sensing (RS) to map out areas that are prone to erosion in Abia State, Nigeria. This was done using the index model and weighted overlay of ArcGIS software. The result showed that about 0.18% (2.325 ha) of the study area, covering the northern part (Abriba and Nkporo areas) and Ikwuano areas is under very high potential erosion risk, while 0.92% (11.475 ha) is under high erosion risk. The high erosion risk areas in the north are all located on the top of the escarpment running from Isuochi, through Isuikwuato, Ohafia and down to Arochukwu.Also 20.98% (262.54 ha) of the study area, covering the following Local Government Areas - Umuahia South, IsialaNgwa North, IsialaNgwa South, Osisioma, Obingwa, Aba North and Aba South is under moderately high erosion risk, while 34.51% (431.82 ha) is under moderate erosion risk and 43.49% (543 ha) covering the Ukwa/ Ngwa area, whose topography is gentle to no slope falls under low potential erosion risk. The study showed that using RS and GIS technologies for erosion risk/hazard mapping, based on the methodology used, resulted in effective and accurate assessment of soil erosion in considerable short time and at a low cost for large study areas or watersheds. It is recommended that Government Agencies and private should explore the advantages offered by RS and GIS in delineating erosion prone areas for planning and design of structures.