GULLY EROSION SUSCEPTIBILITY MAPPING IN IKWUANO LOCAL GOVERNMENT AREA OF ABIA STATE USING GIS TECHNIQUES
This research work assessed the gully erosion susceptibility of Ikwuano Local Government Area of Abia State, Nigeria using the GIS-based multi-criteria evaluation approach. The objectives were to identify susceptible areas, examine and evaluate the causes as well as the impacts and recommend possi...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Zibeline International
2018-01-01
|
| Series: | Earth Science Malaysia |
| Subjects: | |
| Online Access: | https://earthsciencesmalaysia.com/archives/ESMY/1esmy2018/1esmy2018-08-15.pdf |
| Summary: | This research work assessed the gully erosion susceptibility of Ikwuano Local Government Area of Abia State,
Nigeria using the GIS-based multi-criteria evaluation approach. The objectives were to identify susceptible areas,
examine and evaluate the causes as well as the impacts and recommend possible control measures. The multicriteria evaluation approach of pairwise comparison by Analytical Hierarchy Process was used to calculate and
assign criteria weights to the 5 erosion factors. The pairwise comparison matrix was tested using Saaty Consistency
Ratio to ensure accuracy. The five erosion controlling factors were analyzed in the GIS environment and prioritized
as rainfall erosivity (R factor, 36%), soil erodibility (K factor, 30%), slope (LS factor, 19%), vegetative cover (C factor,
9%) and conservation practice (P factor, 6%) in order of importance. The susceptibility map was produced and
validated by ground truthing. Gully initiations are widespread in the study area. Dormant gullies at Umulu, Ihim and
Amuro are well-vegetated with bambusa vulgaris. The active gullies at Elemaga-Ibere and Amaegbu-Ariam are
within the moderate to high susceptible areas. The major anthropogenic causes of erosion in the study area include
sand mining, bad farming practices, lumbering, poor drainage system and abandoned road constructions. The
impacts included the destruction of roads and houses, isolation of communities, loss of farmlands and silting of
streams. Tree planting and regrassing, engineering and structural designs to channel runoff, proper road design,
improved farming practices and engaging in sensitization of all stakeholders targeted on early stage preventive
measures were recommended. The GIS-based multi-criteria evaluation approach has proved both useful and |
|---|---|
| ISSN: | 2521-5035 2521-5043 |