Morphometric analysis and its implication on flood and erosion management in Lower Kwa Iboe River, South Eastern Nigeria

Abstract

The study focused on morphometric analysis and its implication on flood and erosion management in Lower Kwa Iboe River, South Eastern Nigeria. The following objectives were taken into consideration: to map and characterize the Lower (downstream) Kwa Iboe River using Geographic Information System (GIS) and Remote Sensing technology, to examine the morphometric indicators in Lower Kwa Iboe River and its implications on flood and erosion control. Morphometric analysis was carried out at different sub-catchments in lower Kwa Iboe River. The lower Kwa Iboe River has four matured sub-catchments. These include: Anyang sub-catchment, Akpibe sub-catchment, Idim Ibedu/Ikot Ubo sub-catchment, as well as Idim Ntete sub-catchment. The result indicates that the calculated mean bifurcation ratio for the study area is 3.74, an indication that the study area is a lowland area. The length of overland flow of the lower Kwa Iboe basin is 1.25km, the drainage texture of the lower Kwa Iboe basin ranges from 0.77-1.23. This shows that the basin has a very coarse texture which is susceptible to flood disaster. The study area has an average elongation ratio of 0.19, circularity ratio (0.54) and form factor (0.42) which indicates that the shape of the basin tends towards elongation. The result of the study implies that the basin is neither dissected nor prone to erosion but rather flood disaster which depends on a number of natural factors such as climate, rainfall, vegetation, rock and soil types. In conclusion, the watershed is only vulnerable to flood disaster especially the downstream.