Development of Chute Cutoff in the Lower Course of River Mayo-Inne, Yola South, Nigeria
D. J. Ijafiya
Department of Geography and Environmental Management, University of Ilorin, Kwara State, Nigeria
E. Yonnana *
Department of Geography, Adamawa State University, Mubi, Nigeria
*Author to whom correspondence should be addressed.
Abstract
The study investigates the development of chute cutoff in the lower course of River Mayo-Inne, Yola South LGA, Adamawa State, Nigeria. The study employed the integrated approach of Remote Sensing, Geographic Information System, Field Survey, Laboratory Analysis, Oral Interview and Personal Observation in examining the influences of some relevant channel planform parameters (Sinuosity Index, Cutoff Ratio and Braiding Index), land use/land cover, channel bank materials, water stage and channel depth on the development of the chute cutoff over a period of Twenty five years (1990-2015). Results revealed the drastic reduction of Sinuosity Index from 1.57 in 1990 to 1.46 in 2015, changing the channel from meandering to the straight pattern. The analysis of changes in cut-off ratio unveiled the development of chute cutoff in bend II, which ultimately separated the river flow, forming a weak braided channel with a braiding index of 0.43. These developments were attributed to incessant flooding in the study area and floodplain characteristics such as floodplain elevation, bank strength and changes in vegetal cover.
Keywords: Floodplain, chute cutoff, sinuosity index, braiding index, flooding, land use/land cover