Influence of Basin Morphometric Characteristics On the Morphology and Downstream Geomorphic Evolution of River Kontien in Benue State, Nigeria (Published)
This study examined the influence of basin morphometric characteristics on the morphology and downstream geomorphic evolution of River Kontien in Benue State, Nigeria. It was guided by four objectives focusing on spatial variation in morphometric parameters, relationships between morphometry and channel characteristics, identification of key morphometric predictors of channel form, and development of a predictive explanation of downstream geomorphic change. A mixed-methods approach was adopted, combining field survey, laboratory analysis, Remote Sensing, and GIS within a descriptive and observational design. Data were collected using GPS, measuring instruments, sediment sampling tools, satellite imagery, topographic maps, and rainfall records, and analyzed using descriptive statistics, correlation, multiple regression, ANOVA, and GIS spatial overlay techniques. Findings revealed systematic downstream changes in basin characteristics, with increases in basin area, drainage density, stream order, and stream frequency, and decreases in basin slope, relief ratio, and overland flow length, indicating a transition from youthful erosional upstream conditions to mature depositional downstream environments. Basin shape also evolved from elongated to more circular forms downstream. Strong significant correlations (r = 0.989–0.998) showed that morphometric variables are highly interrelated, while strong negative relationships existed between basin morphometry and channel form (e.g., drainage density vs channel width r = -0.984). Regression results indicated that 97.1% of channel cross-sectional variation is explained by morphometric factors (R² = 0.971), with relief ratio as the most significant predictor (β = -1.638). The study concluded that basin morphometry strongly controls river channel form and downstream geomorphic evolution in River Kontien. It recommended integrated watershed management and intensified soil conservation measures in upstream areas to reduce erosion and stabilize channel development.
Keywords: GIS analysis, basin morphometry, channel morphology, drainage density, geomorphic evolution, relief ratio, river kontien, river morphology, watershed characteristics