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
Influence of Rainfall Characteristics, Land Use and Land Cover (LULC) On The Morphology of River Kontien in Benue State, Nigeria (Published)
This study evaluated the influence of rainfall characteristics, land use and land cover (LULC) on the morphology of River Kontien in Benue State, Nigeria. A descriptive survey and experimental research design were adopted to examine how basin processes shape channel form and behaviour. The study population comprised the entire River Kontien drainage basin, including its upper, middle and lower reaches, tributaries, slopes, soil units and hydrometric stations. Primary data were obtained through field measurements of channel dimensions, discharge, slope, soil and sediment properties using standard survey equipment, while secondary data were sourced from satellite imagery and meteorological records. Soil and sediment samples were analysed in the laboratory for physical and chemical properties, while geospatial techniques using ArcGIS 10.5 and Surfer software were applied to delineate the basin and derive morphometric parameters such as drainage density, stream order, bifurcation ratio, basin slope and relief ratio. Data were analysed using descriptive statistics, Pearson correlation, multiple regression and ANOVA with SPSS Version 31. The findings revealed that rainfall characteristics significantly influence channel morphology, particularly through variations in rainfall amount, intensity and erosivity. It was also found that land use and land cover changes, especially the expansion of agricultural land and reduction in vegetation cover, strongly affect channel width, depth and cross-sectional area. A strong relationship exists between rainfall variables, land use parameters and river morphological features, while rainfall erosivity and vegetation cover were identified as key predictors of cross-sectional area. Basin slope was found to exert an inverse influence on channel development, with steeper slopes associated with narrower channels and gentler slopes with wider, more sinuous channels. The study concluded that River Kontien morphology is shaped by the combined effects of rainfall variability, land use dynamics and basin physical characteristics. It was recommended that sustainable land use planning, afforestation programmes and integrated river basin management strategies be implemented to reduce erosion, stabilise channel morphology and ensure environmental sustainability.
Keywords: Benue state; fluvial geomorphology; watershed management, GIS analysis, basin processes, channel morphology, land use and land cover, rainfall erosivity, river kontien, river morphology