MORPHOMETRIC PERSPECTIVE OF THE DELIMI CATCHMENT ON THE JOS PLATEAU, NIGERIA

Abstract

The Delimi River catchment, a headwater tributary of the Lake Chad Basin draining the crystalline basement of the Jos Plateau, is increasingly exposed to urbanisation and flood risk, yet remains ungauged. This study conducted a comprehensive morphometric assessment using 30 m SRTM DEM data and GIS remote sensing based Horton–Strahler analysis to compute 29 linear, areal, and relief parameters, supported by field validation. Results show that the 237.32 km² fourth-order basin exhibits a dendritic drainage pattern typical of basement terrains, with low drainage density (0.98 km/km²) and very coarse drainage texture (1.02), indicating permeable subsoils and infiltration dominance. Its highly elongated shape (elongation ratio = 0.37; form factor = 0.11) favours attenuated flood peaks, while moderate relief (0.52 km), ruggedness (0.51), and a hypsometric integral of 0.56 suggest a mature, moderately dissected landscape under structural control (mean bifurcation ratio = 6.06). Overall, the catchment’s morphometric configuration indicates natural buffering capacity against extreme floods; however, rapid urban expansion in Jos metropolis threatens to reduce infiltration and increase runoff. These baseline findings provide essential inputs for flood forecasting, stormwater planning, and sustainable watershed management in this data-sparse region.