Morphometric analysis of a drainage basin using ALOS PALSAR DEM and GIS in Ogbese watershed, Ayede-Ogbese, Ondo State, Nigeria

This study focuses on the morphometric analysis of the River Ogbese basin, utilizing advanced geospatial techniques for the first time on drainage basins in the area. The ArcGIS (Geographical Information System) 10.7 software was used to analyse the linear, areal, and relief morphometric aspects of the Ogbese watershed, in addition to data from the Advanced Land Observing Satellite Phased Array type and L-band Synthetic Aperture Radar Digital Elevation Map (ALOS-PALSAR DEM), acquired from the Alaska satellite. Quantitative analytical techniques were used to evaluate multiple morphometric parameters, such as stream order, stream length, bifurcation ratio, drainage density, stream frequency, elongation ratio, circularity ratio, form factor ratio, relief ratio, and basin height.

The results showed the River Ogbese to be a fifth order drainage basin with a total of 1,179 drainage networks. Of these, 598 are first-order streams, 297 are second-order, 143 are third-order, 106 are fourth-order, and 35 are fifth-order streams. The average drainage density of the basin is 4.25 km/km². The results also reveal that the micro watershed exhibits sub-dendritic and dendritic patterns. Furthermore, the micro-watershed has a homogeneous texture and lacks structural control over surface flow. The mean bifurcation ratio of the basin is found to be 2.12. The study lastly evaluated and interpreted the principal characteristics of the watershed as outlined above in order to provide an environmental assessment. Together, these results and the environmental analysis can guide effective and sustainable water resource management in the Ogbese river basin.