Hydrological response patterns of some third order streams on the Basement Complex of southwestern Nigeria

Abstract

The hydrological response patterns of some third order rivers in southwestern Nigeria are described in terms of regime, discharge variability and recession of flow from peak discharge in the rainy season to the lowest discharge in the dry season. The maximum and minimum discharges of the rivers coincide with the rainy and dry seasons respectively. Most of the rivers exhibit erratic flow with quick responses to storms and storm water abating quickly, while some have a very low groundwater contribution to streamflow, a phenomenon which accounted for their drying up for considerable periods in the year. The variability indices of discharge of the rivers range from 0.25 to 2.12 while the recession constants range from 0.64 to 0.98. The variability indices are much higher than those of basins of similar size reported from other studies. Three types of rivers are recognizable on the basis of their hydrological response patterns. It is observed that the nature of the surficial and solid geology has a greater influence on discharge characteristics than other factors such as depth of regolith and rainfall.

Hydro-period dynamics of some inland valley agroecosystems in southwest Nigeria

“…This finding is in line with a similar study by Berhanu, Seleshi, Demisse, and Melesse (2015) in Ethiopian rivers, and Reynolds et al (2015) in upper Colorado River basin, USA. The results are also in agreement with those obtained by Ogunkoya (1989), Adejuwon, Jeje, and Ogunkoya (1983), and Ogban and Babalola (2009) in their respective studies in parts of southwest Nigeria. For example, Ogunkoya (1989) observed that due to the peculiar geology of the southwest Nigeria, third-order rivers draining high-gradient areas (such as Am and VS valleys) tend to have high discharges, low discharge variability, and gentle recession.…”

Morphometric Analysis of Ogunpa and Ogbere Drainage Basins, Ibadan, Nigeria

“…This work was based on map analysis carried out on morphometric parameter on topographical map of Ibadan North East on scale 1:25,000 published by Federal Survey of Nigeria in 1965. This is a large scale map which is highly recommended for a study of this nature (Ebisemiju, 1976;Adejuwon, et. al.…”

A Comparative Analysis of Drainage Morphometry on Hydrologic Characteristics of Kereke and Ukoghor Basins on Flood Vulnerability in Makurdi Town, Nigeria

“…Basin boundaries were delineated and drainage networks manually vectorized from topographical maps as well as updated from recent satellite images. Drainage segments were ordered numerically as suggested by [21] to know the exact order of streams in the basins and Bifurcation ratio (Rb) was used to determine the ratio number of stream segments of given order to the number of segments of the next higher order in the basins.…”