GIS-based approach for morphometric characteristics and development of hydrographs for the upper watershed of Jebba Reservoir, Nigeria
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Date
2021-10
Journal Title
Journal ISSN
Volume Title
Publisher
Ethiop. J. Sci. Technol.
Abstract
Nigeria's Jebba sub-basins are synonymous to frequent flooding, high rate of erosion,
depletion of soil nutrients and unsustainable water use. The uncontrolled flooding may be a
result of numerous factors related to topography, geology, climate and human activity. The
present work was an attempt to describe the application of Geographical Information System
(GIS) and Digital Elevation Model (DEM) for the estimation of morphometric characteristics
of eight sub-basins in the upstream watershed of Jebba reservoir, Nigeria. Morphometric
characteristics such as topographic, areal, relief and network were determined. Soil
Conservation Service (SCS) technique was applied to estimate hydrographs. The study
revealed that sub-basin number 3 had the lowest time of concentration and maximum depth of
runoff while sub-basin number 2 had maximum ratio of circulation of 1.8 and it is tagged as
the area that is highly prone to flood. The peak runoff in the sub-basins ranged between
330.10 and 924.86 m3/s (25-year return period) and for 100-year intervals ranged between
502.69 to 1408.40 m3/s. The estimated peak runoffs can be adopted for designing and
constructing erosion control structures in the catchment area.