Assessment of stream order and drainage pattern of flood prone areas of Ebonyi State Southeastern Nigeria

Abstract

This study assessed the stream order and drainage pattern of flood prone areas to determine the relationship between stream order and the magnitude of the flood in Ebonyi state. The river courses, different tributaries and the drainage network within Ebonyi State were identified using the Shuttle Rader Topographic Mission (SRTM) which generated the river network with the aid of Topographic analysis of Spatial Analyst on Hydrology. This SRTM activated the examination of the effects of stream order and drainage pattern on flood areas of Ebonyi State using the Digital Elevation Model (DEM) which proved that the drainage gets heavier down the slope as more volume of water were added to the traversing channel, hence the upsurge resulting in floods. The data was acquired from the field through Geometric Positioning. The LANDSAT data were equally downloaded from United State Geological Survey (USGS) Earth explorer for 2019 and that of the Thematic Mapper (TM) for 2009. The STRM collected its data from its sporadic available drainage encompassing tributaries and drainage network within Ebonyi State. The study revealed the need for an adequate adjustments of the stream order to accommodate more volume of water within the basin that will empty into the major consequent river down the slope avert flood. Therefore there is a need for urgent adjustments and constructions of a drainage system to accommodate more water volumes.