GEOSPATIAL ASSESSMENT OF DRAINAGE NETWORK SYSTEMS IN UYO LOCAL GOVERNMENT AREA, AKWA IBOM STATE.

Abstract

There are numerous effects of natural disaster like flooding in different places all over the world. However, the 
application of GIS and remote sensing technology to map out these areas vulnerable to flood makes it easy to plan 
measures, aimed at mitigating flood damages and risks involved. The study aimed at identifying drainage network 
systems within flood vulnerable areas in Uyo LGA with a view to suggesting control measures. The GIS software, 
ArcMap 10.4 environment, Landsat-8 OLI and Digital Elevation Model (DEM) images of 2022 of the area were used 
to select slope, land use, drainage network, and soil layers. Annual rainfall data were acquired from NASA/NiMET. 
The DEM was used to generate slope, flow direction, flow accumulation, stream network and distance from water 
channel. Flood vulnerability impact map was produced identifying high, moderate, and low vulnerable areas. Flood 
mapping was done to determine flood locations based on a 3D terrain assessment from where the drainage network 
system was developed. Factors that influence drainage in the study area were: hydrological factors, water management 
factors, and institutional factors. The mean annual rainfall of the study area ranges from 4426 mm to 4927 mm. The 
flood vulnerability increases with the increase in rainfall. The mean annual rainfall classes in the study area were 
categorized into: very low, Low, moderate, high, respectively. However, the region is characterized by high slope 
angle and elevation. As such, all flood waters easily flow downstream to many parts of Ekamba Nsukkara and Idu 
communities, putting them at a high risk of floods.