Determination of Peak Discharge for Selected Drainage Facilities in Ilorin Metropolis for the Purpose of Storm Water Management
Authors: Oluwaseun OV, Bilewu SO, Ayangbola DA
The research work was aimed at determining the peak discharge of flow (maximum storm runoff) into some selected drainage systems in Ilorin metropolis for the purpose of stormwater management. The Ilorin municipality has been observed to have drainage system inadequate in capacities to convey storm runoff as a result of solid waste disposal into drainage systems which leads to drain blockage and the excess runoff result in flood. To obtain the value of excess runoff that leads to flood in the drainage systems under study, the required drainage area (m2) for the adequate conveyance of the determined peak flow was compared with the existing drainage area (m2) the difference in both areas results in the excess runoff which leads to flood. The rational method was used to compute peak discharge for the study areas while the Manning’s equation was adopted to compute the expected drainage channel area required for the adequate conveyance of the peak discharge. The result showed that the existing drainage area in most of the selected drainage systems is less than the required area needed to convey the peak stormwater discharge into the drainage system. The average peak discharge obtained for all the drainage channels in the study areas was 266.68 m3/s while the average area expected to convey the discharge was 8.85 m2. However, the average area of the existing drainage systems was 0.349 m2 which is relatively to as compared with 8.85 m2 which represent the excess discharge that leads to the flooding.
Affiliations: Department of Water Resources and Environmental Engineering, Faculty of Engineering and Technology, University of Ilorin, PMB 1515, Ilorin, Kwara State, Nigeria
Keywords: Peak Discharge, Drainage, Stormwater Management, Flood, Rational Method
Published date: 2020/06/30