Estimation of Flood Magnitude and Frequency of Escravos Bay in Delta State Nigeria using Log Pearson Type (iii) Distribution

Abstract

The climate of the world is changing and there are not enough rain/tidal gauges to record the hydrodynamics of water flowing in and out of the sub-tributaries of the western Niger Delta in Nigeria e.g., the Benin, Forcados and Escravos rivers. Flood in low lying coastal area of Ugborodo clan have been causing a lot of havoc, as a recurrence decimal it displaces the habitat and destroys properties especially during the raining season. This paper focuses on the estimation of magnitude on frequency of occurrence of return period 2years, 5years, 10years, 25years, 50years, 100years and 200years of flow using log Pearson type III probability distribution model fitted in fifteen years tidal record taken between 2000-2014 from Escravos bay and the results were 10,891m3/s, 11,912 m3/s, 12,376 m3/s, 12,815 m3/s, 13,068 m3/s, 13,275 m3/s, 13,447 m3/s respectively. The predictions of these result as maximum possible flood is expected to assist coastal catchment managers in their planning because estimation of peak flood for a particular return period is the most valuable information for him to be able to design and construct safe hydraulic structures like gabions, sheet piles, dam, etc., also early warning measures can be put in place to prevent catastrophic scenario by developing flood maps and finally, this result can be used by decision makers as a guide to plan hydraulic structures in the clan.