EFFECT OF URBANIZATION, WASTE-DISPOSAL AND HYDROLOGICAL FACTORS ON FLOODING OF OGUNPA STREAM IN NIGERIA

A statistical analysis of daily stage readings at three gauging statio ns along Ogunpa Stream,Ibadan, Nigeria was performed to gain insight i nto the influence of rainfall, urbanization and waste disposal on floo ding of the stream. The parameters analysed were monthly peak (H-p), m ean of the monthly peak (H-m) and the covariance function (C-v) of the daily stage readings. The result showed that: (1) the daily stage rea dings at the stations are periodic, (2) rainfall depths of 60 mm and a bove could lead to flood events, and (3) bad waste disposal habits wer e mainly responsible for the frequent flooding of the stream especiall y at downstream subreach. It is believed that construction of dykes fo r the downstream subreach and excavation at the upstream subreach coul d minimize the frequent flooding of the stream.