The Impacts of Climate Change on the Discharge of Osse-Ossiomo River Basin, South Western Nigeria under Different Climatic Scenarios

Abstract

The impacts of climate change of Osse-Ossiomo River Basin; South West Nigeria under different climatic Scenarios was investigated using information on rainfall - temperature for forty years (1961 - 2000). Discharge information of Osse and Ossiomo rivers was from 1989-1994. Results revealed fluctuating rainfall pattern with great uncertianties in the mid-1980s. Temperature shows increasing trend and the highest temperature of 37^oC was obtained in 1998 during the 40-year period. There is a strong evidence of global warming using the index of temperature in the drainage basin. River discharge also indicated fluctuating trends from year to year in the decades with available discharge records. It was concluded that the river discharge pattern of Osse-Ossiomo River Basin, S. W. Nigeria exhibited similar behavious as other drainage basins of the world. That climate change has impacted on the river discharge of Osse-Ossiomo River Basin, S. W. Nigeria.

Keywords: River basin, rainfall, temperature, discharge, Osse-Ossiomo Basin