Analytical Study of Rainfall and Temperature Trend in Catchment States and Stations of the Benin- Owena River Basin, Nigeria

Abstract

The impart of climate change is felt worldwide, but the effects are more devastating in countries where flooding or drought has occurred. In the Nigerian context, the impact of climate change is felt majorly in terms of rainfall and temperature. It is on the basis of their variations that the analytical study of their trend is carried out in some catchment States of Nigeria using the Benin- Owena River Basin as case study. Climatic data of rainfall and temperature for 35years were collected and subjected to Cumulative Summation (CU-SUM) and the rank-sum tests. The trend analysis shows that as temperature increases there is a corresponding increase in rainfall. The trend also indicates that no significant departure of these climatic parameters occurred. The least square regression (r²) and the trend as generated from the Microsoft Excel computations show that the temperature variation ranges from 0.4% in Delta to 3.5% in Edo, an indication that the temperature conditions in states understudy are not uniform even though the trend shows an increase. The rainfall least square regression variation ranges between 0.2% in Zaria and 2.7% in Plateau states, implying that the rainfall is varying in an upward trend.

Keywords: Analytical study, Climatic variation, Temperature and Rainfall.