Abstract

Statistical analysis of hydrometeorological data (temperature, relative humidity, rainfall, reservoir inflow, reservoir storage and turbine release) at Kainji dam was done with the aim of detecting trends.  The non parametric Man-Kendall test was used to detect monotonic trends.  The Sen’s slope estimator and regression analysis were used to develop models for the variables.  A Man-Kendall statistic S = 374 and a high Z value of 4.6897 reveals there is evidence of global warming in the areas around the dam.  This has produced favourable climate conditions favouring increased rain in the areas surrounding the dam.  Excess water has been released from the dam to sustain hydropower generation over the years.  This has invariably affected storage at the dam.  Recommendation was therefore made to the operators of the dam to optimize the release of water from Kainji dam to ensure ideal operation of the dam.

Key words: Global warming, Man-Kendall test, Sen’s slope estimator, regression analysis.