Climate Variability and River Benue Discharge in Jimeta, Yola Area, Nigeria

Abstract

It is glaring that climate change is true and has become a monster that every effort must be targeted towards its elimination. Every sector of the economic has been affected by climate change. The impact has been intensified of recent, with the increase in world’s population and her quest for survival. In northern Nigeria, its effect among others range from increase in dry spells, heat stress, drop in water tables and consequent shortage of water. To overcome the problems, many have resulted in planting on the river bed, diging of river bed and sinking of bore hole on the bed not only for agricultural purposes but for domestic need. Using climatic (rainfall and temperature) and hydrological data (river discharge) for the period of 49 years, an attempt was made to examine the response of river Benue discharge to climate change. The result shows great fluctuations of the elements about the mean. Both runoff and rainfall total has decreased but the rate of decrease of rainfall is about 14 times that of runoff. Monthly analysis of runoff in some years of the study revealed increase in runoff  above the mean but this additional runoff do not add to water availability for use because they occur during the wet season and there are no  specific storage to hold the water through to the dry season. For every 0.01mm increase in rainfall there is 1 Million m³ increase in discharge and vice versa. The discharge between 1980 and 1999 decreased noticeably, because the discharge was well below actual mean of 20.419 Million m³. The simple correlation analysis revealed that, 24% and 31% association strength to the variation was accounted for by rainfall and temperature respectively. There was an inverse relation between the temperature and runoff as expected from 1980-1990, when pronounced increase in temperature above the mean coincided with the sharpest drop in runoff. The paper recommended that effort should be geared towards programs that will bring to the consciousness of the community as regard the changing climate pattern so as to prepare for the challenges and the right adaptation techniques to the impacts of climate change on water resources.