Increased streamflow dynamics and implications for flooding in the Lower River Benue Basin

Abstract

The paper dealt with increased streamflow dynamics and implications for flooding in the Lower River Benue Basin. The study utilised data collected over a period of more than fifty years (1955-2012) from three hydrological stations operated by the Nigerian Hydrological Services Agency (NIHSA). The average discharge at Umaisha was 4,919.47 cubic metres per second (m3/s). Average discharge at Makurdi hydrological station was 3,468.24 m3/s. The monthly average discharge for Katsina Ala did not record any amount over 2000 m3/s in any month of year from 1955-2012. The rating curves for Umaisha and Makurdi showed a smooth streamflow with Umaisha surpassing the average discharge at 661 cm. Makurdi surpassed the average streamflow of the station at 654 cm. River Katsina Ala rating curve showed a rough streamflow. The trend of discharge rate for the three hydrological stations showed a rise over the years assessed and staggering discharge rates were recorded during peak periods in some years. Evidence provided show increasing streamflow variability and flood risk due to rainfall intensity and release of excess dam water from Lagdo dam in Cameroun. In order to prevent and control flood damage, useful recommendations have been proffered. Key words: Discharge rate, water resources management, streamflow monitoring, river basin, flooding, River Benue Basin.