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The Middle Niger Basin lies in the sedimentary terrains of the middle part of Nigeria. It has an area coverage of about 27,000km2 . The area falls under the middle Nigeria climat ic belt which is mainly tropical with an average rain fall of about 1250mm. This paper evaluates the hydrogeological potential of the terrain. The methods of investigation include analysis of meteorological, drilling, pu mping tests and water quality data. A total of about 50 boreholes located in the area were selected for study. Results of the analyses of the data showed that groundwater occurs both in confined and semi-confined conditions. Depth to water rarely exceeds 50m, though in some few cases may be over 70m. Averagely, well yield varies between 1.08 and 19m 3 /hr. Transmissivity values obtained using various methods vary between 1.365 and 393m 2 /day. Hydrochemical analyses of groundwater samples showed poor mineralizat ion with low TDS (Total Dissolved Solids) rarely over 300mg/ l. The water is fresh, soft and free of chemical pollution and therefore suitable for many purposes.

DRASTIC index model was employed in the assessment of the intrinsic groundwater vulnerability to contamination in Kaduna metropolis, Nigeria. The model evaluates the contribution of seven environmental parameters (Depth to water level, Net Recharge, Aquifer media, Soil media, Topography, Impact of vadose zone, and Hydraulic Conductivity) in the protection of groundwater against contamination. The mapping was conducted within the framework of Geographical Information System. The study area has very low, low to slightly moderate vulnerability with highest and lowest DRASTIC values of 131 and 77 respectively. To have better understanding of the spatial vulnerability of groundwater in the area, the DRASTIC map was reclassified into five (very high, high, moderate, low and very low) vulnerability zones. Generally, the distribution of the vulnerability classes indicated the low to moderate vulnerability status of the majority parts of the study area, with high vulnerability at the center. Strict control measures should be put in place when locating land uses with high potential hazards in the high and very high vulnerability areas.

Abstract. The strategies and actions in the management of African River Basins in a warming climate environment have been studied. Using the Gurara Reservoir Catchment in North-West Nigeria as a case study, summations were proposed using hypothetical climate scenarios considering the Global Climate Models prediction and linear trend of the data. Four (4) proposed scenarios of temperature increase (1 % and 2 %) coupled with a decrease in precipitation of (−5 % and −10 %) were combined and applied for the study area. The Water Evaluation and Planning Tool was used to model and evaluates the impact of the earth's rising temperature and declining rainfall on the hydrology and availability of water by investigating its resilience to climate change. Modelling results indicate a reduction in available water within the study area from 4.3 % to 3.5 % compared to the baseline with no climate change scenario, revealing the current water management strategy as not sustainable, uncoordinated, and resulting in overexploitation. The findings could assist in managing future water resources in the catchment by accentuating the need to put in place appropriate adaptation measures to foster resilience to climate change. Practically, it is pertinent to shape more effective policies and regulations within catchments for effective water resources management in reducing water shortage as well as achieving downstream water needs and power benefit in thefuture, while also allowing flexibility in the operation of a reservoir with the ultimate goal of adapting to climate change.

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