THE GROUNDWATER HYDROLOGY OF THE MANGA GRASSLANDS, NORTHEAST NIGERIA - IMPORTANCE TO AGRICULTURAL-DEVELOPMENT STRATEGY FOR THE AREA

The Manga Grasslands of northern Nigeria/southern Niger form a unique landscape of dunefields and interdunal depressions (playas or eases) within the semi-arid southern Sahel. Little has been written previously about the hydrogeology of the region, despite the importance of water resources to the existing agricultural and evaporite mineral economy. The paper reports on preliminary investigations into the groundwater hydrology of the area and proposes a simple steady-state conceptual model of groundwater recharge and natural outflow. It is concluded that the development of pumped irrigation in the vicinity of the eases would be unwise in view of its likely short- and long-term effects on groundwater levels, and the consequent damage to the existing economy which would result.