RAINFALL VARIATION AND TUB IMPLICATIONS FOR SDII-SURFACL HYDROLOGY IN THE MANGA GRASSLANDS, NORTH EASTERN NIGLRIA.

This study investigates the relationship between sub-surface water levels and rainfall patterns in the semi-arid zone of northern Nigeria using a groundwater flaw model (Modflow for Windows). ' ' Results show that wet years in terms of high annual rainfall, are ■ accompanied by rising heads, high rate of evaporation from, and subsequent concentration of salt within the lake environment. Drought years however show falling beads, reduced salt accumulation, and in extreme cases, significant outflow of saline water from the system This (rend has serious implications on the various water-dependent socio-economic activities of (he area and on an effective management of the ground wafer resource