1National Geophysical Research Institute Hyderabad, India
2Department of Geological Sciences, Nnamdi Azikiwe University P.M.B., 5025 Awka, Nigeria.
The change in climatic energy balance associated with economic and industrial development has global implications. The groundwater resources of parts of southeastern Nigeria are influenced by the presence of the escarpment and changes in the climatic conditions. The depth to watertable in aquifer in the escarpment area varies between 10 to170m during the rainy season and 80 to 260m in the dry season. The geomorphic characteristics of the escarpment are major controlling factors in groundwater recharge/discharge and availability. Although favourable values of the aquifer parameters of hydraulic conductivity and the transmissivity measured in the area range from 2.08×101 cm/s to 8.46×101 cm/s and 150×103m2/hr to 481×103 m2/hr respectively, variation in watertable and loss of surface water still occur exacerbating water scarcity, public health and food security. The principal flow direction of the surface and groundwater sources in the area is in the NE and NW direction following the influence of the escarpment and consequently creating both surface and subsurface water divide. Nanka Sands and Imo Shale are the major geologic units prevalent in the study area. While huge watertable and confined aquifers are found in Nanka Sands, the Imo Shale forms aquitards except in the sandstone members
Aquifer parameters, escarpment, groundwater recharge/discharge, water divide, climate change
