ABSTRACT
ABSTRACT: Statistical assessment of specific capacity and transmissivity has made it possible to classify hydrogeologic units on a regional scale and to prepare regional transmissivity anomaly maps for the quantitative characterisation and prediction of borehole yields in hard rock aquifers in Ghana. In general, the rocks pertain to transmissivity classes IV and III, representing low to intermediate transmissivity magnitude. Mapping out areas of positive transmissivity anomalies delineates prospective zones for groundwater exploration. In such zones, the minimum expected yields range from 35 to 120 L/min in the various hydrogeological units. These yields are 6-15 times higher when compared with probable yields from regions of negative transmissivity anomalies (6 to 10 L/min). Detailed investigations in zones of positive transmissivity anomalies could reveal potential aquifers where large volumes of groundwater could be abstracted for local supplies. Natural groundwater resources, however, might represent an upper limit for regional groundwater development.
