Projet completion report : Groundwater exploration in southeast Zimbabwe using remote sensing and ground geophysical techniques

ABSTRACT

Regional and local scale investigations, involving remote sensing, ground geophysics and drilling, have carried out in southeast Zimbabwe aimed at increasing the understanding of crytalline, hard-rock aquifers and improving borehole siting procedures. New products derived from satellite imagery that simplify interpretation have been developed and are described. Detailed field studies at a small number of locations suggest that, whilst photolineaments, thought to represent rock fractures for the most part, are an important element in borehole targeting, they are not by themselves a wholly reliable. The role of ground geophysical surveys in site selection is described and evaluated. A hypothesis to describe the nature and role of fracturing in this region is presented, based on the evidence of the field test undertaken. A strategy for medium-term groundwater development in low-rainfall areas underlain by crystalline basement, such as southeast Zimbabwe, is proposed. It is suggested that more effort is put into establishing a network of high-yielding wells at strategic locations to supplement individual village supplies during periods of drought. The work summarised in this report was carried out under the ODA/BGS Research & Development Programme of technical assistance to the devloping countries. A full list of reports arising from the study is provided (AU)