Hydrogeophysical investigation for groundwater at the Dayspring Children's Village, South Africa

Abstract

Over the past 30 years, the water available in boreholes at the Dayspring Children's Village has slowly diminished to the point where the school's viability is threatened. In this same time period, a large stand of eucalyptus and yellow wattle trees has become well established. These trees are known to consume large quantities of water and we are investigating the effect of these trees on the local groundwater hydrology. Many types of geophysical and hydrological data—including gravity, magnetic, electrical resistivity, electromagnetic (EM) and seismic—are being acquired to understand the regional geology, seasonal changes and ultimately the impact of the trees on the local hydrology. Electrical resistivity data collected at the end of the dry season and at the end of the rainy season are used to define seasonal changes of a near-surface aquifer. By quantifying the effect of these trees on the hydrology, predictive recommendations on the benefits of tree removal can be made to government.