SeeKaquA performed major field campaign with drone-based geophysical measurement and hydrogeological sampling
The SeeKaquA project team has successfully completed its first milestone: a joint geophysical survey and hydrogeological sampling campaign in the Cuvelai–Etosha Basin (CEB) in the western Basin of the Kalahari in Namibia. Fieldwork took place in August/September 2025 to explore deep freshwater resources, investigate transition zones from fresh to saline water, and study perched aquifer systems at multiple demonstration sites around the town of Okongo.
International consortium and knowledge exchange
The international research group comprised 17 participants from the LIAG Institute for Applied Geophysics (LIAG, 2), the Federal Institute for Geosciences and Natural Resources (BGR, 3), the University of Namibia (UNAM, 5), the University of Zambia (UNZA, 1), terratec Namibia & Germany (4) and the Ministry of Agriculture, Fisheries, Water & Land Reform (MAFWLR, 2). The campaign enabled intensive transfer of geoscientific and technical knowledge among partners from industry, ministries and universities, and provided valuable experience for future work.
Innovative methods: Drone-based semi-airborne electromagnetics for 3D images of the electrical subsurface structure
LIAG, UNAM, UNZA and terratec conducted drone-based semi-airborne electromagnetics as well as reference measurements on the ground across three areas covering several square kilometres. The data - after the ongoing processing - will provide 3D images of the electrical subsurface structure linked to geological units as well as salt concentrations within the aquifers. This information, together with the borehole and water sampling data, will lead to an improved understanding of the local to regional hydrogeological situation in the Cuvelai–Etosha Basin.
Deep groundwater samples from 23 boreholes
BGR, UNAM and MAFWLR sampled deep groundwater from 23 different boreholes using a pumping trailer, a through-flow cell for measuring parameters such as the pH, the electrical conductivity and the temperature of the groundwater, as well as an extensive set of sample containers. The ongoing hydrochemical analysis of the samples will provide the overall chemical composition as well as isotope and noble gas data for age dating of the groundwater. These new data can provide valuable insights of the so far unknown origin of high trace-element concentrations such as fluoride and vanadium. To keep the recently gained momentum ongoing, a team of UNZA and terratec is currently acquiring transient and magnetotelluric data at the MZB to provide valuable pre-information for planning the second major measurement campaign in the upcoming year.
Authors: Sibel Gürsoy & Dr. Raphael Rochlitz