Interaction of pans and groundwater: A case study in the Khakhea- Bray Transboundary aquifer portion in South Africa

Understanding the groundwater-surface water interaction is important for the sustainable management of water resources and ecology. Most of the studies on groundwater-surface interactions are confined to aquifer-river and aquifer-lake interactions. The interactions of water pans and groundwater have not received much attention. The study aims to provide insights into the interaction of the pans and groundwater at a case study in the Khakhea-Bray dolomite Transboundary Aquifer (TBA) shared by Botswana and South Africa. The study uses field observations, geology, hydrogeophysics, and stable isotopes complimentary tools. Complimentary tools provide several evidence to corroborate the findings. The hydrogeophysics taps into the recently developed Telluric Electric Frequency Selection Method (TEFSM). Groundwater discharge zones/springs were delineated at the geological contact of the boundary of the Khakhea-Bray dolomite transboundary aquifer and the granite of the Kalahari group. 4 of the 33 research pans are in the groundwater discharge zone and are classified as groundwater dependent. The findings highlight the benefits of complimentary approaches to corroborate the findings on groundwater-surface water interactions. The TEFSM hydrogeophysics can be able to delineate groundwater discharge zones, aquifer boundaries, and the mapping of TBAs. More studies are recommended to test the TEFSM hydrogeophysical approach to study groundwater-surface water in different hydrological environments. •Case study in the Khakhea-Bray dolomite Transboundary aquifer (TBA).•Investigate the interaction of pans and groundwater.•Uses hydrogeophysics to delineate groundwater discharge zone.•Hydrogeophysics applied the Telluric Electric Frequency Method.•Discharge located at contact of the TBA boundary.