Piece 4 - Groundwater–Surface Water Interactions
Is the river feeding the aquifer — or the aquifer feeding the river?
How do groundwater and surface water interact in fractured crystalline aquifers under highly seasonal and semi-arid conditions?
How do these exchanges control groundwater recharge, storage and streamflow, and how are they influenced by weathering, fractures and episodic rainfall?
Key findings
- Groundwater–surface water exchanges are dynamic and bidirectional, controlled by hydraulic gradients, geological structures and hydrological conditions. Groundwater can sustain streamflow, while surface water can contribute significantly to groundwater recharge when hydraulic conditions favour infiltration.
- Groundwater circulation strongly controls the transfer of weathering products from soils and rocks to surface waters, influencing dissolved-element fluxes. Natural chemical tracers can reveal contrasting groundwater flow paths and quantify groundwater contributions to headwater streams.
- Wetlands and headwater swamps can regulate groundwater–stream exchanges, modulating both water fluxes and chemical export.
Jean-Christophe Maréchal, Jean Riotte, Christelle Lagane, S. Subramanian, C. Kumar, Laurent Ruiz, Stéphane Audry, M.R.R. Varma, Jean-Jacques Braun
Applied Geochemistry, vol. 26, 2011, pp. S94-S96
Jean-Christophe Maréchal, Jean-Jacques Braun, Jean Riotte, Jean-Pierre Bedimo Bedimo, Jean-Loup Boeglin
Hydrological Processes, vol. 25, 2011, pp. 2246-2260
