Water and energy fluxes at the surface- subsurface interface of the ORACLE/BVRE Orgeval Observatory

Accurately quantifying surface-subsurface water and energy fluxes is challenging because a myriad of morphological and physical factors subject to spatial and temporal variability, and nested interfaces, lead to patterns in residence time over multiple spatial scales. In these scope, we reflect here a new understanding of the stream-aquifer interface functioning, shifting from a pure hydrological characterizing toward a subtler view that accounts for hydrology and thermal processes with wide ranges of field methods and models. The concept of nested stream-aquifer interfaces (Flipo et al., 2014) is used to simulate the variation of the spatio-temporal surface-subsurface exchanges at the watershed scale from LOcal MOnitoring Stations (LOMOSs) measurements of the stream-aquifer exchanges. A fiber optic has recently been set up along a 1 km river to improve our description water and heat fluxes between the stream and the aquifers.