The regions of crystalline basement such as Brittany are regularly faced with hydrological challenges during low water periods despite a temperate climate characterized by regular precipitation, limited evapotranspiration in winter and favourable conditions for aquifer recharge. The vulnerabilities of river flows during low water are the low capacity of aquifers to build a mobilizable water stock to support low water flow and the high heterogeneity of the hydrodynamic properties of aquifers which results in wide variations in the recharge, storage, and flows between aquifers and rivers at the watershed scale. Brittany does not have strategic resources protected from the effects of climate change as large sedimentary basins can, climatic variations can quickly lead to significant consequences and put regional activities under stress.
After a thesis on the characterization of the hydrodynamic properties of watersheds in the geological context of crystalline basement (Figure 1), Nicolas Cornette will work on the CYDRE project (hYdrological cycle, Resource availability and evolution).
Figure 1. Spatial representation of logarithm of hydraulic conductivities (Log(K)) estimated on 79 watersheds in Brittany based on the calibration of the hs1D mechanistic model. The base of the map represents a simplified geology of Brittany.
The general objective of this project is to use the modelling results from the thesis on the characterization of near-subsurface waters to provide seasonal trends in flow trends to watershed managers at the scale of Brittany. The purpose of this project is to provide a simple and operational digital tool to provide seasonal trends in flow rates, based on simulations previously carried out without direct reuse of a model.