identified since a 158-km proportion is directly linked to groundwater uptakes.
Therefore, at the scale of the Seine basin, simulated conditions in the 1900s resulted
in a significant 20.9% increase of the contribution from the groundwater compartment to the surface waters. On the other hand, in the 2100s scenario, slight variations
only in fluxes from underground to surface waters are simulated when compared to
the MIROC5 reference (Table 2), highlighting the relative stability of the stream–
aquifer exchanges.
5.4.3 Hydrological Regimes
A comparison approach for all three cases on simulated discharge rates was carried
out to identify any significant changes in hydraulic behaviour of the main rivers.
Therefore, an analysis based on the usual characteristic flow rates was conducted on
eight gauging stations located either at the downstream limits of the Seine’s main
tributaries or along the Seine River itself (Table 3). The mean annual flow rates
Fig. 9 Relative variations (RV) of average rainfall (a, c) and AET (b, d) for the 1900s (a, b) and
2100s scenarios (c, d). RVs are calculated with regard to their respective reference (2000s for the
1900s scenario and MIROC5 in the current days for the 2100s scenario)
Pluri-annual Water Budget on the Seine Basin: Past, Current and Future Trends
79
Therefore, at the scale of the Seine basin, simulated conditions in the 1900s resulted
in a significant 20.9% increase of the contribution from the groundwater compartment to the surface waters. On the other hand, in the 2100s scenario, slight variations
only in fluxes from underground to surface waters are simulated when compared to
the MIROC5 reference (Table 2), highlighting the relative stability of the stream–
aquifer exchanges.
5.4.3 Hydrological Regimes
A comparison approach for all three cases on simulated discharge rates was carried
out to identify any significant changes in hydraulic behaviour of the main rivers.
Therefore, an analysis based on the usual characteristic flow rates was conducted on
eight gauging stations located either at the downstream limits of the Seine’s main
tributaries or along the Seine River itself (Table 3). The mean annual flow rates
Fig. 9 Relative variations (RV) of average rainfall (a, c) and AET (b, d) for the 1900s (a, b) and
2100s scenarios (c, d). RVs are calculated with regard to their respective reference (2000s for the
1900s scenario and MIROC5 in the current days for the 2100s scenario)
Pluri-annual Water Budget on the Seine Basin: Past, Current and Future Trends
79