Recalculation of historical streamflow series. Impact assessment and valorization

Rating curves used to calculate discharge from water level must be extrapolated beyond the range of measured discharges, due to the difficulty of measuring flood discharge. This induces large uncertainties and the flood discharge series can be unreliable. This paper presents a methodology to update and correct historical flood flows, so as to propose homogeneous and less biased data. The benefit of using hydraulic modeling is discussed. This methodology is applied to a large sample of hydrometric stations of the EDF (Electricite De France) network, and the impact on peak flows deviations is analyzed.