Articles | Volume 20, issue 11
Hydrol. Earth Syst. Sci., 20, 4503–4524, 2016
https://doi.org/10.5194/hess-20-4503-2016
Hydrol. Earth Syst. Sci., 20, 4503–4524, 2016
https://doi.org/10.5194/hess-20-4503-2016

Research article 10 Nov 2016

Research article | 10 Nov 2016

Climate elasticity of streamflow revisited – an elasticity index based on long-term hydrometeorological records

Vazken Andréassian1, Laurent Coron1,a, Julien Lerat2, and Nicolas Le Moine3 Vazken Andréassian et al.
  • 1Irstea, Hydrosystems and Bioprocesses Research Unit (HBAN), Antony, France
  • 2Bureau of Meteorology, Canberra, Australia
  • 3Sorbonne Universités, UPMC Univ Paris 06, CNRS, EPHE, UMR 7619 Metis, Paris, France
  • anow at: EDF-DTG, Toulouse, France

Abstract. We present a new method to derive the empirical (i.e., data-based) elasticity of streamflow to precipitation and potential evaporation. This method, which uses long-term hydrometeorological records, is tested on a set of 519 French catchments.

We compare a total of five different ways to compute elasticity: the reference method first proposed by Sankarasubramanian et al. (2001) and four alternatives differing in the type of regression model chosen (OLS or GLS, univariate or bivariate). We show that the bivariate GLS and OLS regressions provide the most robust solution, because they account for the co-variation of precipitation and potential evaporation anomalies. We also compare empirical elasticity estimates with theoretical estimates derived analytically from the Turc–Mezentsev formula.

Empirical elasticity offers a powerful means to test the extrapolation capacity of those hydrological models that are to be used to predict the impact of climatic changes.

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Short summary
We present a new method to derive the empirical (i.e., data-based) elasticity of streamflow to precipitation and potential evaporation. This method, which uses long-term hydrometeorological records, is tested on a set of 519 French catchments. We compare our method with the classical approach found in the literature and demonstrate its robustness and efficiency. Empirical elasticity is a powerful tool to test the extrapolation capacity of hydrological models.