Hydrol. Earth Syst. Sci., 24, 5519–5538, 2020 https://doi.org/10.5194/hess-24-5519-2020 © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License. On the potential of variational calibration for a fully distributed hydrological model: application on a Mediterranean catchment Maxime Jay-Allemand1,2, Pierre Javelle1, Igor Gejadze2, Patrick Arnaud1, Pierre-Olivier Malaterre2, Jean-Alain Fine3, and Didier Organde3 1RECOVER, INRAE, Aix-Marseille Université, 3275 Route de Cézanne, 13182 Aix-en-Provence, France 2INRAE, UMR G-EAU, 361 rue Jean-François Breton, 34196 Montpellier, France 3HYDRIS Hydrologie, Parc Scientifique Agropolis II, 2196 Boulevard de la Lironde, 34980 Montferrier-sur-Lez, France Correspondence: Pierre Javelle (
[email protected]) Received: 27 June 2019 – Discussion started: 16 October 2019 Revised: 17 June 2020 – Accepted: 31 July 2020 – Published: 23 November 2020 Abstract. Calibration of a conceptual distributed model is ments, which may include considering a non-Gaussian like- challenging due to a number of reasons, which include fun- lihood and upgrading the model structure. damental (model adequacy and identifiability) and algorith- mic (e.g., local search vs. global search) issues. The aim of the presented study is to investigate the potential of the vari- ational approach for calibrating a simple continuous hydro- 1 Introduction logical model (GRD; Génie Rural distributed involved in sev- eral flash flood modeling applications. This model is defined Flash flood prediction remains a challenging task of modern on a rectangular 1 km2 resolution grid, with three parame- hydrology due to a number of reasons. First, the heavy pre- ters being associated with each cell.