Tipping points in hydrology: attribution of regime shifts using historical climate simulations and dynamical system modeling - Archive ouverte HAL Accéder directement au contenu
Poster De Conférence Année : 2023

Tipping points in hydrology: attribution of regime shifts using historical climate simulations and dynamical system modeling

Jérome Demarty
Fabrice Gangneron
Manuela Grippa
Laurent Kergoat
Éric Mougin
  • Fonction : Auteur
  • PersonId : 867982
Christophe Peugeot

Résumé

The Sahel (the semi-arid fringe south of the Sahara) experienced a severe drought in the 70s-90s. During this drought, an hydrological regime shift was observed for most watersheds in the Central Sahel: runoff has significantly increased despite the rainfall deficit. Did the drought cause this regime shift ? What if the drought did not happen ? To answer these questions, we introduce a simple dynamical model that represents feedbacks between soil, vegetation and runoff at the watershed scale and at the annual time step. This model is forced with annual rainfall and evaluated using long-term observations of runoff from selected watersheds. We find that the model forced with observed rainfall reproduces well the observed regime shift in runoff. For the attribution of the regime shift to the drought, we rely on two sets of historical rainfall simulations from CMIP6 global climate models: fully-coupled simulations that do not reproduce the drought, and atmosphere-only simulations (AMIP) that represent the drought. Our results show that a regime shift would have been unlikely without the drought. This approach will be extended to identify areas that are likely to experience an hydrological regime shift in the future.
Fichier non déposé

Dates et versions

hal-04287803 , version 1 (15-11-2023)

Licence

Paternité

Identifiants

Citer

Erwan Le Roux, Valentin Wendling, Gérémy Panthou, Paul-Alain Raynal, Abdramane Ba, et al.. Tipping points in hydrology: attribution of regime shifts using historical climate simulations and dynamical system modeling. EGU General Assembly 2023, Apr 2023, Wien, Austria. 2023, ⟨10.5194/egusphere-egu23-3354⟩. ⟨hal-04287803⟩
22 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More