OATAO - Open Archive Toulouse Archive Ouverte Open Access Week

Flash flood prediction at the regional scale and methodology for ungauged catchments

Garambois, Pierre-André and Larnier, Kévin and Roux, Hélène and Dartus, Denis Flash flood prediction at the regional scale and methodology for ungauged catchments. (2013) In: 7th HyMeX Workshop - Hydrological cycle in Mediterranean Experiment, 7 October 2013 - 10 October 2013 (Cassis, France). (Unpublished)

Full text not available from this repository.


Climate and orography in the Mediterranean region tend to promote intense rainfalls, particularly in autumn. Storms often hit steep catchments and flood quickness only let a very short time lapse for forecasts. Peak flow intensity depends on the great variability of rainfalls and catchment characteristics. As a matter of facts, observation networks are not adapted to these small space-time scales and event severity often affects data reliability when they exist thus the notion of ungauged catchment emerges. Regionalization in hydrology seeks to determine hydrological variables at locations where these data lack. This work contributes to pose the bases of a methodology adapted to transpose parameterizations of a flash flood dedicated distributed hydrologic model from gauged catchments to ungauged ones, and for a large study area. The MARINE distributed hydrologic model is used (Roux et al. 2011), its originality lies in the automatically differentiated adjoint model able to perform calibrations and spatial-temporal sensitivity analysis, in order to improve understanding in flash flood generating mechanisms and real time data assimilation for hydrometeorological forecasts. The first step for MARINE model regionalization is sensitivity analysis which addresses the question of physical process understanding. A large panel of hydrologic behaviours is explored. General catchment behaviours are highlighted for the study area (Garambois, Larnier, et al. 2013). Selected flood events and a multiple events calibration technique help to extract catchment parameter sets. Those parameterizations are tested on validation events and ensemble predictions are performed for a recent flood event. A variance decomposition method leads to parameter temporal sensitivity analysis. It enables better understanding in catching dynamics of physical processes involved in flash floods formation (Garambois, Roux, et al. 2013). Parameterizations are then transferred from gauged catchments with hydrologic similarity to ungauged ones with a view to develop real time flood forecasting.

Item Type:Conference or Workshop Item (Speech)
Audience (conference):International conference without published proceedings
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Université de Toulouse > Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UT3 (FRANCE)
Laboratory name:
Deposited On:03 Mar 2014 13:52

Repository Staff Only: item control page