Publications des scientifiques de l'IRD

Carreau Julie, Naveau P., Neppel L. (2017). Partitioning into hazard subregions for regional peaks-over-threshold modeling of heavy precipitation. Water Resources Research, 53 (5), 4407-4426. ISSN 0043-1397.

Titre du document
Partitioning into hazard subregions for regional peaks-over-threshold modeling of heavy precipitation
Année de publication
2017
Type de document
Article référencé dans le Web of Science WOS:000403712100052
Auteurs
Carreau Julie, Naveau P., Neppel L.
Source
Water Resources Research, 2017, 53 (5), 4407-4426 ISSN 0043-1397
The French Mediterranean is subject to intense precipitation events occurring mostly in autumn. These can potentially cause flash floods, the main natural danger in the area. The distribution of these events follows specific spatial patterns, i.e., some sites are more likely to be affected than others. The peaks-over-threshold approach consists in modeling extremes, such as heavy precipitation, by the generalized Pareto (GP) distribution. The shape parameter of the GP controls the probability of extreme events and can be related to the hazard level of a given site. When interpolating across a region, the shape parameter should reproduce the observed spatial patterns of the probability of heavy precipitation. However, the shape parameter estimators have high uncertainty which might hide the underlying spatial variability. As a compromise, we choose to let the shape parameter vary in a moderate fashion. More precisely, we assume that the region of interest can be partitioned into subregions with constant hazard level. We formalize the model as a conditional mixture of GP distributions. We develop a two-step inference strategy based on probability weighted moments and put forward a cross-validation procedure to select the number of subregions. A synthetic data study reveals that the inference strategy is consistent and not very sensitive to the selected number of subregions. An application on daily precipitation data from the French Mediterranean shows that the conditional mixture of GPs outperforms two interpolation approaches (with constant or smoothly varying shape parameter).
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020] ; Hydrologie [062]
Descripteurs
ZONE MEDITERRANEENNE
Description Géographique
FRANCE
Localisation
Fonds IRD [F B010070270]
Identifiant IRD
fdi:010070270
Contact