Publications des scientifiques de l'IRD

Hertig E., Tramblay Yves. (2017). Regional downscaling of Mediterranean droughts under past and future climatic conditions. In : Lionello P. (ed.), Ozsoy E. (ed.), Planton S. (ed.), Zanchetta G. (ed.). Climate variability and change in the Mediterranean region. Global and Planetary Change, 151 (No Special), p. 36-48. ISSN 0921-8181.

Titre du document
Regional downscaling of Mediterranean droughts under past and future climatic conditions
Année de publication
2017
Type de document
Article référencé dans le Web of Science WOS:000405251100005
Auteurs
Hertig E., Tramblay Yves
In
Lionello P. (ed.), Ozsoy E. (ed.), Planton S. (ed.), Zanchetta G. (ed.) Climate variability and change in the Mediterranean region
Source
Global and Planetary Change, 2017, 151 (No Special), p. 36-48 ISSN 0921-8181
The complexity of the Mediterranean climate with its high precipitation variability and its unequal seasonal distribution with a wet season from approximately October to April and a dry season in summer set general conditions for a high vulnerability of the Mediterranean area to droughts. In the last few decades the risk of drought episodes appears to be enhanced in the Mediterranean area due to temperature increases combined with precipitation decreases. This general change towards warmer and dryer conditions is expected to continue in the future. In the present study droughts are represented by the Standardized Precipitation Index (SPI), at 114 stations located across the Mediterranean area. The SPI is a normalized measure of drought severity relative to a specific location, obtained from rainfall totals aggregated over different time periods. This allows a comparison of different locations and the delineation of homogeneous regions with similar SPI variability. 13 regions have been identified. A downscaling approach using circulation types based on geopotential heights and relative humidity as predictors has been set up to downscale the SPI time series in the different regions. The downscaling approach has been validated using running 21 years validation periods, in order to assess the skill of the method during different climatic conditions and to detect possible non-stationarities in the predictors-predictand relationships. Results show that the downscaling method provided satisfactory results, except for the most arid regions. Future projections, provided from a three member ensemble of the MPI-ESM-LR model under scenario RCP 8.5, indicate an increase in the drought severity and occurrence for the whole Mediterranean region for the period 2070-2100.
Plan de classement
Sciences du milieu [021] ; Hydrologie [062]
Description Géographique
MEDITERRANEE
Localisation
Fonds IRD [F B010070289]
Identifiant IRD
fdi:010070289
Contact