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| Titel |
Effects of climate change adaptation scenarios on perceived spatio-temporal characteristics of drought events |
| VerfasserIn |
J.-P. Vidal, E. Martin, N. Kitova, J. Najac, J.-M. Soubeyroux |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250063280
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| Zusammenfassung |
| Drought events develop in both space and time and they are therefore best described through
summary joint spatio-temporal characteristics, like mean duration, mean affected area
and total magnitude. This study addresses the issue of future projections of such
characteristics of drought events over France through three main research questions: (1) Are
downscaled climate projections able to reproduce spatio-temporal characteristics of
meteorological and agricultural droughts in France over a present-day period? (2) How such
characteristics will evolve over the 21st century under different emissions scenarios? (3)
How would perceived drought characteristics evolve under theoretical adaptation
scenarios?
These questions are addressed using the Isba land surface model, downscaled climate
projections from the ARPEGE General Circulation Model under three emissions scenarios, as
well as results from a previously performed 50-year multilevel and multiscale drought
reanalysis over France (Vidal et al., 2010). Spatio-temporal characteristics of meteorological
and agricultural drought events are computed using the Standardized Precipitation
Index (SPI) and the Standardized Soil Wetness Index (SSWI), respectively, and for
time scales of 3 and 12 months. Results first show that the distributions of joint
spatio-temporal characteristics of observed events are well reproduced by the downscaled
hydroclimate projections over a present-day period. All spatio-temporal characteristics
of drought events are then found to dramatically increase over the 21st century
under all considered emissions scenarios, with stronger changes for agricultural
droughts.
Two theoretical adaptation scenarios are eventually built based on hypotheses of
adaptation to evolving climate and hydrological normals. The two scenarios differ by
the way the transient adaptation is performed for a given date in the future, with
reference to the normals over either the previous 30-year window (“retrospective”
adaptation) or over a 30-year period centred around the date considered (“prospective”
adaptation). These adaptation scenarios are translated into local-scale transient
drought thresholds, as opposed to a non-adaptation scenario where the drought
threshold remains constant. The perceived spatio-temporal characteristics derived
from the theoretical adaptation scenarios show much reduced changes, but they call
for more realistic scenarios at both the catchment and national scale in order to
accurately assess the combined effect of local-scale adaptation and global-scale
mitigation.
This study thus proposes a proof of concept for using standardized drought indices for (1)
assessing projections of spatio-temporal drought characteristics and (2) building theoretical
adaptation scenarios and associated perceived changes in hydrological impact studies (Vidal
et al., submitted).
Vidal J.-P., Martin E., Franchistéguy L., Habets F., Soubeyroux J.-M., Blanchard M.
& Baillon M. (2010) Multilevel and multiscale drought reanalysis over France
with the Safran-Isba-Modcou hydrometeorological suite. Hydrology and Earth
System Sciences, 14, 459-478.doi: 10.5194/hess-14-459-2010
Vidal J.-P., Martin E., Kitova N., Najac J. & Soubeyroux, J. M. (submitted) Evolution
of spatio-temporal drought characteristics: validation, projections and effect of
adaptation scenarios. Submitted to Hydrology and earth System Sciences |
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