 |
| Titel |
Hydrologic benchmarking of meteorological drought indices at interannual to climate change timescales: a case study over the Amazon and Mississippi river basins |
| VerfasserIn |
E. Joetzjer, Hervé Douville, C. Delire, P. Ciais, B. Decharme, S. Tyteca |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 17, no. 12 ; Nr. 17, no. 12 (2013-12-06), S.4885-4895 |
| Datensatznummer |
250086020
|
| Publikation (Nr.) |
 copernicus.org/hess-17-4885-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| Widely used metrics of drought are still derived solely from analyses of
meteorological variables such as precipitation and temperature. While
drought is generally a consequence of atmospheric anomalies, the impacts to
society are more directly related to hydrologic conditions. The present
study uses a standardized runoff index (SRI) as a proxy for river discharge
and as a benchmark for various meteorological drought indices (scPDSI, SPI,
SPEI_th, and SPEI_hg respectively). Only
12-month duration droughts are considered in order to allow a direct (no
river routing) comparison between meteorological anomalies and their
hydrological counterpart. The analysis is conducted over the Mississippi and
Amazon river basins, which provide two contrasted test beds for evaluating
drought indices at both interannual (using detrended data) and climate
change (using raw data) timescales. Looking first at observations over the
second half of the 20th century, the simple SPI based solely on
precipitation is no less suitable than more sophisticated meteorological
drought indices at detecting interannual SRI variations. Using the detrended
runoff and meteorological outputs of a five-member single model ensemble of
historical and 21th century climate simulations leads to the same
conclusion. Looking at the 21st century projections, the response of
the areal fraction in drought to global warming is shown to be strongly
metric dependent and potentially overestimated by the drought indices which
account for temperature variations. These results suggest that empirical
meteorological drought indices should be considered with great caution in a
warming climate and that more physical water balance models are needed to
account for the impact of the anthropogenic radiative forcings on
hydrological droughts. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|