 |
| Titel |
An evaluation of the Canadian global meteorological ensemble prediction system for short-term hydrological forecasting |
| VerfasserIn |
J. A. Velázquez, T. Petit, A. Lavoie, M.-A. Boucher, R. Turcotte, V. Fortin, F. Anctil |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 13, no. 11 ; Nr. 13, no. 11 (2009-11-25), S.2221-2231 |
| Datensatznummer |
250012059
|
| Publikation (Nr.) |
 copernicus.org/hess-13-2221-2009.pdf |
|
|
|
|
|
| Zusammenfassung |
Hydrological forecasting consists in the assessment of future streamflow.
Current deterministic forecasts do not give any information concerning the
uncertainty, which might be limiting in a decision-making process. Ensemble
forecasts are expected to fill this gap.
In July 2007, the Meteorological Service of Canada has improved its ensemble
prediction system, which has been operational since 1998. It uses the GEM
model to generate a 20-member ensemble on a 100 km grid, at mid-latitudes.
This improved system is used for the first time for hydrological ensemble
predictions. Five watersheds in Quebec (Canada) are studied: Chaudière,
Ch-teauguay, Du Nord, Kénogami and Du Lièvre. An interesting
17-day rainfall event has been selected in October 2007. Forecasts are
produced in a 3 h time step for a 3-day forecast horizon. The
deterministic forecast is also available and it is compared with the
ensemble ones. In order to correct the bias of the ensemble, an updating
procedure has been applied to the output data. Results showed that ensemble
forecasts are more skilful than the deterministic ones, as measured by the
Continuous Ranked Probability Score (CRPS), especially for 72 h forecasts.
However, the hydrological ensemble forecasts are under dispersed: a
situation that improves with the increasing length of the prediction
horizons. We conjecture that this is due in part to the fact that
uncertainty in the initial conditions of the hydrological model is not taken
into account. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|