A space-time geostatistical approach for ensemble rainfall nowcasting
Une approche géostatistique spatio-temporelle pour la prévision immédiate d'ensemble de pluies
Caseri, A. ; Ramos, M.H. ; Javelle, P. ; Leblois, E.
Type de document
Article de revue scientifique à comité de lecture
Affiliation de l'auteur
IRSTEA AIX EN PROVENCE UR RECOVER FRA ; IRSTEA ANTONY UR HBAN FRA ; IRSTEA AIX EN PROVENCE UR RECOVER FRA ; IRSTEA LYON UR HHLY FRA
Résumé / Abstract
Nowcasting systems are essential to prevent extreme events and reduce their socio-economic impacts. The major challenge of these systems is to capture high-risk situations in advance, with good accuracy, location and time. Uncertainties associated with the precipitation events have an impact on the hydrological forecasts, especially when it concerns localized flash flood events. Radar monitoring can help to detect the space-time evolution of rain fields, but nowcasting techniques are needed to go beyond the observation and provide scenarios of rainfall for the next hours of the event. In this study, we investigate a space-time geostatistical framework to generate multiple scenarios of future rainfall. The rainfall ensemble is generated based on space-time properties of precipitation fields given by radar measurements and rainfall data from rain gauges. The aim of this study is to investigate the potential of a framework that applies a geostatistical conditional simulation method to generate an ensemble nowcasting of rainfall fields. The Var region (south eastern France) and 14 events are used to validate the approach. Results show that the proposed method can be a solution to combine information from radar fields and rain gauges to generate nowcasting rainfall fields adapted for flash flood alert.
3rd European Conference on Flood Risk Management, 17/10/2016 - 21/10/2016, Lyon, FRA
E3S Web of Conferences