Flash floods events can hardly be forecast with the use of Numerical Weather Prediction (NWP) systems alone; this is due to their small scale, both spatial and temporal. In recent years this kind of events caused many victims and damages in the Mediterranean area, particularly exposed to the risk of flash floods due to its geomorphological configuration and to the massive ur- ban development of the last decades. A suitable approach to forecasting this kind of events should start from the most accurate prediction of the rainfall field to be provided in input to the hydrological model. For this purpose, it is possible to take advantage of the output of the nowcasting, that is a forecast at very short lead time (0 to 6 hours), but also of a NWP sys- tems. The use of an integrated approach that combines the useful information provided by a NWP forecast and the short-term forecast provided by a nowcasting system can offer a full description of the evolving situa- tion starting from the next future. The realization of an integrated hydrological nowcasting chain coupling the combination of different rainfall fields and the hydro- logical model can improve the discharge forecast. In this work the idea is to take advantage of all the Quantitative Precipitation Forecast available at each time of the forecast. The technical elements involved are the nowcasting technique PhaSt, a spectral-based nowcasting procedure, the convection-permitting nu- merical model MOLOCH corrected with data assimila- tion and Continuum, a continuous distributed hydro- logical model. An integrated hydrological nowcasting chain has been realized suitably coupling these elements together and has been tested on some case events over the north Italian domain.
Using radar data in nowcasting techniques and numerical weather prediction system to improve flood forecast
Davolio S;
2020
Abstract
Flash floods events can hardly be forecast with the use of Numerical Weather Prediction (NWP) systems alone; this is due to their small scale, both spatial and temporal. In recent years this kind of events caused many victims and damages in the Mediterranean area, particularly exposed to the risk of flash floods due to its geomorphological configuration and to the massive ur- ban development of the last decades. A suitable approach to forecasting this kind of events should start from the most accurate prediction of the rainfall field to be provided in input to the hydrological model. For this purpose, it is possible to take advantage of the output of the nowcasting, that is a forecast at very short lead time (0 to 6 hours), but also of a NWP sys- tems. The use of an integrated approach that combines the useful information provided by a NWP forecast and the short-term forecast provided by a nowcasting system can offer a full description of the evolving situa- tion starting from the next future. The realization of an integrated hydrological nowcasting chain coupling the combination of different rainfall fields and the hydro- logical model can improve the discharge forecast. In this work the idea is to take advantage of all the Quantitative Precipitation Forecast available at each time of the forecast. The technical elements involved are the nowcasting technique PhaSt, a spectral-based nowcasting procedure, the convection-permitting nu- merical model MOLOCH corrected with data assimila- tion and Continuum, a continuous distributed hydro- logical model. An integrated hydrological nowcasting chain has been realized suitably coupling these elements together and has been tested on some case events over the north Italian domain.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
