Operational flood-forecasting in the Piemonte region – development and verification of a fully distributed physically-oriented hydrological model

摘要

A hydrological model for real time flood forecasting to Civil Protectionservices requires reliability and rapidity. At present, computationalcapabilities overcome the rapidity needs even when a fully distributedhydrological model is adopted for a large river catchment as the Upper Poriver basin closed at Ponte Becca (nearly 40 000 km2). This approachallows simulating the whole domain and obtaining the responses of large aswell as of medium and little sized sub-catchments. The FEST-WB hydrologicalmodel (Mancini, 1990; Montaldo et al., 2007; Rabuffetti et al., 2008) isimplemented. The calibration and verification activities are based on morethan 100 flood events, occurred along the main tributaries of the Po riverin the period 2000–2003. More than 300 meteorological stations are used toobtain the forcing fields, 10 cross sections with continuous and reliabledischarge time series are used for calibration while verification isperformed on about 40 monitored cross sections. Furthermore meteorologicalforecasting models are used to force the hydrological model withQuantitative Precipitation Forecasts (QPFs) for 36 h horizon in"operational setting" experiments. Particular care is devoted tounderstanding how QPF affects the accuracy of the Quantitative DischargeForecasts (QDFs) and to assessing the QDF uncertainty impact on the warningsystem reliability. Results are presented either in terms of QDF and ofwarning issues highlighting the importance of an "operational based"verification approach.