Real-time flood forecasting by relating local stage and remote discharge

A real-time Flood Forecasting and Warning System (FFWS) is the main nonstructural measure for reducing risk in flood-prone areas. A model able to provide reliable stage and discharge forecasts is one of the fundamental FFWS components. In this context, a simple model for real-time flood forecasting is proposed for river reaches where significant lateral inflow contributions occur. The model, based on the real-time Rating Curve Model, allows predicting the discharge hydrograph at a river site where only the stage is monitored when the flow is known at an upstream section. The model performance was found satisfactory for two river reaches of the Tiber river basin, central Italy, characterized by different intermediate drainage areas. Finally, the forecast uncertainty estimate is addressed through 95% confidence interval based on the statistical properties of the forecast lateral inflow.