2018 issue 2-item 05

FEWS news: issue 2, 2018



Flood forecasting for bridge stability assessment: the Bandon FFS

Igor Kerin (University College Cork, Ireland) and Jan Verkade (Deltares)

March 26, 2018

Bridges over rivers may collapse as a result of flood induced scour which decreases a bridge's foundation ability to carry its own weight. Real time forecasting may allow for timely closure of bridges, thus preventing any casualties.

Scour may cause bridges to collapse

Within the context of the EC funded Intelligent Bridge Assessment Maintenance and Management System (BRIDGE SMS) project, a real-time flood and scour forecasting system was developed by University College Cork under guidance of Deltares.

The Bandon FFS is based on the Delft-FEWS forecast production system. A blend of Met Éireann's HARMONIE and the US National Centers for Environmental Prediction's Global Forecasting System precipitation forecasts is used to force multiple HEC-HMS hydrological and streamflow propagation models. Based on the value of the Antecedent Precipitation Index, one of the models is selected as ‘official forecast model'. Thus estimated future water levels and streamflow rates are subsequently used to estimate scour levels.

The Bandon FFS front end

Hydrological models are forced with Met Éireann's HARMONIE precipitation forecasts

The system is implemented as a stand-alone system and resides on a dedicated desktop computer. Workflows are automatically started using the Windows Task Scheduler. The system has run without interruption since mid October 2017. Since that time, several flood events have occurred in which the model forecasts have proven to be very useful indeed.

Forecasts and warnings will be disseminated to stakeholders using a combination of FTP, email and a Telegram channel. In the future, forecasts may also be based on the Deutsche Wetterdienst's publicy available ICON-EU products. These are currently imported but not used to force the hydrological models.

In the future, the Bandon FFS may use the DWD's ICON-EU precipitation forecast to force the HEC-HMS hydrological models


Additional information
For questions or remarks, you may contact Igor Kerin (University College Cork, Republic of Ireland, igor.kerin@ucc.ie) or Jan Verkade (Deltares, jan.verkade@deltares.nl).