WP3 - Reliability of Urban Flood Defences
Urban flood defences comprise both soft soil embankments and hard structures. Failures are very often caused by internal and / or external erosion processes, particularly at transitions between defence types. Complex combinations of defence types are typical in urban areas. Since flood defence systems are only as strong as the weakest links (“risk hotspots”), these have to be identified, assessed and strengthened.
The overall objective of WP3 is to improve the performance (reliability) and assessment of urban flood defences and to underpin the construction technologies developed in WP4. Methods from WP3 will also support and mesh with the integrated decision support methods identified in WP5. The research will build up on the results of recent or on-going projects such as the European FLOODsite and ComCoast projects and national/regional projects such as FRMRC (UK), RIMAX (DE), NOAH/FLIWAS(NL, DE), FloodControl2015, SBW (NL), Criterre and ERINOH (FR).
Two key goals of this work are:
- To improve fundamental understanding of erosion failure processes that have proven to be critical in recent major flood events in urban areas.
- To increase the effectiveness and efficiency of risk based asset management by applying and refining innovative and cost-effective measurement and monitoring technologies in combination with other information sources for the identification of high risk areas (weak spots).
The following specific issues will be addressed for improving the performance characterization of urban flood defences: internal erosion of embankment dikes, structure transitions: (performance, design and repair solutions), performance of vegetation during flooding, rapid, non intrusive geophysical methods for assessing dikes, high density aerial LIDAR survey.
All those information sources will be combined into geographical information system (GIS) for dike diagnosis. This task will develop generic solutions for hard (model parameters that can be measured) and soft (e.g. observations, real-time monitoring data or past experiences) data integration together with dike diagnosis.