Assessing flood risk under uncertainty: a case study for improved resilience

Manousos Valyrakis, John Connolly, Mark Solley

Wednesday 1 july 2015

12:45 - 12:48h at South America (level 0)

Themes: (T) Flood risk management and adaptation, (ST) Flood risk assessment, Poster pitches

Parallel session: Poster pitches: 9J. FloodRisk - Assessment

Flooding in rivers and estuaries is amongst the most significant challenges our society has yet to tackle effectively. Use of floodwall systems is one of the potential measures that can be used to mitigate the detrimental socio-economical and ecological impacts and alleviate the associated costs of flooding. This project aims at demonstrating the utility of such systems for a “real world” case study via appropriate numerical simulations. This study documents the results of characteristic inundation modeling scenarios and flood mitigation options, for the area of Whitesands at Dumfries, Scotland. In particular, the history and hydrology of the area are discussed and the assumptions and hydraulic model input (model geometry including instream hydraulic structures -such as bridges and weirs- river and floodplain roughness, initial and boundary conditions) are presented, followed by the model results. A robust framework is developed to allow utilising coarse grained information about the area and costs involved, in modeling flooding and assessing flood risk. Specific emphasis is given on the potential improvements to flood risk brought about by mitigating it downstream of susceptible areas, using a combination of direct protection measures (flood wall systems), flood prevention measures (storage schemes) and increased preparedness measures (such as communicating flood risk to the public along with the use of early warning systems).