A flood risk analysis model with topographical inundation and life-loss

Abstract

Quantified models of flood risk that incorporate an explicit representation of the performance of flood defence infrastructure are becoming an increasingly important component of efforts to manage flood risk. The models have been applied to support a wide range of decisions, including long-term strategic planning, assessment of investment needs and shorter-term asset management. The model currently applied in practice by the Environment Agency in England and Wales makes a number of simplifying assumptions to achieve computationally practical run-times. One of these simplifications relates to the volume-based flood-spreading algorithm that is applied. This paper describes the implementation of a new time-based inundation model within the existing risk analysis modelling approach. The new inundation model offers a significant increase in the representation of the physical processes within the flood simulation component of the risk analysis model. It also offers new outputs in terms of estimates of maximum depths and flood velocities. Velocities are known to be an important factor in flood-related fatalities. A simplified method to estimate life-loss has been combined with new output from the improved inundation model to illustrate how estimates of risk to life could be provided.

A review of flood impact assessment approaches for underground infrastructures in urban areas: a focus on transport systems

“…Further researches should include analysis on the safety of users/riders from direct water flooding and/or indirect abandonment in tunnels or metro stations with failed infrastructure and worsening environmental conditions. Several publications discuss indepth the development and application of models for estimating fatalities and injuries due to flood events (Di Mauro et al 2012, Gouldby et al 2015. Unfortunately, research focused on the development of such models for underground conditions has had minimal progress at the academic level.…”

Comparing the scale of modelled and recorded current flood risk: Results from England

“…We think a change in flood character in very extreme events is possible, but the evidence is sparse. For example Gouldby, Lhomme, Jamieson, Hornby, and Laeger (2015) investigated this issue and their damage curve rises steeply between the 200 and 300 year return periods, but flattens off substantially after the c. 330 year return period. The increase between the event damages for the 330 year flood and the 1,000 year flood is only approximately 13.5%.…”