The Life Safety Model (LSM) is a dynamic model that represents people's interactions with a flood and provides estimates of the number of people that are likely to be injured or killed as a result of a flood event, as well as the time that is required for them to evacuate the area at risk.
Over the past 15 years a number of methods have been developed that can be applied to estimate the loss of life as a result of flood events. Many of these methods and models were based on empirical methods that were often based on relatively limited experiments or historical events. They often rely on subjective measures that can lead to a considerable variation in the results.
Output from the Life Safety Model showing the potential fatalities and injuries. Ordnance Survey © Crown Copyright 2002. All rights reserved. HR Wallingford licence number 100019904
Animated output from the Life Safety Model showing the potential fatalities and evacuation routes
Moving on from these general empirical models, the focus of the Life Safety Model (LSM) is to develop an approach that provides the ability to simulate receptors (i.e. people, buildings, and vehicles) in a floodplain and base their interaction with a flood wave on fundamental physical equations. This led to the development of an "agent-based" simulator that can assess the "fate" of individual receptors in the floodplain. The LSM uses output from commercially available two dimensional hydrodynamic models (e.g. Telemac-2D, TuFlow) and couples it in a Geographic Information System (GIS) environment with a simulator that models the interaction of receptors in the flood. The interaction of these receptors is based on fundamental physics including mathematical models of "human toppling" defining the stability of people in water or damage to buildings in floods and the stability of vehicles in water.
The LSM can assist in simulating emergency scenarios and enable resource planning and the exploration of the consequences of different decisions by:
- providing credible estimates of loss of life using transparent auditable methods
- using readily available government and commercial GIS based data sets
- displaying results and animations that can improve the emergency response and plans for such disasters.