The Life Safety Model (LSM) is an agent-based 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.
Development of the LSM was started almost 20 years ago by BC Hydro to enable them to improve their assessments of the risks posed to people by their hydropower dams in British Columbia in Canada.
In 2010, HR Wallingford took ownership of the LSM and has continued to develop the software. The development of the LSM has been the subject of many journal papers and conference presentations. We are using it to carry out risk to people assessments and to contribute to emergency plans for fluvial floods, coastal inundations, and dam break studies worldwide.
How does the LSM work?
There are a number of simple, empirically based equations which allow simple estimates of the risk to people from floods to be made. Although these equations may be suitable for simple risk screening exercises, they do not provide the ability to model each individual person, how they interact with the floodwater and the effects of measures such as improvement in flood warnings, as well as evacuations routes.
The Life Safety Model (LSM) provides the ability to simulate each person, building and vehicle in a floodplain and their interaction with the flood wave based on fundamental physical equations. The LSM comprises an “agent-based” simulator which can assess the “fate” of individual people. The LSM uses outputs from commercially available two dimensional hydrodynamic models (e.g. Telemac-2D, TuFlow, MIKE 21) and couples them in a Geographic Information System (GIS) environment with a simulator that models their interaction with the floodwater. This interaction is based on mathematical models which include representations of people’s and vehicles’ stability and the strength of buildings in floodwater.
How can the LSM assist you?
The LSM simulates people’s responses to a flood event or dam break. It can be used to contribute to risk assessments and emergency plans by:
- Providing credible estimates of loss of life using transparent auditable methods
- Allowing estimates of evacuation times to be made both by people on foot, in vehicles, or a combination of these
- Assessing the effects of improving evacuation routes and flood warnings on the risk to people
- Displaying the results in the form of animations.
An animated output from the Life Safety Model showing the potential fatalities and evacuation routes for a re-creation of the 1953 North Sea flood on Canvey Island, which is located in the Thames Estuary in the UK. The animation shows the 1953 flood wave following a failure of the flood defences, with each person represented by a different coloured dot. The red dots show the locations where people perished in the flood.