The agent-based simulator in the Life Safety Model (LSM) enables it to represent a myriad of probable scenarios which could result from a flood event. The LSM allows the effectiveness of warnings, road capacity, as well as the evacuation method, and how they affect the risk to people and time to travel out of the area at flood risk to be investigated.
The Life Safety Model was developed to represent:
- The number of people that are killed or injured by an inundation
The time-varying properties of the flood in terms of its depth and velocity affect people’s survival capacity, and also the speed at which they move. Should a person be caught in the floodwave their chance of survival depends on the velocity and depth of the flood at a particular point in time (i.e. above a certain threshold level people will be drowned or be swept away by the water). However, the effect of continuous exposure to water is also modelled and is represented in the number of fatalities.
- The movement of vehicles is modelled by a simple traffic model
This allows the effects of traffic jams and other bottlenecks to be taken into account when the evacuation time is estimated.
- The dynamic interaction of the flood wave with vehicles
If people are leaving the area at risk in a car the engine will stop once the vehicle has encountered a certain depth of water or if the combination of velocity and depth is too high it will get swept away in the floodwater.
- The capacity of each building to withstanding the floodwater
Depending on the characteristics of the building and the flood, buildings can: suddenly collapse; fail progressively as a consequence of continuous exposure to the flood; or remain intact.
- People being modelled as individuals and also as groups (e.g. families)
People can be represented as individuals or groups (e.g. families). If they are modelled as groups the speed at which the group moves is influenced by every member of the group. The speed at which a group moves is influenced by every member of the group.
- The speed of the dissemination of flood warnings
People can receive warnings from a “warning centre” and also by “word of mouth” from other people who are aware of the impending flood wave.
- The evacuation of people along roads or footpaths, toward refuges is predetermined by the user
The refuges can be areas of high ground, buildings resilient to the flood wave with more than one storey or specially adapted shelters. The location and number of these safe havens can be set by the user.