Factors affecting the expectation of casualties in the virtual range toxicity model

The virtual range (VR) is an environment that integrates in a seamless fashion several models to improve complex systems visualization. A complex system is a nonlinear system of systems whose interactions bring together interesting emergent properties that are very difficult to visualize and/or study by using the traditional approach of decomposition. The VR toxicity model as described here represents the different systems that interact in the determination of the expectation of casualties (E/sub c/) resulting from the toxic effects of the gas dispersion that occurs after a disaster affecting a space shuttle within 120 seconds of liftoff. We present a detailed description of the VR and the factors affecting E/sub c/. The system helps local authorities to estimate the population at risk in order to plan for areas to evacuate and/or for the resources required to provide aid and comfort and mitigate damages in case of a disaster.