Formal model of earthquake disaster mitigation and management system

Wireless sensor and actors networks (WSANs) have become an important research area due to its large number of applications in safety, security and mission-critical systems. Natural disasters such as earthquakes and floods have distressing effects on human lives, economy and environment particularly in the developing countries due to their high population and lack of infrastructure. Earthquake is one of the major such disasters which causes a huge loss in terms of deaths, environment damages and loss of property because of its unpredictable nature. There exists much work on earthquake prediction, disaster mitigation and management but mostly is based on simulation and testing techniques which have certain limitations. Formal methods are mathematical approaches which assure correctness of systems to overcome limitations of simulation and testing techniques. That is why a formal system of earthquake disaster mitigation and management using formal methods and WSANs is proposed. Sensors and actors are deployed in the earthquakes vulnerable areas in the form of subnets which increase energy efficiency of the network as the processing becomes localized at a subnet level. Firstly, graph theory is used to represent subnet-based model which is then transformed into a formal model. Vienna Development Method-Specification Language (VDM-SL) is used to describe and prove correctness of the formal specification. The developed specification is then validated and verified through VDM-SL Toolbox facilities by analyzing the pre/post conditions and invariants over the formal system.