"Hazard mitigation is defined as any sustained action taken to reduce or eliminate long-term risk to life and property from a hazard event. Hazard mitigation results in long-term, cost-effective, and environmentally-sound reduction of hazard vulnerability. The goal of hazard mitigation is to save lives and reduce property damage. This, in turn, can reduce the enormous cost of disasters to property owners and all levels of government. In addition, hazard mitigation can protect critical community facilities, reduce exposure to risk, and minimize community disruption. Examples include hazard mitigation planning, acquisition and relocation of structures out of the floodplain, and the construction of saferooms (e.g., tornado and severe wind shelters) for public and private structures. FEMA's Pre-Disaster Mitigation (PDM) program provides funds to States, Territories, Tribes, and communities for hazard mitigation planning and for the implementation of mitigation projects prior to a disaster event. The PDM program provides a significant opportunity to raise risk awareness and reduce the nation's disaster losses through pre-disaster mitigation planning and the implementation of feasible, effective, and cost-effective mitigation measures. The PDM program provides funding to reduce loss of life as well as damage and destruction to property from natural hazards."
Federal Emergency Management Agency: http://www.fema.gov/index.shtm