Warning Systems

Warning systems for natural hazards provide notification of potential hazard events through the monitoring of natural processes. Monitoring is usually technological with a wide range of detection and notification hardware available and in use. Warning sources can be natural, informal, or official and if available time to respond is short, natural and informal warnings may be the only source of information before impact of a hazard. In recent years there has been an increasing focus on end-to-end warning systems, which focus heavily on community involvement, preparedness, and warning response actions. Response actions are usually to either evacuate or shelter in place, with the added complexity of sometimes protecting valuables. Decisions to disseminate awarning are often difficult tomake, especially if the desired response is to evacuate, because as certainty of the onset or specifics of a hazard such as location, magnitude, and intensity increases over time the time remaining to respond decreases. The delivery and content of a warning message has been heavily studied and there are a range of characteristics of effective warning messages. Warning systems are often not fully effective, so they should be considered along with a range of risk management options, especially land use planning.