By Randall Hanifen
Contributor, EDM Digest
Evacuations are one of the most difficult tasks in emergency management. Evacuations require much knowledge and coordination among many groups, and most importantly, an understanding of the citizens in the community.
Evacuations have technical and human factors that must be blended. The failure of either the technical or the human factor of an evacuation cancause the failure of an entire operation.
Technical Factors Involved in Evacuations
From a technical perspective, emergency managers must fill in the following equation:
Total Evacuation Time = Td + Tn + Tm + Tt
Td is the time delay between a disaster occurrence until the evacuation order. Tn is the time required to notify a community’s occupants and Tm is the time required for people to mobilize and start evacuations. Lastly, Tt is the travel time required for a community to leave the affected area. While this equation is technical and quantitative, many of the technical time segments require human action.
The use of geographic information system (GIS) software and predictability models can help measure the time needed for communities to travel to safe areas, the ability of roadways to handle the volume of traffic, and the estimated number of people and vehicles that need to leave the affected area. Traditionally, we have not had the advantage of quantitatively calculating these factors.
Collaboration with government agencies prior to a disaster is also a vital part of emergency management. For example, emergency managers must work with public works agencies to move traffic in a counter-flow fashion and adjust traffic control devices to better facilitate traffic movement during an evacuation.
Human Factors Affecting Evacuations
The human factors related to evacuation are the preparation for the evacuation and the ability to evacuate. Emergency managers must understand their community because their ability to evacuate and the process it will take to actually evacuate is community-dependent. For example, emergency management plans for an affluent community may not work in a poor community, especially in relation to transportation and replacement housing.
Remember, we must plan to ensure that we establish the correct connections with the needed groups to facilitate evacuation. We must also understand the technical portion of the evacuation plan. However, it is crucial to understand the human and socioeconomic factors of our community that make successful evacuation and relocation possible.