My sister and myself after hurricane Andrew in 1992, south Miami
Hazards are common to every location on Earth and often shape the characteristics that define a given landscape. In the US, California is well known for earthquakes and wildfires, Florida is known for hurricanes, and the Midwest is specifically referred to as “tornado alley.” Of course these occurrences are by no means limited to these locations, and these locations are not limited to these natural hazards. Hazards include any natural event (meteorological, geological, hydrological, biological, etc.) or human-induced process or phenomenon (war, industrial accidents, etc.) that may potentially impact, endanger, or threaten lives, resources, and the environment. Having a sound understanding of how such events impact and shape the geography of a region is essential for efficient planning and mitigation of the affects of damage and loss of life when these events arise in the future. Using GIS as a tool to analyze the factors associated with a specific hazard allows for the rapid assessment and response to costly situations. Although GIS can be used as a powerful tool to analyze information in attempts to reduce risk, damage, loss, and recovery time resulting from any hazard or combination of hazards, the limitations of time and resources frequently characterize the overall usefulness of GIS in three general stages. The May 2000 ESRI white paper, “Challenges for GIS in Emergency Preparedness and Response,” explains the stages of a hazard event and continues to discuss challenges for GIS in management and analysis of information during these periods.
Prior to an event, proactive planning assesses potential risk, and whenever possible evacuation procedures are imposed to limit the affects of the hazard. During this stage, time is limited as the hazard becomes imminent, and valid information is necessary to be produced hastily. The urgency and importance of such information can be exemplified in a situation where rising flood threaten a populated location. In this circumstance, it is imperative to provide planning and rescue efforts a list of affected roadway names. To produce accurate information, a project must begin with accurate and up-to-date information. If changes in a city’s roadway network have been added or altered without being reflected in a GIS coverage, it could be possible to send responding emergency vehicles into flooded areas. Risk mapping and emergency simulation require the most current information. Reactive response begins when the event begins. After the event has ended, another reactive response situation begins to unfold. During this subsequent stage appropriate resource management and planning must occur to efficiently being the path to rebuilding and recovery. Overall, there is a need to move from reactive response to prevention and planning to me most efficient in minimizing loss. Adhering to a proactive planning method will reduce the general cost of evacuation when that time presents itself in the future.
The white paper discusses a number of important factors concerned with the acquisition and integration of spatial data in an emergency planning environment. It is necessary to identify what sources of data are available, what kinds of data needs to be obtained, who needs access to which types of data, what problems to expect when integrating sources of spatial information, and what amount of uncertainty comes with a dataset, and to what extent is the uncertainty acceptable. When working with several agencies in an emergency, it is important to have strategies in place to avoid the loss of efficiency due to poor or difficult methods of integration. One solution to this comes from the advancement of distributed computing systems. Highly efficient, temporally narrow analysis can be conducted on interactive geographic information systems via a link to immediately updated remotely sensed information in the field, however if several organizations are unaware of how to share this information, efficiency of planning and response can be significantly hindered.
The article mentions that dynamic representation, or temporal visualization, is an area that needs to be researched further, and that GIS is not the best method for representing temporal data. This was written in 2000, however, and there have since been a number of powerful options which allow for the integration of GIS information with other software packages to create dynamic maps to render time-lapsed data, etc. quite effectively. Such tools have been built directly into ArcGIS for the past few versions that create powerful digital video with ease from even the most simplistic of datasets.
Finally, scale is an issue that must be addressed in emergency management in GIS. One main problem is that DEM datasets can be inadequate for analysis in (certain) cases – especially when modeling hydrologic events. Shuttle Radar Topography Mission (SRTM) data comes in 30 meter and 90 meter resolutions. Emergency management often deals with larger scales than this would prove useful for more than very basic analysis. Higher resolution Lidar would be a more appropriate choice to acquire in order to perform surface analysis to model emergency situations involving flooding, etc.
GIS attempts to reduce the amount of risk, damage, loss, and recovery time resulting from many different hazards in the field of emergency management. There are many ways to plan proactively to contribute to a safe and efficient means of protecting society. Keeping up-to-date records and communicating with other agencies are some of the most important issues to consider to provide a well prepared emergency response strategy that will minimize loss for many affected parties.
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