GIS for Medical Emergency Preparedness: Siting Medical Distribution Centers in an Emergency

Whether the emergency event is an anthrax plume or the aftermath of a hurricane, the efficient and equitable distribution of medical supplies and services is a critical part of the response. The GIS Division and Health Department in the City of Alexandria, Virginia, teamed up to find the optimal location and number of medical distribution centers using ArcGIS Desktop, ArcGIS Spatial Analyst, and ModelBuilder to develop a raster allocation model.

Under the city’s baseline strategy, which uses its 17 public schools as Emergency Medical Distribution Centers (EMDC), portions of the city are effectively cut off from pedestrian access. To develop a better alternative, both agencies worked to identify 40 potential sites to use as EMDCs. At the heart of the model is a detailed raster that classifies the urban environment into two surface types: barriers and areas of free movement. The barriers were extracted from the city’s high-resolution planimetric and cadastral layers such as building footprints, fences, water bodies, and private residential properties. This complex surface approximated pedestrian decision making during an emergency event and yielded a new and improved set of EMDCs. The resulting distribution is more geographically equitable, pedestrian accessible, and evenly allocated.

Courtesy of the City of Alexandria GIS Division, 2007.