Multiple GIS Databases Support Fire and Rescue Services
Apollo Teng, DIST
The Fire and Rescue Commission (FRC) of Montgomery County started a Critical Issues study in January 1996. One of the issues being examined by the study committee was the locations of the fire stations and rescue squads versus the response times. Under the coordination of Assistant Chief Michael Love, FRC Staff Director Neil Schorb and Analyst Scott Gutschick requested the DIST GIS Team to provide various GIS services to support the effort. Tim Taormino of the GIS Team carried out these tasks during the past two years.
‘Fire Geography.’ There are 19 fire stations providing fire protection to the county residents and business. Thus the County is divided into 19 Fire Station Response Areas (SRA). A more detailed service area unit is FireBox. There are 535 FireBox areas (FBA) in the County. For higher level planning and management control, the County is divided into 5 fire service districts (FSD), each consists of varying number of SRAs.
GIS Layers for Fire Service Areas. With paper maps provided by the Fire staff assigned to the County Emergency Communication Center, DIST GIS Team (Kline, Selbst, Lillis, and Taormino) created the GIS layers (coverages) corresponding to FBAs, SRAs, and FSDs. These data layers were checked by the ECC staff several times before it was finalized. The background coverage used for the service area construction was the GBF/DIME coverage being maintained by DIST.
Rescue Squad Distribution Study. The County’s Rescue Squad Committee has defined effective rescue squad coverage as 90% of the population within 10 minutes’ response time after placing a 911 call (which translates to 5 miles travel distance). Generating 5-mile buffer zones (circular areas) from fire stations and comparing the aggregate buffer zone areas with the area of the County is a simple task. However, if the 5-mile driving distance is used, a more sophisticated GIS software capability is needed¾ NETWORK package in this case. Several iterations were run to see where rescue equipment should be located to cover the 90% population. The goal is maximum coverage with a minimum of locations. GIS technogy clearly made this ‘what if’ analysis possible.
County-wide Response Time Study. The County fire service guidelines specify that 95% of the County should be within 5-mile of any fire station. Generating 5-mile buffer zones (circular areas) from fire stations and comparing the aggregate buffer zone areas with the area of the County is a simpler task. However, if the 5-mile driving distance is used, a more sophisticated GIS software capability is needed—NETWORK package in this case. Several iterations were run to see which, if any, fire station(s) can be closed without falling below the 95% criterion. GIS technology clearly made this ‘what if’ analysis possible.
‘Demand Forecasting.’ Various SRA-based fire statistics (e.g., 91-95 Average Annual Incidents, 91-95 Average Structure Fires, 91-95 Loss Per Structure Fire, CY95 Incidents, and CY95 Primary Unit Responses) were provided by FRC and corresponding thematic maps were generated (see example map). To have some measure of predicting the future demand of fire protection services, the population forecasts (at Traffic Zone level and five-year intervals) provided by M-NCPPC were spatially reapportioned into the SRAs. Again, GIS (Polygon Intersect) software made the reapportionment of summary statistics (from Traffic Zones to Station Response Areas) relatively easy. This capability in turn made the study more objective.
‘Map Book for the Fire Trucks.’ Assistant Chief Love is also interested in computerizing and standardizing the fire truck travel maps being improvised and used by the various fire stations. The DIST GIS Team has created two prototypes of such maps and are being reviewed by various parties within DFRS and the stations. Prototype I has one FireBox Area per page (see example map). For a rural FBA covering a large area, two pages (face-to-face) might be needed to provide legibility. Prototype II has each map page cover uniform area (two 200-scale map sheets stacked, or 6000 feet east-west by 8000 feet north-south). Of particular note is that multiple GIS databases have been tapped for this pilot project As the legend indicates, the FireBox boundaries come from the ‘fire geography’ coverage; Fire Hydrants come from the WATER coverage maintained by WSSC; Building Outlines (for larger buildings) and Hydrography come from MC:MAPS database; and the various roadway centerlines (and street names) come from GBF/DIME database. An effective data integration has been achieved with this pilot project.
The Department of Fire and Rescue Services (DFRS) joins with the Police Department and DIST in the planning and implementation of the 800 MHz communication infrastructure project. More technology (e.g., mobile data terminal, automated vehicle locating, real-time fire apparatus deployment, fire truck and ambulance routing and navigation) can be tapped for providing a even higher level of fire protection in the near future and into the new millennium. The DIST GIS Team stands ready to offer continued and higher level services.