Backcountry Emergency Response: Extending E911 Beyond the Roads

(click to enlarge) One of the most important applications of geotechnology has been Enhanced 911 (E911) location technology that enables emergency services to receive the geographic position of a mobile phone. The geographic position is automatically geo-coded to a street address and routing software is used to identify an optimal path for emergency response. But what happens if the call that “I’ve fallen and can’t get up” comes from a backcountry location miles from a road? The straight-line distance to the closest road location “as the crow flies” is rarely the quickest route in mountainous terrain. A grid-based continuous space solution is a bit more complex than traditional network analysis as the relative and absolute barriers for emergency response are scattered about the landscape. In addition, the intervening conditions affect modes of travel differently— a “stepped accumulation surface” approach is needed that characterizes effective distance …“as the crow walks.”

Poster prepared by Joseph K. Berry for GIS Day, 2012. Supporting paper is based on Beyond Mapping columns in GeoWorld that have been compiled into the online book Beyond Mapping III by Joseph K. Berry posted at www.innovativegis.com/basis/MapAnalysis/. Permission to freely use and distribute these materials is granted.

For more information, see the online book Beyond Mapping III, Topic 29 “Spatial Modeling in Natural Resources” posted at www.innovativegis.com/basis/MapAnalysis/.

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Free-use materials posted at www.innovativegis.com/Basis/Papers/Other/BackcountryER_poster/

BackcountryER_Berry.pdf – a 3’ x 4‘ poster (print shop ready; can be printed smaller)

Backcountry_ER.pdf – a 5-page paper describing the approach presented in the poster (includes further online references)

Backcountry_ER_extension.pdf – a 4-page paper describing the use of “Optimal Path Density Analysis” to identify Corridors of Common Access for emergency response

EmergencyResponse.ppt – a PowerPoint slide set describing the three steps (truck, ATV, hiking), model flowchart, and an animated series of slides showing the propagation of the “splash” algorithm wavefront.

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Further online references: 1) See www.innovativegis.com/basis/MapAnalysis/Topic29/EmergencyResponse.htm for an animated slide set illustrating the incremental propagation of the travel-time wave front considering on- and off-road travel and materials for a “hands-on” exercise in deriving continuous space emergency response surfaces. 2) See www.innovativegis.com/basis/MapAnalysis/Topic14/Topic14.htm#Hiking_time for a more detailed discussion on deriving off-road travel-time surfaces and establishing optimal paths. 3) For background information in applying “effective distance” in natural resources, see www.innovativegis.com/basis/MapAnalysis/Topic29/Topic29.htm. 4) See www.innovativegis.com/basis/MapAnalysis/Topic25/Topic25.htm for detailed discussion of the “splash” algorithm for calculating effective distance.