Georeferencing Incidents from Locality Descriptions and its Applications: a Case Study from Yosemite National Park Search and Rescue
The Search and Rescue (SAR) of individuals who become lost, injured, or stranded in wilderness presents a unique and worthwhile spatiotemporal challenge to investigate. Once incidents are georeferenced they can be spatially queried and analyzed. However, one major challenge for evaluating SAR in a spatial context is the lack of explicitly spatial data (addresses or coordinates) for historic incidents; they must be georeferenced from textual descriptions. This study implemented two established approaches for georeferencing incidents, the ‘Point‐Radius’ and ‘Shape’ methods. Incorporating uncertainty measurements into a spatial database allows for more appropriate analyses of spatial dependence and the spatial distribution of incidents. From 2005–2010, 1,271 of 1,356 Yosemite Search and Rescue YOSAR incidents (93.7%) could be georeferenced using the Point‐Radius Method, with a mean uncertainty radius = 560 ± 51 m and mean uncertainty area of 3.60 ± 0.840 km2. However, when the Shape Method was applied to six case studies by considering the reference object shape, the uncertainty areas were reduced considerably (by up to 99.5% of the uncertain area generated by the Point‐Radius Method). This is the first spatially‐explicit study of SAR incidents and yields valuable insights into the role of georeferenced data in emergency preparedness.
Document Type: Research Article
Affiliations: 1: School of Engineering, Sierra Nevada Research Institute, University of California, Merced 2: Institute of Remote Sensing and Geographic Information Systems, Peking University 3: Museum of Vertebrate Zoology, University of California, Berkeley 4: Department of Geography, University of Kansas
Publication date: 2011-12-01