Applying Least Cost Path Analysis to Search and Rescue Data: A Case Study in Yosemite National Park by Raymond A. Danser A Thesis Presented to the Faculty of the USC Graduate School University of Southern California In Partial Fulfillment of the Requirements for the Degree Master of Science (Geographic Information Science and Technology) August 2018 i Copyright © 2018 Raymond A. Danser ii Table of Contents List of Figures ................................................................................................................................. v List of Tables ................................................................................................................................ vii Acknowledgements ...................................................................................................................... viii List of Abbreviations ..................................................................................................................... ix Chapter 1 Introduction .................................................................................................................... 1 1.1 Motivation ............................................................................................................................3 1.2 Why Least Cost Path? ..........................................................................................................4 1.3 Study Area ...........................................................................................................................6 1.4 Research Objectives .............................................................................................................7 1.5 Study Expectations ...............................................................................................................7 1.6 Thesis Organization .............................................................................................................8 Chapter 2 Related Research ............................................................................................................ 9 2.1 Search and Rescue Techniques and Terminology .............................................................10 2.2 Psychological Limitations and Behaviors of Lost Persons ................................................13 2.3 GIS Tools and Analysis in SAR ........................................................................................14 2.3.1. MapSAR and MapSAR Online ................................................................................14 2.3.2. Integrated Geospatial Tools for Search and Rescue (IGT4SAR) ............................15 2.4 Trail Construction and Signage..........................................................................................16 2.5 Least Cost Path Analysis ...................................................................................................18 2.6 Summary of Related Research ...........................................................................................19 Chapter 3 Data and Methodology ................................................................................................. 20 3.1 Data and Workflow ............................................................................................................21 3.1.1. Missing Persons Incident Planning Points and Found Location Data .....................23 3.1.2. Extent .......................................................................................................................27 3.1.3. Trails and Roads Data ..............................................................................................28 3.1.4. Digital Elevation Model ...........................................................................................29 3.1.5. National Land Cover ................................................................................................31 3.1.6. Lakes ........................................................................................................................32 3.1.7. IGT4SAR Impedance Tables ...................................................................................33 3.2 Preliminary Analyses .........................................................................................................36 3.2.1. Trails, Roads and Lakes ...........................................................................................37 3 3.2.2. National Land Cover Raster.....................................................................................37 3.2.3. Slope Analysis and Assignment of Slope Impedance..............................................38 3.2.4. Stream Order Impedance Assignment .....................................................................39 3.2.5. Feature Class Division .............................................................................................42 3.2.6. Raster Reclassification to Final Impedance Values .................................................43 3.3 Calculation of the Cost Surface .........................................................................................43 3.3.1. Multi-Value Integrity Test .......................................................................................45 3.4 Least Cost Path Analysis ...................................................................................................47 3.5 Trail Divergence ................................................................................................................50 3.6 Sensitivity Tests .................................................................................................................50 3.7 Summary of Data and Methodologies ...............................................................................52 Chapter 4 Results .......................................................................................................................... 54 4.1 Least Cost Paths and Trail and Road Divergence ..............................................................54 4.1.1. Divergence Clusters .................................................................................................57 4.2 Sensitivity Tests .................................................................................................................62 4.3 Results Summary ...............................................................................................................66 Chapter 5 Discussion and Conclusions ......................................................................................... 67 5.1 Study Observations ............................................................................................................67 5.2 Use of Results ....................................................................................................................70 5.3 Recommendations ..............................................................................................................70 5.4 Study Limitations ...............................................................................................................71 5.4.1. SAR Missing Persons Data Limitations ..................................................................72 5.4.2. Least Cost Path Analysis Limitations ......................................................................72 5.4.3. Divergence Point Data .............................................................................................73 5.5 Future Work .......................................................................................................................73 5.6 Conclusion .........................................................................................................................74 References ..................................................................................................................................... 76 Appendix A Park Trail Names and Lengths ................................................................................ 80 Appendix B Least Cost Paths Explained ..................................................................................... 82 Appendix C Links to Project Data on ArcGIS Online ................................................................. 86 4 List of Figures Figure 1 Study area ......................................................................................................................... 6 Figure 2 Park trail sign placement options. .................................................................................. 17 Figure 3 Study workflow .............................................................................................................. 21 Figure 4 Doherty data incident planning points ............................................................................ 26 Figure 5 Doherty data found locations.......................................................................................... 26 Figure 6 Buffer (5.2 miles) extent using near analysis ................................................................. 28 Figure 7 Study roads and trails ..................................................................................................... 29 Figure 8 DEM of Yosemite National Park ................................................................................... 30 Figure 9 Land cover from the NLCD within Yosemite National Park ......................................... 31 Figure 10 Lakes within Yosemite National Park .......................................................................... 33 Figure 11 Preliminary analysis workflow