Inventory Monitoring Division GIS Program Natural Resource Program

Inventory & Monitoring Division – GIS Program Natural Resource Program Center Travel Time Cost Surface Model (TTCSM) Kirk Sherrill - GIS Specialist Brent Frakes – Geographer Stephani Schupbach – GIS Specialist NRPC – I&M Division – GIS Program Fort Collins, CO George Wright Society Conference GIS Rapid Fire – March, 2011 TTCSM - SOP 1

Inventory & Monitoring Division – GIS Program Natural Resource Program Center The TTCSM: Ø Is a GIS Python Model which: - Calculates travel times from defined point(s) to other locations in an AOI -Dynamic: User and Park Specific -Uses readily available GIS Data Ø Efficient Field Data Sampling Design and Planning Ø Packaged as two python scripts Requiring only basic programming experience Moderate GIS experience 2

Inventory & Monitoring Division – GIS Program Natural Resource Program Center Ø TTCSM is a linear model which performs: – – Cost Surface Speed Surface Travel Cost Surface Travel Time Modeling TTCSM - Schematic Inventory & Monitoring 3 Division

Inventory & Monitoring Division – GIS Program Natural Resource Program Center Ø Cost Surface - Represents the amount of travel speed resistance per cell - Generated in a simple overlay manner - Key Steps: - Determine desired input layers and order - Assign Percent of Maximum Travel Speed (PMTS) values for each data layer Inventory & Monitoring 4 Division

Inventory & Monitoring Division – GIS Program Natural Resource Program Center Ø Speed Surface - Defines the travel speed (seconds/per meter) per cell - Function: - Road Network Speed - Trail Speed - Hillslope Speed - Trail and Hillslope Speed are defined using Slope values and Tobler’s (1993) equation: Tobler, W. 1993. Three presentations on geographical analysis and modeling. Technical report. 93 -1, National center for geographic information and Analysis, University of California, Santa Barbara. Inventory & Monitoring 5 Division

Inventory & Monitoring Division – GIS Program Natural Resource Program Center Ø Travel Cost Surface - Final Travel Speed at which movement in a cell occurs. Travel Cost Surface (miles/hour) for ROMO 6

Inventory & Monitoring Division – GIS Program Natural Resource Program Center Ø Final Step: Travel Time Modeling 1. Traditional Cost Distance Modeling • Arc. GIS Cost Distance Function • Isotropic Model (treats all directions as equal) 7 Travel times for a TTCSM which used Cost Distance Modeling

Inventory & Monitoring Division – GIS Program Natural Resource Program Center 2. Path Distance Modeling - Arc. GIS Path Distance Function • Directionality Matters (Anisotropic) – incorporate the influence of Slope • More Realistic User Specific Travel Times (Upslope and Downslope) • 9 Predefined Path Distance Scenarios Travel Speed by Slope for five different flat surface walking speeds when using path 8 distance modeling with a “linear” Path Distance Scenario.

Inventory & Monitoring Division – GIS Program Natural Resource Program Center Ø Travel Time Modeling Output: - Travel Time Grid(s): Hours, Minutes, or Seconds Ø Least Cost Paths • One Way or Round Trip Least Cost Paths 9 Travel time least cost paths using an inverse linear path distance travel time model

Inventory & Monitoring Division – GIS Program Natural Resource Program Center Ø TTCSM Summary - Dynamic in nature to accommodate user Specific Travel Time Modeling Needs Outputs Travel Time Grids and Travel Time Least Cost Paths Runs in the Python Scripting Language on a computer with Arc. GIS 9. 3 Working on Arc 10 functionality – ESRI Problem between versions! Ø Scripts and SOP are Downloadable at: http: //nrinfo. nps. gov/ - Search for “TTCSM” 10

Inventory & Monitoring Division – GIS Program Natural Resource Program Center Thanks & Questions? 11