DESKTOP TRAILSLet the mouse do the walking! R.N. Wilkinson Thanks to: Tom Swinford
3 METHODS • ArcMap 10.1 – 3D Analyst ToolBar • Cutting Temp cross sections • Getting profile graph • Quick and easy, but Temporary • ArcToolbox - 3D Analyst • Creating shapefiles • Tools create tables from shapes for graphics and record keeping • More involved, but can be handed off easier • ON-SITE FIELD WORK (Old fashioned, not-for-GEEKs method) • Head out with a map and wander the woods • Tracking your steps can get involved • Tracing on map with pencil • GPS may not work due to vegetation • Physical demands • MOST FUN for those wanting to be anywhere but behind a computer! • So why do the work in office?
Nature Preserves Mission • Preserves are managed to: • Maintain/restore natural ecological conditions • Generally open to the public: • For Hiking • Nature study • Scientific Research (by advanced permission) • Prohibited by law in preserves to: • Remove or disturb anything from preserves • Campfires • Camping • Picnicking • Rock climbing • Littering • Vehicles • Get people back to nature: • Develop trails for hiking • Many others I will not mention here • Maintain a very lean budget!
Why design trail using GIS • Most cost effective with new elevation data and technology • Better informed decision that affects: • Endangered Wildlife • Endangered Plant life • Natural setting/beauty • By allowing you to geo-locate associated data • Line work verses Cutting trail • Not disturbing natural surroundings for planning • Pre-determine best fit of trail • Account for: • Trail length • Elevation changes • Ground distances • Areas of concern / Restricted areas • Only cost is man hours involved. • No travel costs
Data for Research/Design • Ortho Image for area • DEM of area • Existing trails for area • Plan • What is the trail for? • Restrictions in area? • What difficulty level? • Who is building trail? • Budget constraints? • Areas of interest • May have to tweak • Add attributes for design analysis • Proposed Trail • Line file with Z values • Create: this will be trail legs you analyze • Hillshade (see next slide) • Create from DEM • Spatialanalyst>Surface>Hillshade • *For viewing* – zfactor=1 • Can exaggerate by increasing z factor greater 1
Creating HillshadesDifference of Z factor settings Z factor = 1 Z factor = 5 Original DEM Hillshade tool Z factor
Some of the Tools I use: • Spatial Analyst>Extraction>Extract by mask • Cut the DEM to size of Area of Interest • In this case, NewParkArea • Spatial Analyst>Surface>Hillshade • Create a 3D view of area of interest using DEM • Easier to see than using DEM • 3D Analyst Tools>3D Feature>Add Z Information • 3D Analyst Tools>3D Feature>Stack Profile • 3d Analyst toolbar -
Map for New Preserve AOI created from multiple sources! Hillshade DEMs Ortho Attribute added for Symbols
Set up AOI created from multiple sources! Attribute added for Symbols
‘Guesstimating’ the trail Starting point -Parking lot • Pre-determine best fit of trail • Account for: • Destination • Trail length • Elevation changes • Ground distances • Areas of concern / Restricted areas Destinations
1.Set to DEM 2 4 Quick Look using 3D Analyst Toolbar Ensure 3D Analyst extension is on Open 3D Analyst Toolbar 1. Set this pull down to your DEM 2. Click on tool “Interpolate Line” 3. Draw line where you want to get cross section (black line from tool) 4. Select from “Point profile tool” drop down, Profile graph: 5. You will get the Profile Graph showing: X axis – distance of line in METERS! Y Axis – Elevation in Feet along line *NOTE* *Elevation is in feet because DEM is in feet. Y axis of graph. *Distance in meters since MAP is in UTM! X axis of graph. Analysis of this leg: Slope of Leg – 8 % or 47/574=.08 Slope along roadway = moderate If acceptable, add line to your shapefile as leg 1! 3 5. You can save this graph by: “save as”
Off the road – through the obstacles Run proposed lines 2a – Straight to objective 2b – going around valley to road, then along road, then ? Which requires structures to be built? -Bridge over creeks -Stairs -Switchbacks Leg 1 2b 2a 76’/150*3.2808333= 15% 123/100*3.28083333= 37% 2a 58’/150*3.28083333= 12% 2b 162’/180*3.28083333= 27% Destination
Starting from Parking Areausing 3D Analyst Toolbox Need shapefiles to build upon! Using Stack Profile you get elevation along line at each pixel of DEM Use established trails Using roadway to leave parking area Starting elevation – 565 ft End of line – 605 ft Length of trail leg – 175 meters *Elevation is in feet because DEM is in feet. Y axis of graph. *Distance in meters since MAP is in UTM! X axis of graph. Slope of Leg – 8 % or 47/574=.08 Slope along roadway = moderate
Comparison of: Toolbar vs. Toolbox ArcMap 3D Analyst toolbar results ArcMap 3D Analyst toolbox results Axis labels are compressed Note*: If you are in an edit session on your line file and draw lines from the Toolbar “Interpolate Line” it will add this line to your shapefile! You can do both At the same time.