1. QGIS Lab Exercise
Using QGIS for Trail Management using the Precipice Trail in Acadia National Park
Elise Goplerud and Emma Houston
University of Maine, School of Forest Resources, SFR 400
December 7, 2016

2. Overview What is QGIS What did we collect Goals of exercise Resources
Procedure
Final Product
Pros/Cons of QGIS
Questions

3. What is so special about QGIS?
Quantum GIS platform
Free for Window and Mac computers
Volunteer driven
QGIS stands for Quantum GIS platform. This is one of the only free GIS platforms available to the public. It is available for Windows and Mac users but they are currently working on a version for Android devices It is a completely volunteer driven project and they receive their funding mostly from sponsors. Most sponsor groups are from user groups from different countries and states. In addition to being able to make maps you can also share your projects and layers on their public server.

4. What did we collect? Precipice Loop Trail View sheds Trail Features
Rankings of trail difficulty
View sheds
Trail Features
Hand rails
Signs
Ladders
Staircases
Foot rails
What we did
Using this data…………(next slide)

5. Who would be interested in this exercise?
Natural Resource Professionals!
Design trails
Analyze terrain
Create contours and find elevation

6. What we want people to take away from this lab…
Understand DEM’s and what they can be used for such as terrain analysis and contour line creation.
Basic QGIS functions such as clipping, adding lines/points, deleting line segments etc.
How to create a basic query
Installing plugins

7. Helpful Resources
Using DEM data:  
Editing in QGIS: with_vector/editing_geometry_attributes.html
Creating a layout:

8. Procedure…

9. Create Folder for Lab Work
Open D:Drive on your computer’s file explorer
Create a file with your name (first and last) if you do not already have one
Create a folder named QGIS Labs [Your Initials]

10. Downloading the Data Acadia National Park Data DEM Data
Go to link:
Save digital file named ‘nps_boundary.zip’ to your folder
Go to link:
Save digital file named ‘HikingTrails_2016.zip’ to your lab folder
DEM Data
Go to link:
Under the downloads section on the right side of the page, click on the link ‘Bar_Harbor_DEM_3643.zip’
Save the DEM data to your folder
Data we are going to work with are Acadia National Park Boundaries and their hiking trails. Digital elevation model data from Bar Harbor. Data collected by us (existing trails, viewsheds, trail features)

11. Downloading the Data Precipice Trail Data
Go to N:Drive> SFR 400> QGIS Lab Exercise and copy the following items into your folder:
Existing.shp
Trail_Fe.shp
Viewshed.shp

12. Opening DEM Data in QGIS
Open QGIS application and find your D:Drive folder in the Browser Panel found in the left column of your screen. Here you should see all of the files you recently downloaded.
Under your browser panel, find the Bar_Harbor_DEM_3643 folder.
Double click on the bar_harbor_me_mhw.asc file to open it as a layer.
In the dialog box that appears (see picture), make sure that WGS 84 is selected as the Coordinate Reference System (CRS) - Click OK
The data will take a minute to open and you will see the DEM in the projects window.
This is the instructions for opening up DEM Data

13. Opening DEM Data in QGIS
Your file will look somewhat like this:
Point out MDI

14. Clipping the DEM Data
Click on the Raster Tab on the File Toolbar > Extraction > Clipper…
Leave the input file the same (bar_harbor_me_mhw.asc)
Click the select next to the Output file section and find your QGIS lab folder
Name the file “Acadia DEM Clipped”
Leave file type the same (Tif)
Leaving the Clipper Dialog Box open, drag your mouse (with a cross) over the landmass that is MDI (see pictures below)
Make sure that the Load into canvas when finished box is checked
Click OK
In the Coordinate Reference System Selector Dialog Box, change the projection to be WGS 84 > Click OK
Close out of Dialog Box when ‘Process is Complete’ Box Appears
You will now see “Acadia DEM Clipped” in your Layers Panel
Right click on bar_harbor_me_mhw and select Remove > Click OK
This DEM file is huge. Everytime you move the screen around it takes several seconds to reload. It is also pretty hard to make out MDI. To make this easier we decided to clip the file down to just the area relevant to what we are looking at.

15. Clipping the DEM Data Your screen will look somewhat like this:
Clipped just to include MDI

16. Generating Contour Lines Using DEM Data
Raster > Extraction > Contour
Input file should be the DEM File you just clipped and named “Acadia DEM Clipped”
Click on the search button next to the output file and find your folder
Save file as Contour
The interval between contour lines is in meters - Choose a value you find appropriate (between 20m and 40m)
Click Attribute Name and leave it as ELEV
Make sure the ‘Load into canvas when finished’ box is checked (See picture below)
Click OK
In the dialog box that appears, keep Coordinate Reference System that appears the same (WGS 84) > Click OK
Close out of tabs
We are building a trail and contour lines are important to understand. QGIS makes it easy to create contour lines using the DEM data.

17. Adding a Ruggedness Index Using DEM Data
Raster > Terrain Analysis > Ruggedness Index
Elevation Layer is “Acadia DEM Clipped”
Output Layer > Search > Find your QGIS file > Save as Ruggedness Index > Click Ok
Output format should stay as GeoTIFF
Make sure the ‘Add result to project box’ is selected
Click Ok
Keep the Coordinate Reference Selector Dialog box the same > Click OK
Ruggedness Index will appear as a layer in your layer panel
Drag the Contours layer to the top of your layer panel list so that they appear above the ruggedness index
Terrain Analysis is a useful tool and it can find slope, aspect, hills.hade, relief, and ruggedness index. Since we are working with a hiking trail for this exercise we are going to use Ruggedness Index

18. Changing the Color of the Ruggedness Index
Double click on the layer Ruggedness Index to open properties
Under Style > Band Rendering > Render Type > Single Band Pseudocolor
Under Generate New Color Map, choose color scale that you like > Set Max Value to 20 > Classify > Apply (Note that whenever you want to change color properties you need to click classify before apply)
Under Transparency > Change Global Transparency to approximately 40% > Apply > Click OK
Unclick the black X next to the Acadia DEM Clipped Layer

19. Ruggedness Index
Part of our exercise is to have students explain what the values of the ruggedness index indicate. But since you all aren’t doing the assignment I’ll explain: The ruggedness index value is calculated for every location, by summarizing the change in elevation within the 3×3 pixel grid.  It compares the difference in elevation change with the squares surrounding it.  Ruggedness index values are grouped into categories to describe the different types of terrain. These range from 0 which is level to extremely rugged

20. Importing Acadia Shapefiles into QGIS
Layer > Add Layer > Add Vector Layer > Under Source - Dataset - Browse find your QGIS lab file in the D: drive
Control click Existing.shp, HikingTrails_2016.shp, Trail_Fe.shp, Viewshed.shp and click OPEN to add these layers to your map
*Note: Existing, Trail_Fe, and Viewshed are all data points recorded by Elise and Emma. Hiking Trails_2016 was data collected by the NPS.
Under your Layer Panel, the four new layers will appear
Put the four layers at the top of your Layer Panel List

21. Adding a Trail Segment
*Find the section at the beginning of the “Existing” trail.  Note that the existing trail file is missing some parts to it and diverges from the NPS data, especially at the start of the trail. Our goal is to add the missing trail segment and delete the part of the trail that does not overlap with the NPS data. If you have trail_fe open you will see that there are two points floating to the east that indicate the trailhead. We would like to connect our existing trail to these two points.  Additionally, note that there is a small segment of the “Existing” trail that offshoots from the NPS trail.
Highlight Existing in your Layer Panel by clicking on it
Under the digitizing toolbar > Toggle Editing > Add Feature
Click the last point on the existing trail. Trace along the Hiking Trails 2016 trail by clicking at each point when want to change the direction of the line.
The end of the trail is where you found the trail_fe points that indicated the trailhead.
Once you reach the end, right click
In the dialog box that appears fill in boxes as appears in the image to the right.
Click OK
In digitizing toolbar, click Save Layer Edits
Toggle Editing Off
This is where we get into creating a trail. Our data was missing a section between the trail head and about 100 ft up the trail. Fortunately, we have the park service data for the trail. In this section we edit the data Emma and I created by tracing along the park service trail

22. Deleting False Trail Segments
With Existing highlighted in the layer panel turn toggle editing back on
Note the segment of existing trail that does not correlate to the NPS trail and the nodes (marked by x’s) along that incorrect trail segment
Click Node Tool on > Click somewhere along the trail (note that it highlights nodes in a red box) > Select all of the points that you want to delete by selecting control and clicking on the x’s you want to delete > the boxes will turn blue > click delete on your keyboard
Two Nodes will be left over. With toggle still on, select nodes by using Select features by using area or single click. In the digitizing toolbar, select the Trash Icon for Delete Selected
Save Layer Edits
Toggle Editing Off
There is a part of the data that Emma and I created that goes off trail. We show people here how to delete line segments.

23. Changing Trail Colors Based on Difficulty Rating
Double click on Existing Layer in Layers Panel
Under Style, choose the icon that says single symbol. In the drop down menu choose Rule based
Select Add Rule > Label = Difficulty 1 > Filter > Select … > Under expression type in Difficulty = 1 > Test > If it says the filter has returned a certain number of features
See picture to the right
Click OK
When Emma and I collected the data we ranked the difficult of the trail on a 5 point scale. This can all be found under the attribute table. We wanted to change the color of the trail based on difficulty, similar to how a ski mountain has different colors for their trails. Doing this also teaches students how to do a basic query.

24. Changing Trail Colors Based on Difficulty Rating
Change the color to a bright blue
Continue the same process for five Difficulty levels - assign each difficulty level a distinct, different, bright color  - When finished you should have Difficulty 1, Difficulty 2, Difficulty 3, Difficulty 4, and Difficulty 5
See picture to the right
Remove the empty rule that you did not create
Choose Apply and Click OK

25. Colored Trails

26. Locating Which Trail Feature is the Summit
Make sure Trail_Fe is highlighted in the layer panel by clicking on it
Right click Trail_Fe in your layers panel and open attribute table
Open Select features using an expression
In expression box write Type = ‘summit’
Close out of attribute table
Take note of which point is the summit. It will be highlighted in yellow
Here we do another query to find the summit of the mountain.

27. Installing a Plugin and Determining Elevation
In the Menu Toolbar, Select Plugins > Manage and Install Plugins >Elevation  > Install Plugin > Click Ok
Under your Plugin Toolbar, Select the newly available Obtain Elevation Icon
Click the viewshed icon that represents the summit of the mountain that you found earlier
Take a screenshot of the Google Maps Dialog Box that appears
See picture to the right
Exit out of box - a label of the elevation (in meters) will have appeared
Right click new layer in ‘layer panel’> Save as Summit
Example
Now we are learning how to install plugins. Plugins are just additional applications that have some cool features. For example, the plugin we have them install finds the elevation of a point. In this case we have them find the elevation of Champlain mountain based on the summit we found in the previous slide.
Example

28. Create a Layout
Menu Toolbar > Project > New Print Composer > In Composer Title Dialog Box - Write Name  > Click OK
Explore Layout Features
Your final layout needs to include:
A title with correct spelling
A north arrow
Bar scale
Legend
Location Diagram
Neatline
Notes (Preparer, Date, Projection & Datum, Source(s), Disclaimer)

29. Final Products A map layout showing what we learned.
A paragraph describing what the different colors generated by the Ruggedness Index mean.
A screenshot of the Google Maps Dialog Box with the summit elevation of Champlain Mountain.

31. Conclusions about QGIS
Pros
Cons
It’s free!
It can be used on any computer
Terrain analysis is easy
Not as complex as Arc or MapInfo
No need to worry about mapping directories or accidently deleting your work
Creating layouts is the worst thing ever
You can only zoom using the mouse track
Not as complex as Arc or MapInfo
Not as much information online to help when problems arise
Seriously… creating a layout is the worst

32. Acknowledgments: Special thanks to:
Sam Kucia and Ian Hathaway for going through our exercise and Louis Morin for the help.
(And to the police officer that didn’t give Emma a ticket)

33. Questions?