Introduction:
This week’s exercise involves the use of Arcpad integrated
with Arcmap and the use of Trimble Juno GPS units. Andrew Peterson, Amy Bartel and I worked
together during this project to decide what data to collect, what attributes
pertaining to that data would should be gathered and gathering the data.
Study area:
The data were gathered at the Priory and the immediate
surrounding area. The Priory is located approximately 5 kilometers south of the
University of Wisconsin Eau Claire (UWEC) campus on Priory Road. Directions to
the Priory from UWEC are as follows. From the main campus area take Roosevelt
Avenue east to State Street, turn right on State Street and follow it south
until you come to Lowes Creek Road, turn right on West Lowes Creek Road, you
will cross over Interstate 94 then come to Priory Road, turn right on Priory
Road and watch for the sign for the Priory on your right. The terrain at the
Priory consists of two levels of relatively flat ground connected with steep
hills; the lower level has deep ravines cutting through it. The Priory sits on
the top level of the property, a fairly flat topped hill; the surrounding
terrain drops away sharply to the north and east to the lower level. Much of
the property away from the buildings and parking lots is forested, some a mix
of mature hardwoods and two portions one
on the lower level and one on the south-east slope that have been planted with
conifers varying in age.
Methods:
Our group decided to gather data on dead trees located at
the Priory. Both standing fallen dead trees would be included. We decided to
include attributes such as diameter, length/height, x/y coordinates and several
other attributes specific to each class of tree (figure 1). These would be point features
and with the fallen trees we would also gather azimuth data. The third class we
included was a polygon which would include the area covered by a fallen tree.
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| Fig.1. We chose to gather attribute data on three feature classes all associated with dead trees their present state and use. |
Using Arcmap I set up a folder to work in and started a new
file geodatabase. Within the geodatabase I created three separate feature classes (figure 2).
The first feature class was deadtrees; I created the necessary fields and
inputs. I repeated this for both feature classes fallentrees and treesection. I
set the coordinate system to NAD_1983_HARN_Wisconsin_TM meters for each of the
feature classes. After adding the feature classes to an .mxd in Arcmap I set
the symbology of each to be easily recognizable in the field. I added a .tiff
raster image of the area of interest to aid in navigation and saved this to the
working folder.
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| Fig.2. These feature classes were set up in my geodatabase for use with Arcpad. |
Now it was time to set up the data in Arcpad. The first step
is to turn on the Arcpad data manager extension and add the Arcpad toolbar.
Then click on get data for Arcpad on the toolbar and work your way through the
wizard. Set the action menu to checkout all geodatabase layers, set the
folderto your work folder then change the data storage file to your
folder/checkin folder. Now your data can
be sent from Arcmap to the GPS unit. After connecting the unit we copy the work
folder and paste it into our class folder in the GPS unit.
We used the Juno units to gather the data along with a tape
measure to measure the tree diameters and a True Pulse to get tree heights and
azimuth bearings, which were entered into the Juno units. After gathering the
data we connected the Juno to the computer and simply copied the folder
containing our data into our work folder and used get data from Arcpad to
import the data into the geodatabase and attribute fields of the feature
classes.
Now we needed the x and y positions for each of the points.
I began an editing session, selected the fallentrees feature class and the
point feature. With the attribute table open I selected one of the points and then zoomed to that
point, holding the curser over the point I was able to obtain the coordinates for
each point. After entering the coordinates into the attribute table I saved the
edits and quit editing. I followed the same procedure for the deadtrees. I used
the bearing distance to line tool with the fallentrees to create a new feature
class which showed the locations of the trees, their position on the ground and
the length of each. Now I was free to use this information to create maps of
the area with the newly collected data, each individual attribute separately symbolized (figures 3-9). The raster has been left out to allow easier viewing of the data points.
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| Fig.3. Standing dead trees ranked by diameter. |
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| Fig.4. Standing dead trees ranked by their height. |
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| Fig.5. Fallen trees ranked by diameter. |
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| Fig.6. Fallen trees ranked by length. |
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| Fig.7. Fallen trees separated by leaf type. |
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| Fig.8. Fallen trees ranked by their state of decomposition. |
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| Fig.9. Fallen trees split by the presence of fungus (any species). |
Discussion:
We originally created a feature class to trace the outline of
fallen trees with a polygon; we did not use this because most of the trees we
marked were not covering a large area. The trees were either single stem
deciduous trees or they were highly decomposed with few to no branches left;
either way there was not much area to cover. Much of the data gathering went
without trouble, however there were many more dead and fallen trees than I
believe we could have foreseen; to overcome this we gathered sparingly and
covered more ground in order to gather a broader sample. During the course of
this we gather data on dead trees pertaining to woodpecker use and the presence
of fungus. Biology Professor Chris Floyd has ongoing research in Colorado
dealing with this very subject so I used the opportunity to compare the two (figures 10, 11). I added
a field and used it to combine the two fields and view the result.
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| Fig.10. This image is showing the use of woodpeckers in trees with fungus present, or just woodpecker use or just fungus presence. Their was only a single tree with fungus that was without evidence of woodpecker use. There was also only a single tree with wood pecker use that had no fungal presence. the number of trees that had both or none was about 50/50. This was to small of a sample size to draw any conclusions from, however this could be expanded on. |
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| Fig.11. This image again used fungal presence and woodpecker use but also included the diameter of the trees. We can rank the tree size to see if their is a preferred diameter along with the fugal variable. |
Our final map showing the locations of trees and distance and direction of fallen trees could be overlaid with trail maps to look for obstructions or increased wildlife viewing opportunities (figure 12).
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| Fig.12. This map shows the location and present resting state of the fallen trees at the Priory. |
Conclusion:
The ability to set up a project in the lab and transfer it
to field equipment for data gathering and then transfer the data back to the
database is an invaluable skill to have. The ability to look ahead and
determine what attribute data will be needed for a project could be viewed more as an exercise in predicting
what difficulties may be encountered and be prepared to meet the challenges
with solutions.
