The purpose of this lab was to give the student experience using ArcGis online as well as creating domains related to a particular feature class. The feature class created was used to collect data using the ArcCollector app. Information about different types of trees as well as squirrel nests were collected during this survey.
Study Area:
This week, the study area was at a location other than campus. I was traveling for our Thanksgiving break, so I collected data near Plainview, MN. A family member has an old farm house, with a large lot that has many different tree species present on the property. Since I was not able to be on campus, this was the next closest place that had similar attributes.
Methods:
In order to successfully collect data for this lab, domains needed to be created within the Geodatabase used to hold all of the data. There are two different types of domains that could be used: range or coded. Range domains are used when working with numeric data. In order to set a range, a maximum and minimum value must be entered. Coded domains are able to be used with any type of attribute information. Coded values set what information can be entered for a specific attribute. This makes adding information much smoother while in the field. The domains that were set for this exercise were the size of the tree, type of tree, tree species, if leaves were present and if there were any squirrel nests in the tree.
Once all of the domains were set it was then time to create a new feature class. A point feature class was created for collecting data on different types of trees. The feature class would be used in the Collector app. In order to allow for the data to be shown correctly, the coordinate system of WGS 1984 Web Mercator (auxillary sphere) was set for the feature class' projection.
Once the feature class was created, it then needed to be published on ArcGIS online. If it was not published, it would not be able to be used on the Collector app. It was during this publishing step that I encountered a few problems. I was able to create the feature class and get it onto ArcGIS online, but it would not transfer onto my Collector app. After numerous troubleshooting ideas, I found out that I had not made my feature class and editable layer. Since I could not edit, I was not able to use the file and that is why it was not showing on the app. Once that problem was solved, everything worked how it was intended and I was able to see my map on the Collector app.
The next step was to collect data in the field. I had to walk to each individual tree and make a point and enter the specified attribute information. Since there were numerous trees, I did not have to travel very far to get the 20 points needed for collection. Total collection time took about 30 minutes. Once all of the data was collected, it then needed to be downloaded from ArcGIS online to be used in ArcGIS for desktop.
Discussion:
The data shows that the most distinct difference for the different attributes collected is related to the type of tree present. I broke this down into two different categories: deciduous and coniferous trees. The figure below (Figure 1) shows the results of where the different tree types were located.
As the figure above shows, there is no real pattern as to how the different tree types are dispersed about the property. The one thing that can be noted, from this sampling, there is a much higher percentage of deciduous trees on the property compared to coniferous trees present. Breaking this down even farther, we will be able to see the different types of trees species are present on the property. The figure below (Figure 2) shows the different type of tree species that are present on the property.
This map shows where the different types of tree species are located across the property. Although it is dominated by deciduous trees, there are many different species present.
After completing this lab I realized that I should have done a few things differently. One major flaw I found with my survey method is that I did not have enough domains set for the different types of trees I was going to encounter. There were many trees I was not able to survey simply because I did not have the domains set.
Conclusions:
This exercise helped me to realize the importance of prepping your data before going out to the field. Setting different domains up correctly before going to the field saves lots of time when collecting data. It also makes you think about the data you will be collecting and what will be the most efficient method for field collection. Although the collection of the trees is the goal of this lab, I learned many lessons from it. Learning how to collect data in the field from many platforms, such as a smartphone, is a very valuable skill to learn and continue to develop.
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