Lab 8: Arc Collector Part 1: Microclimate

Introduction: 

Smart phones are a useful tool for GPS data collection because they actually have a higher computing power than most GPS units. Because smart phones have the ability to access online data, the points update as they are being collected so the user can see the progress. For this lab, ArcCollector was downloaded so that each student has the ability to collect data from his/her phone. The objective of this lab was for the class to split up into groups and collect microclimate data in one of the seven designated zones on the University of Wisconsin-Eau Claire campus and then compile all the data together. This group collected data in zone four. The data that was collected in ArcCollector on the smart phones was then accessed on ArcGIS Online and exported to be opened in ArcMap.

Study Area:

The area of study for this lab was within the seven zones located at the University of Wisconsin-Eau Claire campus (Figure 1). The zones were situated on upper and lower campus, as well as across and on the walking bridge.

Figure 1: Study Area Located at the University of Wisconsin-Eau Claire

Methods:

First, a geodatabase was created before the data collection could be stared. Then, eight attribute fields were created: surface temperature, temperature at 2 meters, dew point, wind speed, wind direction, surface type, and notes. This helps to avoid errors because the data collected will fall under each domain in the attributes. For example, integers are rounded and wind direction is limited to 0-360 degrees.

Before the points could be collected, the last task was to connect to the online map through the ArcCollector app. This way the data points could be viewed and analyzed on ArcGIS Online to then be exported. Two different tools were used to help in collecting the data: a compass and a Kestrel. Each group was assigned one of the 7 group zones and then headed to that designated area. Data points were then collected evenly throughout the zone. The data points were updated on ArcGIS online as each group were collecting the points (Figure 2).

Figure 2: Data Points on ArcGIS Online

After all the points were collected by each group, the data could be analyzed online. ArcGIS online gives the user the option to analyze the different attributes on the site. For example, Figure 3 shows the different wind speed values that each data point collected. However, the data points were exported to be used in ArcMap to create a few maps to represent the data.

Figure 3: Wind Speed Data in ArcGIS Online

Results:

Figure 4 is comparing the surface temperatures and the dew point temperatures at each data point. For the most part, it looks like trends with surface temperatures seem to correspond with the dew point temperatures. A noticeable trend with the data points is that the warmer temperatures seemed to be collected in areas where the surface type was pavement. The pavement heats up faster than bare ground under direct sunlight so that could be the cause for high temperatures in those regions. From looking at the colors on the map, it appears that the most common temperatures that were recorded fell between 26-42 (light green) and 43-47 (yellow).  Groups of similar temperatures tend to cluster in the same areas with few outliers. These outliers could be user error or could have been effected by shade, wind, surface type, or snow cover. Referring back to Figure 3, wind speed also appears to correlate with temperatures. Data points that collected higher wind speed also tended to record more cooler temperatures. A great example of that is located along the walking bridge. The data points across the bridge were overall collecting cooler temperatures and also the highest wind speeds. However, as said earlier, there are a few outliers that could be user error or field error.

Conclusions:

Being able to collect data points on a smartphone makes it easy and efficient to gather data points out in the field. The goal of the lab was to collect microclimate data in each of the seven group zones on the University of Wisconsin-Eau Claire campus. ArcCollector was a great app to use for this lab. It was very user friendly and sufficient. Accessing the data points on ArcGIS Online was a great feature. The site itself allows the user to compare the attributes of each point but exporting the data to use in ArcMap was more useful to create maps with all of the necessary map components. ArcCollector would be a great tool to use for future projects.

Sources:
http://uwec.maps.arcgis.com/home/index.html
http://arcg.is/1CK5Sj