The goals of this specific lab were to introduce various geoprocessing tools and to create a map based on a given scenario using the data we were given along with various geoprocessing tools such as overlay, buffer, erase, and dissolve. The use of python code was introduced as well, demonstrating another way for the tools to be operated.
Background:
The scenario given was as follows. The DNR had issued the task of determining suitable bear habitat from within a study area contained in Marquette County, Michigan. Not only did the habitat need to fit the criteria necessary for it to be considered suitable for bears, it also needed to be contained within the DNR's preexisting management areas and exist at least five kilometers beyond any urban or built up areas within the county. All of the data was downloaded from the State of Michigan Open GIS Database, including the landcover, DNR management areas, and streams data.
Methods:
In order for the bear locations file to be analyzed within ArcGIS, the locations needed to be added as a XY theme event, as bear locations originally existed as an Excel Table File. This was done by choosing "File, Add Data, Add XY Data" from the main menu, and selecting the bear locations excel table and matching the XY coordinate fields within the table with the XY coordinate selectors. The coordinate system was set to the NAD 1983 HARN Michigan GeoRef (Meters) in order to eliminate distortion within the final product. This was then exported as its own feature class to save these modifications. This, along with the streams, landcover, study area, and DNR management areas was added to an empty map document.
A special query was performed to check for the importance of streams within bear habitat. A special query was performed to check if reported bear locations were near streams. A spatial query showed that a significant and majority portion of bear locations were within 500 meters of streams. As of such, this area was considered important to our final product. To determine what landcover bears primarily were found within, an intersect was performed with the bear locations and landcover feature classes. The resulting feature class was summarized based on the minor type field to determine what three landcover types bear were most prevalent within. The Mixed Forest Land, Forested Wetlands, and Evergreen Forest Land types were determined to be the most bear prevalent of the minor types. With this information, a query was performed to select these specific areas from the landcover feature class. A layer was created from this selection.
Since the area within 500 meters of streams was shown to contain a significant number of bear locations, a buffer tool was performed on the streams feature class of the area within 500 meters of streams. The output of this operation, along with the selection from the landcover feature class, was input into the intersect tool to create the proper bear habitat feature class. A dissolve tool was run on the bear habitat in order to clean up the internal boundaries. In order to make sure the bear habitat was within the DNR Management Zones, an intersect tool was run with the bear habitat and the DNR Management feature classes, with the output feature class being run through the dissolve tool to remove the internal management zone boundaries.
The final criteria for the management areas involved them being five kilometers or further from Urban or built up areas. Another query was performed to select the necessary areas from the greater landcover feature class, with the selection being added as its own layer. The selection was then run through the buffer tool to create the area five kilometers around all urban areas. This buffer feature class and the bear habitat within the DNR management zones was then run through the erase tool, with the input feature being the current habitat management area and the erase feature being the urban area buffer.
A cartographically pleasing map was created to show the final Bear Habitat Management Area in relation to the overall bear habitat outside of the management zones, including what was within urban areas, all bear locations, and the entire area of study. A data flow model was also constructed to show the entire string of tools used to arrive at the final map results. In addition, some of the previous steps in the process were performed with python in order to familiarize us with python coding, the results of which can be seen below.
Results:
The map shows that although there is much viable bear habitat, bears tend to cluster to the to the west of the central longitude of the study and to the north of the central latitude of the study. However, the only viable DNR management areas lie along the central longitude of the study area, both from west to east. Much of the management area to the east if far from any reported bear locations, and many of the bear locations within the center of the study area falling too close to urban areas. I would recommend the DNR expands its area of management to the far northwestern corner of the map, in which many bears exist far away from the urban areas to the southeast.
Sources:
Hupy, C. (2016). Lab 3: Vector Analysis with ArcGIS. Eau Claire, Wisconsin.
In State of Michigan Open GIS Data. Retrieved May 6, 2016, from http://gis.Michigan.opendata.ArcGIS.com/
DNR Management Units sub-link: http:www.dnr.state.mi.us/spatialdatalibrary/metadata/wildlife_mgmt._units.htm
Landcover sub-link: http://www.mcgi.state.mi.us/mgdl/nlcd/metadata/nlcdshp.html
Streams sub-link: http://www.mcgi.state.mi.us/mgdl/framework/metadata/Marquette.html
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