Goals: For the purposes of this lab, we were asked by the
Michigan state Department of Natural Resources to examine possible suitable
habitats for local bear populations in Marquette County, Michigan. This lab
helped me become more familiar with data manipulation and organization,
followed by geoprocessing and vector analysis to gain insights into the complex
questions with multiple variables. Along with combining skills from previous
MAG_ units, we were introduced to proper techniques like data-flow modeling and
writing simple python scripts.
Background: The Department of Natural Resources (DNR) in
Michigan has been tracking the locations of black bear populations in Marquette
County near Lake Michigan. They contacted the University asking if we could use
GIS to examine the local environment to obtain more detailed information about
where the bear population are more likely to occur. Along with this
information, the DNR wish's to establish where suitable habitats for bears
under the management of the DNR. For this lab, we were given the GPS locations
of 68 black bears, along with ground cover datasets and the study area the DNR
operates in.
Methods:
First, to determine
what types of environments bears generally live in, i wanted to determine the
top three forms of land cover where bears are found. To do this, I took the GPS
locations of the bears, and performed a spacial join. Once i had the output
feature class i used the summarize tool and found the top three types of land
cover the bears were found on. (Evergreen forest, wetland forest, mixed
forest).
Now that I had the types of land the bears were likely to
live on, I wanted to know if proximity to streams was an important factor to a bear’s
habitat. I used a buffer function of 500 meters around streams to determine how
many of the bears were found within that distance from the streams. I found 49
out of the 68 bears were located near streams when they were tracked. Since the
percentage of bears located near streams was high (72%), I concluded this to be
an important aspect of the habitat.
Using my two criteria (top land cover, and proximity to
streams), I performed a intersect of the two feature classes and produced a
suitable habitat area for the bears. The next aspect specificed by the DNR was
to determine which parts of the suitable habitat are located on DNR managed
land. To do this, I took the DNR controlled area feature class and used the
intersect tool to find where the areas of the two (bear habitat and DNR land)
converged. After I had accomplished this, only a few more steps remained.
The DNR contacted us a second time, concerned about the
proximity of bears to urban areas. They were concerned with increased
populations becoming a hazard to local communities, and wanted to diminish the
chances of this as much as possible. To accomplish this task, I got the Urban
areas feature class and performed a 5 Km buffer around the areas. This gave me
an output, which I used to intersect with the feature class for a bear habitat I
just created.
Results: This gave me my final map, which contains the
suitable habitat for black bears, under DNR management, and outside 5 Km from urban
areas. The results displayed in brown are the areas that fit all the criteria
specified by the DNR.
Figures:
Figure 1: Suitable Black Bear habitat under control by DNR.
Work-Flow
Sources: USGS (Landcover)
Department of Natural Resources
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