Lab 4: Vector Analysis with ArcGIS

Figure 4

Goal:
The goal of this lab was to make a map of suitable bear habitats in Marquette County, Michigan, by using several geoprocessing tools.

Background:
Marquette County, in the upper peninsula of Michigan, is one of the few places in the midwestern region of the United States of America to have a remaining black bear population. Having a bear population can lead to some problems, especially when bears interact with humans. Bears can get into garbage, and once accustomed to human food will often forgo their natural diets for one entirely comprised of human food. This leads to bears breaking into houses and becoming nuisances. Once this happens, it is impossible to save the bear, and it must be killed.

In order to preserve the native bear population, the Michigan DNR wants to determine what determines the bear's ideal habitat, and how much of this habitat lies within DNR managed land. They must ensure the bears stay away from human interaction at all costs, so the bear management areas are to be at least 5 kilometers away from any urban areas, for mutual benefit.

Methods:
In order to create this map, I first learned how to map X Y coordinates from an excel spreadsheet. I added the coordinates as an "event theme", then exported them as a feature class once they were mapped. Then I spatially joined the bear locations and the and cover datasets in order to determine in which land cover types the bears were found. I then summarized the resulting dataset in order to determine which land cover types bears were preferred.

I learned how to use a buffer tool, and used it to create a feature class showing the areas within 500 meters of streams. I then used the dissolve tool to simplify this streams feature class by removing the internal boundaries.

After making a feature class of the three land cover types bears preferred, I used the intersect tool to show just the parts of these land cover types that were also within 500 meters of a stream. I then used the dissolve feature to remove the internal boundaries of the newly formed feature class.


I then intersected the new feature class with one showing DNR management zones in Marquette county, so they can determine which parts of the management zones are also good bear habitat. Next, I dissolved the internal boundaries to simplify the appearance of the dataset.

In order to account for the urban areas, I made a feature class of the land cover areas that were labeled 'Urban', then created a 5km buffer around them. After dissolving the internal boundaries of the buffer, I used the erase tool to eliminate the parts of the DNR management zones that fell within 5km of urban areas.

I then made an cartographically pleasing map of my results, showing both the DNR managed rural bear habitat and all the areas of suitable bear habitat on one map, and the land cover types of the region on the other. I also included a locator map, so those viewing the maps can determine the location of the study areas within Marquette county and the state of Michigan. (Figure 4) I also made a data flow model to show the processes I used in order to obtain my final datasets. (Figure 5)

Results:
The maps show that bears were commonly found within 500 meters of streams, but were also found near lakes, reservoirs and wetland areas. If I were to remake the map, I would add a 500 meter buffer to those land cover types, rather than just one around the streams in the area. The maps also show that although there is a large expanse of ideal bear habitat within the study area, only a small quantity of it falls within DNR managed areas far from urban areas.

Figure 5

Sources: USGS NLCD, Michigan DNR, Michigan Center for Geographic Information