The goal of this lab was to determine a suitable habitat for bears in Marquette County, Michigan using ArcGIS and also use Python coding within ArcGIS.
Background:
The DNR is looking to create a management plan for bears in Marquette County, Michigan and I was asked to map the DNR lands that are within suitable habitats for bears and are at least 5 kilometers away from urban areas.
Method:
Objective 1:
The first task of this lab was to plot the location of bears in the study area using a table provided. By simply adding the XY Data and selecting the coordinate system NAD 1983 HARN Michigan GeoRef (Meters) a feature class was created and added to the map.
Objective 2:
Next, the most common landcover that the bears were found in were determined by changing the landcover layer symbology to a unique category map. Once the different land covers were revealed the intersect tool was used to spatially join the landcover layer and the bear_location layer to form the bear_cover layer. In the bear_cover layer the top 3 land covers (Evergreen Forest Land, Forested Wetlands and Mixed Forest Land) that bears were found in were determined through summarization.
Objective 3:
Knowing that bears tend to live near streams, it was important to determine how many bears were found near a stream. By creating a 500 meter buffer using the stream layer a new layer, stream_buffer, was created. Using the clip tool any bears located outside of 500 meters of a stream was excluded from the data in the bears_streams_clip layer. Through this layer is was determined that 72% of the located bears were found near a stream.
Objective 4:
By using the information found from objective 2 and 3 a suitable habitat for bears was determined to be in one of the top 3 land covers and within 500 meters of a stream. First the top three land covers were queried in the land_covers layer. Those land covers were intersected with stream_buffer to create the suitable_habitat layer. The dissolve tool was used to eliminate internal boundaries within the suitable_habitat layer.
Objective 5:
In order to find all of the DNR land that lies within the suitable_habitat layer the clip tool was used, which created the dnr_mgmt_suitable_habitat layer. To rid this layer of the internal boundaries that divides the DNR land into units the dissolve tool was used.
Objective 6:
The next task involved removing any suitable habitat data that was within 5 kilometers of Urban or Built Up land. The Urban land had to be queried in the landcover layer. A 5 kilometer buffer was created around the Urban or Built Up land and then that area was erased from the dnr_mgmt_suitable_habitat layer to create the dnr_mgmt_suitable_outside_urban layer. This layer displays the specific areas that the DNR manages, that is 5 kilometers away from any urban areas and is a suitable habitat for bears.
Objective 7:
The task of this objective was to create a cartographically pleasing map of the information collected throughout the other objectives and a data flow model to show the workflow of the lab.
Objective 8:
For the task python coding was used to perform simple functions. First a code was written to create a buffer of one kilometer around every stream. Next a code was written to intersect the new stream_buf layer with the suitable_habitat layer. Lastly, code was written to erase the urban buffer away from the suitable_habitat layer.
Results:
Objective 7:
Figure 1 is the map of the study area in Marquette County, Michigan that includes all of the layers that were created in the first six objectives. Figure 2 are the data flow models that show how each layer was found.
Figure 1.
Figure 2.
Objective 8:
Below is the python script that shows how the last few layers were created.
First a one kilometer buffer was created around the streams layer.
>>> import arcpy
>>> arcpy.Buffer_analysis("Streams", "streams_buf", "1 kilometer", "FULL", "ROUND", "ALL")
<Result 'H:\\Documents\\ArcGIS\\Default.gdb\\streams_buf'>
Next the buffered streams layer and the suitable habitat layer were intersected.
>>> arcpy.Intersect_analysis(["streams_buf","suitable_habitat"], "land_stream")
<Result 'H:\\Documents\\ArcGIS\\Default.gdb\\land_stream'>
Lastly the urban buffer was erased form the suitable habitat away form urban areas layer.
>>> arcpy.Erase_analysis("urban_buffer","Suitable Habitat Away From Urban Areas")
<Result 'H:\\Documents\\ArcGIS\\Default.gdb\\urban_buffer_Erase'>
Sources:
All data were downloaded from the Stat of Michigan Open GIS data.
Landcover from USGS NLCD
http://www.mcgi.state.mi.us/mgdl/nlcd/metadata/nlcdshp.html DNR management units from the Michigan DNR
http://www.dnr.state.mi.us/spatialdatalibrary/metadata/wildlife_mgmt_uni ts.htm
Streams
http://www.mcgi.state.mi.us/mgdl/framework/metadata/Marquette.html
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