Background: Using multiple criteria including land type, stream vicinity, distance from urban areas, and DNR management, suitable habitat for bears was found in a study area of Marquette County. Specifically, land type criteria and stream vicinity criteria were assessed by looking at the proportion of bears inhabiting those areas. Detailed methods are listed below:
- Add locations as XY event theme.
- Go to the file menu to add XY data.
- Locate the bear location table and assign X Field and Y field based on table columns.
- Choose the correct coordinate system (NAD_1983_HARN_Michigan_GeoRef_Meters)
- Export data points and save in a “lab3” geodatabase.
- Determine bear habitat
- Add and arrange all feature classes from the bear_management_area feature dataset.
- Symbolize landcover by “minor type”
- Intersect landcover and bear_locations to create a table in which the bear ID numbers correspond to the type of landcover they were found in.
- Summarize “Minor Type” to get a count of the total number of bears found in that type of landcover. The top three sites are Mixed Forest Land, Forested Wetlands, and Evergreen Forest Land.
- Determine if bears are found most often within 500 meters of stream.
- Create a 500 meter buffer for the “streams” layer.
- Intersect this stream buffer with the bear locations. Although the resulting area is only about 10% of the total land cover in this study, there are 49 total bear sightings within 500 meters of a stream, of a total of 68 sightings. This is 72%, which is well above 30%, so streams are clearly important habitat for bears and should be used for criteria for suitable habitat.
- Find suitable areas for bear habitat.
- Using previous research, it is known that bears prefer to be within 500 meters of a stream and inhabit the Mixed Forest Land, Forested Wetlands, and Evergreen Forest Land more than other land cover types.
- Create a new layer of the preferred land cover types.
- Intersect the stream buffer with the preferred landcover types. This results in several polygons, so the dissolve tool was used to result in a single, albeit disjointed, shape containing suitable bear habitat in the study area.
- Make recommendations to the Michigan DNR for bear habitat on their land.
- Add the dnr_mgmt feature class and clip to only include the study area.
- Because the units of DNR managent are not important, their boundaries were dissolved.
- An intersection was used to find the common areas.
- Eliminate Urban or Built Up Areas from the DNR Managed Habitat Area
- A new layer from landcover was selected to possess only the Urban or Built Up Areas
- A 5 km buffer was made around the area.
- The DNR Managed Habitat was erased where it was within that buffer. The result is all areas that are suitible for bears, managed by the DNR, and more than 5 km from an urban or built up area.
- Create a cartographically pleasing data flow model and map.
- Throughout the process, queries were made and tools were used in a single data flow model that was kept orderly. This made the process easy to visualize and a simple capture of the model shows the data flow in its entirety.
- A map was created using bright colors to signify various suitable habitats for bears in the study area. The basic map elements, including legend, title, author, source, scale, and north arrow were added. A locator map showing the location of the study area within Marquette County was also include
- Perform geoprocessing commands using Python
- After opening the Python window, “arcpy” was imported by typing “import arcpy.”
- Code for all tasks, including a buffer analysis for within 1 km of streams, an intersect between this buffer and suitable land types, and an erase of areas within 5 km of urban areas was written and/or selected from the drop-down menu as follows:
Sources:
- All of the data were downloaded from the State of Michigan Open GIS Data
- http://gis.michigan.opendata.arcgis.com/
- Landcover is from USGS NLCD
- http://www.mcgi.state.mi.us/mgdl/nlcd/metadata/nlcdshp.html
- DNR management units
- http://www.dnr.state.mi.us/spatialdatalibrary/metadata/wildlife_mgmt_units.htm
- Streams from
- http://www.mcgi.state.mi.us/mgdl/framework/metadata/Marquette.html
No comments:
Post a Comment