Friday, December 9, 2016

Lab 3


Goal: The goal of this lab is to demonstrate skills in spatial analysis in ArcGIS. During the lab we used overlay tools to display bear habitats

Background: The lab looked at a study of bear populations, and worked to find an optimal habitat for black bears in Marquette county, Michigan. Using vector analysis tools I determined the preferred habitat for black bears. The criteria for the habitat was, in the preferred ecological cover, within 500 meters of a stream, within DNR land, and at least 5 km away for urban or built up areas.

We began by taking a zipped file of X-Y coordinates of tracked bears. Once we had our data displayed on a map we began to run analysis of the bears population, and their habitats. By querying the data, it was determined that the optimal location for black bears was in Mixed, Deciduous, and Evergreen forests. I than buffered the streams 500 meters, and ran a intersection to determine that over 30% of the bears were within 500 meters of a stream, in fact 72% were within a stream. Forrest type, and stream proximity were then added as criteria for the bear habitat.

The next step was to intersect the buffer of streams, with the suitable habitats. This generated our first look at where the bear habitat would be. Although this showed where bears could live in the area, it did not display whether or not the data was inside of a DNR managed area. To solve this problem, I ran a clip of the DNR zones within the study area. Next I ran a intersect of the DNR zones, and the previously determined habitat zones. This showed us areas where the bears habitat could be, within the DNR zones. The last objective was to ensure that the bear habitat was outside of 5 kilometers of urban, or built up areas. I began by creating a feature class from the selected "urban or built up" areas in the landcover data. Next I created a 5 km buffer around those urban areas. Lastly running a intersection, of the urban buffer and the DNR_bear_habitat I determined the areas too close to civilization.

The data flow model below shows the steps, and order of the steps, which I used to generate my map of potential habitat areas.

Data Flow Medel

The following maps shows the areas of Marquette county which meet all of the qualifications of a bear habitat, as defined by the lab. The Blue areas show possible habitat locations that a too close to an urban area. The green shows the habitat areas which are outside of an urban area, and inside DNR land. The red shows the urban areas. Dots and lines represent bear location, and stream location respectively.

Python coding for certain operations used in Lab 3.

>>> import arcpy

>>> arcpy.Buffer_analysis("streams", "steams_buf", "1 kilometer", "FULL","ROUND","ALL")

<Result 'H:\\Documents\\ArcGIS\\Default.gdb\\steams_buf'>

>>> 

>>> arcpy.Intersect_analysis(["steams_buf", "suitable_habitat"], "land_stream")

<Result 'H:\\Documents\\ArcGIS\\Default.gdb\\land_stream'>

>>> 

>>> arcpy.Erase_analysis(["Urban_Buffer_All", "Suitable Habitat"], "Erase_Buffer")

<Result 'H:\\Documents\\ArcGIS\\Default.gdb\\Erase_Buffer’>

>>> 
Sources

http://www.mcgi.state.mi.us/mgdl/nlcd/metadata/nlcdshp.html http://www.dnr.state.mi.us/spatialdatalibrary/metadata/wildlife_mgmt_uni ts.htm  http://www.mcgi.state.mi.us/mgdl/framework/metadata/Marquette.html

No comments:

Post a Comment