Thursday, May 11, 2017

GIS 1 Lab 4: Final Project

INTRODUCTION

This project highlights stretches of the bike trails in Eau Claire County and Chippewa County of Wisconsin which are potential spots for bike sharing stations. The purpose of this lab was to answer a simple spatial question using the skills learned this semester in ArcGIS. Eau Claire will soon have a bike sharing program, and locations in which the bikes are parked will heavily influence their use. Selection was made using two criteria: stretches of the bike trails which lie outside areas at risk of floods and within a reasonable distance of a park. Flooded bike stations would be quite problematic due to the cost of the bikes themselves and the electronic station used to pay for the bike use. Additionally, placement of bikes in the parks would alleviate potential complications for the city. Since parks are city owned, it would be easier to add these stations within the property line than to negotiate with businesses or landowners for the use of their property. 

DATA SOURCES

The county borders were extracted from the ESRI downloaded data from 2013. The water and bike trail data was extracted from the Chippewa Valley Bike Map map package. I am concerned the trail and water information I used is incomplete. There were many layers with ambiguous names and missing descriptions, so I had to decipher which contained the data I wished to use. Data was also labeled differently for Chippewa and Eau Claire County, so combining the data that was similar required inference. Additionally, I am not sure if the bike trail layer contains areas of the road which have bike lanes. Theoretically, many types of roads or sidewalks could be considered bike paths, but details about what was contained in the “Bike Trails” layer was not included.


METHODS

To implement the restrictions, I extracted the layers I was interested in from the map package and placed them into my project geodatabase, along with the selection of “Eau Claire” and “Chippewa” counties from the ESRI data. From the CV Bike Map, layers depicting similar features were separated by county, so I first needed to combine these into one coherent layer. To begin, I combined the polygon layers “ChipCo_Water” and “ECCo_hydply” using the Union tool to create one layer of both sets of bodies of water. I used the Merge tool to combine the layers “ChipCo_hydln” and “ChipEC_Sreams_DNR” to create a combined layer of the streams and centerlines. Next, I used the Buffer tool to create a two layers depicting the area within 50 feet of these water features. I used the Union tool to combine these buffers and dissolved the resulting polygons to create the layer depicting areas at risk of flooding. Since 50 feet is relatively small, it is not included in the map as it is not visible at this scale. Next, I combined the Eau Claire and Chippewa parks into one layer using the Union tool. Upon closer inspection, many paths ran very near parks, but often did not overlap them. Since it would be convenient for the city to use park land for the stations, and being near a bike trail is sufficient for users, I created a 200 foot buffer of the parks to allow the nearby trails to be considered in the selection. Next, I used the Erase tool to eliminate areas of the bike trail that overlapped the flood risk area. I intersected this layer with the parks buffer to create a layer of the areas that bike sharing stations could be placed. This area is hot pink on the map.

I have included the data flow model, which maps this process.


RESULTS

This analysis greatly narrowed down the bike path areas that can host bike sharing stations. I think intersections of bike paths in the selected area would be ideal for placement so bikers could travel a loop.




EVALUATION


If this project were repeated, it may be valuable to research the typical flooding range of the rivers in the area. Perhaps a 100 foot buffer or use of water table information would be more appropriate. Additionally, it may be economically beneficial to only place stations near businesses, particularly establishments with food. To make sure bike sharing stations were easily accessible, I was going to eliminate areas that were within a mile or two of a major road. However only one location was marginally outside of that area, and major roads are not necessarily a good indicator of accessibility or population density. Instead, population density would be a good factor to consider in future analysis.

Friday, May 5, 2017

GIS 1 Lab 3: Vector Analysis with ArcGIS

Optimal Bear Habitat Management Areas


PURPOSE

The purpose of this analysis was to determine suitable habitat for pares in Marquette County, Michigan. I was given bear x,y coordinates in an excel file, and a map including the study area, DNR managed lands, land cover, and streams. The pedagogical goal was to learn how to import x,y coordinates as points in ArcMap, and to practice using overlay tools. Additionally, I learned how to organize and build a Data Flow Model. Also, I used Python for the first time.


METHODS

The methods of my analysis are outlined in the Data Flow Model below. To summarize, I first imported x,y coordinates from an excel file to create points on a the map representing the locations bear have been found in Marquette County. Second, I summarized which landcovers the bears were found in to determine which forest types are preferred by the bears. Third, I determined whether bears are found near streams. In this data, 72% of bears were found within 500 meters of a stream. Fourth, using these two criteria and the Intersect tool, I found the ideal bear habitat. Fifth, I clipped this habitat to only include areas managed by the Michigan DNR. Sixth, and lastly, I eliminated the managed habitat areas that were within 5 kilometers of an urban or built up area using the Erase tool. This produced the final suitable bear habitat located on the DNR management lands.


PYTHON SCRIPT

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

<Result 'Q:\\StudentCoursework\\Strand\\GEOG.335.001.2175\\BRUSHADE\\Blog\\LAB3\\marquette_bear_study.gdb\\stream_buff'>

>>>arcpy.Intersect_analysis(["stream_buff", "habitat_dis"], "land_stream")

<Result 'Q:\\StudentCoursework\\Strand\\GEOG.335.001.2175\\BRUSHADE\\Blog\\LAB3\\marquette_bear_study.gdb\\land_stream'>

>>>arcpy.Erase_analysis("habitat_dis", "urbanbu_buffer", "hab_w_o_urban")

<Result 'Q:\\StudentCoursework\\Strand\\GEOG.335.001.2175\\BRUSHADE\\Blog\\LAB3\\marquette_bear_study.gdb\\hab_w_o_urban'>

>>> 



DATA FLOW MODEL


MAP


RESULTS

The resulting area is pink on the map. It appears very few bears were actually found within this area. This is reasonable since the ideal bear habitat areas (which are green on the map) cover much more area than the final selection due to low management areas.

SOURCES

Angeli, E., Wagner, J., Lawrick, E., Moore, K., Anderson, M., Soderlund, L., & Brizee, A. (2010, May 5). General format. Retrieved from http://owl.english.purdue.edu/owl/resource/560/01/

Hupy, C (Spring 2016). Lab 2: Vector Analysis with ArcGIS.

USGS NLCD. Landcover. http://www.mcgi.state.mi.us/mgdl/nlcd/metadata/nlcdshp.html.

DNR. Management Units. http://www.dnr.state.mi.us/spatialdatalibrary/metadata/wildlife_mgmt_uni ts.htm.

State of Michigan. Streams. http://www.mcgi.state.mi.us/mgdl/framework/metadata/Marquette.html.