Friday, December 13, 2013

Lab 5: Vector Analysis Question

Introduction:  The goal of this lab was to create a spatial question on our own and then answer this question using tools in ArcMap and ArcCatalog.   The question I developed for this lab is: Where is the best place in Crow Wing County, Minnesota to build a cabin?   The objectives for this lab include a answering our own spatial question by using at least four tools, and at least three of the tools have to be different.  Also the area of interest must be in the United States and a minimum of three different spatial data layers must be used.   Then end product of this lab will result in a report of the lab, a map representing the answer to the question, and a data flow model showing the tools we used and how the question was answered.   The intended audience of my question would probably be a middle-aged to older male looking to buy or build a cabin to spend the summers in.  This information could be used by people looking to build or buy a cabin and also a real estate agency seeking to find the best location to buy land to sell. 

Data Sources:  First to begin the process of answering my question data had to be brought in from an ESRI database, which included: hydropoly (lakes, bays, glaciers), highways, golf courses, states, and counties.  The ESRI database was downloaded in ArcCatalog and then added to ArcMap.  All of my data was selected from either the ESRI usacensus data or the ESRI usadata database.  This step allowed me to add all of my required data which is key to answering my question.  I had a few concerns with this data, the first being how old the data is.  This could make my map not very useful as new highways or golf courses could have been built.  The second data concern is does the data include every lake and golf course?  As I just mentioned new golf courses could have been built since the data was gathered and what is the minimum size ESRI used to describe a lake. 

Methods:  First a series of requirements of where I think would be the best location for a cabin to be built must be created.  I decided that the cabin must be built within five miles of a golf course and within five miles of a lake.  Then I decided that the cabin must be at least five miles away from a major highway.  These three things were decided because of easy access to the golf course and lake and also far enough away from a highway to not be near a lot of noise. 

-Next US Counties was added to the map and Crow Wing county in Minnesota was selected in exported.  Then golf courses, hydropoly, and highways were added the map and all three were clipped within Crow Wing County. 

-Then all three of my data criteria were buffered to correctly fulfill the requirements I desire.  Golf courses were buffered in a five mile radius and dissolved to delete any existing boundaries.  A query was performed on hydropoly to select all lakes in Crow Wing County.  These lakes were then buffered in a five mile radius and dissolved to delete any existing boundaries.   Highways was also buffered within a five mile radius and dissolved to delete any existing boundaries.   

-Finally to make a map, that answers my question, lakes and golf courses were intersected to find the locations where both exist.  After this intersection the erase tool was used, highways was erased from the lake and golf course intersection.   This step is key because it erases the area of highways with a radius of five miles, therefore excluding this area for a cabin.   Below is a data flow model that shows all of the steps and tools I used in creating my final product. 


Results:  After all of these steps and tools were completed the final map was created.  The area in orange on the map includes all suitable areas to buy or build a cabin.  The green dots represent golf courses, blue areas represent lakes, and the red lines represent highways.  I found it interesting that most of the golf courses in Crow Wing County were located near a lake making the best location to build a cabin easy to predict.   At first I tried to exclude areas within ten miles of a highway but that answer was not sufficient enough because only a very small portion of the county was a suitable area. 

Final Map



Evaluation:  I though the lab was a lot of fun by creating our question and then making a map with the best possible location answered.  My question changed throughout the lab because I had trouble finding the correct features I wanted to use for my question but, I am very happy on how my map turned out.  If I were to repeat the project I would probably expand my area of interest and maybe pick two or three counties.  I also would use more features to come up with a better answer, I would maybe use forest types and urban areas. 

Sources:  ESRI database
-usacensus database

-usadata database

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