Friday, March 7, 2014

GIS 1 Lab 2 Downloading GIS Data

The purpose of this lab was to learn how to download data off the internet in this case it is from the US Census Bureau. After the data is downloaded I had to change it into a form that I can work with and map.
The goal is that at the end of the lab I will know how to download all kinds of data that I may need in the future on a project. Some of the programs I work with provide a lot of data that I need for projects but what if they don't have the data I need? That is what this lab is for, and the data I am looking for is population data about the counties of Wisconsin. Once I have that data I do the same thing I have done many times before and make a map of the data.
The first step of the lab is to visit the US Census website and search for the data I need. Once I find what I am looking for I download the data as a zipped folder and save it so I can go back into it when I need to. Once I had it saved I went in and unzipped the folder which then displays all the data files I downloaded. There are two kinds of data that are in the folder I worked with the .csv files. This file is not a form that ArcGIS can understand so I opened the file and saved it as a Excel Workbook file. This data is just the numbers, but I also need a backdrop to display this info on so I also need to download a shape file of Wisconsin. I find the data I need download it unzip it and open the shape file in ArcGIS which gives me a map of the state of Wisconsin and all its counties, this map however does not have any of the number data that I am trying to display in it. In order to display it I need to join the Excel data with this shape file data. When you join data like this you have to find a field in both data sets that are the same, in this case that was the GEO_ID field. Once the data is joined I mapped the data. 
The map in green is a map showing the total population by county in Wisconsin. I went into the properties of the layer changed the color so it would display in green, I also made the legend easier to understand by labeling the data and normalizing it as well. For the background I went and added a base map of the area in black white. 
The other map is showing the urban population of the counties in Wisconsin. Like the other map I changed some of the properties to make the map look good as well as normalizing and labeling the data in the legend also used a base map in this map. I downloaded the data from the same place and followed the above described steps for both maps. 
The data in both these maps is based on population but you can get all kinds of data from the internet that you can map and display for a report or whatever you may need it for. Knowing how to find data and obtain it is a very important part of  GIS.

Sources: US Census 2010

Lab 2 Map Populations of Wisconsin by County