Thursday, March 12, 2015

GIS 1 Lab 3


The main objective for lab three is to continue practicing GIS and standalone data that can be used for analysis in a GIS project. The lab focused on converting standalone tables containing data into an attribute table that can be mapped and then exercised manipulating the U.S. Census Bureau’s website to acquire information to be used in a GIS.

            The U.S. Census Bureau website is first introduced and the mission of the bureau is to serve as the leading source of quality data about the nation’s people and economy. The data collected is used to regulate the distribution of Congressional seats to states, make decisions about what community services to provide as well as distributing $400 billion dollars in federal funds. Downloading the 2010 U.S. Census of Wisconsin by county is our first task followed by downloading the Wisconsin shapefile, which is also obtained from the website. Once the downloading and saving was complete modifications to the Excel spreadsheet involving Wisconsin’s counties population were made. Deleting an unneeded record, adjusting the population field’s decimal places, formatting the population field to numbers instead of text and finally saving the spreadsheet as an Excel workbook, which ultimately made it possible to add to ArcMap. Tying the Wisconsin shapefile and the spreadsheet together is the next task. The process used to combine the two is called the join technique. This technique helps link the census data and the shapefile into one attribute table. After applying the join method the data is now ready to be projected. Under symbology’s quantities graduated colors the selected value is population, which displays the most common used color ramp for population ranging from red (highest in density) to light yellow (lowest).  The classification method used is defined interval with five classes. I chose this classification method because I thought it best represented the distribution of population by county in Wisconsin.

            The next objective is to project data of our choice onto the Wisconsin county shapefile. Housing units was my selected variable. Following the same steps from the map created before I only changed the joining process. The joining process involved tying Wisconsin’s housing units and the population data table into the county’s shapefile. Once the joining technique was finished projecting the data was next on the list of steps. The map displays the population, which is divided by the number of housing units. I found this projection unique because the number of housing units in the northern counties exceeds the population. The data is projected this way because of the number of cabins present in the north. The classification method used is geometric interval. Once the maps were complete the essential elements of map design were added to ensure the viewer has a well understanding of the goal expressed.

            Downloading and mapping GIS data is an extremely important skill. I can now use data from a source outside of ArcMap. I’ve learned to convert along with join data tables as well as import shapefiles to project my data selected.

Source
 
American FactFinder. (2015, January 6). Retrieved March 12, 2015, from http://factfinder2.census.gov/faces/nav/jsf/pages/index.xhtml