The goals and objectives of this lab were to learn how to download data from the U.S. Census Bureau and map the data using ArcMap. We were to download 2010 Census data, specifically total population of Wisconsin counties, from the U.S. Census Bureau, and then we chose our own data set to download from the same census. The final product is a map displaying both variables separately.
Methods
Our first objective was to download 2010 Census Data from the U.S. Census Bureau website. We narrowed down our search by using Advanced Search, and selecting Population total through the Topics option. We then chose Wisconsin counties (County 050), through the Geographies option. By adding these options to my selection window, I was able to view all the data available for me to download. On the third page, I found the P1 variable for TOTAL POPULATION from the 2010 SF1 Dataset, and downloaded it. I saved the downloaded file to the Lab2 folder I created for this project. From windows explorer, I found the data I had just downloaded (Lab2 folder) and extracted all the files to my folder. I then opened the two CSV files in the Lab2 folder in MS Excel. One of the files displayed the metadata while the other file displayed the actual tabular data. I saved the latter of the two files (DEC_10_SF1_P1_with_ann.csv) as an MS Excel Workbook file.
The second objective was to download the shapefile for the WI census data. I returned to the U.S. Census Bureau website, and chose the Geographies option again. I then navigated to the Map tab, and double checked that Wisconsin Counties was highlighted on the map shown. I then downloaded the map as a shapefile.zip through the spatial data formats. I saved this file in my Lab2 folder. I extracted these files as I had previously done.
The third objective was to join the data I had downloaded together in a table. I opened up a blank map in ArcMap, added the shapefile to the map, and viewed it's attribute table. I then added the P1 table to the map (the Excel file I had saved in my Lab2 folder) and opened this table as well. In order to view both table at the same time, I arranged the tables in a new vertical tab group. In order to map the total population, I joined the two tables together through a Table Join through the 050_00 shapefile , using GEO#id as the common attribute. I reopened the attribute table for the shapefile to double check that the both data was shown in the one table. The D001 field contained the population data.
The fourth objective was to map the population data. I navigated through the Properties of the shape file, to the symbology tab, and chose a graduated colors map for the D001 value field with 6 classes that best represented the population of WI.
The fifth objective of the lab was to download and map a variable of my choice from the U.S. Census Bureau website. I chose SEX BY AGE as the variable I was going to map. I followed the same workflow as in objective one to download my data. I added a new data frame to my previous map, added the shapefile, and the table I had just downloaded and saved as a MS Excel file in my Lab2 folder. I joined the two tables together, as done in objective three, and chose one specific variable I was going to map. Since the SEX BY AGE data was not labeled appropriately in the attribute table, I viewed the table from the website to have a better idea of how the fields were grouped. I chose the variable Females age 21 (D033) to map and normalized the data to Percent of Population (D001). I chose to display my data in a graduated colors map and use percentage labels.
The sixth objective was to build a layout displaying both maps I created with the data I downloaded from the U.S. Census Bureau. I changed the data frame projection for both maps to NAD_1983_2011_Wisconsin_TM_US_Ft. and included the Title, Legend, North Arrow, Scale Bar, source, author, and date. Lastly I added a base map, and exported the map as PDF document.
Results
The map on the left displays the percent of females age 21 per Wisconsin county. Northern Wisconsin seems to have the least percent of females age 21 with the exception of a few counties. A band of Central Wisconsin shows a higher percentage of females age 21 as well as a band of Southern Wisconsin which shows the same pattern. The map on the right shows the total population of each county. South-east Wisconsin seems to have the highest density of population per county, whereas Northern and some Central-western counties have the least density of population per county. The two maps show some correlation in regards to population densities of counties, and population density of females age 21.
Sources:
http://factfinder2.census.gov/faces/nav/jsf/pages/searchresults.xhtml?refresh=t
"U.S. Census Bureau, 2010 Census, Total Population and Sex by Age.
No comments:
Post a Comment