Challenge 8

Module 8 covers layouts and making presentation maps. In this "Challenge" session, I'm asking you to continue applying what you learned in LAD Module 8 and earlier Challenges.

The data is included in the Challenge8 zip file which you can download and unzip. If you already downloaded this data for "Show & Tell" you don't need to download it again.

CHALLENGE

In this Challenge you will need to use the precinct data, table joins and/or relates, as well as Data Driven Pages to answer these questions and make a map.

1) Which precinct in Maui has the highest percentage of registered voters compared to VAP?

     DP:   ___________________

     RV/VAP percentage:   __________________

2) Which precinct in Maui has the lowest percentage of registered voters compared to VAP?

     DP:   ___________________

     RV/VAP percentage:   __________________

3) Make a map that shows the precincts colored based on the RV/VAP percentage. Also show the census block boundaries. Label each precinct with its DP number and its RV/VAP percentage.

4) Now make a layout and add a title, legend, scalebar and credits. Also add a location map that shows where the precinct is within Maui County.

5) Create Data Driven Pages and add some Dynamic Text boxes to your layout.

Show & Tell for Module 8: Election Data

In this "Show & Tell" session, I'll show you some useful things that were not included in  LAD module 8.

If you'd like you can try these yourself. The data is included in the Challenge8 zip file which you can download and unzip. Here are the notes to re-create what I show you.

ELECTION DATA

PRECINCTS

The State of Hawaii Office of Elections works with County Clerks to conduct elections in Hawaii. These elections are for Federal, State and County offices as well as other issues that voters decide. Hawaii is divided into precincts to facilitate managing an election and reporting the results. Most precincts have a polling place where voters come on election day to cast their ballot. Schools are often used as polling places which is one of the reasons you get a holiday on election day. Precincts with few voters don't have a polling place and instead vote an absentee ballot.

Here is a map of the precincts in Maui County.

Every precinct has a unique identifier, called a DP. For example, the area around Hana is precinct 13-03. Let's look at the feature table.

You can see that each feature has its DP designation. "PollingPlace" is the name of the place where ballots are cast on election day. "BallotType" shows the combination of Federal Congress (US2), State House (H08) and State Senate (S05). Maui does not delineate County Council districts based on population, so every ballot lists all of the County Council races, thus all end in "MAU". Hawaii and Honolulu do have population based Council districts so their BallotType would show those Council numbers.

REGISTERED VOTERS

Voters are assigned to a specific precinct depending on where they live. Some precincts have a large percentage of voting age population registered to vote, others have less. The State Office of Elections wants to map which precincts have high percentages and which have low.

You've already seen how census block data records the total population and voting age population. From redistricting we know which census blocks make up which precincts so it is easy to summarize and obtain the total population and total voting age population in each precinct. These results have been combined with the number of registered voters in each precinct in this table:

You can see that the DP field is common in both tables so that is a good field for establishing joins and relates. The fields are pretty self-explanatory. "Pop2010" is the total population from the 2010 census. "VAP_2010" is the total voting age population (age 18 years and older) from the 2010 census. "RV_20130513" is the count of registered voters on May 13, 2013.

DATA DRIVEN PAGES (DDP)

Here is a handy way to navigate between the different precincts using Data Driven Pages (DDP). The DDP toolbar looks like this:

At first most of the buttons are not active. Click the button on the left of the toolbar to set up DDP.

Fill out the Definition page as shown here. Basically you are saying to use the features in the "precincts_Maui" layer to define a page, one page for each feature. There are other options but let's keep it simple for now. Click the "OK" button.

You'll see that your map has panned and zoomed automatically to the first page based on the first feature, precinct 08-01.

You can click the right arrow...

...to advance to the next page. This page is based on precinct 08-02 so it again automatically pans and zooms such that 08-02 is in the center of the page and fills most of the page.

This is a very handy way to move between features, just configure DDP using that feature class.

DDP AND LAYOUTS

Another huge benefit of DDP is with layouts. In LAD module 8 you learned about layouts for making presentation maps. You can design layouts that will change page to page using DDP. You design your layout like you learned already, but you can also insert special Dynamic Text boxes that will display attributes for the current DDP page.

You insert a Dynamic Text box based on a Data Driven Page Attribute. Here's an example:

You can see that I have inserted five special text boxes, one a title box that shows the DP of the current page. The other four show four different values from the table for that feature. This is a very powerful tool for making presentation maps and map books.

You will need to use this precinct data for Challenge 8.

Show & Tell for Module 6: Census Data

In this "Show & Tell" session, I'll show you some useful things that were not included in  LAD module 6. This blog covers census data. Another blog covers table joins and relates.

If you'd like you can try these yourself. The data is included in the Challenge6 zip file which you can download and unzip. Here are the notes to re-create what I show you.

CENSUS DATA

Every ten years the United States Census Bureau conducts a census of the United States for redistricting purposes. The United States population is continually growing and moving. Here you can see how the weighted center of population has moved westward with each decennial census.

The first census was conducted in 1790, shortly after the Constitution was ratified. The most recent decennial census was in 2010. It's interesting to see how we have grown.

Here you can see how the total US population has grown from about 4 million in 1790 to more than 300 million in 2010. New York has always been the most populated city.

The United States census is broken down by several different geographies. For our project we'll be using the following hierarchical breakdown:

     Country - State - County - Tract - Block Group - Block

Our country is composed of states, states are composed of counties, counties are composed of tracts, tracts are composed of block groups, and block groups are composed of blocks - census blocks. You're familiar with the first three, maybe not the last three. They are special geographies used for census purposes.

TRACTS

To help you understand these last three, let's look at Maui County.

The gray lines delineate the census tracts in Maui County. Including Kalaupapa, there are 36 census tracts in Maui County. I have selected a tract in the Kihei area to look at more closely.

As you can see here, census tracts can cover both land and ocean. Every census tract has a unique ID. In the Challenge 6 dataset this field is called "GEOID10".  It is composed of three parts:

     - a unique code for the State of Hawaii (15)

     - a unique code for Maui County (009)

     - a unique code for the tract (030707)

The first two are combined together to create what's called a FIPS code. Every county in the United States has a unique FIPS code. Maui County is 15009.

All three are combined together to create the unique tract ID - 15009030707.

BLOCK GROUPS

Let's add in the next level, the block groups.

Block groups also can cover both land and ocean. You can see that this tract is divided into four block groups numbered 1 through 4. The unique block group code is added to the tract ID to create a unique Block Group ID. For example, the block group that covers land and ocean is block group 2, so it's unique block group ID is 150090307072.

BLOCKS

Let's add in the final level, census blocks.

Blocks generally do not cover both land and ocean. The pale orange lines are the block boundaries. You can see that one of them follows the coastline. There are too many to label them, so let's zoom in to block group 150090307074.

Now you can see the census blocks outlined in pale orange with a label showing their four digit block code. The first digit is the block group code followed by three digits that make a unique census block code. For example, the unique Block ID for 4001 is 150090307074001.  Here the Identify window for that block:

Every census block in the United States can be identified by it's 15 digit Block ID - in this table called GEOID10. The field TOTAL in this dataset is the 2010 Census total population count for this block - 806 total residents.

The census block is the smallest geography that the Census Bureau reports counts of population and households. More detailed demographic and economic data is not published at the block level to preserve privacy - instead being published at the block group or tract level. In our project we'll be using block level data. In your Challenge 6 dataset you'll see the table for census blocks for the entire State of Hawaii:

You can see the same fields as in the Identify window including TOTAL, the total population. 

VAP - VOTING AGE POPULATION

There is another table, this one showing the VAP population. This is the voting age population, meaning those 18 years and older.

The field TOTAL18 reports the VAP for each block. In LAD module 6 you learned how to join tables. You could use GEOID10 to join the VAP table to the blocks table.

RACE

And one more table, this one showing total population by race for each census block in the State of Hawaii:

The race fields are:

     WHITE

     BLACK

     AIAN        (American Indian or Alaska Native)

     ASIAN

     HPI           (Native Hawaiian or other Pacific Islander)

     OTHER

     MLTMN   (two or more of the above races)

There is also a field called MAJPOPTOT which identifies the dominant race in each block with a one letter code:

     W   White

     B    Black

     I     American Indian or Alaska Native

     A    Asian

     H    Hispanic

     M   miscellaneous, none of the above are a majority

     X    no population

Again, GEOID10 could be used to join this table to the blocks table.

CENSUS GEOGRAPHY AND OTHER GEOGRAPHY

Let's look again at the block map:

Now look at the census block outlines. These boundaries come from Census TIGER files that identify things like roads, streams, coastlines and other features that we can see on maps. Most census block boundaries follow some sort of natural or man-made features.

Look at Block 4003. This census block is actually the area inside Oluea Circle.  Note that the census geography, the census lines, do not match up with Oluea Circle as shown on the basemap. This does happen occasionally and is most often due to inaccuracies in the TIGER data. If you look at the other roads you'll see they match pretty well.

This problem, inaccurate census block boundaries, is one we will work on when we start our project.

You will need to use this census data for Challenge 6.