5/2/2011 American Community Survey (U.S. Census Bureau)

A subtitle should be “Working with Census Data: BE CAREFUL!”

This morning, the Merrimack Valley Planning Commission hosted a Census Data Workshop at Northern Essex Community College in Haverhill, MA. Laura Medrano represented the U.S. Census Bureau, and showed us how to access both Census 2010 data and American Community Survey data through the Census Bureau web site. For this demostration, we will examine Social Characteristics from the American Community Survey for Andover, MA.

Go to the Census Bureau Home Page, and click on the “American FactFinder” text:


You currently have both factfinder and factfinder2 available.
Click factfinder.census.gov
At the FactFinder screen, type Andover for City, select Massachusetts from the drop-down list, and click GO


Unfortunately, three listings appear:


We know that North Andover is a different city/town from Andover, so we can ignore it. But what is the difference between Andover CDP and Andover town, Essex County?
And is there any difference in the data?

Click the link for Andover CDP (CDP stands for Census Designated Place), and the Fact Sheet appears:

Print this page (or take a screen-shot), then go back to the Andover listings and select the link for Andover town, Essex County, and the Fact Sheet appears:

Well, you can see that there is a huge difference between the two listings!

Unfortunately, the Glossary is confusing (click on Glossary and find "Census designated place" and "Town").
Which means we must go to the map for clarification. Close the Glossary window.
On the left, click MAPS > Reference Maps


In the REFERENCE MAPS window, select Massachusetts from the State pull-down menu, and click GO. A Big Messy map appears:

If we zoom-in on Andover, and adjust the Boundaries being displayed, we see a pink Andover - Census Designated Place within the Town Boundary of Andover:


Which gets us back to our first line:

If you are Working with Census Data (“Andover, MA”): BE CAREFUL!

To download a 10-page expanded document (with extensive screenshots), click herehttp://www.dixonspatialconsulting.com/AmerCommSurvey.doc

4/2/2011 Visions of The Future

American Pastor W. A. Criswell (1909-2002) is credited with saying, "We're all fascinated with the future because that is where we will live the rest of our lives."

All my life, I have lived with both the expectation of living into, and the disappointment of the reality of, the future (as one of my favorite t-shirts says, “this was supposed to be the future – where is my jetpack”).

Isolated communities are the past.
Interconnected communities are the future.

The “one guy in the car with the map” is the past.
The “everyone in the car can see the map on their smartphone/GPS/iPad” is the future (hopefully, “relying on the nice GPS voice for directions” is just a middle step).

It is not the point of this blog, but a wonderful area-of-study is Past Visions of the Future (amazon.com even offers a book: "Yesterday's Tomorrows: Past Visions of the American Future").


I imagine my personal framework started with The Jetsons, progressed through Science Fiction authors (60’s: Asimov, Bradbury, Clarke, Heinlein; 70’s: Dick, Herbert; 80’s/90’s: William Gibson, Neal Stephenson), and was reinforced through movies:
the work environment of Minority Report


and Quantum of Solace


and, of course, the Stellar Cartography room in Star Trek: The Final Frontier



Which brings us to today. A nice little article in today’s Barron’s
Barron's Corning article
discusses Corning and its 6-minute video “A Day Made of Glass”
http://www.youtube.com/watch?v=6Cf7IL_eZ38

Aside from an in-vehicle navigation display (Automotive Display Glass) [and, of course, their Wall-Format Display Glass and Flexible Display Glass!], the Computer Cartographer in me LOVED their All-Weather Surface Glass used in a bus stop:

As a woman approaches the city map,

her cell-phone-preferences RFID tag alerts the Display to change language


She uses the pull-down menu to select her destination


The display draws the route

and, by holding her smartphone/portable device near the Display, it syncs with the map:

And off she goes!

Currently, maps are everywhere, and the “general public” is certainly becoming much more Geographic-savy. GIS is a “field of the Future” - I look forward to be living with it the rest of my life.

3/24/2011 2010 Census Tracts in Google Earth

There are a number of ways to get MapInfo .tab files (and Esri .shp files) into .kml format, for display in Google Earth. Having said that, I feel that it is a "Best Practice" (if you have the native software program - MapInfo for .tab files) to work in the native program as much as possible. MapInfo offers Google Earth Link, which is "a MapBasic application that automates the export of vector and raster maps created in MapInfo Professional to the Google Earth application."



Unfortunately, even now in 2011, the size of these files can get pretty big, and things can move pretty slowly (zooming in-and-out, panning around the map). The AZ_2010_Census_tracts_2011_3_24_13_06.KML file is 28.6 MB (built from 5.35 MB in MapInfo files); the MapInfo files for California are 19.1 MB, but they explode to 113 MB as a Google Earth kml file.

The files need to be thinned. MapInfo has an operation that specifically thins a file:


I recommend specifing Thinning for 3-Node Collinear Deviation and Node Separation of only 10 meters. This pair shows the blue nodes in Census Tract 2051.20, before and after thinning:



The resulting thinned files still follow streets, which is the ultimate test in Google Earth. The thinned California kml file is 25.9 MB, a reduction of 87%. This reduction makes everything run smoother, with no sacrifice in visual integrity.

The link to the thinned 2010 Census Tracts for Google Earth:
http://www.dixonspatialconsulting.com/kml_files.html

Help yourself!

2/25/2011 Charts: Looking at the Data

In looking at the CDC maps, I was curious about the data. Some of the ranges seem extremely tight:

3.7 percentage points on the Physical Inactivety map
1.1 and 1.2 percentage points on the Diagnosed Diabetes map
3.1 and 3.6 percentage points on the Obesity map

Depending upon the colors used, and the number and type of ranges, radically different maps can be created. As a result, very different stories can be told.

I downloaded the data for each map, and, in a new spreadsheet, displayed the ADJPERCENT (Estimated percentage adults with diagnosed diabetes or risk factor in the county after adjusting for age) values for each category, as charts:




The shape/curve of the data means that ~80% of the data are within a narrow range, with the “10% tails” going to extremes.

80% of the Physically Inactive data are between 19.4% and 32.7% (the lowest 5% range from 10.1% to 19.4%, the highest 5% range from 32.7% to 43.0%).

80% of the Diagnosed Diabetes data are between 6.7% and 11.6% (the lowest 5% range from 3.7% to 6.6%, the highest 5% range from 11.6% to 15.7%).

80% of the Obesity data are between 24.6% and 33.1% (the lowest 5% range from 11.5% to 24.6%, the highest 5% range from 33.1% to 43.9%).

What that means is that “it is not inappropriate to make sweeping statements about the data”:

Between one-fifth and one-third of the country are Physically Inactive.
Between 6% and 12% of the country have Diagnosed Diabetes.
Between one-quarter and one-third of the country are Obese.

The maps show that, unfortunately, most of the counties that are high in one problem area are also high in the other two problem areas. What that says to me is that, to avoid Diagnosed Diabetes and Obesity, I should eat moderately and exercise.

2/25/2011 Inactivity & Diabetes maps from the CDC

After reading it on vacation, my wife and switched our morning newspaper from The Boston Globe to USA Today (with the Weekend Edition Wall Street Journal on Saturday). We have been very pleased.

From a “Business GIS” point of view, USA Today has been doing a very nice job covering the state-by-state release of the Census 2010 data, with articles about ‘Latinos guide growth spurt’ (in Texas), ‘Population continues to shift away from rural areas’ (in South Dakota), and ‘Hispanic surge seen in USA’s Pacific Northwest’ (in Oregon and Washington).

On Thursday, February 17, 2011, they published a page 1A article titled ‘Activity, health: By county’ with a subheading “CDC maps show diabetes, inactivity ‘very closely tied’”. Unfortunately, they did not show any maps!

A search on the “Centers for Disease Control and Prevention” website turned up the maps:

http://apps.nccd.cdc.gov/DDT_STRS2/NationalDiabetesPrevalenceEstimates.aspx?mode=PHY

Indicator = ‘Physical Inactivity’ is the first map, Indicator = ‘Diagnosed Diabetes’ is the second map:



A third map shows Percentage of Adults Who Are Obese:


“When you actually take all three maps together, it really does give you this clear picture that the Southern and Appalachian areas on all three — obesity, diabetes and inactivity — are very closely tied to each other. It lets you step back and gives the big picture,” says Ann Albright, director of the CDC’s Division of Diabetes Translation.

In a nutshell, that is what a Geographic Information System (or Computer Cartography, or Desktop Mapping) is very good at: allowing the user to step back and get "the big picture".

2/16/2011 Using Pie Charts to represent Bank Activity

Way back on December 13, 2010, I discussed "Income as a % of MSA Median". It is essential for any financial institution to create such a map of their Assessment Area. Using a Geographic Information System (or Desktop Mapping program), the institution has the ability to see their own activity on the map. By geocoding their loan applications, each loan application record is assigned to a Census Tract. You then display all of the loan applications as Pie Charts (one pie for each census tract); the size of the pie corresponds to the number of loan applications in each Census Tract (more applications = larger pie); and each slice of the pie represents the outcome of the loan application (Originated, Denied, Purchased, or Other). The legend indicates that the most loan applications in any single Census Tract is 27. The other Legend numbers are simply for visual reference: a pie one-half the large size corresponds to a count one-half of the maximum value (in this case, 13.5); and a pie one-tenth the large size corresponds to a count one-tenth of the maximum value (in this case, 2.7). The "pie chart sizes" are ment to be "visual references" allowing spatial interpretation (more over here, less over there) - spreadsheets, on the other hand, are very good at conveying exact information (there are exactly 25 loan applications in Census Tract 2054.00, and exactly 12 loan applications in Census Tract 2084.00).

This map shows the Census Tracts shaded by Income Level, with the Pie Charts representing Fictional Bank's 2010 activity in the area:


Of course the first two questions are:
Why does Fictional Bank have so few applications in the low-income areas of Lynn?
Why does the Bank have a much larger percentage of denials in the low- and moderate-income areas?

2/1/2011 new TIGER files for the 2010 Census, part 2

Last week the Census Bureau finished releasing their 2010 TIGER files (all 50 states, plus the District of Columbia and Puerto Rico). These contain the Census Tract boundary files to be used when mapping Census 2010 data.

The 2010 release is 74,022 Census Tracts, an 11.6% increase from the 66,317 Census Tracts for use with Census2000 data. Generally, “inner city” census tracts, and rural census tracts, remain unchanged, while the additional tracts come from spliting suburban census tracts (almost all population changes from 2000-to-2010 are “increases in suburban areas”).

For 2010, there are 3,221 counties (up from the 3,220 previously because two counties in Alaska were split into three). Although the count of Census Tracts remain unchanged for 1,827 counties,1,120 gained Tracts, and 247 lost Tracts.

Forsyth County in the Atlanta, GA MSA increased +462.5%, from 8 Tracts to 45 Tracts (largest percentage increase):



Los Angeles County in the Los Angeles, CA MD increased +14.2%, from 2,054 Tracts to 2,346 Tracts (+292 is the largest count increase).

Ziebach County in the South Dakota non-MSA area decreased -80.0%, from 5 Tracts to 1 Tract (largest percentage decrease).

Cuyahoga County in the Cleveland, OH MSA decreased +11.0%, from 502 Tracts to 447 Tracts (-55 is the largest count decrease).

for a complete list of all County counts and changes, please email
dennis.dixon@dixonspatialconsulting.com
subject: TIGER 2010 Counties