HomeDiagramsDatabaseMapsForum About
     

Go Back   SkyscraperPage Forum > Discussion Forums > City Discussions


Reply

 
Thread Tools Display Modes
     
     
  #1  
Old Posted Jul 23, 2015, 9:44 PM
memph memph is offline
Registered User
 
Join Date: Dec 2010
Posts: 1,854
Urban core growth 2000-2010

Something I've been looking into lately is how fast urban cores have grown. I started out looking at population growth by distance from city hall.

http://swontariourbanist.blogspot.ca...owth-2000.html
http://swontariourbanist.blogspot.ca...h-2000_16.html

All in all "MSA cores" defined as the 20% of the MSA closest to city hall have seen their populations decline by 0.33% for the 1mil+ MSAs.

That's even though many city halls are located relatively close to greenfield development, or in cities where the inner 20% is very suburban.

Now I'm looking at different ways of defining urban cores that might match more closely what most here would consider the urban cores of their cities.

One method is looking at the areas that had a certainly census tract density in 1960, I'm thinking 5,000 ppsm.

Another way is looking at the census tract density and auto commute mode shares relative the the mode share and weighted density of the MSA, and defining areas that are denser/lower auto mode share than the MSA average as "urban".

Last edited by memph; Aug 4, 2015 at 9:01 PM.
Reply With Quote
     
     
  #2  
Old Posted Jul 23, 2015, 10:52 PM
ThePhun1 ThePhun1 is offline
Registered User
 
Join Date: Sep 2014
Location: Houston/Galveston
Posts: 1,870
As with pretty much any list or subject matter posted here, the criteria comes under question. Not all cities are created equal in how they grow and what is considered their urban area. Some are San Francisco and some are Phoenix or even Houston, so analyzing urban growth as measured by population growth from a city hall seems silly.

Look at a place like Detroit. Since Windsor technically does not count as part of its metro area, even if it was thriving, it would not make sense to refine it's growth and character to the corner it's pinned into between the suburbs and Canada.
Reply With Quote
     
     
  #3  
Old Posted Jul 24, 2015, 6:21 PM
dave8721 dave8721 is offline
Registered User
 
Join Date: Jul 2005
Location: Miami
Posts: 4,036
Cool idea. Of course Miami always throws off these "from city hall" calculations since its city hall is nowhere near Downtown. Use "County Hall" (111 NW 1st St, Miami, FL) as the ground zero address and the core numbers would look quite different.
Reply With Quote
     
     
  #4  
Old Posted Jul 27, 2015, 7:51 PM
memph memph is offline
Registered User
 
Join Date: Dec 2010
Posts: 1,854
In order to address the fact that some metros are more urban than others, and that urbanity might not form a concentric area around downtown, I made another comparison, based on 1960 census tract densities.

http://swontariourbanist.blogspot.ca...h-2000_25.html

The top ten 1 million+ MSAs for total urban core growth:

1. New York
2. Los Angeles
3. Washington
4. Seattle
5. Boston
6. Miami
7. San Francisco
8. Portland
9. San Jose
10. San Diego

The bottom ten were

42. Indianapolis
43. Baltimore
44. St Louis
45. Cincinnati
46. Buffalo
47. Pittsburgh
48. Cleveland
49. New Orleans
50. Chicago
51. Detroit

Of course, New York and Chicago are much bigger than Portland and Buffalo, so it's not surprising that the changes there are amplified by their greater size and it might also make sense to look at urban core growth relative to the size of the MSA. In that case, the rankings would be

Top 10

1. Seattle
2. Washington
3. Portland
4. New York
5. Boston
6. San Francisco
7. Miami
8. San Jose
9. Austin and Los Angeles (tie)

and the bottom 10

42. Indianapolis
43. Memphis
44. Cincinnati
45. Pittsburgh
46. Birmingham
47. Chicago
48. Buffalo
49. Cleveland
50. Detroit
51. New Orleans

Of course Katrina was a big factor with New Orleans. While it did experience population loss prior to Katrina, it seems to have be less. From 1990 to 2000 it was definitely much less, from 2000 to the 2004 estimate it seems to have picked up, but then again, those are just estimates.
Reply With Quote
     
     
  #5  
Old Posted Jul 27, 2015, 8:08 PM
memph memph is offline
Registered User
 
Join Date: Dec 2010
Posts: 1,854
I posted maps of some of the urban cores in these two posts so you can see how they shape up to your expectations.
http://swontariourbanist.blogspot.ca...h-2000_25.html
http://swontariourbanist.blogspot.ca...h-2000_27.html

Here's a sample

The numbers are total growth, % growth and % growth relative to MSA size with the rankings for each category in brackets.

New York has (unsurprisingly) the biggest urban core, including almost the entire city proper, a good chunk of Nassau County, parts of Westchester County and much of NE NJ.


LA looks like it had already spread out across much of the basin and San Fernando and San Gabriel valley by 1960.


For Houston it amounts to a somewhat smaller area than I expected. A decent chunk of the West Loop didn't meet the 1960 density threshold.


For Atlanta and some of the other sunbelt boomers it's pretty much just downtown and immediately adjacent areas.


Here's Seattle where the urban core grew the most relative to the size of the MSA.
Reply With Quote
     
     
  #6  
Old Posted Aug 4, 2015, 9:07 PM
memph memph is offline
Registered User
 
Join Date: Dec 2010
Posts: 1,854
Posted some maps for the cities that experienced the greatest core losses (other than Chicago which was already shown in the top 10 biggest MSAs post).

Cities with greatest core losses:
http://swontariourbanist.blogspot.ca...owth-2000.html

Detroit


New Orleans


Cleveland


Pittsburgh


Buffalo
Reply With Quote
     
     
  #7  
Old Posted Aug 4, 2015, 9:10 PM
memph memph is offline
Registered User
 
Join Date: Dec 2010
Posts: 1,854
Cincinnati


St Louis


Baltimore


Indianapolis


Birmingham
Reply With Quote
     
     
  #8  
Old Posted Aug 4, 2015, 9:35 PM
Ryanrule Ryanrule is offline
BANNED
 
Join Date: Sep 2013
Posts: 772
chicago should package up the south side and glom that onto indiana.

Reply With Quote
     
     
  #9  
Old Posted Aug 4, 2015, 10:20 PM
memph memph is offline
Registered User
 
Join Date: Dec 2010
Posts: 1,854
I'm hoping that many of these losses were just due to the housing crash and will be reversed with the recovery + shift back towards cities. If you have a 2-3 percentage increase in the share of housing units that are vacant in 2010 vs 2000, plus a decrease in household sizes over a large area, that can add up.

In the case of Chicago though, it's not just the South Side, there's been relatively significant losses in the north side as well. The % loss in the North side is smaller, but there's a lot of people living there so it still adds up. There's been losses in the Hispanic areas too, not sure if that's been due to reductions in household sizes or abandonment.

Anyways, I'm working on the next set of criteria now, which will add census tracts where the non-auto mode share and density is about the MSA average (weighted density for density) to the tracts that qualify based on 1960 densities. That should expand the areas included in the cores of sunbelt cities by multiples. In older cities where the core that's based on 1960 densities is already large, it should change little - if at all (already did Buffalo, not a single census tract was added).
Reply With Quote
     
     
  #10  
Old Posted Aug 4, 2015, 11:48 PM
led_tool_mises's Avatar
led_tool_mises led_tool_mises is offline
Registered User
 
Join Date: Jul 2009
Posts: 18
memph, what website are you using to shade the census tracts on your maps?
Reply With Quote
     
     
  #11  
Old Posted Aug 5, 2015, 12:18 AM
SHiRO's Avatar
SHiRO SHiRO is offline
Registered User
 
Join Date: Aug 2002
Location: Barcelona
Posts: 15,728
Great maps memph! Very interesting!
Reply With Quote
     
     
  #12  
Old Posted Aug 6, 2015, 2:25 AM
memph memph is offline
Registered User
 
Join Date: Dec 2010
Posts: 1,854
Quote:
Originally Posted by led_tool_mises View Post
memph, what website are you using to shade the census tracts on your maps?
Just Google Earth.
Reply With Quote
     
     
  #13  
Old Posted Aug 7, 2015, 5:51 PM
chris08876's Avatar
chris08876 chris08876 is offline
NYC/NJ/Miami-Dade
 
Join Date: Jul 2013
Location: Riverview Estates Fairway (PA)
Posts: 45,696
Found this interesting:
==============








====================
http://www.6sqft.com/50-of-americans...gest-counties/
Reply With Quote
     
     
  #14  
Old Posted Aug 7, 2015, 8:40 PM
ThePhun1 ThePhun1 is offline
Registered User
 
Join Date: Sep 2014
Location: Houston/Galveston
Posts: 1,870
^

Obvious assumption:

I'm assuming that DC is counted among the 42 smallest "states." In that case, they could have included some of the territories such as Puerto Rico.
Reply With Quote
     
     
  #15  
Old Posted Aug 8, 2015, 5:17 AM
memph memph is offline
Registered User
 
Join Date: Dec 2010
Posts: 1,854
Here's a map to show the results of the different methodologies I'm considering, using Las Vegas as an example.


In red there's the boundaries based on 1960 densities (5000+ ppsm) - or in areas where only 1970 census tract data is available, then densities of 6000+ ppsm.

In yellow I've also allowed census tracts with densities above the MSA weighted average AND auto commute mode share below the MSA average to qualify. Also in MSAs where the urban core(s) is still less than 20% of the MSA, such as with Vegas, I've also lowered the 1960/1970 density requirements to 3000 ppsm and 4000 ppsm respectively.

In blue, in addition to allowing census tracts to qualify in all the ways above, I've also allowed them to qualify if the either the density OR non-auto commute mode share is at least 2x the MSA average and that variable is above the average by more than the other factor is below the average. The main purpose of this is for places like CBDs, river fronts, harbours, or in this case the Vegas strip that have low residential densities because most of the land is non-residential in use but very high non-auto commute mode share. You could also have census tracts especially in cities where auto mode share is high everywhere and not necessarily as good of a great predictor of urbanity (by that metro area's standards) as density.

Example:

Density is 2.3x more than the weighted average
Non-auto mode share is 2.2x less than average
= qualifies

Density is 1.9x more than the weighted average
Non-auto mode share is 1.8x less than average
= does not qualify

Non-auto mode share is 2.2x more than average
Density is 2.3x less than the weighted average
= does not qualify

In most cities this last criteria probably won't make much of a difference, but in Las Vegas it does because the strip has little housing (that isn't hotels) and also separates some census tract clusters from the main urban core that don't form a sufficiently large cluster to qualify as a secondary urban core (pop of 25k+), but which would otherwise qualify.
Reply With Quote
     
     
  #16  
Old Posted Aug 10, 2015, 2:51 AM
memph memph is offline
Registered User
 
Join Date: Dec 2010
Posts: 1,854
Here's Atlanta using the 1960 density + 2000 density & mode share criteria.



Red is the inner core based just on 1960 densities, purple is the expanded core.

Inner Core
2000: 146,334
2010: 152,201
Change: 5,867

Outer Core
2000: 938,384
2010: 902,302
Change: -36,082

Total
2000: 1,084,718
2010: 1,054,503
Change: -30,215

Last edited by memph; Aug 13, 2015 at 4:49 AM.
Reply With Quote
     
     
  #17  
Old Posted Aug 13, 2015, 4:49 AM
memph memph is offline
Registered User
 
Join Date: Dec 2010
Posts: 1,854
DFW using the 1960 density + 2000 density & mode share criteria.



2000: 1,438,671
2010: 1,415,425
Change: -23,246 (-1.62%)
Reply With Quote
     
     
  #18  
Old Posted Aug 13, 2015, 11:02 PM
memph memph is offline
Registered User
 
Join Date: Dec 2010
Posts: 1,854
Houston using the 1960 density + 2000 density & mode share criteria.



2000: 1,269,485
2010: 1,259,027
Change: -10,458 (-0.82%)

Most (-9,077) of the population loss was in Galveston.
Reply With Quote
     
     
  #19  
Old Posted Aug 15, 2015, 2:42 AM
memph memph is offline
Registered User
 
Join Date: Dec 2010
Posts: 1,854
South Florida using the 1960 density + 2000 density & mode share criteria.


(that's West Palm Beach/Palm Beach in the inset)

2000: 1,673,801
2010: 1,724,687
Change: +50,886 (+3.04%)

The vast majority of the increase was in Miami-Dade, with a little bit of population growth in the Hollywood cluster. The Fort Lauderdale and Palm Beach clusters lost a few thousand people.
Reply With Quote
     
     
  #20  
Old Posted Aug 16, 2015, 3:38 AM
Hamilton Hamilton is offline
Registered User
 
Join Date: Mar 2005
Location: Journal Square
Posts: 446
very cool. thanks!
Reply With Quote
     
     
This discussion thread continues

Use the page links to the lower-right to go to the next page for additional posts
 
 
Reply

Go Back   SkyscraperPage Forum > Discussion Forums > City Discussions
Forum Jump


Thread Tools
Display Modes

Forum Jump


All times are GMT. The time now is 12:23 PM.

     
SkyscraperPage.com - Archive - Privacy Statement - Top

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.