Monday, May 6, 2013

Natural Disasters, Resilience, and the Connx Between Social and Physical Integration

Klinenberg responded to my piece and confirmed my suspicions, that Auburn-Gresham, despite being a higher crime area (at least at present) coped with the heat wave much better than Englewood, which had 11 times the heat-related deaths during the '95 heatwave.  Again, it was easy to assume based on the eroded physical fabric, but this post explored the morphology and dynamics why one area's physical interconnectivity eroded, which then eroded its social bonds, critical in Klinenberg's analysis to an area's resilience.
I've written this intro several times of my recent few posts, but here it is again:

About two weeks ago, I attended the Resilient Cities forum organized by the Dallas Institute for the Humanities and held at Dallas City Hall's council chambers.  The second of two featured speakers was Eric Klinenburg, a sociology professor at NYU, and expert on city preparation and response to natural disasters. He was an interesting and engaging speaker, a rare combination amongst academics.

His talk focused on the two natural disasters his research/professional career led him to experience first hand, midwest heat wave of 1995 and the deaths in Chicago from it as well as Hurricane Sandy in New York and New Jersey.

What was most interesting, at least to me and my area of study, was his conclusion about the core reason for deaths in Chicago, because it wasn't the heat that was solely responsible for the majority of the 750 deaths in the city.

While most of the deaths did come from largely poor and African American communities, Klinenberg's research found that the majority only occurred in certain neighborhoods fitting this demographic profile, but not others, some of which turned out to have some of the lowest incidence of heat-related deaths.  How can this be?  How can demographically similar neighborhoods be at both ends of the scale?

Instead, it was the cause of social isolation.  Klinenberg's point is that the real first responders are the friends and family around you and those social bonds help make individuals and, in turn, neighborhoods, more resilient.

So my question was then, what might be the connection between physical form and social isolation?  Does the design of our cities and their inherent networks lead to increased or decreased social and economic isolation?  And has Klinenberg found any connection yet?

So I first asked him via twitter whether he was familiar with Don Appleyard's work correlating social connections of San Francisco based on street vehicular traffic.  Now this has inherent limitations, not the least of which being place and time dependent of being in San Francisco in the late '70s.  However, what I take from Appleyard's work is: 1) there exists a disconnect between the way we design streets to maximize vehicular capacity and the purpose of cities, which is to facilitate social and economic exchange efficiently, and 2) there is a relationship between form and function of our streets, or physical connectivity, to social connectivity.  In the case of his work diagrammed below, the amount of through traffic actually decreased physical connectivity because residents could not as easily cross the street, the streets were less safe, and thus repulsive.


Klinenberg responded that he didn't know it well, but had seen the Atlantic Cities synopsis of it.  Because he had mentioned that demographically similar neighborhoods experienced drastically different results to the heat wave, I wanted to take a look at the physical form of those places.  So I asked him for a couple that fit this description and he provided two sets: North and South Lawndale (which is sort of West-ish Chicago) and Englewood and Auburn-Gresham, which is in South Chicago.   This post takes a look only at Englewood and Auburn-Gresham.  I haven't yet dug into the Lawndale sets.

I should at first note that I did not ask him for which areas of the two had more or less deaths and I don't want to know.  I want only to examine the physical and morphological aspects of these neighborhoods to see if that played a role in the social connections or lack thereof.

Above you can see (click to embiggen) the location of Englewood and Auburn Gresham in relation to the rest of Chicago.  I've highlighted the area with a red square, because this is the area I've mapped in DepthMap, Space Syntax's software to mathematically measure spatial integration and physical connectivity. I'll get to that at the end because I only wanted to use that to verify my visual findings from google earth.  I thought it interesting to use Space Syntax given their work correlating the London Riots to areas of physical segregation, and in turn, socio-economic isolation, primarily due to the dis-urban design of post-war public housing.  Double that down for the Paris riots of 2005.

Since I came across this article ranking the 25 most dangerous neighborhoods in the country this weekend, I mapped the 3 of the 4 Chicago neighborhoods on the list that are within this southern study area.  You'll notice that the 4th and 16th most dangerous neighborhoods are in Auburn Gresham.  The 25th is across the highway from Englewood at the border of Washington Park and the sliver of Englewood disconnected by the highway.

So if that article is to be believed, Auburn Gresham is more dangerous than Englewood.

Here is a more zoomed in version of the two areas highlighted based on the boundaries found here.

Now let's get some of the other similarities out of the way aside from demographics.  Both are in Chicago's southside, both have a highway running down their east side and rail lines with larger rail yards (almost everywhere) running along their west side (though, Englewood has West Englewood to its immediate west before the rail yards).

It's worth noting that Chicago has one of the lowest highway lane miles per capita count of any city in the country.  In other words, the city is not very burdened by highways physically or economically.  On the other hand, it has many more at-grade and elevated train lines for the local street networks to either be severed or perform some form of engineering gymnastics to traverse.

The rail lines and rail yard locations are important because rail infrastructure can be just as destructive and pernicious to local networks and neighborhood fabric as highways.  And the rail yards can be more difficult to physically traverse with tunnels, bridges, overpasses, etc., though Chicago still does it quite often.  Nevertheless, even when tunnels or overpasses are used to connect road networks across rail lines and rail yards, there is still a negative "edge" created.

Along those lines, I find it most critical to identify neighborhood centers, which are for more identifiable and critical to neighborhood structure than boundaries which tend to be fuzzy (though we planners insist on focusing on boundaries, borders, and gateways in the same manner that we focus entirely too much on the visible ELEMENTS of cities as complex symptoms rather than the more critical components of systems: CONNECTIONS and PURPOSE).

There are macro-geographic issues at play, the entire "peninsula" of land here in relation to the rest of Chicago, socially and economically.  But to distinguish the difference between the two, we have to examine the micro.

Right off the bat, I pinpoint these two areas as the effective centers of gravity of the two neighborhoods, where the most important "high streets" intersect which instills the most demand and in turn the greatest supply of buildings and intensity of uses.

Also, worth noting is that Englewood appears to have better transit access, with green line coming directly into its neighborhood center of gravity.

So let's take a closer look at the centers:

Above is an axonometric bird's eye of W. 79th St. and S. Ashland Ave.  As you can see it is a pretty intact area, with some minor erosion along Ashland due to commercial vacancy and increased surface parking.  I say minor erosion with the full knowledge of what is to come, because for the most part, Auburn-Gresham (AG) still has fairly high quality urban form from both a road network and physical building standpoint, though the commercial corridors are seeing some in-migration of suburban form fast food drive-throughs, gas stations, and convenience stores.

Now for Englewood:

Oh my.  Clearly there have been some pretty drastic changes to this area over the years.  Whatever had been there before had been replaced by Kennedy-King Community College.

Above is the same area in plan view.  The most obvious things that jump out are the diversion from the orthogonal grid, so omnipresent in Chicago, lots of vacant land, and lots of parking.

Moving away from the core of the neighborhood we see pretty severe erosion of the residential blocks of Englewood, almost to the degree of Detroit.

Another section of Englewood above.

However, it is not enough to merely suggest the lack of buildings led to social isolation.  We have to understand the deeper dynamics that led to the erosion and decay of the buildings and neighborhood fabric.  And to do so, we have to go back in time.

Using older aerials I wanted to go back in time and see if I can determine when the shift in geometries occurred.  So let's hop into the way back machine to 1999, much closer to the actual time of the '95 heat wave:

Yikes!  It's even worse.  Here, let me highlight what somebody thought was a good idea at some point.

You can still see the historic neighborhood core in place, far different from what is there now as shown above.  However, a 120' bypass/boulevard was built to circumnavigate the town center at suburban geometries for high speed travel.  To make matters worse, there is a shopping mall like ring road within this mini-beltway to service all the surface parking lots.  This is almost the exact diagram of many "town centers" aka malls without roofs built today, only that it happened in reverse order.  Let this be a lesson to what will happen to the majority of these faux town centers over the next 20 years (see: malls).

This engineering geometry effectively disconnected the surrounding residential neighborhood from the very center of gravity that it orbited.  If you buy Bill Hillier's explanation of cities as effectively co-planar with commercial corridors and nodes at one level and the fabric of residential neighborhoods enveloping those points of social and economic exchange as their centers of opportunity and amenity, then you understand that this commercial node was (one of the) raison d'etres for the neighborhood around it.  This raison d'etre was strangulated by traffic engineers trying to move cars and thus disconnecting, fragmenting and isolating the constituent parts of the neighborhood.

To ensure that this wasn't too new to have its wheels already in motion in the 90's I looked at the surrounding areas:

And yep, by 1999 the erosion was already well under way, suggesting this work had been done a few years before.  Unfortunately, I don't have enough historic aerials/maps to track it to when the engineering of the street network was so badly damaged/redesigned.

To explain this in metaphor, think about a tree with the trunk being the neighborhood center of gravity and the branches and leaves being the surrounding neighborhood streets and houses.  What they did to this neighborhood was the equivalent of taking a pocket knife and cutting a ring around the trunk of the tree, through the bark, and into the cambium, the connective tissue that transmits nutrients to all parts of the tree.

When you cut the cambium all the way around, you have effectively killed the tree, though it displays no ill effects for some time.  Slowly but surely the leaves stop getting the nutrients they need from the roots, they dry, whither, and die and fall away.

As for Auburn Gresham, which we have shown to apparently be more dangerous and have lesser access to transit, its fabric is much more cohesive, intact, and durable over time (despite some creep of car-dependent uses).

As you see above and below, there are minimal differences between the 1999 and 2012 aerials.  I'm willing to bet there isn't much difference to the 1980 and 1960 aerials either.  Could physical resilience be indicative of spatial integration which therefore yields increased social and economic connectivity?

Because I brought up Appleyard's work, it is worth looking at the traffic counts.  None of the roads are particularly over-scaled with the exception of the odd Bypass/Boulevard around Englewood's neighborhood center (transit stop: Halsted Green), which has since been mildly rectified, narrowing it from 120' to ~45', removing some of the flying right turns, though it still hasn't been particularly well-stitched back to the surrounding neighborhoods.

The traffic counts suggest that Englewood has much lower numbers of vehicles using the "main and main" streets crossing at the respective neighborhood centers, with 8,000 per day moving east-west and 12,000 per day N-S.  On the other hand, at AG's core, more than 25,000 cars are moving through each day

The disparity between the two sets of traffic data are worth noting because the physical fabric seemingly suggests that this diverges from Appleyard's conclusions, that higher trafficked streets tend to have more social connections.  However, traffic is also an indicator of a certain amount of activity, of vibrancy provided the vehicles, their speed, and the size/scale of the street don't overwhelm the ability to cross the street and the street network to function for its intended purpose, of safe social and economic exchange.  

In other words, there are apples and oranges at work with regards to traffic counts given the context of where the counts are taken, the design of the streets, etc.  In this case, Englewood appears to be a decaying area, so of course there are lower traffic counts.  Traffic (of all forms) relates to desirability, provided it is suitably tamed from overwhelming the feel and function of the place.

As I mentioned earlier, I wanted to first examine the two areas in question visually before mapping the street and block network in DepthMap, which if you're unfamiliar is a mathematical model measuring degree of interconnectivity of networks, locally and globally.  As I often write, for areas to succeed, for them to be integrated while providing suitable opportunity for residents, they need both local and global connectivity.  However, the infrastructure of global connectivity often disrupts local networks.  What results is many of those top 25 high crime neighborhoods, because they are physically isolated from the rest of the city around them.

Above is the spatial integration model for the two neighborhoods with adjacent West Englewood and Back of the Yards also in there to provide context and comparison.  It is worth noting that like all data samples the more the better.  This would need all of Chicago to paint the full picture, likely suggesting that this entire "peninsula" is more fragmented and physically isolated than most other areas of the city (with the exception of extreme suburbs and exurbs).  However, it is still useful to compare the apples to apples, the two neighborhoods in question against one another.

The map above is local spatial integration.  Red are the most connected or "spatially integrated" to their surroundings; green and blue are poorly interconnected.  The global integration map is pretty similar.  The only difference is that the east-west roads drop a color code from red to orange, indicating the elongated, peninsular N-S shape favoring N-S aligned corridors linking larger and more areas.

Above, I highlighted to areas worth note.  The larger red outline consists of Englewood's core and everything from it east towards the many heavy infrastructure rail and highway lines to the east.  This is the most disconnected area of this part of the city, much of it has to do with the redesign of the streets in and around the Halsted Green area.  Though some seeds of decay were sewn from larger dynamics of the city and its infrastructure, the particular physical decay and related social isolation in comparison to surrounding areas was primarily due to the destruction of the historic urban fabric and the disconnecting of the neighborhood to its center of gravity.

On the other hand, there is a small area just northeast of the AG core where the fabric noticeably breaks down.  So let's take a closer look at that area:

You'll notice a blue line across the top, that's a rail line that is crossed by every second or third north-south street.  The connections are still there, but diminished compared to other parts of the network.  That's part 1, but not why this area jumps out as green/blue.  What I want to point out is what looks to be public housing Loomis and 76th.  The problem isn't that it is public housing, but rather the design of it, that it clips the grid and breaks up the street network similar to the public housing mentioned in discussion of the London Riots.  Now this is much smaller and disconnected to a lesser degree than the more (in-)famous Cabrini Green and similar 'towers in the park' style public housing developments around the country.

If anything, I think this line of study relating physical networks to social networks is critical to understanding cities and their potential resilience, and that the strength of the physical networks are the most critical component for both sudden, short-term disruptions by way of natural phenomena and disasters as well as long-term, incremental social and economic decay apparent only over decades of change.

To come later this week:  I will take a similar look at the North and South Lawndale areas to determine whether physical form played a role in the social isolation deemed guilty of far too many preventable deaths during the 1995 Chicago Heat Wave.