Green space and overcrowding within urban areas

[memph]

Regarding fewer parks in the suburbs, I'm not sure this is true, at least not true for all cities. Here's how far (by foot) public greenspaces are from my parents' suburban house according to google maps.

4min: park with tennis courts, playground and baseball field
6min: park with several gardens and access to Lake Ontario. It's a good place to meet people and is often used for wedding pictures.
6min: schoolyard with soccer field and basketball courts
10min: park with public outdoor pool, playground, baseball field and wooded ravine
11min: schoolyard with soccer field
11min: park with playground, grass field and wooded ravine
13min: small park with public lake access
15min: a couple little parks, just wooded/swampy ravines
16min: wooded ravine
18min: tennis courts
19min: schoolyards with track, football, soccer and baseball fields, basketball, wooded area and playground
20min: schoolyards with soccer, baseball fields, basketball, wooded area playground

In the end, at least around here, the 20th century suburbs tended to avoid burying creeks like in the 19th century, and kept ravines around them. School yards also got bigger, with larger sports fields. I wouldn't say this is a suburbs vs cities thing though, as much as a product of the times.

Mid/late 20th century development in the cities also had a lot of greenspace with apartments/rowhouses in the park, and then when that didn't work out so well, with better defined public greenspaces. In Toronto, this shift started in the 70s and 80s, and the redevelopment of industrial and waterfront areas near downtown now includes a fair bit of parks, and also some courtyards. In addition to courtyards, you also have something similar to SoCal's bungalow courts, except with townhouses, as well as a lot of private outdoor terraces on condos.

Nowadays, there is a push (at least around here), to protect a ton of different kinds of natural areas, not just ravines but also waterfronts, woodlots and wetlands. My parents' suburb is planning to develop the Northern part of the municipality to hold 50,000 people and 30,000 jobs, and the park area would be almost 3 times Central Park: www.mshplan.ca/NorthOakvilleEastSP.pdf

There are several different kinds of parks, and they serve different purposes. One type I'll call "play areas", sports fields/courts, playgrounds and dog parks where you, your kids or your pets can go play or be active, but also end up being social places since you play with others, and if you're a parent or pet owner, it's a good platform for socializing with other parents or pet owners. Then you have plazas which exist mostly for socializing, and squares and gardens which are for both socializing and relaxing. Finally you have natural areas like ravines and woods that are more for escaping the city, and people. Some of these benefit from getting a fair bit of use (the social ones), some benefit from getting little use (natural areas), some are in between. Some require lots of space, some do well with little space. Some also can have a mix of purposes, like a playground with an area next to it for parents to relax or socialize. Where I find suburbs often fall short is when it comes to places for people without pets or children to hang out, from teenagers to seniors.

[memph]

I think the cause for the feeling of overcrowding is different depending on the location. In Toronto, I would say it's often because residents are often exposed to heavy traffic. Although most of the road network (side streets) has little traffic, people spend most of their drive to their destination on arterials and highways which have heavy traffic. In Venice, some people would find it crowded because many of the streets are packed with pedestrians and it's difficult to escape the crowds (although there are quiet streets at the edges of the island). In Tokyo, some people might not be used to the small gardens and crowded transit, and in San Francisco, the lack of nearby parks...

[memph]

For heat islands, I'm not convinced that trees have an advantage over narrow streets, or that suburbs have an advantage over cities.

I've visited a lot of old Mediterranean towns in Croatia. Their summers hit temperatures similar to that of many American cities at around 85-90F highs on average, but instead of having trees, they have very narrow streets lined by stone buildings like this:


Walking there didn't feel too hot, often breezy and you were often in the shade. I felt more comfortable in streets like that than on the beaches or mountain sides.

Here is a satelite heat island map of the Toronto area (based on surface temperature).

The hottest places are actually in the suburbs (red), mostly areas with office, industrial and retail uses with lots of paved and roof area and little trees. Next you have single family residential neighbourhoods with little tree cover, like inner Toronto's West end where most residents haven't bothered planting many trees, and new subdivisions on the suburban edge where trees haven't had time to grow big yet. Then you have single family residential neighbourhoods with more and bigger trees in yellow, with lots big and small. Finally you have ravines and large parks with tons of tree cover, farmland and... the Financial District! It looks like the shadows cast by the downtown office towers were able to create a substantial cooling effect. Surprisingly the highways are not hot like you would expect but pretty average (yellow lines on the map).

What I wonder is about a neighbourhood with narrow streets and low to midrise buildings that cast the street in shadows but where much of the surface area is rooftops. Would the street be cool and the rooftops hot? What would the building interiors be like? And how do the cooling effects of white roofs compare to trees?

[wburg]

Big stone buildings like that have the advantage of thermal mass: they spend all day heating up while it's hot, and surrender the heat to the surrounding environment at night when it's cool. It is like living in a big heatsink. You found that sort of construction in the Southwest, adobe construction, before the days of air conditioning. Trees and shade are an alternate strategy for reducing the effects of heat, but require a different approach, and are dependent on a reliable water supply.