Cities in a world with rapid winds and denser atmosphere?

Question

I am looking for information on how the trees and the flora would be in a world with a denser atmosphere and stronger winds.

I have read that due to the greater kinetic movement of the wind, that in all likelihood the trees would adapt to have lower and thicker trunks with stronger roots, and if they were higher, probably adapt to be more similar to palms.

This led me to ask myself, in such a scenario how would the buildings be built in that world? Materials, architectural design or size. I'd like to get an idea of what kind of cities humanity would build in such a world.

Answer 1

https://www.woodmagazine.com/materials-guide/lumber/wood-species-1/bristlecone-pine

http://www.gondwana-collection.com/news/article/2017/09/29/welwitschia-mirabilis-a-botanical-wonder/

Here are 2 wind adapted plants: the bristlecone pine and the welwitschia. Interestingly both types have super long lived individuals. This morph for pines can be seen in other pines from very windy areas as you put forth in the OP. But the welwitschia has an unusual strategy - the wind just beats the poo out of it and the leaves flop all around, but the thing does not die.

As regards buildings, your people might build longhouses. Here is a reconstruction of a Viking example.

https://phys.org/news/2017-04-iron-age-viking-longhouses-funerals.html

They are long and low, and this one has a windcutting prow like a boat. Oriented with the prow towards the prevailing wind the streamlined low profile shape minimizes wind resistance. Similar longhouses were built by the Iroquois. Some examples of viking longhouses from the Shetlands or Iceland have sod roofs which is kind of cool although possibly drippy when it rains.

Answer 2

The other answers have addressed the tensile limitations of concrete, and proposed that buildings might keep a low profile, etc. etc., and I totally agree.

If your society is still using natural materials for construction (timber, stone) I'd say they would be making very squat buildings with very thick stone walls. Thick enough, even a 'pile of stones' (a wall without mortar) will withstand strong winds.

There are three things I've not yet seen mentioned: doors, windows and roofs.

Depending on how primitive (or modern) your society is, they might not even use windows. Slit windows might be common - they let in (some) light and fresh air, but keep out flying debris picked up by storms. If wider windows are used (esp. if glazed) then really-substantial shutters on the outside will be the norm.

Regarding doors - people might build a through-corridor, from one side of a house to the other, and open at both ends, with the main entrance to the building half-way down the corridor. And, the corridor would be aligned across the prevailing winds. This arrangement prevents direct pressure against the door, and (depending on the exact wind direction) minimizes strong air currents in the corridor (because the pressure at the ends of the corridor will be roughly equal).

Regarding roofs - I have seen news reports of thin metal roofs being lifted by the suction of strong windows (that is, after all, how airplanes fly!). Roofs, therefore, will be heavy, and nearly horizontal. Pitched roofs will have one side facing (more or less) into the wind ... and the other side will face the suction of being in the wind shadow. You might find that dwellings will be single-story buildings, with substantial turf roofs, built into the landscape (i.e. few walls exposed to the wind, that would deflect it up and over roofs).

Think, hobbit houses!

Answer 3

The first and most obvious thing that would be different is the absence of concrete.

Most architectural designs today focus on the ability of a building to support the weight primarily, and handle torsional (sideways) movement and stresses as a secondary concern for very tall buildings. In your world, both are important and depending on how dense the atmosphere is and how much faster the winds are, torsional stress could easily become the primary concern.

So why no concrete? Well, concrete has exceptional compressive strength, but it's very weak in terms of tensile (stretching) strength. This is why we often reinforce concrete with iron, which has similar thermal shrinking and expansion figures, and has very good tensile strength. That said, in a world where highly energetic winds are pushing against a flat panel of concrete, the bowing from the 'sail' effect could easily crack it faster than such a thing would happen today. When you only want to go up (say) around 5 stories and you're primarily concerned with supporting the mass of the building vertically, concrete is an ideal material for building many office buildings but in your world, not so much.

That said; your architecture would likely contain many outer curves, designed to deflect the wind rather than withstand it. Expect a lot of dome based structures, and buildings designed similarly to the Sydney Opera House, which ironically is covered by a form of concrete tile; perhaps that would be how concrete would be used in such a world.

That said, expect a lot of curved outer walls, interlocked tiles of various materials and a limitation on just how high you can build your buildings due to the engineering possible with such lateral kinetic energy to contend with.

Answer 4

I'll ignore your question about trees and other flora, because it is unrelated to your title question. If you want discussion of trees and flora, start a second question.

For the most part, buildings would not change. There's actually not that many buildings which are tall enough to care about winds, even in a denser atmosphere.

The force of wind is going to be proportional to air density and proportional to the velocity of the wind, squared. Most houses are well over that point, until you get into hurricanes. If you had 2x denser atmosphere, then wind speeds that are a Category I here would do damage comparable to a Category II or Category III, because the extra density would give you the equivalent damage of a hurricane 40% faster. There's a decent chance that big cities would not be built anywhere near a hurricane belt.

You did not specify how thick the air is, nor how violent. If it got too violent, you'd start seeing cities take advantage of natural shelters to protect themselves from the wind. You might see more cities dug into the ground a bit. It's not very cost effective on Earth, with our atmosphere and winds, but it could be cost effective on your planet.

Skyscrapers would be much harder to build, so I would expect few of them. How hard they are to build depends entirely on precisely how much worse the weather is.