With minimal terraforming, what features/structures would need to be built to protect a 25mi radius city from wind?

Question

I understand that the wind is caused by a differential in atmospheric pressure, but say that a city built in an extremely flat landscape is constantly threatened/harassed by the wind and wind-related incidents.

What would the core of engineers come up with as a solution given a tech level of present-day to perhaps 25 years in the future?

Background: The city has poor soil structure (hence minimal terraforming) and the wind threatens their crop yields because of poor water retention in soil and root structures. Bedrock is fairly reachable and building materials are not scarce through trade.

Answer 1

Windbreaks, and wind turbines.

Per the US Department of Energy, a good windbreak can reduce windspeed for a distance of around 30 x the windbreak's height. A 30-metre high windbreak would be needed to protect 1 km of space. That's a decent height to build, but it's not impossible.

Construction methods will vary depending on conditions and available materials. It could be as simple as an earthen bank - you could make it even more efficient by digging soil from the field you want to protect, reducing its height, and using that to build your windbreak. If you're worried about erosion, flood waters, etc, you would build around a central core of steel pilings driven into the soil, surrounded with gravel and/or concrete, then pile the soil around that.

You would then line the windward side of your bank with wind turbines for power generation. Exactly how the turbines would affect the wind flow is not currently clear - it's an area of active research - but in 25 years, and with a lab as effective as this colony, we can be reasonably sure the engineeers would be able to place them efficiently.

And, nitpick - the engineers are a corps, not a core. It's pronounced the same, but has a very different meaning.

Answer 2

The traditional solution is to use rows or trees.

A windbreak (shelterbelt) is a plantation usually made up of one or more rows of trees or shrubs planted in such a manner as to provide shelter from the wind and to protect soil from erosion. They are commonly planted in hedgerows around the edges of fields on farms. If designed properly, windbreaks around a home can reduce the cost of heating and cooling and save energy. Windbreaks are also planted to help keep snow from drifting onto roadways and even yards.1 Other benefits include contributing to a microclimate around crops (with slightly less drying and chilling at night), providing habitat for wildlife, and, in some regions, providing wood if the trees are harvested.

The more of these rows you create on the windward side of the city, more energy you remove from the lowest level of the wind. This will decrease the wind in the city unless you build taller than the trees.

Answer 3

This problem was earlyer faced in the dust bowl during the great depression in America. Look at dry land farming technics for some idea.

https://en.wikipedia.org/wiki/Dryland_farming

If trees cannot grow here you could use artificial wind breaks instead (walls). You could genetically engineer trees to be able to grow better at this location. Or you could build underground.

My favorite is gene edited trees. Once done you just plant the seeds about. There are however potential ramifications.