posted 10 years ago
Wind and sound breaks really need two different approaches.
Wind bounces off hard surfaces and rapidly reforms with very little slowing of the windspeed. Earth banks might make a small difference immediately down wind of them but less the you would intuitively expect/hope for. Wind breaks are best thought of as wind filters. You want a dense and thick barrier of twigs and leaves that the air can penetrate, pass through and drop energy in... emerging more slowly on the other side.
Sound breaks on the other hand are better made of hard reflective surfaces - an earthen bank at an angle of 45 degrees will bounce sound straight upwards and away from the ground. Sheltered behind this bank noise levels are significantly less. This is why motorway landscaping in the UK often has steep banks either side to reflect road noise up and away from residential areas. On the other hand sound will pass pretty much unhindered through "soft" barriers like hedges and trees - there will be some reduction in intensity but not massive.
We experience both of these effects where we are - we have a motorway 1km away over open fields which we can hear clearly, but only from the place where there is a gap in the earth banks. We have an excellent screening of leylandii at the end of the garden. Sheltered behind these there is almost no wind, but the sound still carries through (albeit lessened).
Moderator, Treatment Free Beekeepers group on Facebook.
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