<
https://grist.org/solutions/sand-motor-erosion-beach-nourishment-netherlands-benin/>
"When governments find themselves fighting the threat of coastal erosion, their
default response tends to be pretty simple: If sand is disappearing from a
beach, they pump in more sand to replace it. This strategy, known as “beach
nourishment,” has become a cornerstone of coastal defenses around the world,
complementing hard structures like sea walls. North Carolina, for instance, has
dumped more than 100 million tons of sand onto its beaches over the past 30
years, at a cost of more than $1 billion.
The problem with beach nourishment is obvious. If you dump sand on an eroding
beach, it’s only a matter of time before that new sand erodes. Then you have to
do it all over again.
Beach nourishment projects are supposed to last for around five years, but they
often disappear faster than expected. Moreover, a big coastal storm can wipe
them out in a single night. And the costs are staggering: Dragging in new sand
requires leasing and operating huge diesel dredge boats. Only the wealthiest
areas can afford to do it year after year.
Now, after decades of reliance on repeated beach nourishment, a new strategy
for managing erosion is showing up on coastlines around the world. It’s called
the “sand motor,” and it comes from the Netherlands, a low-lying nation with
centuries of experience in coastal protection.
A “sand motor” isn’t an actual motor — it’s a sculpted landscape that works
with nature rather than against it. Instead of rebuilding a beach with an even
line of new sand, engineers extend one section of the shoreline out into the
sea at an angle.. Over time, the natural wave action of the ocean acts as a
“motor” that pushes the sand from this protruding landmass out along the rest
of the natural shoreline, spreading it down the coastline for miles.
While sand motors require much more upfront investment than normal beach
nourishment — and many times more sand — they also protect more land and last
much longer. Developed countries such as the Netherlands and the United Kingdom
are turning to these megaprojects as an alternative to repeated nourishment,
and the World Bank is financing a sand motor in West Africa as part of a
billion-dollar adaptation program meant to fight sea-level rise. But these
massive projects only work in areas where erosion is not yet at a critical
stage. That means they’re unlikely to show up in the United States, where many
coastal areas are already on the point of disappearing altogether."
Via
Fix the News:
https://fixthenews.com/ritual-technology/
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
