Atlantis Online
November 30, 2021, 06:52:52 am
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Satellite images 'show Atlantis'
http://news.bbc.co.uk/1/hi/sci/tech/3766863.stm
 
  Home Help Arcade Gallery Links Staff List Calendar Login Register  

Venice Offers Lessons on Coping with Rising Seas

Pages: 1 [2]   Go Down
  Print  
Author Topic: Venice Offers Lessons on Coping with Rising Seas  (Read 620 times)
Bianca
Superhero Member
******
Posts: 41646



« Reply #15 on: July 12, 2008, 09:21:59 pm »










Giant Gates Filled with Air



At the Malamocco inlet, the walls of the MOSE project are being built just like the original walls in Venice. But workers are driving 125-foot-long steel and concrete pilings into the lagoon bed, instead of wooden pilings.

When the giant doors are at rest, they will be lying on the bottom of the inlet channel, invisible to the world. Each gate will be up to 92 feet long, 65 feet wide, and will weigh 300 tons.

When a dangerous tide is forecast, compressed air will be released inside the gates, emptying the gates of water. They will then rise and block the entrance of the tide.

In another effort not to alter the landscape, the worksite is on a specially built artificial island that will be demolished once the project is completed.






Protests Fail to Slow Construction



A debate over the floodgates has been under way for nearly four decades. The design was finally approved by the Italian government in 2003. Costs now stand at $7 billion.

Claudio Mantovan, supervisor at the Malamocco worksite, says the project is on schedule. Some 37 percent of the work has been completed, and MOSE should open as planned in 2012. One key element already finished is a navigation lock to allow large ships to enter the lagoon when the gates are up.

Mantovan says a few days of work have been lost due to peaceful protests by environmentalists and others.

"In order to build trenches for the MOSE gates, they are going to dig up millions of cubic meters of seabed and replace it with cement, which could seriously alter the ecosystem," says Alberto Vitucci, a journalist who has been covering the project for years.

"The entire mechanism will be underwater, making maintenance extremely difficult and costly. And the authorities never took any alternative projects into serious consideration."

Other proposals to control flooding in Venice have included narrowing the inlet channels to reduce the water flow from the sea into the lagoon, and banning tankers and large ships from entering.

Some criticize the project as irreversible and outdated. They say it was designed without taking into account predictions on rising sea levels over the next century.

MOSE engineers respond that the mobile gates are designed to last at least a century and to protect Venice from a difference in water level between the sea and lagoon of up to six and half feet.

The latest prediction of the United Nations Intergovernmental Panel on Climate Change is for a one- or two-foot increase by the end of this century.

Despite opposition, the MOSE project is moving ahead, and it's being closely watched not only by Venetians.

Coastal cities all over the world, from New Orleans to Singapore to Bombay, know that due to rising sea levels, Venice's seasonal flooding could soon become a shared, global phenomenon.
Report Spam   Logged

Your mind understands what you have been taught; your heart what is true.
Pages: 1 [2]   Go Up
  Print  
 
Jump to:  

Powered by EzPortal
Bookmark this site! | Upgrade This Forum
SMF For Free - Create your own Forum
Powered by SMF | SMF © 2016, Simple Machines
Privacy Policy