Going…Going…Gondola Pre-Assessment

Name: ______Date: ______

1.  What is the Venice Water Authority?

2.  Why is Venice a “City Besieged”?

3.  What is causing Venice to sink?

4.  What kinds of problems are there in Venice as a result of over-flooding?

5.  Describe at least two ways the Venetians could solve their problem.


Going…Going…Gondola

Information Students Should Learn from the Video

The Sinking City of Venice (NOVA)

The first two minutes:

This will set the stage for their learning and give the causes and resulting problems.

--Flooding almost every day

--High tide

--Bricks dissolving away

--City is sinking

--Sea level is rising

--Built right at sea level

--Built on a salt marsh

--Pollution

--Schools can’t run

--Boats can’t get under bridges

--Salt water eats away at floors and walls causing corrosion

The next ten minutes discusses the following:

--Geography

--Inlets satellite view

--Tides – not the moon at fault – caused by the weather and strong winds – predicting storms

--Platform 12 miles out that collects data for predicted storms and floods

--Doorway barriers

--Venetian foundation: can pump canals for repairs

--Forest of wooden pilons below and several layers of water resistant stone. Now water is rising above the stone and into the buildings

--Chemists at Univ. of Venice studying the problem

--Residents move away

--But 15 million tourists come every year

--Less of a living city and more like a museum…a wet museum

The next six minutes discusses the following:

--Netherlands – half of country is below sea level and not a drop gets in because of their solution.

--Did use earthen dikes but the protective banks were destroyed in the 50’s. A third of the Netherlands was under water.

--Country spent billions walling itself off from the sea. Came up with the idea of two mobile gates. Arms as long as the Eiffel Tower is high.

--Safer and less effect on the landscape

--Rotate towards the center

--Finished in 1997…only needed once every 10 years. Engineering marvel

The next eight minutes discusses the following:

--The plan for three sets of mobile gates

--Compressed air pumped in causes them to raise up and hold back a high tide

--Internal steel framework

--Innovative – swing back and forth with the wave

--This solution has the backing of many engineers but only exists in computer simulations

--Italians have been talking, and talking but not able to make a decision

--Politicians in Rome unable to make a decision

--Inertia

--Late 1980’s a single prototype was made and was displayed for four years in Venice.

--Venetians are skeptical

--14 years later, the Venetians are still waiting as the barriers have not been built

--Engineers say science and technology take a backseat to politics

--Gates required years of testing

--Set up scale models…engineers found potential problem…gates waving back and forth created holes…improvements were made…

--Fight against the gates…complicated, expensive and have a negative impact on the environment

--Worry the gates will hurt the ecosystem

--Engineers don’t agree

--Massive interference from humans

The next six minutes of the video discusses the history of Venice:

--Picked because it was so inconvenient for foreign invaders

--Monopoly on trade – became rich and powerful

--14th century

--Swamps invade the city and bring disease and death

--Silt being deposited from rivers and it became more swamp-like with mosquitoes, etc.

--Venetians take control of their destiny. Launched a public works project…large canals so the silt would be deposited elsewhere. It worked but left with another problem. The city was sinking…in fact since the very beginning

--The Alps

--The salt marsh under the city

--Below that a mile thick of river sediments that are compacting creating a giant sponge. The sponge is getting thinner

--Archeologists uncover evidence…gradual progressive build up of the land surface. Continually adjusting the ground level upward.

The rest (20 minutes) of the video shares the other various and alternative solutions and problems. The following points are discussed in this section of the video:

--Anything built on these marshes will eventually sink into the sea

--Many of the buildings were torn down and rebuilt

--Eventually they stopped building up the ground level

--Raising the sidewalks could help One section has been done. Some people say this is the answer

--Plans to raise the ground in the lower parts of Venice

--Critics of the gates, support this

--Also, narrow the inlets to the lagoon

--Lowering the tide by 8 to 12 inches

--This solution will only work for lower and short lasting tides

--If too high and too long, the floodwaters will eventually get in

--The gates are considered a soft solution

--Effect would reduce the amount of clean sea water flowing in

--The marsh and lagoon are currently a bird-watching mecca

--Flow of new seawater will deprive creatures of oxygen and nutrients also pollution will get worse

--Pollution includes soapsuds, sewage straight from house, no sewage treatment, just piped into canals

--Also factories dump chemicals and there are fertilizers from agriculture

--The pollution is swept out of the lagoon and into the sea twice a day by the tides

--The gates would close this off completely

--Nov. 6, 2000 storm…flooding…93% of city

--Computer simulation

--Gates would have been shut for 9 hours

--What about repeated closures over a season…what effect would that have?

--Some say not much

--Say would only need to be closed about 7 times a year

--What about in the future?

--Middle of last century Venice started sinking faster

--Pumping under the city (one solution that was tried) was a catastrophe causing the loss of about 9 inches of sea level. Some believe that if this pumping had never been allowed, it would have taken until about 2050 before Venice would have sunk naturally to the point where it is today.

--Engineers tried various scenarios but they were proven to be wrong

--Archeologists inadvertently learned about sea level…sinking faster than was thought

--Global warming Waterworld movie and AI the movie (clips that show and underwater future world)

--Even with a little bit of global warming the oceans will expand

--Climate changes…wind changes…storm surges change…we don’t really know how much sea level will rise

--Closings may have to be too frequent and for longer and longer time periods

--Building pollution to dangerous levels

--Water quality has improved somewhat over the last decade

--Venice building a sewage treatment facility

--If global warming continues though, there will simply be too much water and it won’t matter.

--The mobile gates won’t work or be needed.

--Others say the gates are a precautionary measure and will be useful for at least 100 years.

--Are they the best way?

--Are there more choices?

--Engineers say it is time to build the gates

--Scientists say we need to act and learn simultaneously…can’t keep studying and planning, must act

--Italian government intent on building gates

--Take 8 to 10 years but at some point they may not be enough to hold back the sea

--Costing 3 billion us dollars

--It may have to be sealed off from the sea

--A permanent solution

--Wall off the city from the lagoon

--Or wall of the lagoon from the Adriatic making it a fresh water lake

--Venice we know today cannot be preserved as it is today

Causes of Venice’s Flooding
Arguments for the Mobile Floodgates
Arguments Against the Mobile Floodgates
Alternative Measures Proposed
Arguments for or against the Alternative Solutions

Going…Going…Gondola Note Taking Sheet

Name: ______Center Day:______


Going…Going…Gondola Great Debate Viewpoints

The Great Debate – Will Venice Survive?

Venice is like a person trying to run forward by looking backwards, “Look at how good we were; how great we were!” Venice is trapped between a huge past and no future. Professor Andrea Rinaldo

So what should be done about this sinking city? Abandon it? Raise it? Learn to live with it?

This is a controversial topic. Controversies are subjects about which people have very different opinions. Controversies can be troubling, and upsetting and sometimes people get angry. But they can also lead to progress. When people are free to voice their opinions, even unpopular ones, there is more information on which to base decisions.

We will be role playing a public meeting being held to hear the concerns of the various interest groups involved in this debate. Students will be divided into groups, and each group will use the information you collected on your note taking sheet, and the websites in ikeepbookmarks.com to report on the advantages and disadvantages of the Moses Project and the other alternative solutions. Each group will represent an interest group concerned with the Venice controversy. Each group will research and prepare a group position statement. The reports should be typed on the computer so you can present oral arguments in a debate. Groups may also create visual aids. Reports should answer these questions: What is promising about this project? What might be a source of assistance or resistance? What might make it easier to accept or more difficult? What are some possible obstacles, objections, or concerns? What is the most likely to hinder the successful implementation of this plan? What is the short term problem and solution and what is the long term problem and solution?

Viewpoints

Engineers and scientists offer technical solutions and, given the nature of the professions involved, different people usually come up with conflicting ideas. Those operating in the field of precision science, such as hydrologists, usually resent social scientists, such as archaeologists, for interfering. Their methods are not scientific enough, the hydrologists say.

Italian politicians tend not to want to go out on long limbs for such a costly and massive undertaking that, in the face of weather and global-warming trends, may not work. They worry more about the next election than they do the next decade. Building controversial mobile gates for Venice does not necessarily win votes.

But Venice is facing a reality that the seas are warming and the sea level is rising. The Intergovernmental Panel says that even if greenhouse gases were brought under control tomorrow, it would still take centuries to reverse the impact that twentieth-century industrialization has had on the planet.

Politicians:

Narrowing the mouths of the ports or building mobile flood barriers are unattainable objectives given the limited funds. It would take trillions of lire to build mobile gates. Prefer to take the attitude of wait and see. The issue of saving art in Venice from the floodwaters that never kill anyone does seem to be in conflict with problems elsewhere. After all, thousands die in raging floods, mudslides and earthquakes.

Citizens:

Living conditions are intolerable. Do the work on the lagoon first…all of the restoration proposals other than the gates themselves, and monitor that work to see how it affects the problem of rising water. Monitor the trends of global rise of sea levels. Once this trend has been established, then that is the moment to make decisions about whether to protect Venice from the sea. If we delay the gates, is there a real, immediate threat to the existence of Venice? Is Venice going to be exposed to unreasonable danger? Just continue to do preservation and protection of old structures. Venice has always had high water. It is part of the life here. To know that you will have some flooding is acceptable, especially if you know two or three hours before by a series of alarms.

The Consortium says that the gates will be obsolete in one hundred years. Then we will need to find different solution. So let’s just wait until then.

Environmentalists:

The gates will create bad water quality since the tides will not be sweeping the pollutants out of the lagoon twice a day. Waste flows out of buildings into the canals, where it awaits the next high and low tidal cycles. These cycles occur twice a day, flushing the waste out of the city, into the lagoon, and then through the narrow entrances out to sea. Often, during exceptionally low tides, these spouts are above the water, exposing this process to passersby.

Because of global warming, the mobile gates, if built, would have to be raised with increasing frequency. During the time the gates are in use, the lagoon will be completely cut off from the sea. Open circulation with the sea is essential to the life of the lagoon; after any one closing, it will take several tidal cycles to flush out the pollutants that accumulate from various sources and to restore the lagoon’s equilibrium.

Art historians:

You save the art; and you must save the art, because one hopes this may be a phase, a cycle, and therefore the water will go down again. The reason why Venice is one of the unique cities is that so much has remained from previous centuries. It has been a backward city, if you like, but no other city has retained its heritage in quite the same way. People in England, or America – anybody who is collecting money for Venice - ask, “What are the Italians doing about the flooding?”

Engineers and Scientists:

It is obvious that something has to happen in 40 or 50 years, the mobile gates could be called for, or perhaps we will find ways to close the lagoon. This will take one or two generations to solve.

The only thing that has been done since 1966 has been to increase the understanding of the science and technology. But has all been just ideas, as far as action is concerned, very little has been done.

City Planners:

Deal with the maintenance work on the urban system, safeguard buildings along the minor canals, and conduct sanitary and hygiene operations. Once we build the new sewer system, we can turn the lagoon into a walled lake and preserve the historic part of Venice. The city must come first – always! If the gates are needed, let’s do it tomorrow, but we worry that the gates are not a solution that looks at the future. It will cost 9 million dollars to maintain the gates each year.

The Venice Water Authority has looked at three options: 1) doing nothing; 2) only raising the city’s and outlying islands’ foundation to protect the city from floods up to 1.2 meters above mean sea level, and reinforcing the Adriatic sides of the barrier islands; and 3) building the mobile gates. The conclusion was that damage to the lagoon, the city, and its inhabitants would be “extensive” with options 1 and 2, and “marginal” if the gates were built.