On Fri, 16 May 2008 21:47:39 -0700 (PDT), sir.jpturcaud@[EMAIL PROTECTED]
>On 15 mai, 03:19, "jonathan" <H...@[EMAIL PROTECTED]
> wrote:
>> "Skeats" <notmeeit...@[EMAIL PROTECTED]
> wrote in message
>>
>> news:y1GWj.3516$DZ6.159@[EMAIL PROTECTED]
>>
>>
>>
>>
>>
>>
>>
>> > You might like to see the article today 14th May in The Independent.
>>
>> > The Three Gorges seems to be ok this time but others aren't.
>>
>> > "Thousands of troops are tonight fighting to plug dangerous cracks in
a dam
>> > above an earthquake-hit Chinese town.
>>
>> > Zipingpu Reservoir is upstream from Dujiangyan which was near the
epicentre of
>> > the 7.9-magnitude quake.
>>
>> > China's top economic planning body said today that the earthquake had
damaged
>> > 391 dams. It said two of the dams were large and 28 were
medium-sized.
>>
>> > The official Xinhua news agency said the ministry had set up an
emergency
>> > command centre at the dam.
>>
>> > The death toll from the quake may already by more than
>> > 50,000".................
>>
>> > Further down
>>
>> > .......................
>>
>> > "Sichuan had other major dam projects, including the massive Three
Gorges dam,
>> > the world's largest about 350 miles to the east of the epicentre, but
>> > officials said it escaped undamaged.
>>
>> > He Biao, the director of the Aba Disaster Relief headquarters in
northern
>> > Sichuan, said there were also concerns over dams closer to the
epicentre.
>>
>> > "Currently, the most dangerous problems are several reservoirs near
Wenchuan,"
>> > he said.
>>
>> > "There are already serious problems with the Tulong Reservoir on the
Min
>> > River. It may collapse. If that happens, it would affect several
power plants
>> > below and be extremely dangerous," he said."
>>
>>
>http://www.independent.co.uk/news/world/asia/creaking-dam-adds-to-ear...
>>
>> > Skeats
>>
>> And on the link below, I didn't point out how much
>> the Chinese have underestimated the risks at the
>> Three Gorges. Pretty much at every step they seemed
>> to have low-balled the problem. When I see that kind
>> of bias combined with such potential for disaster, it
>> gives me the willies.
>>
>> "Examples of the flaws in CYJV's analysis are as follows:"
>>
>> Underestimation of earthquake ground accelerations
>>
>> Inadequate analysis of reservoir-induced seismicity
>>
>> Inadequate analysis of structural stability
>>
>> Underestimation of the risks caused by catastrophic landslides
>>
>> Underestimation of risk of spillway failure
>>
>> Failure to consider downstream effects of cofferdam failure
>>
>> No provision for decommissioning of the dam
>>
>> Flawed Bases of CYJV's Sedimentation Analysis
>> Unreliable Equilibrium Slope Calculation
>>
>> Miscalculation of Bed Load
>>
>> Inadequate Empirical Estimate of Reservoir Trap Efficiency
>>
>> Underestimation of Reservoir Sedimentation Rates
>>
>>
http://www.threegorgesprobe.org/pi/do***ents/three_gorges/damming3g/c...
>>
>>
>>
>> - Masquer le texte des messages précédents -
>>
>> - Afficher le texte des messages précédents -- Masquer le texte des
messages précédents -
>>
>> - Afficher le texte des messages précédents -
>
>Thank you for interesting input but this said some of the World dams
>are at risk as well since built on well known faults.
>Foremost is the Aswan dam in Egpyt on the Nile & built indeed right on
>the African Rift fault. A major quake there would send a great part
>of Egpytians flowing to the sea
What African Rift Fault? THE Great Rift Valley originates on the
north in the Holy Land, becomes the Red Sea, and goes ashore at
Afar to become the East African Rift, the famous rift valley
where Africa is spreading apart.
I can't find any plate tectonic maps showing a plate boundary at
Aswan.
There is a long term danger to such dams though. It is the
eventual fate of all dams to silt up.
http://www.ilec.or.jp/database/afr/afr-19.html
Almost every hydroelectric generating station will be rendered
useless at some point in the future, with the length of time
being variable. Some dams on the Missouri River and in other
parts of the USA have already been decommissioned and demolished.
The high siltation rates of the Yangtze and Nile rivers does not
bode well.
--
************* DAVE HATUNEN (hatunen@[EMAIL PROTECTED]
) *************
* Tucson Arizona, out where the cacti grow *
* My typos & mispellings are intentional copyright traps *
|
