Posts Tagged ‘weather forecasting’
How to predict early safe release of dam water – 2nd comment from Philippine Star Federico Pascual
FYI… Postscript for Thursday, Oct. 18,
quotes Mr. M. Ocampo.
POSTSCRIPT/ PhilSTAR/ Oct. 15, 2009/ Thursday
By Federico D. Pascual Jr.
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UNSTEADY HAND: In the Senate, one listens in horror to the testimony of dam managers and executives of the National Power Corp., upon whose judgment rests the crucial decision of when and how to release impounded water from the dams.
Their unsteady hand is poised on the lever that could unleash death and destruction on communities downstream — as had happened in the recent flooding in Central and Northern Luzon that killed hundreds and destroyed properties worth billions of pesos.
Their testimony and buck-passing gave the impression they think that dam water is released only when the reservoir is dangerously full, and that that is done mainly to save the structure from collapse. More »
How to predict early safe release of dam water – reaction from Philippine Star Columnist Federico Pascual
FYI… Postscript for Thursday, Oct. 15, quotes Mr. M. Ocampo.
POSTSCRIPT/ PhilSTAR/ Oct. 15, 2009/ Thursday
By Federico D. Pascual Jr.
* * *
DAM FIASCO: Some managers of dams in Luzon may have thought that impounded water should be released only when it is about to reach a critical level, or that point when it will overflow by itself or might damage the dam if the pressure is not relieved soon enough.
Some experts think, however, that it is better to release gradually small volumes of water BEFORE the spilling point is reached instead of letting loose all the excess water in one deluge when the dam is full.
A post-mortem of water-release data indicates that the fast and massive flooding that hit communities downstream could have resulted from misconceptions of some dam managers.
It has been days that energy technologist Marcial Ocampo, former executive director of the PCIERD-DOST, called our attention to this, but we ignored his thesis because it was loaded with formulas and equations that we laymen cannot follow. More »
How to predict early dam water release – the key to minimizing flooding during typhoons
How to predict early dam water release – the key to minimizing flooding during typhoons
The Philippines is in the news around the world today. CNN, local media ABS-CBN and other international and local news media reported that five (5) major hydro dams have released water at the onset of Typhoon “Ondoy”, and after a lull, did some pre-emptive release again in anticipation of a new Typhoon “Pepeng”, only to be overwhelmed again with the return of Typhoon “Ondoy” as a result of the “Fujiwara” effect when two adjacent weather disturbances are close to one another.
Unless the dam itself is in danger of collapsing under the weight of its stored water, one could not release dam water at the height of a storm as this will either aggravate existing flooding or initiate wide spread flooding as the rampaging waters will cause land slides and casualties, and destroy earthen dikes, bridges, roads, homes and agricultural lands.
The value of damage and loss of lives could simply not justify the storage of water for future use during summer months for irrigation and power generation. This necessitates a closer review of the operating “rule curve” of the dam being followed by dam operators in the light of the very recent severe storms bringing large volumes of water over a very short period of time, perhaps as a result of global warming and climate change (warm waters and low pressure areas create extreme weather disturbances characterized with strong winds, heavy rainfall and storm surges that flood coastal areas). More »
