Posts Tagged ‘flooding’
Flooding in Brisbane and Australia – need for dam water release simulation model
Flooding in Brisbane and Australia – need for dam water release simulation model
It is all over CNN and the cable news. Brisbane has been hit by an “inland tsunami” arising from dam water release at the height of a typhoon and massive rainfall over the past few days.
It appears that the dam above Brisbane that was designed to protect it from flooding experienced in 1976 released excess water in order to avoid serious damage to the dam structure itself.
This article below will perhaps help the Australian authorities in calculating the needed advanced warning and time for pre-emptive discharge in order to remove excess water at a safe rate so that the incoming storm could be safely contained by the dam. Having sufficient storage capacity of at least one storm (4-6 meters to handle one storm) is a must that should be maintained at all times, especially after a previous storm has exited and an incoming storm has been spotted by the weather bureau through Doppler Radar which locates storms and estimate its rainfall potential. More »
Avoiding Widespread Flooding Thru Predictive Dam Water Release Modeling – Recent Nigeria, Pakistan and Philippine flooding
Avoiding Widespread Flooding Thru Predictive Dam Water Release Modeling – Recent Nigeria, Pakistan and Philippine flooding
The very recent Nigeria flooding that affected over 2 million people and the continuing widespread misery due to flooding in Pakistan is a portent warning of serious effects of global warming and unabated release of Green House Gas (GHG) emissions of CO2 and other similar gases such as methane (21 times of equivalent CO2).
This increasing severity of weather changes from widespread flooding to severe drought has indeed impacted on the daily lives of peoples, especially the poor whose makeshift houses along dangerous and hazardous terrain and communities are subject to more frequent dislocations and damage to property as well as loss of lives, which is magnified by the lack of adequate planning (such as doing predictive dam water release simulation), preparations (pre-positioning of emergency safety and rescue equipment), and lack of maintenance of flood control infrastructures such as dams, dikes, levies and embankment supports that separates the flood plains from low-lying communities.
Indeed, the lack of foresight (pre-emptive release of dam water) to avoid catastrophic release later at the height of a storm as what happened in the Pangasinan-Agno River system in the Philippines and the continuing saga in Pakistan is just another grim reminder of the need to use advanced computing technology (dam simulation logic and a Excel spreadsheet) to avoid the tragic consequences of damaged levees, embankments as a result of high releases of impounded water. More »
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.
* * *
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 »
