LEGAZPI CITY, Dec. 29 The Department of Science and Technology (DOST) through its weather bureau will install next year water level sensors in selected major river basins across the country to further improve the governments hazard mitigating capability.
Since the 1980s, only four rivers were installed with sensors to measure water-level rise. The President has given instructions and allotted resources to fast-track our river monitoring system nationwide to aid in forecasting potential floods, DOST Secretary Mario Montejo in a statement reaching here Thursday said.
In compliance, Montejo said the Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) upgrade monitoring systems and install 1,000 water level sensors as well as improve the integration of data from Doppler radars, satellites, automated weather systems and rain gauges through numerical model Weather Research and Forecasting (WRF) to enhance rainfall and weather forecasting.
The agency uses the latest Weather Research and Forecasting (WRF) model acquired in September 2010 to combine other data from satellites and Doppler radars as well to make a final prediction.
It also had weather maps where weathermen look at the upper levels of the atmosphere to determine typhoon directions.
The agency uses Doppler radars positioned in Subic, Baguio and Aurora to measure the amount of rainfall, the location of the center of the typhoon, and its wind speed. Another Doppler radar facility is undergoing construction in Catanduanes.
DOST is also looking at enhancing its flood forecasting system to determine expected impact to local communities. This includes the use of several techniques such as the use of 3D maps.
On the reported dam collapse along the Cagayan de Oro River that aggravated the flash flood which killed hundreds of people in the Northern Mindanao and Southern Visayas areas at the height of tropical storm Sendong, Montejo said the continuous rains may have caused the accumulation and build up of water upstream of the dam.
At some point, the dams may have collapsed when the trapped water filled with debris overtopped the dam. This could have led to dam breakage and failure, he explained.
When the large volume of water trapped behind the landslide debris dams was released, it triggered the flash floods. The landslide dam break mechanism caused the flash floods, which would explain the sudden surge of water reported by survivors in Cagayan de Oro, Montejo added.
He also clarified that although the rainfall brought by Sendong was not like Typhoon Ondoy that generated 181 mm of rain for one day that caused the disastrous flashfloods in 2009.
The landslide dam break that happened in Sendong had happened during the 2004 Infanta, Quezon and 2008 Iloilo flashfloods, Montejo added. (PNA)