Department of Science and Technology Undersecretary Graciano Yumul

MANILA - The Philippine government has only one explanation behind the magnitude of devastation brought by tropical storm “Ondoy" and typhoon “Pepeng” (international code names Ketsana and Parma, respectively): climate change.

An official of the Department of Science and Technology (DOST) said Monday the rapid rise of floodwaters in Metro Manila and northen Luzon should not be blamed alone on the release of waters from dams.

The past two storms carried an unusually big amount of rainwater, said DOST Undersecretary Graciano Yumul in a briefing in Malacañang. He warned that this is just the start of a pattern of more destructive typhoons.

“There will be an increase in the frequency, there will be an increase in intensity and there will be an increase in the duration of the typhoons,” said Yumul.

The warmer atmosphere now causes more water to evaporate from the oceans causing more rain from the atmosphere and increasing the power of storms, said the government official.

But aside from its strength, Typhoon “Pepeng” exhibited another abnormality.

Flooded mall in Rosales, Pangasinan

“For the first time in the country, you are seeing a typhoon, a tropical cyclone that basically made landfall in the country three times… Usually whenever you are on top of land, there is no way you are supposed to have more water because precipitation is sourced from the oceans,” said Yumul.

"Pepeng" made landfall on October 3 in Cagayan, again on Oct. 6 in Ilocos Norte and the third time on Oct. 7 again in Cagayan.

“Pepeng” dumped an enormous amount of rainwater - as much as 675 millimeters of rain or three times more than that of the definition of a heavy rainfall which is at 180 millimeters. This means, this is also three times the amount of rainwater enough to trigger landslides.

Rainfall volume comparison

Meanwhile, the flooding in northern Luzon, particularly in Pangasinan, was also due to the downhill movement of water from areas of higher elevation, such as Benguet.

This explains why the flooding continued even if the rains have already stopped, and the dams have already decreased or stopped the release of excess water from its reservoirs.

'Blurred lines' between wet and dry seasons

Climate has clearly changed in the Philippines, blurring the lines between wet and dry seasons, said the experts.

The APEC Climate Center (APCC) had said that “forecast for October-December 2009 indicates anomalously warm conditions in the tropical and extratropical regions around the globe. Below (above) normal rainfall is expected in the Philippines….”

This climate outlook of the APCC however apparently has been invalidated.

The Philippines is also supposed to experience the El Niño phenomenon this year.

“El Niño is supposed to be dry but we are very, very wet… It’s raining during dry season and it’s raining harder during wet season. There is no such thing as summer… Climate uncertainty is now the norm,” said Yumul.

Parched ricefield

From March to May, the country was supposedly on its dry season but stroms such as "Cresing" and "Emong" arrived. And now supposedly with El Niño, "Ondoy" and "Pepeng" came with large volume of rainfall.

And this phenomenon is expected in the years to come.

Meanwhile, the only defense against disasters is that families be prepared, presidential deputy spokesperson Anthony Golez said

Golez said families and communities should start preparing for disasters, and should identify disaster-prone areas. Willard Cheng, ABS-CBN News