Why the flood rose so high, so fast

I AWOKE to bird song Sunday morning, with sunlight peeking through the slats of the Venetian blinds. It was a beautiful morning after a dark night of a deluge that submerged almost the whole of Metro Manila and surrounding provinces.

Outside, the grass was green, the flowers colourful and the trees undamaged. Unlike other storms, Ondoy did not have strong winds that toppled trees and electric posts, unroofed houses and made life miserable for everybody. Ondoy, however, made up for it by dumping so much rain that it brought unprecedented high floods in many areas, particularly those near rivers and creeks. So it brought just as much misery as its stronger cousins.

We should be thankful that Ondoy did not bring with it strong winds, otherwise the damage would have been even more terrible. As it is, the damage was already terrible, mainly to homes inundated by the flood, some up to the rooftops, and to roads and bridges. But the terror to people marooned on their rooftops, pleading for help and no help coming must have been horrific.

The government was not up to par in rescuing marooned residents and providing evacuees with relief goods, probably because our officials did not expect the floods to be that high or that widespread. Ondoy, after all, was tagged by the weather bureau PAGASA as a baby storm with only 60kph winds. But the storm dumped a months' volume of rain in just six hours, so the floods rose very quickly and very high. Many people said they had never experienced floods that high before. Others were surprised at how quickly the waters rose.

Many people were disappointed and angered by the slow government rescue efforts. The governments excuse was that the deep floods made many areas inaccessible even to heavy trucks and it did not have enough rubber boats. What does this teach us?

The Boy Scout motto provides a valuable lesson: Be prepared.

Why did the waters rise so high and so fast? many people ask. Because of an unfortunate combination of factors. First of course was the unprecedented amount of rain that caused the rivers to swell and dam reservoirs to fill. Water had to be released from the dams to prevent the pressure of water from breaking them. This water released from the reservoirs swelled the rivers even more, causing them to burst their banks and flood surrounding areas. With the creeks and rivers overflowing, there was no place for the rain water to go. So it flowed into the streets and the houses and yards of low-lying villages.

Some say that it is also because the heavy rains coincided with high tide. Not true. Navotas, which is beside the sea and, like its neighbour Malabon, usually floods with every high tide even without rain, was not, curiously, as deeply inundated as the inland towns like Cainta, Marikina, Taytay, Montalban and Tanay, which is mountainous, another curious phenomenon.

Malabon and Navotas folk live each day with one eye on the calendar to know what time the high tide will be so they can leave before the high tide and the ensuing flood arrives. Those working outside Malabon and Navotas wait for hours eating snacks in restaurants until the high tide ebbs before going home.

But Navotas was relatively better off than inland municipalities. So it was not the high tide. All the areas that were heavily flooded were beside rivers and other waterways. The floodwaters came from upstream and from the dams.

The third factor is global warming, the phenomenon everybody has heard of but few understand. Simply put, global warming is caused by the carbon dioxide that is produced by vehicle exhausts, cooking and other forms of burning, exhausts from factory machines and so on, and which forms a veil, the so-called greenhouse gases, around the earth that prevent the sun's rays from bouncing out.

This heat trapped in the earth's atmosphere gradually heats the planet. The extra heat melts the ice caps that hold a big part of the earth's water. The melted water raises the level of the world's oceans. The rising seas submerge low-lying islets and coastal areas.

The trapped heat also evaporates water from bodies of water and stores them in the clouds. Cooled, the clouds drop as rain. The rains that drenched us two days ago came from these clouds, exacerbated by global warming.

 Paradoxically, the global warming that causes too much rain to fall in some areas also causes droughts in other areas, so that agricultural produce, which is dependent on water, is diminished.
 
So if global warming is not stopped soon, the Philippines will cease to be a country of 7,000-plus islands. Many low-lying islets on the planet will disappear, consumed by the seas. Also, there will be widespread famine because of reduced harvests.

So everybody has to pitch in to stop, or lessen, global warming.

How do we stop it? By reducing the emission of carbon dioxide. Carbon dioxide is the product of any form of combustion by vehicles, by cooking fires, by factories, by heavy use of electricity because power plants burn so much fossil fuels, and by many other innocent-looking actions that we assume are a part of modern living.

There are many ways we can reduce global warming. Read the newspapers, they will tell you how. Do not think that you are only one of billions of people on earth.

"How can what just one person does make a difference?" many ask. Yes, it will make a difference. Small acts, replicated billions of times, can save the earth and us all. Every little bit counts.

ANN/Philippine Inquirer