INQUIRER -
Group sees unfettered urbanization and political gridlock as main factorsThere was no storm over Metro Manila last week. But why was there so much rain? Why was the flooding so severe?
Those
were the questions asked by Jose Ma. Lorenzo Tan, CEO of the
environmental group Worldwide Fund for Nature (WWF)-Philippines.
Filipinos,
not the monsoon rains, are to blame for the deluge that paralyzed the
metropolitan area of 14 million residents last week, according to Tan.
In
an analysis, Tan said the latest disaster to hit the Philippines was a
result of an unfettered and mindless march to urbanization that had
replaced soils and trees, which could absorb the rains and reduce
flooding, with concrete jungles.
One classic example is Quezon
Memorial Circle. What used to be a vast green space has been transformed
into a giant “tiangge” (market) and “carinderia” (eatery).
Construction
by the Quezon City government of buildings continues unabated in the
park, where grass is fast disappearing just a spitting distance from
cavernous shopping malls.
Now, during downpours, the areas surrounding the park are flooded and traffic is snarled.
The
buildings, the concrete and the asphalt have trapped and increased the
temperature in the metropolis, making it an “urban heat island,” or UHI,
Tan said.
Pollutants from buses, cars and factories also
contribute to the warming of the city as they block the heat rising to
the atmosphere.
Because of all these urban development and human
activities, there is more heat that lingers on the ground that interacts
with the weather, Tan said.
In the case of Metro Manila this time of the year, the UHI worsens the southwest monsoon, the dominant weather system.
Along
with the Philippines’ location on the typhoon path and climate change,
UHI is the third factor for the unusually heavy and relentless rains
that crippled the capital last week, Tan said.
“Urban heat
islands” are aggravations that intensify the water cycle. They are
“magnets” that draw in and enhance weather systems such as cyclones,
low-pressure areas and the monsoon.
“In some cases, they have
been known to spawn local tornadoes. We saw that right in Quezon City
just last year, where seven barangays (villages) were reported to have
been badly affected,” Tan said.
Record rain since ‘Ondoy’
The
monsoon drenching last week produced the highest volume of rainfall
seen in the city since the record-breaking downpours brought by Tropical
Storm “Ondoy” in 2009, claiming close to a hundred lives in the
rampaging flood tides.
The amount of rain from August 6 to 8
reached 1,007 millimeters. The weather bureau’s projected accumulated
rainfall for August was only 540 millimeters.
The torrential
rains that enveloped the city forced 2 million people in Metro Manila to
evacuate to safety and crippled 80 per cent of the city.
Tan’s
statement aligns with the findings of a researcher at the Philippine
Atmospheric, Geophysical and Astronomical Services Administration
(Pagasa).
The UHI effect distorts the heat balance, wind
circulation and precipitation in the city, according to Nivagine
Nievares, a weather specialist at the Pagasa.
Nievares’s 2010
masteral thesis showed that rapid development in the city had made
Manila hotter compared to the rural regions around it.
Metro
Manila’s buildings, the roads and the pollutants in the air absorb and
trap the heat from the sun, pushing the mercury higher especially during
summer, Nievares said.
Solar heat flux
According to
Nievares, Metro Manila’s temperature during April is 1-2 degrees Celsius
higher than in the nearby and less developed province of Bulacan.
“Later
in the day, as net solar radiation increases, most of the urban surface
materials absorb and store a lot of energy [and] convert most of this
energy into sensible heat flux,” Nievares said. “The increase of
sensible heat flux contributes to the increase of temperature over the
urbanized area.”
During the dry season, the UHI phenomenon could
generate oppressive heat. But at this time of the year, during the wet
season, the phenomenon could help intensify monsoon downpours, she said.
Nievares noted that pollutants interact with the water molecules in the atmosphere.
“A
chemical reaction takes place; the pollutants stick to the molecules of
the water vapor,” she said in an interview yesterday. “This makes the
raindrops bigger. This is why sometimes the rains feel heavy.”
Depending
on the season, the UHI could also change the wind circulation and the
patterns of cloud formation, variables that affect rain clouds and
thunderstorms, she said.
Politics, poor planning
But the
UHI effect could not be blamed on the vagaries of weather. Tan’s and
Nievares’ findings clearly showed that rapid urbanization was the
culprit for the UHI.
“The problem lies in Metro Manila’s poor
planning, political gridlock, inadequate or inappropriate urban
management, the inadequate implementation of zoning rules and land use
plans, haphazard real estate development, among others,” Tan said.
“Like
most megacities in Asia, Metro Manila has adopted the long outdated
Western development model referred to as ‘the urban sprawl.’ Megacities
that extensively convert porous and water-absorbent land to impervious
expanses of concrete generate a tremendous amount of heat. When land
conversion and real estate development are allowed to grow in a
haphazard manner, it only makes things worse,” he said.
Nievares
said the concrete and the asphalt that covers Metro Manila generate a
lot of heat that contribute to the warming of the city. The dark color
of the city’s roofs is also a problem.
Because Metro Manila
residents tend to use gray or red paints on their roofs, the heat from
the sun is not reflected to the atmosphere. Instead, it is absorbed on
the ground.
More erratic weather
Tan warned that Metro
Manila would see more extreme and erratic weather in the future, thanks
to the triple whammy of the UHI effect, climate change, and the
country’s position on the typhoon path.
“Historically, most
typhoons entering the Philippines come from the Pacific Ocean. Over the
last four years, however, we have seen extreme weather systems develop
in the West Philippine Sea,” Tan said.
“Although this was not a
frequently recurring situation ten or twenty years ago, the West
Philippine Sea is now occasionally warm enough to be a spawning area for
a phenomenon called tropical cyclo-genesis, i.e., the birth of storms.
The province of Pangasinan has experienced this, first hand. With global
warming, we should not be surprised if this is happening,” he added.
“Climate
change changes everything. Humankind created it. The haphazardly built
megacities of Asia are aggravating it. Metro Manila’s garbage mess and
woefully inadequate transport system just makes it worse. We started it.
We can stop it. But, let’s stop pointing fingers at the monsoon,” Tan
said.
“Some of the decisions will not be easy. But we have no choice. We only have one Philippines, and one planet.”
For latest update on real estate
development and its RA 9646, the Real Estate Service Act of 2009, visit
www.ra9646.com.
