Wednesday, September 30, 2009

Environmental scientists do the Ondoy post mortem

Environmental scientists from the University of the Philippines convened a special meeting yesterday at the National Science Complex to do an initial post mortem of the Ondoy (Ketsana) disaster.

Our team of scientists included climatologists, meteorologists, a geological hazards specialist, ecologists and a hydrologist.

Several points were assessed

1) Comparisons with Hurricane Katrina

Ketsana and Katrina are two different tropical cyclones. Ketsana hit Manila and Central Luzon as a tropical storm while Katrina swept through southern Louisiana as a CAT 4 cyclone. Katrina generated a huge storm surge that broke the levees protecting New Orleans causing massive flooding. Mrs Gloria Arroyo got her facts right in saying that Katrina dumped about 280 mm of rain, although 380 mm was recorded in Slidell LA. Ondoy (Ketsana) dumped 455 mm of rain in PAGASA's Science Garden station in Diliman.

The massive flooding in Louisiana is due more to the storm surge. In the Metro Manila, the flooding was due to runoff which the river systems cannot handle.

While I have noted the similarities between Katrina and Ketsana, the only point of comparison between the Louisiana disaster and the one we have here is that people NEVER REALIZED NOR WERE PREPARED THAT SUCH FLOOD CAN HAPPEN IN THEIR CITIES.


2) Flooding in Metro Manila

Residents of Marikina, Cainta and Pasig (all part of the Marikina River Valley and floodplain) have experience of floods inundating their homes. My mother grew up in Malinao, Pasig and she has childhood memories of the church plaza being under waist deep of water for a month or so in the 1940s. However what struck the Marikina valley residents is that the water rose up to 3 meters or more within 15-20 minutes. This just shows how the surrounding environment was unable to hold the water.

On the Quezon City plateau, residents near the creeks that drain into the San Juan River have experience of minor flooding. Only the very low Tatalon area experiences worse floods each year. We lived in Kamias district for 30 years and I only recall one instance of flood when I was 4. In the same neighbourhood on K7 street the water rose to 4 meters in 30 minutes. In front of the barber shop I still go, the water rose to 2.5 meters. These areas are 200 meters away from Diliman creek.

In West and Timog Avenues several areas had water up to 1.8 meters deep. Once believed unsinkable UP Diliman had 1 meter of water at the amphitheater (where commencement rites are held). In front of the UP Elementary School the street was flooded 0.5 meters deep.

The same tale is told. Quezon City residents never thought that the water can rise to those heights in 20 minutes or less.

A preliminary scientific analysis of how this happened requires geographic approaches. Prof. Mahar Lagmay of the National Institute of Geological Sciences has put up a google map for people to pinpoint where the floods happened and how deep they got. It is important that people immediately document their experiences before time (and the stress!) makes them forget.

Prof. Trina Listanco of the UP Geography Department made a study (2004-2005) of Manila's flood risk. She predicted the flood heights that could happen as related to the channeling and loss of esteros. She also noted that a philosophical shift in how people viewed these waterways happened right after WWII. Whereas before, the waterways were considered more as a routes for transport (hence the need to keep these dredged and clear of obstructions) now they are merely considered as storm drains.

It is a good idea to know if her model predictions were validated. Ondoy certainly provided the opportunity.

Hazards specialists think that the disaster is largely due in fact to Metro Manila's unregulated urban sprawl. We looked at satellite maps (2007) of Metro Manila and noted that in many areas subdivision roads were aligned with permanent and intermittent watercourses. Thus in a deluge like what we had last Saturday, streets became parallel rivers (Note my whitewater account on Quezon City's Aurora Blvd) with water seeking the natural watercourses but its flow was blocked by houses and buildings. The streets became intermittent streams or as the Arabs would call it "wadis". People living in deserts are much aware of the dangers that wadis can bring.

There is likely a need to revisit our land use planning schemes. The mandatory 20 m setback from a watercourse (which is almost never followed) will have to be rethought.

Hydrological assessments of how much water can city streets carry needs to be done ASAP. Professor Listanco's 2005 study is valuable here.

3) Historical approaches

The Ondoy deluge is not that unusual in Manila's ecological history. Perhaps the most historically documented is the November 1943 flood that sank Manila. All Manila resident memoirs about the Japanese occupation have this and even my grandfather's diary (which I saved from the Ondoy deluge that flooded my QC house). My grandpa's diary survived six floods, 1956, 1962, 1971, 1972, 1987 and 2009! Grandpa mentions that their Cubao residence (near what is now E Rodriguez Avenue) flooded.

Dr Benito Legarda's wartime memoirs even documents the fall of their Faura barometer and has estimates of how deep the water got. Mr Jack Garcia's (now Sydney based) memoirs of WWII on Taft Avenue mentions the water being more than a meter deep. Another San Juan resident mentions the doctor and nurse who were swept by raging waters near where UERM is now today.

It is obvious that Greater Manila went underwater then. But UST Rector Father Juan Labrador mentions in his wartime diary that Intramuros did not sink. This is interesting.

Historian Ambeth Ocampo writes that even Blair and Robertson is a mine of climate related information. Climate scientists will have to do ecological history before concluding that human induced climate change is to blame!

4) Is it really climate change?

Since climate is always changing, then the answer is yes. But we have to recall that the popular view equates natural climate change with human induced climate change. Scientists will have to figure out if the current events deviate from model predictions made from long term data. We don't have a clear answer yet.

Climate change has now become a significant issue that attracts advocacy and science research money. Scientists will have to walk the thin rope on being objective and scientific and pandering to the NGO gallery! However based on what I saw on the NDCC TV press cons, our top scientists seem to be pandering to the NGO gallery!

However some disturbing trends can be noted in the climate/oceanographic data. The South China Sea has been unusually warm and may contribute to enhanced rainfall.

5) The social science story

What I find interesting is that Filipinos seem to have weathered the disaster quite well as compared to the Louisianians. Since I saw how Katrina did New Orleans in, I know how society becomes unraveled in a disaster. This is aptly documented in Douglas Brinkley's "The Great Deluge". This should be interesting material for our top social scientists some of which are PDI and Star columnists who have specialized too much in political science!

6) The disaster response

The centralized nature of our governance has made disaster response more effective than in the Federal System that is the USA. Brinkley's book tells how because of State Sovereignty, then US President GW Bush had to ask if the then Louisiana Governor Katherine Babineux-Blanco would allow federalization of the Louisiana National Guard. Bush had the powers to bypass Blanco but chose not to. The disaster sank Blanco's chances for a second term and Bush got a lot of undeserved flak (although his administration also carries some of the blame). So Pinoy Federalists take note!

The problem is that we don't have many disaster response assets, like rubber boats, helicopters, dinghies etc. But Congress can easily remedy that by fiat.

A centralized authority with expanded powers for disaster response for Metro Manila is needed. While the MMDA has some powers in clearing obstructions in national roads, it surely isn't enough.

7) PAGASA.... hopeless?

PAGASA was able to forecast the approach of the storm quite well but does not have the capability at present to forecast HOW MUCH RAIN will fall. Nathaniel Cruz has said on DZMM that while PAGASA has the Doppler radars needed, they still are in the process of installing them and training of people to operate then is on going. Dr Prisco Nilo said that they targetted December 2009 for operation. But then as Ondoy has it, it is too late.

Also our typhoon warning system is based on wind velocities. With Doppler radar forecasts, rain density can be assessed and people can decide on precautions to be taken based on two kinds of information. Then the days of the joke still reiterated in the media

"Signal number 2 na pero uma-araw!"

will be a thing of the past.

PAGASA can take comfort that it has Climate Change to share the blame with!

24 comments:

Neil said...

If only Imperial Manila paid a little attention to "provincial" Iloilo and Kalibo after Frank's devastation, she could have learned a lesson or two, and Ondoy the disaster - not Ondoy the "weak" storm - could have been less disastrous.

Remember Frank, not Katrina.

Deany Bocobo said...

The sociological subtext in the "climate change" debate is that if it is man made, or exacerbated by human activities, then if man changed his behavior maybe the climate wouldn't change, or change as much. Unfortunately this leads to paralysis by analysis. Better is the attitude human beings as a species has adopted throughout its successful history as survivors: ADAPT TO CHANGING CONDITIONS!

Ben Vallejo said...

@Neil

Frank's is more similar to Ondoy. But you see people have this mental colony in their minds!

Ben Vallejo said...

DJB

True. That is more Darwinian!

Cpt. Robespierre said...

"Bush got a lot of undeserved flak"

Are you serious? Bush deserved nearly all the flak he got for Katrina! He ignored recommendations for strengthening the levies, he ignored the predicted severity of the storm, he stayed on vacation clearing brush and celebrating John McCain's birthday while New Orleans drowned, and he had appointed a friend with no emergency management experience to run FEMA and then said "Heckuva job, Brownie" while Mr. Brown was debating with his secretary as to whether his sleeves should be rolled up or down for the cameras.

Bush's handling of Katrina was a total fiasco. He deserves the flak.

Anonymous said...

Been looking forward to reading this, but having done so, I'm disappointed. Precautionary principle, people. WHAT DO WE DO NEXT apart from more studies? You're giving us facts and pointing at the non-science-based decisions but who will make the right ones when scientists can't seem to offer solutions for fear of not yet knowing for certain until more research is done? The 20m easement regulation needs to be rethought? Meantime, do we do our best to enforce it or do we just support research while Rome continues to burn? (Oh, and it's only 3 meters in urban areas)

Anonymous said...

Scientists/environmentalists are like modern-day prophets shouting in the urban wilderness. Many have read the signs and warned the government and yet noone really listened. Many called for positive actions and yet it fell on deaf ears. True, when the calamities strike, Filipinos can cope and survive the crisis. I hope for the day when everyone listens to nature's silent call and live daily the solutions that will answer the problems of climate change.

Anonymous said...

dear scientists, engineers, environmentalists, urban development planners, and other experts surrounding powerful government offices:

i know that you are perfectly more aware and adept to the basic principles of fluid flow and hydrodynamics than anyone else. please do your part. kayo at ang mga ginastusang utak nyo ang pagasa ng gobyerno at ng mamamayan, hindi ang bulok na pulitka at pulitikong pinagsisilbihan nyo.

what just happened was very predictable, alam kong alam nyo yan. kung inuna nyo sana yung isipin ang kawawang maapektuhan, kaysa takot sa mga amo nyo, edi sana masnaagapan ito. pilit nyong isinisisi sa climate change, eh natural na nangyayari yan...pilit nyong isinisisi sa mga pobreng iskwater na nagtatapon ng basura sa ilog at estero, eh malamang ndi alam ng mga yan ang maaring idulot nyan... ndi kaya dapat eh pilitin nyong sisihin ang mga sarili nyo dahil pinalampas nyo ang pagkakataong umaksyon agad sa twing mapapadaan ka sa ilog pasig at marikina river o kaya me makikita kang smoke belching vehicle sa kalsada?

sa mga eksperto, syentipiko, inhenyero o kung sinu ka paman, wag na din muna kayong magsisihan pala. ndi makakatulong. gawin nyo nalang ang kaya nyong gawin. alam kong sukdulan ang kakayanan nyo at ndi kayo matatahimik kung uulit pa ito, sapagakat sigurado akong naisip nyong minsan ay meron kayong nagawa.

pasensya napo, basa pa tong kompyuter na gamit ko.

bugoy
(hamak na tambay ng marikina, pasig, espanya at bagyuhing samar)

Luctor et Emergo said...

First I note that the Gustave Doré etching appears to be for Shakespeare's The Tempest. Or from Dante's Divine Comedy. It is in fact from The Holy Bible, The Deluge.

As an initial postmortem, the talking heads only appear to dispel perceptions of the event and offer very little environmental science and less going for urban policy and disaster prevention qua disaster management.

I went away with risk management as a core applicable discipline in the face of ecological risks to property, life and limb. If the scientists are to reconvene, definitely the "loss" aspects of the disaster could become a starting and ending point for concrete analysis as opposed to the airey and politicized aspects of the science and the response and relief.

Ben Vallejo said...

Scientists are waiting for the loss statistics from the people responsible for counting the losses.

BTW we are not prophets and the validity of predictions are based on data given by disasters like these. If you are seeking prophets, go to the nearest Feng shui experts.

Anonymous said...

@ BLACKSHAMA "...mental colony in their minds..." hahahaha

interesting discussion.

my 2cents' worth: after the relief efforts, there should be more effort to change and adapt to changing climate and needs.

eg:

1. decentralize the population through decentralization of the industries/commerce centers; creation of more opportunities for people in other parts of the country.

2. POPULATION CONTROL!!!

on a different note:
with all the relief effort going on in different parts of the metro, will there be a big clean up of the plastic bags, bottles, sacks that were used for the donations/relief goods?

binglast said...

Over the past week almost all reactive efforts were for the humanitarian response to this tragedy and rightfully so. Now politically opinionated people are starting the blame game. But equally important is that we also need to seriously examine the science side of this. I'm glad that this group has initiated this. I hope the scientific community and schools will mine the data found in the link to google map to create a graphic and animated simulation of last weeks event. The expensive GIS and GPS systems of the government will not work as these are monetary-based knowledge and is only available to those who can afford it. The info updates from Google Earth and Google Maps are resource-based knowlege ( community-based )and in the long term will build greater consciousness of understanding these events which in turn will help us to better prepare & respond to it.

Anonymous said...

I think the comments above have better insight than the original article. I'll comment on #5 The social science story: Filipinos wetahered it better than Louisianians because
a) Rains and floods are no strangers to Filipinos. Floods are as natural as the rains.
b) Filipinos know how to react to floods and know how to take care of themselves in such situations. Filipinos do not wait for the government for rescue.

Cpt. Robespierre said...

The preceding comment is extremely offensive and disrespectful to the people of New Orleans, and it shows a serious misunderstanding of what happened with Hurricane Katrina, just as this post does.

For example, many of the residents had no means of evacuation, so they were stuck in the city. When they did try to leave after the storm hit, the sheriff and deputies in neighboring parishes blocked the bridges out of New Orleans or took similar actions to prevent people from leaving.

So, they waited. And what else could they do? Nothing. Yes, they waited for the government, and you probably would have in the same situation.

BetLOG said...

@Dean George Bocobo...yes ADAPTATION! but how about MITIGATION to lessen its impact...You don't want floating houses along waterways and all existing shanties raised to second floors anticipating sea level rise - do you?

Climate Change is a serious issue. You cannot just adapt your way to deal with it.



Rodel Urmatan, AIA, LEED AP
Senior Sustainability Consultant

Anonymous said...

Human really does not want to learn. We accept disaster as anthropogenic when in fact its not. Just in one month multiple type of disaster happened around the globe. Yet we keep on insisting that this is global warming blah blah.Like sustainability issue, we cannot be sustainable by our own. It is impossible. We can be responsible but we cannot manage or produce our own nor can we destroy the world we live in. There is God. We should surrender to the reality that there is a creator that has been neglected by humanity trying to govern themselves to utter failure. Whatever intellegence we have, its just limited. We can learn from history that human aside from the God of the Bible have created there own catastrophic destiny by continously disobeying God. When are we going to learn? When the final hour has come?

Anonymous said...

That is very insulting to God.

Ben Vallejo said...

Monsieur Robispierre

Since I was there when that happened, I do know how Louisiana's government response went haywire to the amazement of this Filipino in the bayou. Filipinos responded better to Ondoy since their local government was able respond better given their limited resources. Now the government of then Gov Katherine Babineux Blanco had more resources. I lay the blame on her government for the bad decisions coupled with FEMA ineptness.

There is no intended disrespect for Lousianians. They have done good themselves by rebuilding their parishes and making sure Blanco did not get a 2nd term.

Mike H said...

I am not asking for speculation but the results of mathematics or modelling ---- have Pilipinas scientists computed yet by how much the Marikina river rose because of the Angat dam release?

Amadeo said...

Blackshama presents a fairer narrative of the Katrina disaster. But let’s not forget NO Mayor Nagin who found it quite difficult to explain on TV why rows and rows of unused city buses were not sent to transport evacuees. Pundits then surmised that he had become overly cautious since during an earlier storm he had ordered evacuation and it missed NO entirely.

Unknown said...

1) Mayors should lose jurisdiction over their esteros, main roads, and right-of-way so that the MMDA can demolish the illegal structures and remove the squatters.

2) Conduct an honest to goodness Disaster Risk Assessment Study for the whole Metro Manila and nearby environs.

3) Congresss should provide more funds for more trucks, amphibs, rubber boats, and rescue training.

Unknown said...

I still agree with what my sister texted to a TV Commentator(which the TV commentator read on air) in ABS-CBN while they were with a panel of PAGASA people. If the Government was just so Corrupt...then PAGASA would have had the radars, the rubber boats etc.

Jesusa Bernardo said...

Mike H. poses a good question. Can blackshama or any one in the know kindly reply to this:

"I am not asking for speculation but the results of mathematics or modelling ---- have Pilipinas scientists computed yet by how much the Marikina river rose because of the Angat dam release?"

Unknown said...

Everybody calls the 1943 flood as the most historically documented. Where can I get more info on this "documented" event? All I know was I was born during this flood but google can only give a few hits. Manolo Quezon talks of a water color done by Trudl Zipper and Manila Grand Opera Hotel of a Luna painting that was partly damaged only to burn in a later fire. And a few people selling "baha" postal stamps for the flood relief campaign. Yes, commentaries from Messrs. Legarda and Garcia. Well Documented? Let me add that they had to bring my mom to the hospital on a kariton. Luckily she got there on time, otherwise I may join the list of babies born in taxi cabs, airplanes and other forms of conveyance.