Tuesday, July 20, 2010

LATEST FLOODS - It's time to start a proper investigation

Jul 20, 2010

AS A concerned citizen watching the physical transformation of Singapore over the last 50 years, I have often wondered whether there are any downside risks that come with such development.

Our land mass has grown by an amazing 25 per cent in almost half a century to 775.5 sq km. In fact, the entire shape of Singapore has changed along with our ethnography, transportation and management of water resources, down to the way we work and play.

[I always get wary when writers used big words that don't mean what they think it means. "Ethnography" does not mean ethnic composition.]

According to a study, Singapore's coastline has been strikingly transformed not solely by territorial expansion through land filling or reclamation, but also by the closure of the estuaries of the main rivers draining the interior of the island.

To what extent has such a closure and relentless construction contributed to the floods in recent years?

To what extent, too, has the loss of 40 per cent of our natural forests, from 37.8 sq km to 22.6 sq km between 1960 and 2006, affected the island's ability to absorb torrential downpours?

It would be unfair to pick on the PUB or hold drainage as the culprit for the flooding. Neither should we cite Typhoon Conson as being a possible cause for our floods. It is simply too convenient.

[Ah! So you want an Inconvenient Truth? A conspiracy theory perhaps? So if it walks like a duck, quacks like a duck, and swims like a duck, it might well be a talented chicken who can swim and speak a second language? Or maybe... IT'S A DUCK!]

The Government should start a Commission of Inquiry to examine why the recent floods have been concentrated mainly in the central and southern parts of the island, whereas the northern, north-western and north-eastern parts have been largely spared.

[Let's see, could it be because the storm came from the Southeast and by the time it passed the central region, it had dumped most of the rain? Or that really, if the rain fell in the forest and there was no one around to see it, did it flood?]

Has this to do with the closing of the river estuaries and the massive construction and urbanisation in the city and the surrounding suburbs?

Until we arrive at a more multi-dimensional root cause for the problem, we will, at best, get only a piecemeal solution.

[Or maybe it's the fact that 100 mm of rain fell within 2 hours which is 60% of the entire month's average rainfall (June), and 180 mm of rain fell in 2 hours which was MORE than the ENTIRE month's average rainfall (July). The wettest month in Singapore is Dec with an average of 300 mm in total for the whole month. So 180mm in 2 hours is FREAKING unusual for ANY month. This is a "convenient" excuse? As a comparison, Typhoon Ketsana in 2009 dumped over 400 mm of rain on the worst hit region of the Philippines over 6 t0 12 hours. In other regions, the same amount of rain, 180 mm, fell over 6 to 12 hours.

But yes, there is more to it than, "it rained a lot" or "it was as wet as a typhoon". The question we should be asking is, whether the past can be used to predict the future. Whether past averages are a valid baseline for measurement. Or whether the 3 floods within the period of 1 month is going to be a freak occurrence. It is not impossible that 2 freak incidents (Sumatran squall and typhoons) occurs one after another. Just as it is not impossible to roll 6 on a dice 3, 4, 5, or even 6 times in a row. The point is, it could well be coincidence, aided by a confluence of factors. La Nina could be a cause, and if it is, then we might expect this to repeat every three years. Or if this is due to a long term or permanent trend in Singapore weather, then definitely we should upgrade our drainage to meet the new storm patterns. But, if this is only a freak confluence of "the perfect storm" conditions, then upgrading the drainage would be unnecessary.]

As a world-class city, we cannot afford to sink like Venice or swim like New Orleans.

Patrick Low

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