Straits Times Forum 21 Jun 10;
I REFER to Mr Sin Wei Xiang's letter, "Orchard flood: Were there lapses?' (last Saturday). I agree that a clogged drain may not have been the only factor that caused the massive flooding.
There was an exceptionally dry spell in Singapore in February, which turned out to be the driest month ever and one of the hottest on record.
From my observation and a study of the National Environment Agency's rainfall statistics, the last two north-east monsoon periods - from December 2008 to February last year, and December last year to February this year - have brought largely dry weather rather than wet weather.
In fact, there was more rain over the period from June to July last year than from December last year to January this year - the latter usually very wet due to prevailing heavy rains from the north-east monsoon.
I am not sure if we are witnessing a permanent shift in weather patterns, but climate change models generally point towards drier weather in some places and wetter weather in other areas, as well as more extreme weather conditions.
This has long-term implications not only in terms of storm water drainage during periods of exceptional rainfall, but also a need for more water storage or reservoirs, and water sprinklers to maintain Singapore's greenery during periods of prolonged drought.
Clarence Andre
