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
