SINGAPORE - There were more than 200 reported incidents of fallen trees and snapped tree branches on Tuesday during an "extreme storm", the National Parks Board (NParks) told The Straits Times on Wednesday (Jan 31).
NParks streetscape group director Oh Cheow Sheng said the board received those reports by late evening. Most of the fallen trees and branches were cleared by 8pm that day.
Extreme weather conditions with intense rain and strong winds were reported in the north and north-eastern parts of Singapore such as Yishun, Sembawang, Seletar, Mandai and Gambas late on Tuesday afternoon, he said.
"Tuesday's storm event is an example of extreme storms consisting of strong winds of up to 70kmh or more and heavy rains that we have seen in recent years," said Mr Oh.
These events include an incident in 2012 where some 100 trees fell in a wooded area during a storm at Changi Beach Park. Before that, a storm destroyed 10,000 forest trees in the Mandai area in 2011.
"To prepare for such weather events, NParks has strengthened our management of trees by replacing storm-vulnerable trees, and carrying out targeted pruning and crown reduction prior to the monsoon season," said Mr Oh.
On Wednesday morning, NParks employees returned to the affected areas to inspect the trees there and clear remaining debris.
Mr Oh said NParks has in place "a comprehensive tree management programme since the early 2000s".
It has been training tree maintenance staff, in conjunction with the International Society of Arboriculture (ISA), as certified arborists since 2001.
Since 2003, NParks has been carrying out replacement of self-sown, storm-vulnerable tree species, such as Albizia and Spathodea trees, in forested areas near roads.
NParks took further steps from 2012 to implement a tree management programme, such as by undertaking crown reduction and pruning.
"Further measures were implemented in May 2016 to refine crown reduction and pruning processes, such that they were carried out prior to periods of more severe weather conditions," said Mr Oh. "This enhanced maintenance regime is over and above our normal tree pruning programme. In addition, second-level inspections are carried out on trees more than 4m in girth since November 2016."
He said regular inspection and pruning are key components of NParks' tree management regime and they are based on the tree care guidelines of the ISA.
During inspections, NParks' certified arborists assess the condition of each tree based on their location and site factors. Where necessary, diagnostic equipment is used to ascertain the trees' internal conditions.
The frequency of tree inspection and pruning varies according to location, species, age and tree condition.
"We are also currently developing modelling techniques to better understand the behaviour of trees under varying environmental conditions," he said. "We will continue to review our tree management regime to ensure that it remains robust and comprehensive."
Members of the public can inform NParks of fallen tree and branch incidents through NParks' helpline on 1800-471-7300.