Fallen Trees

Mr David Ong asked the Minister for National Development (a) what is the number of reported cases of fallen trees in 2011; and (b) given the frequent heavy downpour and storms, whether the Minister will provide an update on the technology used by NParks to monitor the condition of trees to prevent future disruptions by fallen trees.

Mr Khaw Boon Wan: There were 1,511 cases of tree failures in 2011. Tree failures refer to uprooted trees, snapped branches and broken trunks.

NParks has intensified its monitoring and inspection efforts to look out for signs of poor condition, disease, pests or structural defects in our trees. It pays special attention to the larger mature trees, especially those in areas with high vehicular traffic.

The types of instruments and technology used by NParks include decay detection micro-drills (such as the Resistograph which measures the level of resistance in the tree trunks), and sound wave imaging (using the PiCUS Sonic Tomograph to measure the speed of sound waves through the tree trunks), to detect and identify the extent of internal defects, such as cavities and decay, in the internal wood of our trees. If the trees' condition or structural stability is found to be compromised, NParks will remove and replace the trees.

Page: 790