Staff from the HCM City Green Park Company is using maintenance vehicle to cut off branches of a huge urban tree in HCM City’s District 3 to prevent falling branch risk. — VNS Photo Bồ Xuân Hiệp

Speaking at a recent training session conducted by a Singaporean expert, Lê Công Phương, director of the HCM City Green Tree and Park Company, said the city is home to over 7,600 trees that attain heights ranging from 20 to 50 metres.

He said that the absence of adequate equipment and resources for comprehensive inspections presents significant risks.

Phương also noted that the current reliance on visual inspections and professional experience for tree condition assessments is severely constrained by the lack of advanced technological tools.

He highlighted that certain species, such as Hopea odorata, exhibit a propensity for branch breakage due to their inherent growth patterns.

A tragic incident underscoring this risk occurred in August when a 10-metre branch fell in Tao Đàn Park in downtown District 1, resulting in two fatalities and three injuries among elderly individuals engaged in exercise, despite favourable weather conditions.

Speaking at the training session, Eric Ong, director of Singapore’s National Parks Board (NParks), elucidated the risks associated with urban trees exceeding 20 metres in height.

He noted that while urban areas enforce a height limitation of 15 metres for trees, no such restrictions exist in parks or conservation zones.

Tree breakage can arise from root damage, pest infestations, or weakened trunks, according to Ong.

NParks employs advanced technologies, including ultrasonic tomography and jet drill machines, to detect tree defects.

The cost of the drilling machine is around VNĐ400 million (US$17,000), while the ultrasonic machine is valued at around VNĐ900 million ($36,000).

To mitigate risks associated with large trees, NParks has installed 3,000 tilt sensors that notify a control centre if a tree tilts beyond 5 degrees, prompting an appropriate management response.

Ong said it was essential to regulate tree height and ensure canopy balance to safeguard public safety.

Recent initiatives involving tree pruning and removal have elicited public concern regarding excessive trimming and potential loss of tree vitality.

In response, NParks has commenced the practice of posting notifications on trees designated for removal, providing explanations, and facilitating community inquiries.

Preventive strategies

HCM City authorities have recently announced the implementation of measures aimed at assessing urban trees that are at risk of falling, including the adoption of drone technology to mitigate potential incidents.

The city has acquired specialised maintenance vehicles and advanced trimming equipment to improve the management of urban greenery.

A task force of professional engineers is conducting regular inspections of trees that are over 20 years old.

Currently, the company oversees nearly 100,000 trees, routinely inspecting and removing those that are aging or afflicted by disease.

However, evaluating tree stability presents challenges, as some trees that appear healthy may still pose significant risks.

Experts have cautioned that the rainy season, which spans from May to November, may worsen the condition of trees due to restricted access to water and sunlight, a consequence of urban development.

Residents are advised to maintain a safe distance from trees and to refrain from traveling during storm conditions.

HCM City is home to over 122,650 trees lining over 1,200 streets, with more than 6,000 requiring urgent attention.

The city has recently faced multiple incidents involving falling trees, resulting in three fatalities and four injuries. — VNS