The Risk Assessment Of Trees In East Rail Line By Hong Kong Special Administrative Region Government

Trees are an important factor in making cities livable,but maintaining the healthy growth of trees needs the cooperation of different departments to formulate tree protection policies.Among the trees growing on both sides of of railways in Hong Kong,only about 33% of the trees are managed by MTR Corporation,the remaining 61% are managed by other government departments,and 6% are privately managed.For safety considerations,MTR will take action to the target tree when can’t reach the tree owner.Some of the trees in question are not under the management of MTR Corporation.In general Hong Kong the railway company will first contact the actual tree management unit or manager,and communicate and discuss.The tree risk management of the railway is to be responsible for the entire railway system and property.MTR’s tree risk rating is different from the three-level system of the government’s tree management office it has its own set of codes.The latest rating is segment two categories: risk indicators and health status.Each tree has a set of two codes.The first code is the risk indicator to divide into two to six levels according to the height of the tree and the distance from the track.The five levels of low to high risk,depending on height,distance,and growth status by numbers 2 to 6.The second is the condition of the tree.According to the tree health,it is divided into five levels: good(G),fair(F),weak(W),poor(P),and dangerous or dead(D).The tree will add "S" that require special attention.Trees were rated as 6D,6W and 6P high-risk categories,MTR will follow up immediately.Trees that are more susceptible to strong winds or more vulnerable trees will be included in the special concern group,extra inspections every four months.The tree risk management of the railway is to be responsible for the entire railway system and property,to reduce the risk of the trees on the railway system,reduce the demand for environmental at the same time.This paper through assess of trees on the along of the east railway:(1 Hung Hom – Mong Kok East Station;2 Mong Kok East – Kowloon Tong Station;3 Kowloon Tong – Tai Wai Station;4 Tai Wai – Sha Tin Station;5 Sha Tin – Fo Tan Station;6 Hu Tan – University Station;7 Along the Sha Tin-Race Course-University Station;8 Along the University-Tai Po Market Station;9 Along the Tai Po Market-Taihe Station;10 Along the Taihe – Fanling Station;11 Along the Fanling– Sheung Shui Station;12 Sheung Shui– Luohu Station).A total of 3551 trees managered by MTR to 40 families and 119 genera were assessed.Trees of the mimosoideae are the main species planting groups along the railway,followed by the Caesalpiniaceae.Thorough analysis the growth of trees along the East Railway 150 mm ≤ DBH <300 mm,total 1732 nos,6 m ≤ tree height <10 m,total 1833 nos,3 m ≤ tree crown width <6 m,taotal 1867 nos,which is the largest number of trees.The age structure of the trees along the East Rail is young and the majority,followed by mature trees.There are 60 dead trees that need to be removed urgently,accounting for 1.69% of the total number atfer tree assessment.This means that the tree condition was fair.Through of scientific tree risk assessment models and modern technical equipment to systematically assess tree risks in urban landscape green spaces is an important area that will require attention in the future of landscape tree research and management.However,there are many uncertain factors that affect the risk of trees.Although various advanced technical instruments have been continuously developed and applied to the trees of railway tree risk diagnosis,their diagnostic characteristics have certain limitations,that is,they can only diagnose the local location of trees,and cannot master of the overall risk condition of trees.The SDI of tree diversity along railway is 11.89.This shows that the species diversity along the East Rail line is still relatively diverse.Trees are even more closely related to our lives.Trees green our environment on the urbanized of Hong Kong.We will do best in tree risk management.At the same time,different departments and owners are required to maintain the trees.The trees monitoring depends on your assistance and cooperation.Trees will be damaged under the bad weather.Tree risk assessment will be to use advanced instruments and the professional knowledge of arborists to cooperate to assess the condition of trees early and conduct mitigation work to improve the health of trees in the further.