Risk Assessments of Trees and Urban Spaces under Attacks of Typhoons: A Survey and Statistical Study in Guangzhou, China

Abstract

Typhoon, as one of the extreme climatic disasters, attacks the southeast coastal cities in China every year. To countermeasure the risk of a typhoon on urban tree safety, we established a cooperation research team including professions on urban design and city planning, wind engineering, and tree health assessment and management. This paper presents some statistical studies on the data of the damaged urban trees causing by the typhoons in Guangzhou and some other cities in Pearl River Delta (PRD), China in 2016 - 2018. The data of the damaged trees is imported in a geographic information system (GIS) database and a local climate zone (LCZ) map to analyze the distribution of damaged trees in different urban morphologies and underlying surface patterns. Results show a series of high-risk tree species such as Ficus microcarpa, Ficus virens var.sublanceolata, and Bauhinia variegate in typhoons. Then, six LCZ typologies and four main typologies of urban space are figured out basing on the statistical analysis of the damaged trees. Preliminary results reveal that some kinds of tree species and urban space are at a higher risk level during the typhoons. Current works will support the research on urban tree management, risk management and forecasting, urban planning, and landscape design.