Hong Kong struggling to breathe under weight of ‘maximum’ urban density, academic says
Academic argues against city building more high-rises as already weaker winds are leaving heat and pollutants to shroud the concrete jungle
Urban parts of Hong Kong cannot cope with any more high-rises as street-level airflow has become more stagnant and unable to disperse heat and pollutants, an academic says, warning of an "urban dome".
The winds are weakening as more tall towers are built close to one another, Observatory data shows. Average wind speeds at the King's Park urban weather station in Hung Hom dropped from 3.5 metres per second in 1968 to two metres per second last year. With the still air came a 2 degrees Celsius rise in average temperatures in the same period.
"Further densification of our city is highly not recommended," Professor Li Yuguo, who heads the mechanical engineering department at the University of Hong Kong, said. "Future land reclamation may also need to be more disciplined."
Li said poor ventilation might be a factor behind days of very high pollution as the winds could barely disperse the pollutants.
The urban lethargy contrasts with the Observatory's remote Waglan Island weather station, where wind speeds have been stable over the last 50 years.
The Observatory says dense developments increase roughness at the surface, exerting a drag on winds near the ground.