Environment | Accurately forecasting air quality app under development in HK

A system that reportedly provides accurate air quality forecasts to inform users of upcoming air quality is underway.

By the fourth quarter of this year, a mobile app called “Praise-HK” will be launched, providing accurate air quality forecasts up to 72 hours in advance.

Coverage extends across mainland China, Hong Kong, Macau and Taiwan, as cited in a report issued by South China Morning Post.

The app aims to reduce users’ exposure to unhealthy air by informing them of air quality in advance.

The system that helps provide the advanced, accurate predictions is called the Atmospheric Dispersion Modelling System (ADMS), which Dr. Alexis Lau Kai-hon from the Hong Kong University of Science and Technology helped develop.

According to him, the system takes into account anything that affects air pollution.

The system considers emissions sources, vehicle fleet composition and real-time traffic flow across 30,000 roads and streets.
However, the entire East Asian weather system is also considered.

“Our model actually considers pollution from the whole Greater China
region. Sometimes pollutants in [mainland] China or the Pearl River Delta
region will affect us [and vice versa] so we cannot just look at Hong
Kong,” said the scientist.

“It is a clear spatial map showing what air pollution is and information about its evolution,” Lau added.

Users can see wind directions with the app, making them aware of when northerly winds will prevail and when transboundary pollution from the mainland is more likely.

If there are winds from the south, which usually occur in summer, Hong Kong generally sees cleaner air.

As cited in the report, color-mapping will reveal high pollution spots in Hong Kong, such as the entrances of tunnels during rush hour.

The scientist notes that the app will also help users understand air pollution better.
According to Dr. Kenneth Wu Wing-cheung from the Hong Kong College of Emergency Medicine, the app will tell users to avoid highly polluted areas, particularly areas that are not accurately captured by the government’s air quality monitoring stations.
“I believe the app will be helpful for those with chronic illnesses or
respiratory problems and reduce their exposure to heavy pollution,” he
said. “But this also depends on its accuracy.”