Several Chinese cities will conduct research on building wind corridors to improve natural ventilation and air convection systems in an attempt to better fight punishing smog.

The cities of Hangzhou in Zhejiang Province and Nanjing in Jiangsu Province are looking to construct wind corridors by widening roads and increasing vegetation cover while reducing the density of concrete structures that tend to come in the way of natural wind passages over urban spaces.

Some of the cities, such as Nanjing, have poor air convection conditions owing to geographical factors, which make it hard for pollutants to diffuse. Meteorologists also blame high-rises for poor air passage.

Successful examples of similar projects are seen in cities and municipalities including Wuhan and Shanghai.

In a recent circular, the Ministry of Environmental Protection, asked 31 provincial regions to sign a liability agreement to control air pollution by the end of November with the central heating system expected to be switched on soon.

Coal-based public heating had resulted in smog or haze in the past few years. The latest circular stated that pollution-intensive industries will be strictly supervised and enterprises with a shoddy waste disposal mechanism will face criminal charges.

Meanwhile, China plans to adopt flexible working hours and suspend classes in schools when air pollution warnings are severe, the ministry said in the circular.

The government is eager to respond to rising public concern over the environment.

The ministry also intends to sign a liability contract with 31 provinces, autonomous regions as well as municipalities across the country, which stipulates that local governments will be held responsible if air pollution in their region exceeds tolerable limits.