ISSCC member city: Guangzhou explore sustainable, affordable and integrated solutions for urban cool

Against the backdrop of global warming, high temperatures and heat waves continue to sweep across the globe, and since 2020, Guangzhou has partnered with the World Bank to pilot the "China Sustainable Urban Cooling Project" to promote Guangzhou's "Cool City" initiative and explore sustainable and affordable solutions to urban cooling. Guangzhou has been working with the World Bank on the pilot "China Sustainable Urban Cooling Project" to promote Guangzhou's "Cool City" initiative and explore sustainable, affordable and comprehensive urban cooling solutions. What is the progress of the "Cool City" initiative? Recently, Guangzhou has established a strategy system at three levels, namely the general unit and neighbourhood levels, to create a cooler Guangzhou.

Guangzhou is located in a subtropical monsoon climate zone, with a high density of population and buildings, exacerbating the urban heat island effect. Long-term high temperatures and high humidity affect the livability of the city and increase the consumption of resources and energy needed for cooling. Creating a comfortable and healthy living environment under hot and humid conditions has become a key challenge for Guangzhou at this stage in building a healthy, livable and resilient city.

Natural ventilation to reduce heat accumulation is one of the most effective ways to cool down the city. Guangzhou has constructed a system of six major ventilation corridors in the city area through a WRF simulation study of the overall wind environment in Guangzhou, combined with the layout of the city's rivers, green spaces and other open spaces in the preparation of the overall planning of land space. These include the Hongqili Waterway - Pearl River West Channel Ventilation Corridor, Jiaomen Waterway - Nansha Harbour Express - Pearl River Front and Rear Channel Ventilation Corridor, Shiziyang - Hengfengshan Ventilation Corridor, Xintang - Jiulong Avenue - Pearl River Delta Loop Expressway Ventilation Corridor, Liuxi River Ventilation Corridor, and Zhengguo - Zhonglutan - Baini River Ventilation Corridor.

Ventilation corridor areas will strictly protect open spaces such as water systems and green areas, control the construction increment of major wind inlets, strengthen the control of building height, building spacing and density, and avoid screen-like buildings.

In order to promote the application of climate analysis research to the practice of territorial spatial planning and management, and to connect climate assessment with urban and building form control, Guangzhou has innovatively carried out the practice of thermal environment control zoning. Taking into account the heat load and wind flow potential of Guangzhou, the thermal vulnerability of Guangzhou is identified, and the thermal environment control zoning of Guangzhou is defined on the basis of the planning and management unit, which integrates the future planning and development needs. Each zoning unit puts forward targeted planning and design proposals according to its own geographical and climatic conditions, and implements differentiated development control requirements and urban cooling measures. For example, Thermal Environment Control Zones 1 and 2 give priority to the implementation of micro-improvement means to increase green coverage and the proportion of permeable surfaces, while Thermal Environment Control Zones 3 and 4 strive to raise the threshold for development, and construction projects need to meet the construction standards for sustainable urban cooling.

Thermal environment control zoning map

At the same time, Guangzhou has also compiled design guidelines for sustainable urban cooling neighbourhoods. With openness, permeability and close connection to the natural ecology as the core elements, the guidelines promote the design patterns of four typical neighbourhoods, namely residential, commercial, industrial and historical neighbourhoods, to cope with the hot and high humidity climate, in order to promote Guangzhou's neighbourhoods to respond to the local Lingnan climate, and to improve the comfort, resilience and sustainability of the community.

Residential neighbourhoods emphasise "people" as the core, and are oriented to the thermal comfort of residents' outdoor and indoor spaces, encouraging the provision of protection from sun and rain, capturing cool breezes, and opening up local building spaces to the outdoors; commercial neighbourhoods focus on "business", and are oriented to the comfort and vibrancy of commercial activities; and commercial neighbourhoods focus on "business". commercial neighbourhoods are oriented towards "industry", and the comfort and vitality of commercial activities, encouraging buildings that breathe, maximising ventilation and shading design, and multi-dimensional green landscaping; industrial neighbourhoods are oriented towards "production", and the climate-friendliness of industrial production and production spaces, encouraging energy-efficient refrigeration, reduction of anthropogenic heat emissions, and the recycling of industrial waste heat; historical neighbourhoods are oriented towards "Lingnan", and the climate-friendliness of industrial production and production spaces. "Lingnan" as the core, in order to co-ordinate the protection of traditional features and enhance outdoor thermal comfort as the focus, to encourage the inheritance and innovation of Lingnan passive cooling, ventilation, heat insulation wisdom.

The relevant person in charge of the Municipal Planning and Natural Resources Bureau said that the climate of Guangzhou defines to a certain extent the city's culture and style, the way of life and activities of the citizens, but the hot and long summer heat often prevents people from enjoying the outdoor life, activating the city's "fireworks" footsteps. The Guangzhou Cool City initiative is dedicated to creating a cooler Guangzhou, through a more comfortable and pleasant climate environment, regrouping the popularity of outdoor spaces, activating outdoor activities, and helping Guangzhou realise the new vitality of the old city.