Shenzhen, China
City population: 12590000
Duration: 2017 – 2017
Implementation status: Completed
Scale: Sub-microscale: Street scale (including buildings)
Project area: 90 m2
Type of area: Residential, Building
Last updated: October 2021

The Gangxia 1980 green roof, a pilot of the Green Cloud project, was launched by The Nature Conservancy (TNC) in collaboration with key partners, including: Zhubo-AAO; Glocal Estate Management; and Urban Planning & Design Institute of Shenzhen (UPDIS) [1]. Located on an old building in Gangxia village in Shenzhen, the project utilizes three-dimensional light steel structures that are simple to construct and have the capacity to hold over 420 plant containers, filled with plants mostly native to Southern China [1, 2]. The original concrete rooftop is transformed by vegetation, which is capable of absorbing and preserving rainwater, creating a nature-based stormwater management system for the residential building, achieving a 65% of run-off control rate [1, 2]. As a result, a living “green cloud” is formed on a rooftop of Gangxia village, showcasing “a model to improve the urban village’s stormwater management system and its living environment” [1. p.33].

Overview

Nature-based solution

  • Nature on buildings (external)
  • Green roofs
  • Green areas for water management
  • Rain gardens

Key challenges

  • Climate action for adaptation, resilience and mitigation (SDG 13)
  • Climate change adaptation
  • Climate change mitigation
  • Water management (SDG 6)
  • Stormwater and rainfall management and storage
  • Green space, habitats and biodiversity (SDG 15)
  • Habitat and biodiversity restoration
  • Habitat and biodiversity conservation
  • Green space creation and/or management
  • Environmental quality
  • Air quality improvement
  • Regeneration, land-use and urban development
  • Promote natural styles of landscape design for urban development
  • Social justice, cohesion and equity (SDG 10)
  • Social cohesion
  • Social interaction
  • Environmental education
  • Health and well-being (SDG 3)
  • Creation of opportunities for recreation

Focus

Creation of new green areas, Knowledge creation and awareness raising

Project objectives

The aim of the project was to showcase a model to improve the urban village's stormwater management system as well as providing a green and comfortable commonplace for residents, from which the current living states of residents could be improved [1, 3]. It works with indigenous plants from Shenzhen's coastal region, recreating the original natural habitat of the city and enhancing biodiversity in the area [4]. Through the installation of the green roof, this project also "help regulate room temperature within the building, reduce the urban heat island effect, improve air quality, and lower greenhouse gas emissions." [1, p.33]

Implementation activities

The construction of the rooftop garden includes the installation of a three-dimensional light steel structure that carries over 410 plant containers/boxes filled with indigenous plants from Shenzhen’s coastal region and a rainwater collection barrel. "The application of the sponge modification is in the planting box embedded in the (steel) grid. There is an aquifer at the bottom of each planting box to trap about 4 litres of rainwater and an overflow at 10 cm where the surplus rainwater can be discharged outside the planting box without causing the roots of the plants to rot due to too much water. After the water in the planting box on the roof overflows, it is collected and discharged into the water storage tank on the second floor. The water storage tank can store up to 400 litres of water. When it is not raining, the water in the water storage tank can be used to water the plants and form the water circulation system of the building itself." [5, p. 82] It is a low-technique project that is designed to be replicable [4]. Meanwhile, to lower the maintenance need and energy consumption, the project selected many native plants in Shenzhen, such as wild peony, Mao Ren, and Rhaphiolepis indica, which accounted for more than three-thirds of the green plant species [4, 5]. Community engagement was one of the key elements to the success of the Green Cloud project. "Due to the unique design of the Gangxia 1980 green roof, some residents of Gangxia village thought illegal construction was going on and filed complaints to the district law enforcement, resulting in the project being forced to stop during the beginning stages of construction. To resolve the problem, TNC made various visits along with Glocal, the property manager, to local community centers, government authorities and law enforcement. The team explained the project and its objectives in further detail, invited them to visit the site and shared details of the design plan with them. After several meetings, the project finally received oral approval from local authorities and the community, allowing construction to recommence... These days, neighbors are friendly and engage with the project by asking questions about the plants in the garden." [1, pp. 33-34]. "Realizing the importance of community and local support, TNC took the lead in engaging many university students, residents and youth volunteers in Shenzhen to come together and be a part of building the Green Cloud Project." [2] Since the garden’s official opening, TNC has led two summer nature education programs for local children, where students from the village have had the opportunity to be outdoors and learn about subjects like the ecosystem and biodiversity. The program also uses the green roof for children to practice and observe nature in action as they try out their gardening skills. To help build relationships among neighbors, in June 2018 TNC also worked with the Sinolink Education Center in Shenzhen to host a live music concert on the green roof, bringing a piece of cultural life to local citizens [1, 3].

Climate-focused activities

Climate change adaptation:

  • Implement solutions to capture/store water to increase its availability and prevent shortages from droughts
  • Increase or improve urban vegetation cover to help reduce outdoor temperature
  • Implement green walls or roofs to lower indoor temperature and provide insulation

Climate change mitigation:

  • Implement solutions to help reducing energy consumption or support the use of sustainable energy resources
  • Install vertical or horizontal artificial surfaces that help with carbon storage and cooling

Biodiversity conservation or restoration-focused activities

Biodiversity conservation:

  • Protect and enhance urban habitats
  • Create new habitats
  • Protect species
  • Undertake specific measures to protect species
  • Undertake specific measures to protect native species
  • Means for conservation governance
  • Raise public awareness
  • Public engagement

Biodiversity restoration:

  • Rehabilitate and restore damaged or destroyed ecosystems

Main beneficiaries

  • Local government/Municipality
  • Non-government organisation/Civil Society
  • Citizens or community groups
  • Young people and children

Governance

Management set-up

  • Led by non-government actors

Type of initiating organisation

  • Non-government organisation/civil society
  • Business association or network

Participatory approaches/ community involvement

  • Unknown

Details on the roles of the organisations involved in the project

The project was launched by The Nature Conservancy (TNC) in collaboration Zhubo-AAO (a design institute); Glocal Estate Management (who manages the project building and owns the renovation project); the Paradise International Foundation (a nonprofit environmental organization), and Urban Planning & Design Institute of Shenzhen[1, 4, 5].

Project implemented in response to ...

... an EU policy or strategy? No
... a national policy or strategy? Yes (The rooftop garden is a prominent example of the “Sponge City” initiative, a Chinese national policy framework that focuses on sustainable urban stormwater management [1]. )
... a local policy or strategy? Yes ("In 2016, Shenzhen became a pilot city of the “Sponge City” initiative and has been working to help urban communities in Shenzhen become more resilient to urban flooding with green infrastructure. TNC has been assisting the local government in restoring the city’s natural stormwater management system by increasing the amount of green spaces within the city. The availability of empty rooftops is a largely untapped resource, which makes it a perfect location to install green infrastructure." [1, p.33])

Financing

Total cost

Unknown

Source(s) of funding

  • Private Foundation/Trust

Type of funding

  • Unknown

Non-financial contribution

Type of non-financial contribution
  • Provision of land
  • Provision of labour
  • Provision of other services
Who provided the non-financial contribution?
  • Public authorities (e.g. land, utility services)
  • Citizens (e.g. volunteering)
  • Private sector (businesses, financial institution)

Impacts and Monitoring

Environmental impacts

  • Climate change
  • Lowered local temperature
  • Reduced emissions
  • Environmental quality
  • Improved air quality
  • Water management and blue areas
  • Improved water quality
  • Improved stormwater management
  • Green space and habitat
  • Promotion of naturalistic styles of landscape design for urban development
  • Increased green space area
  • Increased conservation or restoration of ecosystems

Economic impacts

  • Unknown

Socio-cultural impacts

  • Social justice and cohesion
  • Improved social cohesion
  • Improved liveability
  • Improved access to urban green space
  • Increased opportunities for social interaction
  • Increased sustainability of agriculture practices
  • Health and wellbeing
  • Gain in activities for recreation and exercise
  • Cultural heritage and sense of place
  • Improvement in people’s connection to nature
  • Increased sense of place identity, memory and belonging
  • Increased appreciation for natural spaces
  • Education
  • Increased support for education and scientific research
  • Increased knowledge of locals about local nature
  • Increased awareness of NBS and their benefits

Type of reported impacts

Expected impacts, Achieved impacts

Presence of formal monitoring system

Unknown

Presence of indicators used in reporting

Yes

Presence of monitoring/ evaluation reports

No evidence in public records

Availability of a web-based monitoring tool

No evidence in public records

References

Information about this nature-based solution was collected as part of the UNA global extension project funded by the British Academy.