Course:CONS200/2025FL1/Green Infrastructure

Rapid urbanization and climate change have intensified flooding, the urban heat island effect, and the problem of biodiversity and inhabitants’ loss in Chinese cities, revealing that traditional building constructions have a bad impact on the urban climate.  Green Infrastructure (GI) refers to a strategically planned network of natural and semi-natural areas that are designed to solve urban environmental problems and support the urban ecological system . By allowing water to soak into the ground, cooling the air, and providing shade, GI helps cities become more resilient and maintain biodiversity.

In practice, China uses GIS-based methods to design GI layouts that reduce flood risk and remote sensing tools to study the transformation of green areas in fast-growing cities like Shenzhen . The national Sponge City Program also promotes NbS in urban planning. However, some studies reveal that GI projects are not always well managed, often lacking coordination and long-term ecological goals. Lu et al. (2024) indicate that public preferences in Wuhan focus on the aesthetic value of GI, rather than its ecological functions in infiltration, air cooling, and therapeutic value. When benefits are not visible, residents may discount GI’s value, leading to resistance to siting, low stewardship, and even preventing the construction of GI (p.314).

Fang et al.(2023) conclude that “It is still unclear how to quantify the spatial processes leading to green infrastructure changes with urban expansion”. Therefore, the response measurement of GI under the expansion of urbanization remains a challenge in the future.

Background

Definition

Green Infrastructure in Chongqing China

Green Infrastructure (GI) is a strategically planned network of natural and semi-natural areas that are designed to solve urban environmental problems and support the urban ecological system . Compared with traditional single-purpose infrastructure, GI connects ecological, social, and economic functions to improve urban resilience. For example, in Beijing, integrated GI layouts reduced flood risk by 35% compared to conventional drainage systems , while in Wuhan, residents reported a large improvement of thermal health and psychological restoration in GI-focused neighborhoods . These examples demonstrate that GI enhances resilience not only through hydrological regulation but also by enhancing ecological and social co-benefits in the urban environment.

GI Development History in China

Following decades of rapid urbanization, Chinese cities have faced severe challenges such as flooding, waterlogging, and ecosystem degradation. Traditional “grey” infrastructure is no longer capable of coping with extreme weather events and rapid land-use change. To solve these issues, the Chinese government began to promote the concept of Green Infrastructure (GI) under the circumstances of Ecological Civilization and sustainable urbanization .

In 2014, the Chinese State Council officially published the Sponge City Initiative (SCI), which was the first nationwide program in China based on the concept of GI and Low Impact Development (LID). The strategies aim to renovate natural hydrological cycles and strengthen urban resilience by using permeable pavements, urban wetlands, and green roofs. Having selected 30 cities all around the country, the central government established a specific fund to support the program implementation.

Between 2016 and 2020, a series of policy documents were published, such as the Technical Guide for Sponge City Performance Evaluation and Urban Flood Control Plans. These policies further emphasized that GI should become a core component in water-sensitive urban planning. In Beijing, existing GI systems reduced flood risk by 35% , while in Wuhan, pilot areas witnessed a 27% reduction in stormwater runoff and an 18% increase in permeable surface coverage. Therefore, GI is a significant tool to resist the urban extreme weather and climate.

Since 2020, GI has become a core part of national strategies in China, which are connected with climate mitigation and biodiversity protection. Policymakers increasingly take GI as an important Nature-based Solution (NbS) to provide environmental, social, and economic benefits for cities at the same time .

GI Ecology Functions

Under traditional hard-surfaced urban conditions, stormwater is mainly drained through underground pipelines. This system often causes a large amount of surface runoff during heavy rainfall, which easily leads to urban flooding. In hot weather, the lack of water storage and retention areas also increases the risk of heat island effects and other ecological problems. In contrast, Green Infrastructure (GI) shows clear advantages in hydrological regulation. It mainly includes five mechanisms: infiltration, detention, evapotranspiration, purification, and connectivity.

Infiltration is achieved through facilities such as rain gardens and green spaces that allow rainwater to seep into the soil and recharge groundwater. This not only reduces surface runoff but also provides water for urban vegetation. Hu et al. (2023) found that infiltration facilities can reduce peak runoff by 30–50%. However, rain gardens and green spaces are often small in high-density urban areas. Therefore, artificial wetlands are needed to increase temporary water storage capacity and regulate runoff volume. Li et al. (2017) suggested that detention facilities in sponge cities can improve the annual runoff control rate by up to 70% which demonstrates that the storage ability of GI is vital to the urban environment.

Filtration and purification refer to the ability of soil and plant roots to lower the concentration of pollutants such as heavy metals and nitrogen, and phosphorus compounds. Herath and Bai (2024) pointed out that GI can also enhance the self-purification capacity of urban water bodies and reduce the chemical oxygen demand of water by 20–40%.

In addition, the evapotranspiration of plants in urban green spaces can recover 10–25% of water within 48 hours after rainfall, while the use of this water by plants helps lower urban temperatures and mitigate the heat island effect .

In conclusion, GI plays an important role in regulating urban water and temperature. It not only helps reduce urban flooding but also lowers air temperature, purifies the air, and improves the ecological environment, forming a positive biological and hydrological cycle.

Case Studies

Shenzhen

Shenzhen's green building development is a great example of how to make the most of a tropical coastal city's natural environment, and it's all about thinking outside the box when it comes to green infrastructure. Take urban planning, for example. Mangrove wetlands and intertidal ecosystems are seen as natural green infrastructure, doing things like regulating stormwater, storing carbon and protecting biodiversity. Architectural design uses green roofs and vertical greening to reduce energy consumption and the urban heat island effect. What's more, Shenzhen's green building assessment system uses a multi-dimensional indicator evaluation framework combined with geographic information systems to make it more accurate and reliable. But research shows that even though Shenzhen is a leader in China when it comes to green building and policy, the city's rapid growth is still having a negative impact on ecosystems, green space quality and how evenly green space is distributed . Also, there has not been enough progress on carbon sink markets . Shenzhen's green building practices are a great example of a balanced approach to urban ecological conservation and sustainable development. They're a really good reference model for other coastal cities.

Wuhan

Wuhan, as one of China's inaugural Sponge City pilot projects, has implemented a comprehensive control system encompassing infiltration, detention, storage, purification, utilisation and discharge through the establishment of sunken green spaces, rain gardens and wetland parks. This approach has been demonstrated to engender synergistic benefits, including carbon sequestration, temperature reduction and biodiversity conservation. In the Qingshan District case study, the use of SWMM modelling revealed that sponge infrastructure could reduce surface runoff by 20–35% during a one-hour downpour. Concurrently, the presence of sponge cities has been demonstrated to exert a positive influence on both land and property values. Residential areas in close proximity to green-blue spaces have been shown to command significant premiums. As Zhang et al. (2018) demonstrate, public perception, supportive attitudes, and willingness to pay also significantly influence GI development. Nevertheless, challenges persist in the realms of governance coordination and long-term operation. Projects are predominantly government-driven, lacking social capital and sustained monitoring support. To deal with these problems, experts suggest a number of solutions. This includes improving how we monitor stormwater, making clear who is responsible for what, and adding features like green spaces and water bodies to plans for the city as a whole. The point of these measures is to get more people to pay attention. The Wuhan case shows that combining blue-green and grey systems can balance costs and benefits. But it is very important to remember that we need support from institutions and the public to keep the environment and society working well in the long term.

Ma’anshan

Ma'anshan's green infrastructure development features a network of greenways connecting urban and rural areas, which is great news for ecological sustainability restoration, low-carbon travel and rural tourism. The city came up with its Greenway Master Plan in 2013, which included about 549 kilometres of 'urban-regional greenways' that would go through the urban-rural fabric. By 2017, they'd done over 250 kilometres. These greenways are located along riverbanks, mountain slopes and scenic areas, and they meet the daily needs of local residents for walking and cycling. They also improve the city's image and tourism potential by creating ecological corridors. When it comes to the indicator system, Ma'anshan mostly looks at things like how much green space there is per person, how often people use the greenways, and how satisfied the residents are. But research also shows that the greenway network isn't very connected, the funding model relies a lot on local government spending, and there's not enough long-term monitoring of the ecological performance. This has, to some extent, limited the deepening of its ecological service functions . In the future, we're looking to improve how the greenway system connects urban and rural areas, as well as include things like carbon sequestration and biodiversity as performance indicators. We're also going to set up different ways to fund the maintenance and operation of the greenway. All in all, Ma'anshan's greenway development shows how a city can change from an industrial steel city to a city that's good for the environment. It's a useful example for other small and medium-sized cities.

Challenges and Future Development Directions

Less payment aspiration for GI.

Not everyone is willing to pay for green infrastructure. Take the sponge city as an example, only 60% to 75% of all respondents in this city are willing to support the city's green infrastructure initiatives . Even among those most willing to participate in green infrastructure projects, the average monthly contribution is only about 0-5 RMB (equivalent to 0-0.72 USD per month). People's willingness to pay for green infrastructure is not particularly high. Future research might be conducted on the solution to enhance public acceptance of green infrastructure.

Risk

There are numerous uncertainties in the process of green infrastructure development. The results of Fuzzy AHP show that policy and regulations are the most significant risk associated with green infrastructure finance in China, followed by financial risks, and technical risks . To mitigate the impact of these developments, we must understand what the primary drivers are for advancing green infrastructure. The governments, practitioners, and policymakers should focus on the strategy of green infrastructure in urban areas (GIDS2), green community center development strategy (GIDS3), green business parks development strategy (GIDS4) in managing the GID practices.

Investment

Another issue is that while green infrastructure projects require substantial capital investment and typically won’t deliver direct economic benefits to stakeholders. Therefore, in order to attract more investment, Junlan Tan & Yasir Ahmed Solangi analyzed and weighted the impact of investing criteria for green infrastructure on sustainable development in China using the fuzzy Analytical Hierarchy Process (AHP) method and give us some suggestions including establish regulations and policies to encourage private investment, enhance public awareness and participation in sustainable infrastructure development, establish public-private partnerships to leverage resources and expertise and develop capacity-building programs for investors and project developers.

Uneven Development

The development of green infrastructure across China's various regions is extremely uneven. According to a survey of the Yangtze River Economic Belt region, cities with higher urbanization indices tend to exhibit greater economic development and more advanced green infrastructure. To address this issue, a multidimensional analysis approach for green infrastructure can be adopted. This involves studying development models for green infrastructure across different regions, formulating green infrastructure development strategies, and providing policy recommendations and actionable advice to relevant government departments.

Conclusion

Green Infrastructure (GI) has become the most important Nature-based Solution to the environmental problems caused by the fast urbanization process in China. Research shows that GI can significantly migrate urban flooding, ease heat island effects, enhance biodiversity, and improve public well-being by promoting natural water cycling and restoring ecosystems. Apart from national initiatives like the Sponge City Program, which spans over the entire country, city-specific instances in Shenzhen, Wuhan, and Ma’anshan also reflect GI’s capacity to transform urban ecosystems in China towards being more resilient and sustainable.

However the effectiveness of the development of GI is still hindered by the governance fragmentation, uneven regional development , lack of public support and uncertainty in financing for the long term. These challenges highlight the need for better policy coordination, better risk management, more diverse funding sources, and more public participation and environmental monitoring. Improvements of the spatial evaluation method, performance assessments’ deepening, and multi-stakeholder participation encouraged are the future work openers to make GI recognized not only for its looks but also for its environmental and social benefits.

Overall, China’s achievement is a clear indicator that the GI can actually serve as a powerful means of transforming cities into climate-adaptive, biodiversity-friendly, and liable places. The transformation of green infrastructure from separate projects into a robust urban system that can sustain sustainable development for the coming decades will depend on constant trials, innovative policies, and active public participation.

Reference

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