Project Title： ‘Incomplete’ Green Infrastructure: Lessons Learned from Rapid Urbanization in Beijing,China
Project team: Huaqing Wang, Ming-Han Li
China’s rapid urbanization in recent decades has resulted in various negative effects, such as urban floods. For the example of Beijing, serious urban floods have hit the city annually since 2004. Each time when a flood occurred, the city’s infrastructure was traumatized, including 41 major corridors and highway intersections inundated in 2004; Beijing International Airport paralyzed in 2006; 79 fatalities on July 21th, 2012. However, urban floods seemed not affecting the urban parks in Beijing. Urban parks are valuable green infrastructure with a potential for mitigating floods. Unfortunately, the rapid urbanization process in Beijing overlooked hydrologic benefits parks can provide. Several parks in Beijing are considered ‘incomplete’ green infrastructure because they are not designed to be hydrologically connected with the surrounding areas and therefore, do not mitigate floods for the areas.
We took Taoranting Park, an urban park in Beijing, as an example, and analyzed the catchment area and green land ratio. We identified the factors that contributed to the form of ‘incomplete’ green infrastructure. Our study tasks included reviewing the park’s construction history, interviewing the chief of the park, interviewing witnesses of urban floods, analyzing the topography and calculating the catchment area of the park based on ArcGIS 10.
We found mismatch exists between grey and green infrastructure. The calculated catchment area of the Taoranting Park had the capacity to store the stormwater runoff volume produced by not only the park itself but also its surrounding area. However, underground pipelines and road drainage system around the park directed stormwater runoff to the municipal storm sewer system at the perimeter instead of towards the park. These findings indicate three oversights. The first is the lack of consideration in fully using the ecosystem service of green infrastructure when designing parks. The second is the lack of communication between the departments that are in charge of grey infrastructure and the one that is responsible for green infrastructure. The third is the lack of authority of green infrastructure management departments in retrofitting green infrastructure to reduce the pressure on grey infrastructure.
Lessons learned are summarized. For these parks, inadequate planning and execution occurred from a hydrology perspective. We suggest effective communications must be established between grey and green infrastructure departments and proper authority should be given to infrastructure management departments. New planning practice should integrate both grey and green infrastructure. Retrofit should be done to establish the link between green and grey infrastructure.
(Citation: Wang H Q, Li M H (2016). ‘Incomplete’ Green Infrastructure: Lessons Learned from Rapid Urbanization in Beijing, China, Council of Educators in Landscape Architecture, Salt Lake City, Utah. [Abstract and oral presentation by Wang H Q in March])