Hydrological urbanism in China's Pearl River Delta : how water landscape shapes the urban form in a changing climate

Abstract

When standing among urban villages, residential towers and warehouses in an urbanizing city in the Pearl River delta (PRD), it is hard to imagine that just forty years ago this area was filled with streams, ponds and rice paddies. Since the Reform in 1978, the PRD metropolitan area, with the name as "World Factory", has been a pilot in urbanization together with millions of migrant labors rushed into the industries. Hydrological system accompanied with corridors for species is disrupted, fragmented and polluted when big infrastructures, industries and neighborhoods are planned without considering natural system. Storm water runoff causes flooding in the cities every year, and at the same time, extreme weather events linked to climate change and sea level rise threatens urban life and property in the future. This thesis proposes hydrological urbanism which not only can solve problems of flooding and water pollution, but also provides continuous corridors for species and recreational parks for citizens. In hydrological urbanism, water is given more room to meander and this room can catch more water runoff when it is flooding. Phytoremediation cleans the water from upper streams and swells into a wetland buffer between big infrastructures and neighborhood. Water behaves as the park to shape the neighborhood and recreational space for public access. The thesis investigates PRD through urban and hydrological analysis on different scales. With the example of Lijiao in Guangzhou (the capital city in PRD), this thesis asserts a hydrological urbanism prototype between the highway infrastructure and existing water system. An overall plan identifies similar types of urbanization which may possibly happen on the whole PRD system. The case of Lijiao can be transformed and generalized in these similar locations. Not only is for today's redevelopment, the hydrological urbanism is also changeable for future climate changes.