ABSTRACT
Chapter three moves the discussion from villages to towns and cities. In low-lying villages we advocated the repair of ponds and canals to manage water, its flow, storage and discharge. In cities with their more confined spatial structure, a strategy of covered basins, reservoirs and amply dimensioned pipes is needed. The increase of non-permeable surfaces necessitates water storage on roofs, below streets and in open spaces. It also increases the need to design horizontal surfaces that can absorb water whenever possible. The result is a city structure compared to a sponge that absorbs water below the city surface when needed and drains water out at low tide. The water plan for the city of Rotterdam served as a precedent. We discuss this plan in part III of the book. The chapter starts with Jiangmen near the West River in the southern part of the delta. Jiangmen, once a concession port, is a town of nearly five million inhabitants. Built against the south facing slope of a hill, the historic center is characterized by much colonial architecture with arcade streets. Like the rivers in Guangzhou and Foshan, the nearby West River at Jiangmen is under tidal influence. The banks of the distributary facing Jiangmen’s historic center will require flood protection in the future. The historic structure of Jiangmen was recently recognized by the central government. Thus an earlier plan to demolish the historic city center was abandoned. The compact urban form can now be preserved, but significant challenges exist to bring the narrow and very long shop house typology into compliance with fire standards and improved sanitary conditions. What is needed is a contemporary expression of a historic building typology. The chapter illustrated how such improvements can be made through infill on vacant sites and by reforming urban blocks without abandoning the crucial dimensions that support public life. The intent was that such a process take place in an incremental fashion in order to limit the displacement of current residents. The chapter then turns to Guangzhou, to an island in the North River near the central business district and the Canton Fairgrounds. On our visit in 2014, Pazhou Island still had remnants of its former rural character. The island used to flood periodically, inundating its rice paddies and later its vegetable farmland. Framed between the large convention center and the new central business district, the island is now slated to concentrate new media technology on very large urban blocks. The chapter illustrates an alternative approach that combines housing and workplaces. It also illustrates how such a city extension can be built on raised land with a sponge-like structure below the city surface. The chapter and part II of the book ends with modeling done at Key Laboratories for Coastal Studies in Shanghai, at the Hong Kong Observatory and at the Atmospheric, Marine and Coastal Environment Program at Hong Kong University of Science and Technology. The results of such modeling point to a precarious future. The modeling takes into consideration the customary prediction of sea level rise, but also the more frequent advent of cyclones and monsoon-related storm events. In addition, like the Dutch Delta, the land between the rivers of the Pearl River Delta is subsiding and the river floors are rising due to sediment transport. All urbanization has to include water management practices. As a consequence, more room has to be made for water.
