Abstract:

As an emergent urban phenomenon in the beginning of the 21st century, polycentric megacity regions have arisen through the extended decentralization from big central cities to new or adjacent smaller ones. This paper introduces the formation background, concept and relative research development of the megacity region and points out that the megacity region is composed of a series of 20 to 50 cities and towns, which are physically separated but functionally networked, clustered around one or more larger central cities, and demonstrating enormous ecological strength through a new functional labor division. Then, taking the methods of POLYNET program and relative researches into account, the paper confines the boundary of the megacity region in the Yangtze River Delta by constructing functional urban region(FUR) and analyzes functional connections between the 16 main FURs on the basis of the data of employment structure in service industries. It is concluded that the megacity region in the Yangtze River Delta is composed of 55 contiguous FURs, which have more than 80 million overall population and occupying 78 thousand square kilometers; there will be a development trend to bring Wenzhou and Taizhou into the Yangtze River Delta megacity region, although they are on the edge of the region at present.

Key words: the Yangtze River Delta, megacity region, functional urban region, spatial boundary