On spatial definition of metropolitan area in Ningbo

Metropolis area is a new type of human settlement, established when the urbanization develops unto a certain stage. It can be described as the highest form of urbanization development by far. Under the new trend of urbanization in the world, and in the context of the acceleration of Yangtze River Delta integration, to construct Ningbo metropolitan area bears new practical significance. This paper firstly describes the background of the construction of Ningbo metropolitan area. And then the author conducts quantitative calculation and qualitative analysis on the spatial range of Ningbo Metropolitan through probing into three indicators, namely economic distance, gravity and the gravitational field strength. Next, the author also illustrates the multi-center spatial structure of Ningbo metropolitan area based on analyzing the intercity interaction within the area.