Reconsideration of the methodology for estimation of land population carrying capacity in Shanghai metropolis.

How to estimate the urban land carrying capacity (ULCC)? Based on our previous research, this paper made improvements in two aspects: One is to subdivide land use types from four subspaces to seven subspaces (i.e. urban construction, industrial development, agricultural production, rural living, green ecological, other ecological and other subspaces), so as to distinguish more detailed the urban functional and spatial heterogeneities; the other is to reconstructing evaluation index system and estimate both maximum and appropriate population carrying capacities. The results demonstrate as follows: ① There is a significant difference between the population capacities in different types of subspaces. The urban construction and industrial development subspaces are the main carrier of population and economy. The agricultural production and rural living subspaces have low population capacities. The ecological protection and other subspaces have only a very low share of load. ② The appropriate and maximum population capacities of Shanghai metropolis are estimated to be approximately 20-23 million persons and 27-30 million persons, respectively, in 2009. There were 22.1028 million permanent residents of Shanghai in 2009, approaching the limit of the appropriate population capacity but lower than the limit of the maximum population capacity. ③ The methodology for estimation of maximum and appropriate ULCC in this paper not only gives the quantitative range, but also can provide the basis for growth control of urban population.