Spatial-Temporal Evolution Pattern and Future Scenario Analysis of Water Resources Carrying Capacity of Ningbo City

Abstract

Contradictions between population distribution and socio-economic development has been taken as a major topic regarding to the realization of coordinated growths of resource, society, economy and ecosystem, especially in city region. Water resources carrying capacity (WRCC) can reflect the quantitative relationship between the total regional population, economic scale and the volume of water resources, which can objectively demonstrate the regional water consumption level under a certain scale of population and economy. Indices of WRCC (WCC and WCCI) were applied to analyze the WRCC of Ningbo city, based on the relationship between population size and water resources of Ningbo city. WCC and WCCI can effectively solve the uncertainty among the total regional population, economic scale and the volume of water resources. Because of different trends in counties, there are different WRCC in these counties. Time-series and multi-scales of WRCC in Ningbo city were assessed using geographic information system (GIS) method. Also, the future WRCC and its regional variation of Ningbo city in 2020 and 2030 were analyzed based on the practical situations using scenario analysis method. Results showed that in the presence of water resources volume of Ningbo city fluctuated, affected by water resource endowment in the past 15 years, the entirety of Ningbo city of WRCC was from abundance to surplus, then surplus with relatively high, and when the flow year was from high flow years to normal flow years, then to low flow years. In terms of the differences of the WRCC among counties, the various WRCC grades of prefecture-level counties should need different kinds of strategies during different flow years to reach their stable states because that in average flow years, water resources existed surpluses beyond balance in Cixi (county-level) city and Ningbo city municipal district. In low flow years, critical overload happened in both Cixi city and Ningbo city municipal district. In the context of the year of 2020 and 2030, the overall WRCC of Ningbo city would stay in abundant levels, whereas the contradictive relationship between population and water resources would be fairly remarkable.