长三角一体化下城市规模提升的水环境风险——以合肥市为例

Study on water environment risk of city size increase under the integration of Yangtze River Delta:A case study of Hefei city

在长三角一体化背景下,中心城市规模能级得到快速提升,引发资源环境承载压力的升高,尤其是作为制约城市高质量发展的水环境风险备受关注。通过PSIR-TOPSIS模型对合肥水环境综合风险水平进行测度,结合环境库兹涅茨曲线和脱钩分析对城市规模与水环境风险的动态关系进行分析。结果表明:(1)2006-2020年间合肥城市规模水平呈线性增长,水环境风险指数经历持续上升—波动下降—波动上升三个阶段,提示合肥当前水环境风险压力加剧。(2)环境库兹涅茨曲线拟合显示合肥城市规模与水环境风险呈现“N”型曲线关系,两个拐点分别处于城市规模0.2和0.8水平处,对应城市增长起步阶段和高规模阶段。(3)脱钩分析表明合肥城市规模取得显著增长后,城水关系的脱钩状态进入不稳定时期,强脱钩与扩张负脱钩交替出现,虽然风险水平仍处于上升阶段,但水环境风险的扩大趋势已被抑制,表征合肥城市规模与水环境风险将进入新的平衡发展状态。本文为避免传统水环境评价单一性局限,结合多种理论模型构建城水关系研究框架,为推动长三角一体化高质量发展提供城市与水环境协调共生的理论支撑与参考。

In the context of the integration of the Yangtze River Delta,the size of the central city has been increased rapidly,which leads to the increase of the bearing pressure of resources and environment.Especially the water environment risk which restricts the high-quality development of the city has been deeply concerned.The comprehensive risk level of Hefei water environment was measured by PSIR-TOPSIS model.The dynamic relationship between city size and water environment risk was analyzed by combining environmental Kuznets curve and decoupling analysis.The specific conclusions include:(1)The city size level of Hefei grew linearly between 2006 and 2020,and the water environment risk index went through three stages of continuous increase-fluctuating decrease-fluctuating increase,suggesting that the current water environment risk pressure in the city has increased.(2)The environmental Kuznets curve fitting shows N-shaped curve relationship between city size and water environment risk in Hefei.The two inflection points are at the level of 0.2 and 0.8,respectively,corresponding to the initial stage and large-scale stage of city growth.(3)The analysis shows that the decoupling state of city-water relationship enters an unstable period after the city size of Hefei increases significantly.Strong decoupling alternates with extended negative decoupling.Although the risk level is still in the rising stage,the expanding trend of water environment risk has been restrained.This indicates that Hefei city size and water environment risk will enter a new balanced development state.In this paper,in order to avoid the limitations of traditional water environment evaluation,we combine various theoretical models to build a research framework of city-water relationship.To provide theoretical support and reference for promoting the integrated and high-quality development of the Yangtze River Delta with the harmonious coexistence of city and water environment.