基于能值分析及小波变换的城市生态经济系统研究——以深圳市为例

Study on the Urban Eco-Economic System of Shenzhen City Using Emergy and Wavelet Analysis

深圳市是我国快速城市化进程的典型区域,其城市生态经济系统的结构和功能30年间发生了较大改变。本文运用能值理论,对深圳市1979年-2008年城市生态经济系统资源流、货币流、人口流和信息流等进行核算,利用小波变换分解环境负载率(ELR)时间序列,并对比M-K法分析结果,测度环境负载率突变时间点及其与影响因子间协同关系。结果表明:深圳市1979年-2008年生态经济系统流入能值增加,能值产出下降,可持续发展指数大幅下降,环境负载率不断升高。M-K法验证小波变换结果与Morlet小波作为母函数的小波变换结果基本一致,环境负载率存在3年和13年的特征时间尺度,且3年特征时间尺度下波动幅度小于13年尺度,但两者突变年份基本一致,1994年为最显著突变点。政策扶持、开放的贸易形势、高外部资源依赖是深圳市环境负载率变化的主要驱动因素。

Shenzhen is a typical area with rapid urbanization processes. During the past 30 years, the structure and function of the urban ecological economic system have drastically changed. The paper presents an eco-economic system analysis method and applied it to Shenzhen City, Guangdong Province, China. On the basis of statistical data from the Shenzhen Statistic Bureau and population data from the China Public Security Management Bureau, we summarized the input and output flows of the study area from 1979-2008. By applying emergy analysis, wavelet analysis and M-K test, we calculated resources flow, money flow, and population flow and information flow, decomposed the environmental loading ratio （ELR）, and measured the turning points and the cooperative relationship between factors. Emergy analysis is an interdisciplinary approach for the estimation of the real wealth of resources, products, and services by accounting the total natural work previously involved of generating them. Wavelet analysis and M-K test were used to detect the mutations to determine the ongoing human-nature interactions so as to formulate policies for regional sustainable development. Compared with the single method, the accuracy of qualitative and quantitative authentication for environmental loading turning points can be improved by a combination of various methods. It is found： 1） the Shenzhen’s environmental loading ratio has 3a and 13a characteristic time scales and corresponding changes from the figures of wavelet coefficients. The 13a period is more prominent than the 3a period; 2） the turning points of the changes occurred in years 1981, 1988, 1994, and 2002, with showing the most significant mutation in 1994. Compared with results from other scholars, the derived environmental loading ratio of Shenzhen presents essentially the same trend with respect to the national change, but the changing frequency is slightly higher than the national change and also ahead of 2-3 years; 3） policy support, the openness of trade, and the high input mode are the major drivers of the change in the Shenzhen’s environmental loading ratio; and 4） having advanced high-technology and low-energy consumption and clean industries is the most remarkable characteristic of Shenzhen. The high environmental loading ratio is an inevitable consequence of social development. Based on the above analysis, it is suggested that the utilization efficiency of resources in Shenzhen should be further improved. Developing production goods of higher emergy transformation rate and promoting energy grading of native products are important approaches for regional sustainable development.