城市病诊断与城市生态系统健康评价

Syndromic city illnesses diagnosis and urban ecosystem health assessment

在总结国内外城市病现象和病因的基础上,提出了城市生态系统健康的五大功能,即承载力、支持力、吸引力、延续力和发展力,概括为CSAED模型,分析了与此相对应的限制城市功能的瓶颈因子,将城市病的各项病征与城市功能相联系,并以此为基本框架,构建了城市病诊断和城市生态系统健康的评价体系。基于城市生态系统的发展目标,将梯度型隶属度函数、改进均方差法、加权欧氏距离算法等进行综合集成,建立了一套便于推广比较的城市生态系统健康评价模型算法。以北京市为案例,进行了城市病的单因子诊断和城市生态系统健康评价,计算了北京市1999-2005年的城市生态系统健康指数,并分析了北京市发生城市病的原因、城市病所处的阶段等。研究对于我国城市病诊断与解决,以及城市生态系统健康评价具有重要参考意义。

Based on the summary of city illnesses in both here and illnesses are analyzed. As a matter of fact, urban ecosystem is a natural ecosystems. From this view, the methodology for urban abroad, multi phenomena and causative factors of city kind of special system which is different from general ecosystem health assessment should not be directly transferred from that of the natural ecosystems. In other words, more attentions should be addressed on this specified ecosystem for its structures and functions, such as its supporting function for economical growth, and its bearing capacity for human living. Due to the discussions above, this study brings forward an integrated and muhilayer system for urban ecosystem health assessment, which is called CSAED model. This system is composed of five subsystems which could represent the primary and leading functions of a general city. An 〈 sc）, forward. integratedsystem of CSAED model including five subsystems： Carrying capacity （CC）, Supporting capability Attractive capability （AC） , Evolutional Each of the five subsystems is consisted capability （ EC ） , along with Developing capability of six to eleven indicators. Altogether there are 40 （DC） is brought indicators. All the subsystems and the indicator groups are combined together to build up an integrated system. Through the comprehensive indicator framework, the connection between city illnesses and restrictive factors could be detected. After the relationship analysis framework, a comprehensive system for Urban Ecosystem Health Assessment （UEHA） was build, with a propagable UEHA model. The UEHA model was an integrated model system composed of several mathematic methods, including ： （ 1 ） trapezoid shapes of subject functions, （2） modified mean square method, （3） weighted Euclidean distance arithmetic method, （4） weighted consecutive addition method, and （5） weighted consecutive multiplicative method, etc. This UEHA model has some good qualities that it is capable for comparison among both temporal and spatial objectives. Furthermore, the model is easy to actualize on computer and it could treat data groups for multi-year and multi subsystems simultaneously. Based on the above theory and model, a case study of Beijing City was utilized in this paper. Not only the single factor diagnosis was applied, but also a series of temporal index for UEHA was calculated for year 1999 --2005 using the integrated UEHA model. Then the nosogenesis of city illnesses and disease course of Beijing City were discussed. The result shows that there are six aspects of constraint factors for Beijing＇s city illnesses, including： （1） atmospheric pollution; （2） water pollution and water resource shortage ; （3） natural resource shortage ; （4） infrastructure imperfection ; （5） Economy needs more development; （6） more strategies should be addressed on industrial pollution control. The urban ecosystem health assessment for Beijing City demonstrates the whole theory and model of this study are feasible and viable. This study is referable for many other Chinese cities with illnesses like Beijing, and the whole urban ecosystem health assessment model was also propagable to other cities.