城市环境影响模拟的系统动力学研究

城市化进程的加快已导致严重的环境问题。对城市环境影响的模拟研究是确定合理的城市发展规模和制定科学的发展规划的重要依据,以采取措施从源头控制环境质量的恶化。城市环境属于复合多动态系统,传统的一些方法可以实现城市环境影响的模拟预测,但参数调控方面的功能较不完善。文章将基于信息反馈控制理论的系统动力学引入城市环境影响模拟中,构建城市环境、社会、经济之间的系统动力学模型,通过调整环保投入、科技投入、经济增长速率以及单位能耗等系统变量,对武汉市未来发展的主要污染物（SO2、COD）排放量和主要资源消耗量（能源、水）等进行了四种情景动态模拟。结果表明：（1）系统动力学适合于研究复杂系统行为,具有较强的模拟和调控能力,同时可以避免繁琐的计算和信息成本高等缺点;（2）＂两型＂发展模式（Ⅳ）下的资源消耗量和污染物排放量明显低于其它3种情景,但仍处于较高的水平。武汉市污染物削减、生态环境保护任务依然繁重,开发新的替代能源、提高资源利用率仍是今后工作的重点。

Simulation of environmental impact on city by system dynamics

The accelerating urbanization process has caused serious environmental problems.The simulation of the environmental impact on a city can provide an important basis for determining the reasonable development scale of a city and for designing development plans by taking measure to impress environmental deterioration from the source.The urban environment is a compound dynamic system,traditional methods may simulate and predict the environmental impact,but the function of parameter regulating is imperfect.This article details the introduction of System Dynamics（SD）,which is based on the information feedback control theory,into the simulation of environmental impact and constructs an SD model between environment,society and economics.Through changes in environmental protection investment,science and technology input,economic growth speed as well as unit energy consumption and other system variables,four scenarios are dynamically simulated focusing on the main pollutant＇s（SO2,COD） emission quantity and resources consumption quantity of Wuhan in future development.Results showed that：（1） SD has a strong simulation and regulative ability,is well suited for researching complicated system behavior,and can avoid tedious computation and higher information cost shortcomings;（2） the pollutant＇s emission quantity and resources consumption under the ＂Two-Oriented＂ developmental mode（Ⅳ） are lower than the three other modes,but still reached a higher than acceptable level.Therefore,the task of reducing the pollutants and protecting the environment is still serious,and developing new alternative energies while improving the utilization ratio of resources are still the working focus in the future.