乌鲁木齐市建设生态城市现状的比较分析及发展对策研究

乌鲁木齐是绿洲城市,自然环境比较脆弱,由于城市建设缺乏生态环境规划,能源消费结构不合理以及特殊的自然地理等原因,致使城市的生态环境问题十分突出,建设生态城市是乌鲁木齐市未来发展的必然选择。从城市生态系统的结构、功能和协调度三个方面构建了生态城市的评价指标体系,采用层次分析法对乌鲁木齐市生态城市建设现状进行了定量分析,同时选择北京、上海、成都、西安、兰州等5个城市的生态化程度进行对比,结果表明:乌鲁木齐市的结构指数为0.241,低于对比的5个城市;功能指数乌鲁木齐为0.271,远低于上海(0.615)、北京(0.466)和兰州(0.343),与西安(0.272)接近,略高于成都(0.222);从城市协调度来看,乌鲁木齐市的指数值为0.306,为6个城市的最小值,生态综合指数由高到低分别为北京(0.580)>上海(0.579)>成都(0.382)>西安(0.380)>兰州(0.360)>乌鲁木齐(0.270),乌鲁木齐市生态化程度为第Ⅳ级,即生态化程度较低,为6个城市中的最低值。总体上为较发达地区城市的生态化程度较高,中西部地区城市的生态化程度较低。乌鲁木齐市建设生态城市应采取的关键对策包括以下几个方面:1、编制城市综合生态区划,做好城市生态规划;2、优化能源结构,大力发展清洁能源;3、建立排污权交易制度,控制大气污染;4、采用边际成本定价方法、制定科学的水价、优化配置水资源;5、合理布局城市景观生态,搞好城市绿化及荒山绿化。

Current status of building an ecocity in Urumqi and its development countermeasures

Urumqi is an oasis city with a relatively fragile natural environment.Due to lack of ecological environment planning during urban construction,unreasonable energy resources consumption and special natural and geographic reasons,the ecological problems of the city become more and more acute,so it is an inevitable choice to build Urumqi to an eco-city in future.From the prospective of urban ecosystem structure,function and coordination,this paper sets up an evaluation index system of eco-city with analytical hierarchy process(AHP) method,conducts a quantitative analysis towards current status of building Urumqi to an eco-city.It chooses Beijing,Shanghai,Chengdu,Xi'an,Lanzhou and compares their ecological degrees,and the results shows that structure index of Urumqi is 0.241,lower than the other 5 cities;function index is 0.271,much lower than that of Shanghai(0.615),Beijing(0.466),Lanzhou(0.343),close to that of Xi'an(0.272),slightly higher than that of Chengdu(0.222).From the prospective of coordination degree,the index of Urumqi is 0.306,remaining the minimum value.The Ecological Comprehensive Index(ECI) of 6 cities are sorted out in sequence from the high to the low: Beijing(0.580) > Shanghai(0.579) > Chengdu(0.382) > Xi'an(0.380) > Lanzhou(0.360) > Urumqi(0.270),the ecological degree of Urumqi is level IV,which is a relatively low degree,remaining a minimum value of that of 6 cities.A conclusion can be reached that the ecological degree of cities in developed areas appear higher,that of western areas appear lower.Building Urumqi to an eco-city should be commenced from following countermeasures:(1) Compiling comprehensive ecological divisions and ameliorating the urban ecological planning;(2) Optimizing the energy resources consumption and accelerating clean energy development.The air pollution in Urumqi is very serious,and the city should carry out cleaning production comprehensively to reach grade-two of the national standard in 2008 atmospheric environment evaluation with clean coal replacing raw coal,increasing concentrated heat input,popularizing building heat preservation and energy reservation,enlarging the proportion of natural gas in energy consumption.Urumqi is abundant with solar energy and wind energy,but at present the electricity they provided is less than 1 % in energy consumption,more efforts should be made to realize the 5 % of wind power and electric energy in energy consumption.(3) Setting up emissions-trading system to control atmospheric pollution.Referring to coal-smoke pollution of Urumqi,the economic measure of emissions-trading system is an effective way to reach level 2 of air environment quality in national atmospheric environment evaluation in 2008.(4) Setting reasonable water price and optimizing the allocation of water resources based on marginal cost method.Marginal cost is equivalent to the sum of marginal directive cost(MDC),marginal user cost(MUC) and marginal external cost(MEC).The resources tend to be abused if its price is lower than marginal cost;normal consumption will be restrained if the price is higher than marginal cost.Urumqi,on one aspect,is short of water resources,but on another,has a huge waste of water,the radical reason behind this phenomena is the low price of water.A scientific water price has to be set to ensure the sustainable using of limited water resources.(5) Rationally fabricating urban ecologic landscapes,afforesting the urban city and barren hills.Highly adaptable indigenous species of trees should be selected for forestation in order to strengthen the ecosystem service value and build up the local tourism features of Urumqi.