摘要
城市如同生命体一样,需要持续不断的代谢过程完成其正常运转.城市可持续发展研究的关键是城市物质代谢流量及其代谢效率研究,但物质代谢流量仅能反映代谢速率,而其生态效率则反映了支持社会经济发展的物质代谢能力.采用能值分析方法,引入“生态效率”概念,构建了城市物质代谢生态效率的度量模型,从代谢流量及其效率2个方面核算了北京市资源环境及经济发展的代谢状况.结果表明：1990-2004年,北京市可利用总能值非常丰富,经济发展程度较高;来自本土可更新自然资源相对匮乏,大部分来源于不可更新资源和系统购买的资源与服务;城市废弃物资源化水平有待提高,环境压力较大;生态效率指数呈现出增加的趋势,2004年生态效率指数比1990年提高了3.6倍,表明城市自组织能力、发展潜力以及再生循环能力不断提高.说明提高城市物质代谢生态效率的根本途径是经济效率、资源效率和环境效率的协同发展,以及逐步构建废物资源化的循环链条.
A city, considered as a life system, relies on metabolic processes for its operation. The keys to studying urban sustainable development are material metabolic flux and metabolic efficiency, but urban material metabolic flux can reflect the metabolic rate, and its eco-efficiency can determine the metabolic capacity to support socio-economic development. By introducing the concept of eco-efficiency based on emergy analysis, a model of ecoeffieiency of urban material metabolism is proposed, and the metabolic flux and metabolic efficiency of the Beijing ecosystem are calculated. The results show that, from 1990 to 2004, the total emergy utilized in the whole system was abundant and the level of economic develoment was high, but local renewable resources were comparatively deficient, so economic development depended on input from the outside environment. The renewable resources used are limited, the recycling of waste should be improved and the pressure on the environment is high. The index of eco-efficiency is increasing, and the eco-efficiency of Beijing in 2004 is 3.6 times than that in 1990. It shows improvement in its capacity of self-organization, development potential and regenerative capacity. The keys to improving the eco-efficiency of urban material metabolism are increasing economic efficiency, resource use efficiency and environmental efficiency, and building a recycling chain for resource utilization of waste.
出处
《环境科学学报》
CAS
CSCD
北大核心
2007年第11期1892-1899,共8页
Acta Scientiae Circumstantiae
基金
国家重点基础研究计划项目(973)(No.2005CB724204)
国家自然科学基金项目(No.40701004)~~
关键词
能值
城市
物质代谢
代谢流量
代谢效率
生态效率
cmergy
city
material metabolism
metabolic flux
metabolic efficiency
eco-efficiency
