北京城市绿地的蒸腾降温功能及其经济价值评估

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 北京城市绿地的蒸腾降温功能及其经济价值评估 DOI: 10.5846/stxb201203150345 作者: 作者单位: 中国科学院 地理科学与资源研究所,环保部 南京环境科学研究所,中国科学院 地理科学与资源研究所,中日友好环境保护中心 作者简介: 通讯作者: 中图分类号: 基金项目: 环保公益性行业科研专项(201209027);中国科学院地理科学与资源研究所"一三五"战略科技计划项目(2012ZD007) Preliminary evaluation of air temperature reduction of urban green spaces in Beijing Author: Affiliation: Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Science,Nanjing Institute of Environmental Sciences of the State Environmental Protection Administration of China,Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Science,Sino-Japan Friendship Center for Environmental Protection Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:尽管已有大量研究证实,城市绿地具有明显降温作用,但是从生态经济学角度定量评估城市绿地降温功能及其价值的研究不多。以夏季高温热害显著的北京建成区为研究区,在前人多项绿地降温功能实测结果基础上,利用第七次园林绿地资源调查数据,定量评估了城市绿地夏季蒸腾降温的功能及其价值。结果表明:北京建成区6.1万hm2 绿地每年夏季蒸腾吸热可达4.61×1015 J,平均每公顷绿地每天吸热8.4×108 J,相当于10台1000瓦空调的降温作用。参照居民用电价格,建成区绿地夏季降温价值为6.4亿元,单位绿地降温价值约1.05元/m2。此外,不同绿地类型和区县绿地的降温功能差异较大,主要受绿地面积和组成结构的影响。 Abstract:Climate change is the most serious problem we face in the 21st century. Accompanied by the rapid expansion of cities worldwide, the phenomenon of urban heat islands has become a critical environmental issue in many large cities, since it is associated with a warmer climate. An exposure to higher temperatures can result in a spectrum of outcomes in the realms of human health and well-being. These outcomes range from mild discomfort to life-threatening medical conditions. Fortunately, trees and vegetation in the urban environment help to cool urban climates. This occurs through shading and evapotranspiration. Although there have been numerous studies on microclimate-adjusting effects of urban green spaces, few of these studies quantify the economic value of air temperature reduction provided by these spaces. This is especially true for cities suffering from the heat island effect. Urban heat island conditions have been observed for more than half a century in the city of Beijing. The area affected by this heat island rapidly expanded from 111 km2 in 1987 to 292 km2 in 2009, and the percentage of heat island to built-up area increased sharply from 11% to 27%. Therefore, it is very important for city managers to estimate and achieve economic benefits of the cooling effect of green spaces. Based on a number of empirical studies and inventory data concerning urban green spaces in Beijing (2009), this study estimates the economic effects of the city's green space on air temperature reduction through evapotranspiration. The results show that green areas in Beijing could reduce the temperature by 0.8-4.8℃. As a consequence, urban green spaces totaling 6.1×104 hm2 in built-up areas of the city could absorb 4.61×1015 J of heat via evapotranspiration during summer. The average heat absorbed by these spaces could reach 8.4×108 J·hm-2·d-1, which corresponds to the cooling effect of ten 1000-W air conditioners. According to the price for residential electricity, the summer temperature reduction from the urban green spaces could save 641 million RMB of the cost of electric energy consumption per year. This figure is based on annual average savings reaching 1.05 RMB/m2 for urban green area with temperature reduction. In addition, the temperature reduction effects of urban green spaces varied with type and location. The amount of heat absorption of protected green zones was significantly less than those of public, roadside, affiliated, and productive green spaces. Average values of air temperature reduction per unit area of green space in Dongcheng District, Xicheng District, Miyun County, and Yanqing County were significantly higher than those of the districts of Pinggu, Fengtai and Shijingshan. These cooling effect variations may be related to differences in area and structure of urban green spaces. Therefore, evidence is provided to support the commitment of resources to urban green infrastructure enhancements. Furthermore, such evidence conveys the importance of the structural characteristics of green land. Urban foresters, ecologists, and landscape planners should take advantage of this type of data to plan, design and manage green spaces in heat island areas. In this way, communities can realize energy savings, and cities and urban neighborhoods can be made more livable. 参考文献 相似文献 引证文献