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4.61×1015J,平均每公顷绿地每天吸热8.4×108J,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。
Climate change is the most serious problem we face in the 21 st 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 g
出处
《生态学报》
CAS
CSCD
北大核心
2012年第24期7698-7705,共8页
Acta Ecologica Sinica
基金
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)
关键词
城市绿地
蒸腾降温
价值评估
北京市
urban green space
air temperature reduction
valuation
Beijing City
