成都市城市森林格局与热岛效应的关系

Analysis on relations between the pattern of urban forests and heat island effect in Chengdu

城市森林对城市热岛效应有显著的缓解作用,其景观格局对热岛的分布有巨大的影响。以成都市为研究对象,采用该地区2003年的spot、landsat-7卫星影像资料,在对成都市进行城市森林景观格局的定量分析和热量反演算的基础上,结合土地利用分类图、气象观测资料、绿地统计资料,建立动态监测和空间分析模式,对城市热岛的热力分布特征和城市森林格局对热岛效应的缓解作用进行综合分析。研究结果表明:(1)成都市热量分布呈现东南多西北少的格局,这与成都市城市森林西北多东南少的格局成负相关;(2)城市绿化覆盖率越高,降温效应越明显;(3)在绿化覆盖率相当的情况下,大面积集中的绿地的降温效应明显高于面积小的绿地。基于研究结果,建议成都市在合理规划城市森林布局的同时,适当增加大面积城市森林公园的建设。

To understand the role of urban forests in the heat island, the heat island effect and its relationships with the pattern of urban forests in Chendu, Sichuan Province, has been analysed in this paper. The pattern of urban forests in Chendu was derived from spot and landsat-7 images using GIS. The dynamic model was established based on land use/cover types, meteological data and statistic data of green cover, which has been used for the comprehensive analysis on the relationships between heat island effect and urban forest pattern. The result shows that the heat distribute more in the northwest of Chengdu than in the southeast, which is on the contrary of the urban forest pattern. The higher the urban green coverage, the more apparent the cooling effect. Under a certain green coverage, a large area of greenbelt has a higher heat reduction than the smaller one. This suggests that at the same time of reasonable planning of the urban forest pattern, it is necessary to appropriatly increase the size of urban forest park.