成都市小区景观格局的热环境影响研究

Study on the effects of the landscape pattern on the thermal environment in urban communities in Chengdu city

以2014年8月13日的GF-1遥感影像为主要数据源,获取了成都市典型城市小区的土地覆被数据以及相应的地表温度,从密度、形状、蔓延度和连接度分别提出类别水平的景观指数,分析了类别水平上城市小区景观格局与热环境的定量关系。结果表明,植被的斑块面积以及作为优势类型斑块占小区景观的面积百分比越大、植被斑块形状越复杂、边界连续性越好、分布越集中、连通性越高、破碎度越低时,有利于缓解城市小区热效应;水体斑块的形状越复杂,对小区的降温效果越明显;房屋建筑斑块破碎、形状复杂且分布密集,会使小区温度升高;相反,硬质地表斑块被分割得越小且分布分散,会使小区温度降低。因此,城市小区的设计中,应注意当小区由植被、房屋建筑与硬质地表3种土地覆被类型形成小区景观时,植被与房屋建筑斑块密集度增大,房屋建筑与硬质地表的斑块形状复杂度与房屋建筑斑块分布分散性增大,硬质地表景观百分比增加,小区热效应增强;植被与硬质地表斑块被分割程度增加,小区热环境效应减弱。

Taking the GF-1 remote sensing image of August 13,2014 as the main data source,the land cover data and the corresponding surface temperature of the typical urban district in Chengdu are obtained.The landscape index of the category level is put forward from the density,shape,spread and connectivity,respectively,and the quantitative relationship between the landscape pattern of the urban district and the thermal environment at the category level is analyzed.The results showed that the larger the patch area of vegetation and the percentage of patch in plot landscape,the more complex the shape of vegetation patch,the better the boundary continuity,the higher the concentration of distribution,the higher the connectivity and the lower the degree of fragmentation,which was beneficial to alleviate the thermal effect of urban district.The more complex the shape of water plaque,the more obvious the cooling effect of the community.The building plaque is broken,the shape is complex and the distribution is dense,which will cause the temperature of the community to rise.On the contrary,the smaller the hard surface plaque is divided and the distribution is dispersed,causing the temperature of the cell to decrease.Therefore,in the design of the urban community,it should be noted that when the urban residential quarters is formed by the vegetation,the building and the hard surface,the three types of land covered to form the cell landscape,the density of vegetation and building plaque is increased,the shape complexity of the plaque in the building and the hard surface and the distribution of the building patches are increased,the percentage of the hard surface landscape is increased,the thermal effect of the urban residential quarters is enhanced,the degree of the division of the vegetation and the hard surface patch is increased,and the thermal environmental effect of the urban residential quarters is reduced.