森林城市景观格局与热环境的关系——以龙泉市为例

景观格局分异特征在相当程度上影响着城市热环境.本研究以国家森林城市龙泉市为对象,通过地温反演和空间分析反映9类景观温度特征,运用景观格局分析方法从1～3.5 km 6个尺度探索格局指数与热环境的相关性.结果表明: 龙泉市高温区及次高温区主要分布于东北至西南一带,以城乡居民地为主,低温区和次低温区主要分布于西北、东南区域,以公益林为主;对海拔700 m以下区域各景观类型地表温度的统计发现,针叶林地、阔叶林地、针阔混交林地、竹林地、水域的地温均值相对较低,灌木林地、其他林地、耕地、建设用地的地温均值相对较高;对景观格局与热环境的分析发现,类型水平格局指数较景观水平格局指数更具实际意义,建设用地与热环境的相关系数可达0.835,针叶林地、阔叶林地、针阔混交林地、水域次之,在-0.5～-0.4,不同林地类型的降温效果在空间尺度上的表达不同,阔叶林地、针阔混交林地更利于在大尺度上降温;林地的面积和蓄积量越大,越易出现地表温度低值.

Relationship between forest city landscape pattern and thermal environment: A case study of Longquan City,China.

The differentiation characteristics of landscape pattern affect the urban thermal environment. In this study, temperature characteristics of nine types of landscape in a national forest city, Longquan City, were analyzed by temperature inversion method and spatial analysis. The landscape pattern analysis method was used to explore the correlation of landscape metrics and the thermal environment from 1 km to 3.5 km. The results showed that the high and sub-high temperature zones of Longquan City were distributed in northeast-southwest, mainly composed of urban and rural residential areas. The low and sub-low temperature zone were mainly distributed in the northwest and southeast areas, mainly composed of public welfare forests. By calculating the mean land surface temperature of each landscape type in the area below 700 m above sea level, the temperature of coniferous forest, broadleaf forest, conifer-broadleaf forest, bamboo forest and water was relatively low, whereas that of shrub land, other forest land, cultivated land and construction land was relatively high. Through the analysis of landscape pattern and thermal environment, it was found that the class pattern index was more practical than the landscape pattern index. The correlation between thermal environment effect and construction land distribution reached 0.835, coniferous forest land, broadleaf forest land, coniferous-broadleaf forest land and water were the second, up to -0.5 to -0.4. The cooling effects of different forest types vaied across different spatial scales. Broadleaved forests and coniferous-broadleaved forests were more conducive to cooling at large scales. The larger the area and volume stock of forest land, the more likely it had the lowest land surface temperature.