快速城市化地区景观格局对地表热环境的影响研究

Effects of Landscape Pattern on Surface Thermal Environment in Rapidly Urbanized Areas

以杭州城区为例,基于Landsat8数据完成土地利用分类和地表温度反演,并利用Fragstats软件完成景观格局分析,实现了城市地表温度与绿地景观格局的关联分析.结果表明:1)典型地物的地温均值呈现“林地<草地<水体<裸土<建设用地”的趋势.2)建成区绿地破碎度最大、面积最小;林区较为规整,绿地破碎度最小、面积最大.二者景观多样性均偏低.3)绿地景观格局对地表温度影响作用不一.其中,绿地破碎度与分维数普遍与地表温度呈现显著正相关关系;而绿地面积与地表温度均呈现显著负相关关系.由此可见,通过降低城市区域绿地景观的破碎程度,提升其连通完整性,适当降低绿地景观边界的复杂程度和增大绿地面积,可有效缓解城市热岛效应.

Taking Hangzhou urban area as an example,this study made land use classification and surface temperature inversion based on Landsat8 data,completed landscape pattern analysis by Fragstats software,and realized the correlation analysis between urban surface temperature and green space landscape pattern.The results indicated that the mean ground temperature of typical surface features showed the trend of“woodland<grassland<water body<bare soil<construction land”.The green space in the built-up area had the highest degree of fragmentation and the smallest area,while in the forest area was the opposite,and the landscape diversities in both land use types were low.The effects of different landscape patterns on the land surface temperature were varied,i.e.,the degree of green space fragmentation and the fractal dimension generally had a significant positive correlation with the land surface temperature,while the green area and land surface temperature exhibited a significant negative correlation.This showed that urban heat island effect could be effectively alleviated by reducing the fragmentation of the urban green spaces,improving its connectivity and integrity,and properly reducing the complexity of the green patch boundary and increasing the green space areas.