城市地表热环境与景观格局的定量关系研究——以杭州市为例

The Relationship between Urban Surface Thermal Environment and Landscape Pattern:A Case Study of Hangzhou

城市规模的不断扩大和区域气候变暖的双重影响使得城市热岛问题愈加突出.本研究以长三角城市群南翼中心城市杭州市为研究区,利用SPOT 6数据完成土地利用类型信息提取,同时基于Landsat 8 TIRS数据反演地表温度,在此基础上以1 km×1 km为固定窗口完成类型水平上景观格局指数测算,进而探讨了土地利用景观格局与城市地表温度之间的相关性.结果表明:(1)在各类景观中,地类均温呈现“工矿仓储用地>教育用地>商服用地>在建设用地>道路>公共设施用地>住宅用地>裸地>城市绿地>耕地>林地>库塘>河渠”的规律趋势;(2)在所选取的景观格局指数中,12个指数(CA、PLAND、LPI、TE、ED、AREA_MN、GYRATE_MN、SHAPE_MN、FRAC_MN、COHESION、DIVISION和MESH)与4个时相(3月、7月、10月和12月)的地表均温具有显著相关性,其中与7月和10月的温度相关性最强;(3)林地、河渠、工矿仓储用地、道路和住宅用地等几种地类的景观格局指数与4个季节地表均温具有显著的正、负相关性,其中林地、河渠和工矿仓储用地的景观格局对地表均温的影响作用最为明显.研究结果表明,可通过提高绿色空间景观斑块的聚集度与连通性,以期达到缓解城市热岛效应、提升城市环境质量的目标.

The double effects of the continuous expansion of cities and the regional warming trend unavoidably exacerbate the urban heat island(UHI)effect.Taking Hangzhou City as the study area,this paper extracts the land use classification information by using SPOT images,retrieves the land surface temperature with Landsat 8 TIRS data,calculates the landscape pattern index in a fixed window with 1 km×1 km in size,and discusses the correlation between land use landscape and urban surface temperature.The results show that the average temperature of land use shows the regular trend of industrial land>educational land>commercial land>land under construction>road>public facilities>residential land>bare land>urban green space>cultivated land>forest>lake and pond>river.Among the selected landscape pattern indexes,12 indexes(CA,PLAND,LPI,TE,ED,AREA_MN,GYRATE_MN,SHAPE_MN,FRAC_MN,COHESION,DIVISION and MESH)have significant correlation with LST of four phases(March,July,October and December),and all have the strongest correlation with July and October temperature.The landscape pattern indexes of forest,river,industrial and mining storage land,road,and residential land have significant positive and negative correlations with the surface average temperature in the four seasons.Particularly,the landscape pattern of forest,river and industrial land have the most obvious effects on the surface average temperature.In conclusion,by improving the aggregation and connectivity of the green space landscape,the urban heat island effect can be alleviated,and the improvement of urban environmental quality can be achieved.