城市热岛对热舒适度的景观格局影响演化分析

为明确城市热岛对热舒适度的空间格局过程的影响规律,给城市空间的合理规划布局提供理论支持,以1992—2011年天津市主城区为例,采用同季同时相的TM遥感数据和地面实测数据,基于人体舒适度和高温生理反应构建地表热岛对热舒适度的影响等级划分标准,划分成5个强度不同的影响区,进而利用景观格局指数评价方法进行分析．研究结果表明:热岛对热舒适度的影响区面积和强度都不断增大;二级影响区斑块破碎化,最大斑块面积减小,但其总面积却在升高,热岛影响无实质改善;引起人体不适应的三、四级影响区,斑块的数量与密度不断增大,总面积和最大斑块面积也迅速增加;热岛景观斑块的破碎化、斑块类型的混合、强热岛区的斑块连通度降低,都会改善热岛对热舒适度的影响;高层小区建设虽然节约用地,却增加了热舒适度的恶化总面积,并使局部热舒适度受影响等级异常增高．

An analysis of landscape evolution for the thermal comfort degree affected by urban heat island effect

To clear the influence rule that the spatial pattern process of thermal comfort degree affected by urban heat island, and to provide theoretical support to the reasonable layout of city space, this paper constructed the criteria for the classification of thermal comfort degree affected by surface heat island effect, adopted the same phase of TM remote sensing data and ground measured data at the same time based on human comfort and human physiological reaction for the environment temperature. Utilizing the landscape pattern index evaluation method, this paper analyzed the urban heat island effect in downtown Tianjin from 1992 to 2011. The results show that, first, the space area is expanding of the thermal comfort degree affected, and the impact intensity is rising; second, for the secondary thermal comfort degree affected regions, the largest patch area is decreasing, but the total area is increasing; third, for the third and fourth thermal comfort degree affected regions which cause people feel discomfortable, patch classes area, the largest patch area, patch density are rising, indicating the heat island effect on the thermal comfort in the continuing deterioration; fourth, the fragmentation of heat island landscape patch, the mixture of patch types, the reduction of connectivity among strong heat island areas can weaken the impact of the urban heat island effect on thermal comfort; fifth, although saving land, high-rise residential building will increase the total area of deteriorating thermal comfort and make the local thermal comfort affected by super grade.