京津冀城市群土地利用变化对地表热环境的影响研究

Study on the impact of land use change on urban land surface thermal environment in Beijing-Tianjin-Hebei urban agglomeration

近年来,城市化进程的不断加快引发了城市下垫面性质的改变和人为热源的增加,导致城市群热环境的不断恶化。为探求城市群土地利用变化对地表热环境的影响,本研究基于MODIS地表温度产品和土地利用数据,分析了京津冀城市群土地利用/覆被和地表热环境的时空变化特征,并通过不同土地利用/覆被类型的热效应贡献度、土地利用与地表温度的相关关系,来定量表征土地利用变化所引起的热环境效应。研究结果表明:(1)2000—2015年京津冀城市群的建设用地大幅增加,城市化进程显著;(2)2000—2015年京津冀城市群的温度西北低东南高;以特高温区为中心,温度向四周递减,温度相近的区域呈集聚状态,随时间变化各温度分区的破碎度均有所降低;(3)土地利用变化对地表热环境有显著影响,建设用地、耕地均与地表温度呈显著正相关,绿地与地表温度呈显著负相关。

In recent years, the acceleration of urbanization has led to the change of the nature of urban underlying surface and the increase of man-made heat sources, leading to the continuous deterioration of urban agglomeration thermal environment. In order to explore the relationship between land use change in urban agglomeration and urban surface thermal environment, based on MODIS surface temperature products and land use data, this paper analyzes the temporal and spatial characteristics of land use/cover and surface thermal environment in the Beijing-Tianjin-Hebei urban agglomeration, and analyzes the thermal contribution of different land use/cover types and the correlation between different land use and surface temperature. The above analysis is used to quantitatively characterize the thermal environmental effects caused by land use changes. The main research results are as follows.(1)The construction land of the Beijing-Tianjin-Hebei urban agglomeration increased significantly from 2000 to 2015, and the urbanization process was of significance.(2)From 2000 to 2015, the temperature of the Beijing-Tianjin-Hebei urban agglomeration was low in the northwest and high in the southeast;with the ultra-high temperature zone as the center, the temperature decreases in all directions, the areas with similar temperatures showed a concentrated state, the temperature changed with time, and the fragmentation of the partitions is reduced.(3)Land use changes have a significant impact on the surface thermal environment. Construction land and cultivated land have a significant positive correlation with surface temperature, and green land has a significant negative correlation with surface temperature.