地表利用城市化在一次极端高温过程数值模拟中的影响

THE IMPACT OF URBANIZATION-INDUCED LAND USE/LAND COVER CHANGES ON NUMERICAL SIMULATION OF AN EXTREME HEAT EVENT IN FUZHOU CITY

关键词:  城市热岛效应  地表利用/地表覆盖  MODIS  WRF  海陆风

Key words:  urban heat island  land use/land cover  MODIS  WRF  land-sea breeze circulation

摘要:

地表种类的城市化对城市区域的热力结构和局地环流都会产生巨大的影响。利用地面、高空观测资料和MODIS地表覆盖资料，使用耦合城市冠层模式(UCM)的区域中尺度数值模式(WRF)，对2013年8月8日福州地区的一次极端高温天气过程进行数值模拟，研究地表利用变化对福州城市热岛效应及其对福州城市区域局地环流的影响。结果表明：地表利用的城市化使得午后城市热岛现象更加明显而夜间热岛效应呈现出减小的趋势；地表利用城市化后，中心城区的近地面风速减小，但城区与山区以及城区与海洋之间的局地热力环流明显加强，促进了山谷风和海陆风环流的发展；同时地表加热效应增强，促进了垂直运动的发展。

Abstract:

Urbanization-induced land use/land cover (LULC) changes have a great influence on the thermal structure and local circulation in urban areas. In this paper, observation data, the MODIS data and the simulated results of the WRF model coupled with the urban canopy model (UCM) are used to investigate the impacts of LULC changes in Fuzhou urban area and discuss the urban heat island effect and the local urban circulation closely related to urbanization-induced LULC changes during an extreme heat event on August 8, 2013 in Fuzhou city. The results show that urbanization-induced LULC changes make the urban heat island effect more obvious in the afternoon, while the nocturnal heat island effect tends to decrease. The near-surface wind gradually reduces after urbanization-induced LULC changes in Fuzhou city. On the contrary, the local thermal circulation between urban area and mountainous area and between urban area and ocean is strengthened obviously, facilitating the development of valley wind, sea wind and land wind circulation. Meanwhile, the surface heating effect of urban area is enhanced, promoting the development of vertical movement.