杭州湾地区城市群热岛效应的模拟研究

SIMULATION OF URBAN HEAT ISLAND EFFECT ON HANGZHOU BAY

利用NCEP/NCAR再分析气象资料和卫星遥感资料,应用WRF模式,从热岛效应及其引发的辐合、辐散和降水变化等方面,对杭州湾地区城市群的热岛效应进行了模拟研究。根据近年杭州湾地区的地面遥感图像确定城市下垫面的范围,再结合相应的GIS数据,确定若干年后可能的城市范围;根据模拟数据计算得到月平均气候资料。结果表明,城市群扩张后,在杭州市附近出现了明显的气温高值区。夜间的城市热岛效应要比昼间明显。在杭州市附近出现不同方向的风矢量聚集,杭州市附近风向和风速改变较大。风场在城市扩张区域有较大的差值。城市热岛效应对降水量变化影响不大,但降水量有增大的趋势。

With the use of NCEP/NCAR reanalyzed meteorological data and satellite remote sensing materials, the urban heat island effect on Hangzhou Bay was simulated with WRF model from the aspects of heat island effect as well as the corresponding convergence, divergence and precipitation. Based on the satellite data and GIS data, the range of the underlaying surface on Hangzhou Bay was estimated and the possible range in the future was also determined. The monthly mean climatic data were obtained according to the simulation. The results indicated that there occurred noticeable high temperature area near Hangzhou city after the city agglomeration＇s expansion. The heat island effect was more remarkable at night than that at daytime. Near Hangzhou city, the wind vectors with different directions accumulated while the wind direction and speed changed significantly. The wind field showed great difference in the expansion area. The heat island effect had little influence on the precipitation. However the precipitation was on an ascending trend.