影响杭州城市高温因子的数值模拟研究

Numerical Simulation Study of the Factors Influencing High Temperature over Hangzhou

随着全球气候增暖和城市化进程的加剧,城市高温灾害的影响越来越突出。基于WRF/UCM模式,研究了西湖与城市化进程两个因子对杭州城市高温的影响。设计了三组试验:试验1为采用2010年土地利用数据的控制试验;试验2在试验1的基础上将西湖替换为水田;试验3与试验1相同,但采用2000年的土地利用数据。对比试验1与试验2,发现西湖的存在对杭州白天高温有减缓作用、夜间高温有促进作用,总体而言对杭州城市高温有正贡献;对比试验1与试验3,发现城市化进程所带来的热岛效应加剧了杭州高温,使高温区域面积显著增加;热岛效应对白天高温与夜间高温均有促进作用,但对白天高温的影响更为明显。

With global w arming and the accelerated urbanization-process,the impact of urban high temperatureinduced disaster becomes more and more distinct. By using the WRF / UCM model,the influence of tw o factors of existence of the West Lake and urbanization-process on high temperature over Hangzhou is investigated. Three experiments w ere designed: Experiment 1 is set-up as the control run with the land-use data in 2010 is adopted.In experiment 2,the West Lake is replaced by paddy field and other parameters are the same as that in the first run; In experiment 3,the land-use data in 2000 is adopted and other parameters are the same as that in the first run. While comparing the result of experiment 1 run with that of experiment 2,it can be concluded that the West Lake is able to reduce high temperature in daytime and prompt high temperature at night,respectively. Generally,the West Lake contributes to enhance high temperature over Hangzhou. While comparing the result of experiment 1 with that of experiment 3,it can be found that urban heat island effect( UHIE) induced by the urbanization-process helps to intensify high temperature over Hangzhou and enlarge the high temperature area. UHIE prompts high temperature both in daytime and at nighttime,and exerts more important influence in daytime.