城市化建设对广州夏季降水过程的影响

城市化造成城区下垫面的热力学、动力学特性以及大气成分发生显著变化,从而对降水过程产生显著影响。基于广州市近30年土地遥感数据,分析了该市城市化历史进程,并用城区上风向、城区和城区下风向1984~2015年夏季逐时降水资料,分析了城市化建设对城区及周边降水过程的影响,结果表明:(1)城市化对城区和下风向降水过程产生显著影响,对城区上风向降水过程作用不明显;(2)与城市化前期对比,城市化后期城区和下风向夏季降水总量、降水日数、降水强度和极端降水等指标均发生明显变化,具体表现为城市化后期大雨以上级别降水明显增加,强度增大,极端降水向短历时演化,过程雨量分布更加集中。

Impact of Urbanization on Summer Precipitation Process in Guangzhou

With the process of urbanization, the special ground constructions and changes of atmosphere layers affect the precipitation process in the related urban regions. The urbanization process of Guangzhou is identified with the method of MODIS land cover. Based on hourly summer precipitation data in upwind of the urban, urban and downwind of the urban during 1984- 2015, the possible effects of urbanization on precipitation process were analyzed. The results show that (1) the urbanization made significant impacts on precipitation process of urban and the downwind, but had no obvious effect in upwind; (2) comparing with rainfall in the early period, the precipitation indices, including summer precipitation, precipitation days, precipitation intensity, precipitation duration etc., have obviously changed in the late period, in which urban and its downwind region experienced higher occurrences of short diachronic strong precipitation.