城市化对广州降水的影响分析

An analysis study of the impacts of urbanization on precipitation in Guangzhou

利用1959—2009年逐日降水观测数据,分析了广州51 a来降水的变化规律。发现城郊增城年总降水量变化趋势不明显,但大暴雨降水日数有所增加;广州年降水总量总体呈波动变化,1991年以来有微弱的增加趋势,增率为10.5 mm/a。而从降水等级日数和降水负荷上分析发现,1982年以来,广州年降水日数有下降的趋势,减少率为7.2 d/10a;而1991年以来,广州大雨以上等级降水日数和降水负荷均有明显的上升趋势,其中大雨降水日数增长率为2.8 d/10a,暴雨降水负荷增长率为2.4%/10a;城市化造成了广州大雨、暴雨和大暴雨等年强降水日数增加,相比1960—1979年,分别增加了6%、11%和23%;相对于城市化之前,从1991年开始,城市化过程使得广州降水量增加的趋势明显,城市化对广州城市降水增加的贡献率为44.7%。

Using the observation data from 1959 to 2009,the precipitation variation in Guangzhou was studied.We found that the trends of annual total precipitation in suburban Zengcheng station is not obvious,but number of the heavy rain days has increased;the total annual precipitation in Guangzhou fluctuated and there is a slight upward trend with the increasing rate of 10.5 mm/a since 1991.The total precipitation days tend to decrease with the decreasing rate of 7.2 d/10a since 1982,what＇s more,the heavy rain days and rainfall precipitation levels were significantly rising,the increasing rate of heavy precipitation days is 2.8 d/10a while the growth rate of precipitation load is 2.4%/10a.Urbanization in Guangzhou have caused heavy rain to occur more frequently in Guangzhou.Compared to pre-urbanization,the precipitation in Guangzhou indicated a significant increase since 1991.The contribution rate to the precipitation increase due to urbanization in Guangzhou is 44.7%.