南京地区暴雨变化特性分析

选取南京地区7个雨量站长系列逐时降水资料,分析暴雨时空分布规律与变化特性,并解析暴雨雨型特征。结果表明:南京地区暴雨时空分布不均性显著,市区年暴雨量和暴雨次数多于郊区;不同历时年最大降雨量总体呈现增大趋势,且主城区增加趋势更显著;暴雨以一般暴雨、弱暴雨为主,但容易引起内涝的短历时、高强度的暴雨频次呈现增加趋势,且主城区相对郊区增加趋势更显著;主城区弱暴雨、中暴雨和强暴雨分别具有14年、8年和3年的丰枯变化周期,特短暴雨、短暴雨和一般暴雨也都具有3年左右的丰枯变化周期;雨型(历时12 h暴雨)以容易引起内涝的单峰Ⅲ型雨型为主,加大了城市内涝防治压力。

Analysis of rainstorm variation characteristics in Nanjing region

The temporal and spatial distribution and variation characteristics and the rainstorm type of rainstorm were analyzed using long series hourly precipitation data of 7 precipitation stations in Nanjing region. The results show that the temporal and spatial distribution of rainstorm in Nanjing region is uneven, and the annual rainstorm amount and the number of rainstorm in urban area are more than that in suburban area. The annual maximum rainfall in different durations shows an increasing trend, and the increasing trend in the main urban area is more significant. The rainstorm mainly consists of general rainstorm and weak rainstorm, but the frequency of short duration and high intensity rainstorm which is easy to cause waterlogging shows an increasing trend, and the increasing trend of main urban area is more significant than that of suburban area. In the main urban area, weak rainstorm, medium rainstorm and heavy rainstorm have 14-, 8- and 3-year plentiful and withered circulation period, respectively. The extremely short rainstorm, short rainstorm and general rainstorm also have 3-year plentiful and withered circulation period. The rainstorm type(lasting for 12 hours)is the single peak type III rain, which is easy to cause waterlogging and increases the pressure of urban waterlogging control.