岳城水库控制流域暴雨洪水的时程分布规律及分期划分研究

Study on temporal distributing characteristics of rainstorm flood and partition of flood season in the drainage basin of Yuecheng Reservoir

从两个方面全面分析了岳城水库控制流域的暴雨洪水时程分布及分期规律:一是根据实测水文资料,通过统计暴雨日数,典型历时年最大降水量、年最大洪峰流量和5日洪量在各旬出现的频率,对流域暴雨洪水时程分布特性进行了多方面的综合分析;二是通过对流域所处地区暴雨形成的天气成因分析,为前述的统计分析结果提供必要的成因基础。还利用旬平均降雨量的相对系数来确定汛期的起止时间。分析结果表明,岳城水库控制流域的暴雨洪水时程分布具有比较明显的变化规律,其中有一个时期暴雨洪水出现的次数多、量级大,主汛期特征显著,汛期可以划分为3个分期,即前汛期、主汛期和后汛期。

In this paper, the temporal distributing characteristics of the rainstorm floods in the drainage basin of Yuecheng Reservoir are discussed in two aspects. On the one hand, the temporal distributing characteristics are identified by counting the number of rainstorm days, the estimated frequencies of the annual maximum typical duration rainfall, the flood peak discharge, and the five-day flood volume in various ten-day according to the observed daily rainfall data and the flood events data. On the other hand, the weather factors of the rainstorm in the drainage basin described in order to validate further the temporal distributing characteristics. The starting and ending time still determined by using the relative coefficients of ten-day average rainfall. The results show that there is a distinct pattern of the temporal distributing characteristics in the drainage basin of Yuecheng Reservoir. The rainstorms occur frequently with more volume during one period, so there is an obvious main flood season. The flood season in the drainage basin of Yuecheng Reservoir may be partitioned three flood seasons, namely, the former flood season, the main flood season, and the latter flood season.