黄河宁夏段干支流洪水组成分析

黄河宁夏段干支流洪水特性差异,洪水来量及遭遇组合复杂,再加上汛期青铜峡水库防洪形势严峻,故需要对青铜峡水库入库洪水来源及洪水组成进行分析。基于Copula函数构建青铜峡水库上游干支流洪水变量的联合分布,并采用最可能地区组成法计算青铜峡水库上游最可能发生的干支流洪水要素组合。结果表明:青铜峡水库断面设计洪水主要来自上游干流,合理的洪水管理应当考虑支流对青铜峡水库断面影响。通过与同频率地区组成法和典型年实测洪水组成对比分析可知,基于Frank Copula函数的最可能组成法能得到更加合理的干支流洪水遭遇组成情况,从而为青铜峡水库断面提供了更加合理的上游洪水组成方案。

Analysis of flood composition at main stream and tributary in Ningxia section of Yellow river

Because of the difference of flood characteristics in Mainstream and its tributaries of Ningxia section of the Yellow River,the flood volume and the complex combinations,and the severe flood control situation of Qingtongxia reservoir during flood season,so it is necessary to analyze the sources and combinations of Qingtongxia reservoir inflow floods.The paper built the joint distribution of flood variation in mainstream and its tributaries based on Copula function, and then calculated the composition of the flood elements which were most likely happen in mainstream and its tributaries by the method of the most likely composition. Results show that the design flood in Qingtongxia reservoir section is mostly from the mainstream in upstream section of the Yellow River.It is necessary to consider the influence of tributary on Qingtongxia reservoir section for reasonable flood management.Through comparing the method of the equivalent frequency composition and the measured flood, the result indicated that the situation of flood composition and flood hydrograph derived by method of the most likely composition is more reasonable. So we can gain the reasonable influence by the mainstream and its tributaries to Qingtongxia reservoir, The method can provide a more reasonable scheme of upstream flood composition for Qingtongxia reservoir section.