黄河小北干流漫滩洪水分析和预报方法探讨

摘要

The paper analyzed the characteristics of channel and overbank flood,such as the bankfull discharge,runoff and sediment and the e-volution rule of Xiaobeiganliu section of the Yellow River.It built the actual relationship of storage capacity to forecast the overbank flood based on the measuring data of the stage and cross-section.When the high sediment overbank flood happened,the runoff volume decreased and stored in the bottomland and the peak hydrograph was attenuating. The paper built the runoff and sediment detention model to forecast the high sedi-ment overbank flood.The results show that the test qualified rate of 21 forecasted overbank floods is 85.7% since 1960,the certainty coefficient is 0.87 and 0.93 and the peak discharge accuracy is 86.5% and 96.3% respectively of"August 1992"and"August 1996"flood forecasting.%在分析黄河小北干流河道特性、漫滩洪水水沙特点和演进规律以及平滩流量随来水来沙和河道冲淤变化情况的基础上,考虑小北干流宽浅河道的特点和漫滩洪水调蓄特征,用实测淤积断面资料和水位站资料建立了河道槽蓄关系,用"蓄率中线法"对漫滩洪水进行演算预报.对高含沙漫滩大洪水在滩地滞蓄淤积,洪量减小、洪峰曲线坦化的情况,建立了滞水滞沙处理模型.结果表明:1960年以来21场漫滩洪水的预报检验合格率为85.7%,对黄河"92·8"洪水和"96·8"洪水预报的确定性系数分别为0.87、0.93,洪峰流量预报精度分别为86.5%、96.3%.