降雨径流相关法在水库洪水预报中的应用研究

Study on the Application of Rainfall-runoff Correlation Method in Reservoir Flood Forecasting

洪水预报在防汛减灾与洪水资源开发中扮演着重要角色,是水库运行管理的基础。尽管洪水预报方法在科学研究上经历了由降雨径流相关、集总式水文模型到分布式水文模型的发展历程,但因降雨径流相关法具有计算简单、易于使用等特点,在水库调度等实际生产中至今仍被广泛应用。以山东半岛龙角山水库为例,对以往所采用的降雨径流单线预报方法进行改进,在充分考虑该流域降雨前期土壤含水特性的基础上,采用人工试错法将降雨径流关系的主要影响因子———前期影响雨量Pa划分为不同的区间,建立了P+Pa-Rs和P-Pa-Rs两套降雨径流关系图。结果表明,相比于降雨径流单线预报方法,两套降雨径流关系图的合格率分别提高了6%和7%,预报精度由乙等提高至甲等级别,增强了降雨径流相关法在龙角山水库的实用性,为水库调度决策提供了重要的科学依据。

Flood forecasting plays an important role in flood prevention and reduction and flood resources development,which is the basis of reservoir operation and management.The flood forecasting method has witnessed the development process from rainfall-runoff correlation and lumped hydrological model to distributed hydrological model in scientific research.Because the rainfall-runoff correlation method has the characteristics of simple calculation and easy to use,it is still widely applied in actual production such as reservoir scheduling.In this paper,taking the Longjiaoshan reservoir in Shandong Peninsula as an example,the single-line forecast method of rainfall and runoff used in the past was improved.On the basis of fully considering the soil water characteristics in the early period of the rainfall in the basin,the manual trial and error method was used to divide the main influencing factor of the rainfall-runoff relationship(the early impact rainfall Pa)into different intervals,and two sets of rainfall-runoff relationship charts of P+Pa-Rs and P-Pa-Rs were established.The results show that compared with the previous single-line rainfall-runoff curve,the qualified rate of the two new charts has been increased by 6%and 7%respectively.The prediction accuracy is improved from grade B to grade A,which enhances the practicability of rainfall-runoff correlation method in Longjaoshan reservoir and provides an important scientific basis for reservoir operation decision.