基于跳跃性诊断的非一致性水文频率分析

Study on Frequency Analysis Method of Non-Stationary Observation based on Jump Analysis

气候变化及人类活动等的影响致使水文系列的一致性遭到破坏,传统频率分析方法对水文系列的一致性要求已很难满足。为此,探索非一致性水文系列的频率分析方法显得尤为重要。基于假定"发生跳跃性变异的实测系列存在着某种理想化的平稳性(一致性)状态,且这种平稳状态所具有的振动中心(即均值)是系列变异点前后两实测样本系列均值的线性组合",通过综合变异点前后两段系列,开展跳跃性变异系列的一致性修正及频率分析计算。应用该方法对黄河上游唐乃亥站1961—2007年的年径流系列进行了研究,结果表明:基于未修正系列和修正系列的水文频率计算结果存在明显差异,10 a一遇设计标准以上设计年径流量的差异幅度在6.7%以上;且随着设计标准的提高,差异表现得更为明显。

Effect of climate chanfe and human activities caused the damafe of the consistency of flood volume series. The conventional frequency analysis method is not valid because of the lost of the flow series consistency. So,it is necessary to develop the modified technique for non-stationary observations. In this paper,based on the assumption that the observation series existed an ideal state and the vibration center（ mean）of the ideal state was a linear combination of two mean values of the two sample series which were respectively the part before and after the Jumpinf point of the observation series. This paper proposed an approach for the modification of non-stationary observations. Annual runoff series（ 1961 -2007 ）in Tanfnaihai Station was analyzed by the proposed method. The frequency analysis results show that the fap of desifn value between non-modifyinf series and modifyinf series are lafer,the difference rate of annual runoff desifn value with more than ten years return period is freater than 6. 7%and with the desifn standard improvement,the difference is more sifnificant.