| 冯平,黄凯.水文序列非一致性对其参数估计不确定性影响研究[J].水利学报,2015,46(10):1145-1154 |
| 水文序列非一致性对其参数估计不确定性影响研究 |
| A study about the impacts of non-stationary characteristic on the uncertainties of parameters estimation in hydrological series |
| 投稿时间：2015-01-10 |
| DOI：10.13243/j.cnki.slxb.20150044 |
| 中文关键词: 非一致性 变异点 一致性修正 Gibbs-MCMC算法 参数不确定性 |
| 英文关键词: inconsistency change point consistency correction Gibbs-MCMC simulation method parame-ter uncertainty |
| 基金项目:国家自然科学基金项目(51179117,51209157) |
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| 摘要点击次数: 3482 |
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| 中文摘要: |
| 随着气候变化、人类活动影响的加剧,水文序列一致性条件遭到破坏,本文选择下垫面变化剧烈的西大洋水库控制流域为研究区域,采用水文变异诊断系统,分析其年最大洪峰流量序列的变化趋势及变异点,确定序列变异形式,并对非一致性洪峰流量序列进行还原修正;根据贝叶斯理论将先验信息和样本信息有机结合,采用Gibbs-MCMC 算法对修正前后的P-Ⅲ型频率分布曲线参数不确定性进行估计,给出了参数95 %置信区间。将估计后的参数与适线法耦合进行水文频率分析计算,得到修正前后设计频率洪峰流量预估区间。选取覆盖率、平均带宽、平均偏移度等3 个指标对修正前后预报区间优良性进行评价,其中覆盖率修正后比修正前提高17.10 %,平均带宽修正后比修正前减少15.77 %,平均偏移程度修正后比修正前减少3.27 %,可见,对于人类活动影响较大的非一致性水文序列进行一致性修正可使得预报不确定性区间的可靠性得到提高。 |
| 英文摘要: |
| The inconsistency of hydrological sequence was destroyed by climate change and human activi-ties. Xidayang Reservoir with significant change of the land surface condition in the control watershed was chosen as the study area. The change trend, change point and type of the variation of the annual maxi-mum peak flow series of the reservoir were detected using the hydrological variation diagnosis system. The peak flow series and designed peak flows of different frequencies corresponding to the past land surface con-ditions were calculated by the frequency analysis method for inconsistent hydrological series. The uncertain-ties of parameters of Type Pearson-Ⅲ distribution (P-Ⅲ distribution) were estimated by Markov Chain Monte Carlo (MCMC) simulation method, and 95% confidence intervals of parameters were determined. The hydrological frequency analysis was calculated based on the coupling of estimated parameter and curve fitting, then the estimates ranges of flood peak flow of design frequency after and before were determined. The indexes coverage rate, average bandwidth and average bias degree were chose to evaluate the optimal benign of estimates ranges. The results show that the revised coverage rate has increased by 17.10%, and the revised average bandwidth and average bias degree reduced by 15.77% and 3.27% separately. Thus, the reliability of predicted uncertain ranges was improved by consistency correction of inconsistency of hydro-logical sequences influenced by human activities. |
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