摘要
研究黎河、沙河、淋河年降水系列的丰枯变化规律及其补偿特性,是深入研究于桥水库流域水文动力系统演变特征的重要内容。本文首先运用马尔可夫分析法研究了黎河、沙河、淋河流域年降水系列的丰枯变化特性,然后运用游程分析法研究了这3个区域年降水的丰枯持续特性,最后利用Copula函数建立了3个区域年降水的联合分布模型,并计算了它们之间具有丰枯补偿作用的概率。结果表明,黎河、沙河、淋河流域年降水的丰、枯两种状态均有较强的自保守性,3个区域降水的丰枯持续性总体上表现为丰水和枯水的持续性较强,平水较弱,3个年降水系列具有丰枯补偿作用的概率为29.8%,其中有良好补偿作用的概率仅为0.9%,说明于桥水库上游3个子流域之间的丰枯补偿能力较小。
Yuqiao Reservoir is the biggest reservoir in Tannin City and also a regulating reservoir of the Luanhe River to Tannin Water Transfer Engineering,playing an important role in the water supply system of Tianjin City.During the last three decades,because of global climate change and variations in the Yuqiao Reservoir basin’s underlying surface,the annual runoff in the basin decreased significantly.In the meanwhile,rapid development of economy of the region has resulted in a higher requirement and demand for water resources over the area.Thus,studying on the mechanisms of wetness-dryness change and compensation characteristics of annual precipitation in the basin can be of significance to regional water resources planning,scheduling and optimal allocation.A 47-years rainfall time series of three sub-basins,i.e.,the Lihe River,Shahe River and Linhe River watershed,were utilized in this study.On the basis of reasonable dividing criteria,the three precipitation series were divided into three wetness-dryness state sequences using the Markov chains.First,by means of Markov chain’s probability transfer matrix,wetness-dryness transfer regularity and the change mechanisms of the three annual rainfall series were studied.Second,the wetness-dryness state run length of the three series were counted,and the run analysis theory was applied to calculate the prior probability of annual rainfall at high,normal or low levels,with studying the wetness-dryness persistence characteristics of the three annual rainfall series.Third,by using the copula functions,a trivariate joint distribution was constructed among the rainfall series of the Lihe River,Shahe River and Linhe River watersheds,and then the joint distribution model was used to compute the wetness-dryness encounter probability of the three regions.Results from the Markov process analysis show that high precipitation level and low precipitation level of the three regions were very conservative,yet the normal precipitation level was likely to transfer into other states.Results from the run length analysis show that the three rainfall series had the persistence characteristics of stronger high level and weaker normal level.Results from the wetness-dryness compensation analysis show that the wetness-dryness compensation probability of the three regions was about 29.8%,in which there was only 0.9% can be regarded as a good compensation action.This indicates a relative small wetness-dryness compensation capability of the three sub-basins.A joint application of the Markov process analysis method,run length analysis and multivariate joint distribution based on the Copula function would be more effective and of more practical applications in studying mechanisms of precipitation wetness-dryness change and analyzing wetness-dryness compensation characteristics among different regions.
出处
《资源科学》
CSSCI
CSCD
北大核心
2010年第6期1127-1132,共6页
Resources Science
基金
国家自然科学基金项目(编号:50579049)
