摘要
为研究长江下游干流与鄱阳湖洪水遭遇的特征,基于长江下游干流重要水文站(九江站和大通站)以及鄱阳湖入汇控制站(湖口站)1950—2023年的流量序列,采用有序聚类分析法识别了长江下游的年径流总量和年最大洪峰流量突变点(2003年)。以年最大洪峰流量、年最大7 d洪量、年最大15 d洪量作为年最大洪水的特征参数,采用混合von Mises分布和P-Ⅲ分布分别拟合了三站的年最大洪水发生时间和量级边缘分布,并采用二维Archimedean Copula函数构建了长江下游二维年最大洪水发生时间联合分布、量级联合分布,依此分析了三峡水库蓄水前后长江下游的洪水发生时间、量级的遭遇风险以及变化特征。结果表明:三峡水库蓄水后长江下游年最大洪水发生时间遭遇风险有增有降,当前湖口站与长江干流的九江站、大通站的洪水发生时间遭遇风险于6月上旬至7月上旬达到最大值,九江站与大通站的洪水发生时间遭遇风险于6月下旬至7月下旬达到最大值,应予以重点关注;三峡水库蓄水后任意两站遭遇某量级洪水的风险率有所降低,三峡工程的运行能较好地降低长江下游干流与鄱阳湖年最大洪水量级遭遇的风险,其中九江站与大通站的年最大洪水量级遭遇的风险下降最大。
To investigate the characteristics of flood encounters between the main stream of the lower Yangtze River and Poyang Lake,based on the discharge series(from 1950 to 2023)from important hydrological stations on the lower Yangtze River(Jiujiang Station and Datong Station)and the inflow control station of Poyang Lake(Hukou Station),the ordered clustering analysis method was used to identify the mutation point(2003)of the annual total runoff and annual maximum flood peak discharge in the lower Yangtze River.Using the annual maximum flood peak discharge,annual maximum 7-day flood volume,and annual maximum 15-day flood volume as characteristic parameters of the annual maximum flood,the mixed von Mises distribution and the P-Ⅲdistribution were used to fit the marginal distributions of the annual maximum flood occurrence time and magnitude at the three stations,respectively.A two-dimensional Archimedean Copula function was employed to construct the two-dimensional joint distributions of the annual maximum flood occurrence time and magnitude in the lower Yangtze River.Based on this,the encounter risks and changing characteristics of flood occurrence time and magnitude in the lower Yangtze River before and after the impoundment of the Three Gorges Reservoir were analyzed.The results show that after the impoundment of the Three Gorges Reservoir,the encounter risk of annual maximum flood occurrence time in the lower Yangtze River increased in some aspects and decreased in others.Currently,the encounter risk of flood occurrence time between Hukou Station and the main stream stations(Jiujiang Station and Datong Station)reaches its maximum from early June to early July,while the encounter risk between Jiujiang Station and Datong Station reaches its maximum from late June to late July,which should be paid special attention to.After the impoundment of the Three Gorges Reservoir,the risk rate of encountering a certain magnitude of flood at any two stations decreased.The operation of the Three Gorges Project effectively reduces the risk of encounter in the annual maximum flood magnitude between the main stream of the lower Yangtze River and Poyang Lake,with the greatest risk reduction observed between Jiujiang Station and Datong Station.
作者
卞佳琪
史常乐
何琦
曹双
李明生
韦立新
吴张勇
BIAN Jiaqi;SHI Changle;HE Qi;CAO Shuang;LI Mingsheng;WEI Lixin;WU Zhangyong(Lower Changjiang River Bureau of Hydrological and Water Resources Survey,Bureau of Hydrology,Changjiang Water Resources Commission,Nanjing 210011,China)
出处
《水利水电科技进展》
北大核心
2025年第6期38-46,共9页
Advances in Science and Technology of Water Resources
基金
国家自然科学基金长江水科学研究联合基金项目(U2240209)。
