变化环境下武江超定量洪水门限值响应规律及影响  

Changing rule and influence of threshold for peak-over-threshold flood series under the changing environment in Wujiang,China

作　　者：叶长青[1,2] 陈晓宏[1,2] 张丽娟[1,2] 庞园[1,2] 张家鸣[1,2] 

机构地区：[1]中山大学水资源与环境研究中心,广东广州510275 [2]华南地区水循环与水安全广东省普通高校重点实验室,广东广州510275

出　　处：《水科学进展》2013年第3期392-401,共10页Advances in Water Science

基　　金：国家自然科学基金资助项目(50839005;51210013)~~

摘　　要：世界众多江河洪水超定量(POT)系列门限值已发生变化,门限值选取不当会影响频率分析合理性。结合历史洪水资料,采用洪水POT理论分析变化环境下武江门限值响应规律及影响。结果表明:武江流域下垫面植被和径流系数在1991年明显改变,变化环境下不仅洪水门限值显著增大,且超过特定量级洪水的发生次数也在增加,POT模型能捕捉洪水在量级和发生次数方面的变化信息。分别选用变化环境前后门限值来推算设计洪峰,当重现期大于200年时,坪石站差异度达19.21%,犁市站达8.12%以上。选用变化环境后高门限值可有效提高线型对大洪水的拟合程度和设计洪水计算精度。The threshold of peak-over-threshold（POT） flood series has changed for many rivers in the world.Improper selection of threshold will affect the rationality of frequency analysis.The changing rule and influence of the threshold selection for POT flood series under the changing environment in Wujiang River was analyzed using historical flood data.The research results indicate that watershed vegetation and runoff coefficient varied significantly in 1991.After the environment was changed,the threshold increased significantly,and the occurrence number of flood exceeding a certain magnitude also increased.The POT model can flexibly capture the information on changes of flood magnitude and frequency of occurrence.The threshold values,which changed before and after environment,were selected to calculate designed flood peak.The difference degree of designed flood peak for different threshold is up to 19.21% at Pingshi and more than 8.12% at Lishi station when the return period is greater than 200a.High threshold in the selection after the environment was changed can effectively improve the fitting degree of distribution to higher flood flow and improve the accuracy of design flood under the changing environment.

关 键 词：超定量 门限值 历史洪水 线性矩法 设计洪水 

分 类 号：P333[天文地球—水文科学]