摘要
近年来受全球气候变化和人类活动的影响,流域洪水特征也发生了变化,查明流域洪水极值变化特征及趋势是流域治理的重要内容。以西柳沟流域为研究对象,应用Mann-Kendall秩次检验法分析流域出口控制站龙头拐水文站年最大洪峰流量序列的变化趋势,研究流域洪水极值的统计特征,同时从降雨和下垫面变化两个方面分析流域洪水极值变化的原因。结果显示:1960—2015年西柳沟流域年最大洪峰流量呈现显著的减少趋势,突变年份在2005年左右;对于年最大洪峰流量序列,突变后年最大洪峰流量与突变前的有显著差异,对于全部序列和突变前序列,Burr分布都是最优拟合分布函数;与突变前序列相比,对于相同洪峰流量,采用全部序列数据拟合的最优分布函数计算的重现期大于突变前序列对应的重现期,大洪水出现的概率变小。通过对流域内洪峰对应的1日及3日降雨和下垫面变化进行分析发现,降雨变化不是导致流域洪峰流量发生变化的主要因素,植被恢复及淤地坝建设改变了流域下垫面情况,成为造成流域洪峰流量显著减少的主要原因。
Affected by global climate change and human activities,the characteristics of river basin floods have also changed in recent years.It is an important part of river basin governance to clarify the characteristics and trends of extreme value changes of river basin floods.Taking the Xiliugou basin as the research object,this paper applies the Mann-Kendall rank test method to analyze the variation trend of the annual maximum peak discharge sequence at the Longtouguai hydrological station of the watershed export control station,and studies the statistical characteristics of the extreme flood value of the basin.At the same time,from the two aspects of rainfall and underlying surface changes,the reasons for the changes in flood extremes in the basin are analyzed.The results are as follows.Firstly,from 1960 to 2015,the annual maximum peak discharge in the Xiliugou basin shows a significant decreasing trend,and the year of mutation is around 2005.Secondly,for the annual maximum peak discharge sequence,the annual maximum peak discharge after the mutation is significantly different from that before the mutation.For all sequences and sequences before mutation,the Burr Distribution is the best fitting distribution function.Thirdly,compared with the sequence before the sudden change,for the same flood peak flow,the return period calculated by using the optimal distribution function fitted with all sequence data is greater than the return period corresponding to the sequence before the sudden change,and the probability of the occurrence of floods is smaller.Through analysis of the 1st and 3rd day rainfall and underlying surface changes corresponding to the flood peaks in the basin,it is found that the rainfall change is not the main factor leading to the change of the flood peak discharge in the basin.Vegetation restoration and the construction of silt dams have changed the underlying surface of the watershed,which has become the main reason for the significant reduction of peak discharge in the watershed.
作者
党素珍
姚曼飞
何宏谋
殷会娟
郭欣伟
DANG Suzhen;YAO Manfei;HE Hongmou;YIN Huijuan;GUO Xinwei(Yellow River Institute of Hydraulic Research,Yellow River Conservancy Commission,Zhengzhou 450003,China)
出处
《华北水利水电大学学报（自然科学版）》
2020年第6期26-31,共6页
Journal of North China University of Water Resources and Electric Power：Natural Science Edition
基金
国家重点研发计划项目(2017YFC0403600)
国家自然科学基金项目(51809104,51909099)。
关键词
西柳沟流域
洪峰流量
演变特征
频率分析
Xiliugou basin
peak discharge
evolution characteristics
frequency analysis
