摘要
利用Nash-Sutcliffe效率系数评估不同基流分割方法的计算结果精度,选用适合的基流分割方法对黄河中游河龙区间红河等13条主要一级支流长时间序列的逐年汛期基流深以及基流系数进行了计算,并结合区间内水土保持的情况、降水量的情况对基流变化进行了分析.结果表明,河龙区间内主要一级支流的汛期基流深在长时间尺度上,大多呈现出显著的下降趋势,区间北部的河流基流系数呈减少趋势,区间南部的河流基流系数呈增多趋势;进一步的分析表明,这两种不同趋势的基流变化规律与在不同降雨条件下开展的大规模水土保持活动存在着显著的相关关系:在500mm等降水量线以北的流域,大规模开展水土保持对汛期基流深有明显的削减作用,而在区间内500mm等降水量以南的流域,水土保持对汛期基流深的影响则不显著;在区间的半干旱地区水土保持面积占比与逐年基流系数变化呈现出显著性负相关,在半湿润地区则呈现出显著性正相关.
Baseflow is the most stable component of streamflow,and it is of great significance for the rational development and allocation of water resources in the river basin to study the spatial and temporal variations of the baseflow.The Hekouzhen-Longmen section in middle reaches of the Yellow River is a place lacking of water recourse,but most studies in this area focus on the changes of streamflow,other studies concerning about baseflow lack of breadth of space,which cannot reflect the changes of water resources well.In this study,Nash-Sutcliffe efficiency coefficients were used to evaluate the accuracy of different numerical simulation methods to calculate baseflow.Based on the fittest digital filter model,the baseflow and the baseflow index of the 13 major primary tributaries,such as Red River,of the Yellow River in the middle reaches were calculated,and which were analyzed combined with the situation of soil and water conservation.The results show:the baseflow in the flood season of the main tributaries mostly shows a significant downward trend on a long time scale,the baseflow index of the river in the northern part of the section shows a significant downward trend,but which shows an upward trend in the southern part.A large-scale soil and water conservation measures has been implemented in Hekouzhen-Longmen section and in the basins,the area of which in each basin shows a significant growth trend.Further analysis shows that there are significant correlations between the two different trends of the baseflow and the large-scale soil and water conservation activities under different rainfall conditions.The baseflow in flood season can be significantly reduced by the large-scale soil and water conservation activities in the north of 500 mm rainfall isohyet,but the function of which is not significant in the south of it.The proportion of soil and water conservation area of the interval was negatively correlated with the annual base flow coefficient in the semi-arid area,and there was a significant positive correlation in the semihumid area.The impact of human activities and natural changes on the baseflow is the result of the combined effects of various factors,so more in-depth research is needed to find out the mechanism of changes in the baseflow.
作者
韩鹏
王艺璇
李岱峰
HAN Peng;WANG Yixuan;LI Daifeng(College of Environmental Sciences and Engineering,Peking University,Beijing 100871,China;Shenzhen Graduate School,Peking University,Shenzhen 518055,China;Key Laboratory of Water and Sand Science,Ministry of Education,Beijing 100871,China)
出处
《应用基础与工程科学学报》
EI
CSCD
北大核心
2020年第3期505-521,共17页
Journal of Basic Science and Engineering
关键词
河龙区间
汛期
水土保持
基流分割
基流系数
黄河流域
Hekouzhen-Longmen Section
flood season
soil and water conservation
calculate baseflow
the baseflow index
the Yellow River
