黄河水沙变化趋势及成因分析

自2000年以来,黄河中上游河道非汛期出现变清趋势,黄河呈现"枯水枯沙"的新水沙特征。本文依据黄河干、支流24个主要水文控制站1950-2016年实测水沙资料,采用数理统计法和趋势分析法,分析了60多年来黄河干、支流水沙变化趋势及其影响因素。结果表明:(1) 1950-2016年黄河干、支流各站年均径流量、年均输沙量和年均含沙量随时间总体呈减小趋势,其中2000-2016年(Ⅲ时段)各站年均输沙量和年均含沙量降幅最大。(2) 1950-2016年黄河中游流域干、支流各站年均中数粒径随时间呈减小趋势,黄河水沙状况枯丰期差异显著,但随时间呈减弱趋势。(3)黄河水沙变化是自然因素和人类活动综合作用的结果,近年来黄河中游河道变清是泥沙锐减造成的,其中水保措施、水库工程、河道采砂及流域调水调沙引水引沙是主因,且人类活动影响的比重逐渐增大。

Analysis on the trend and cause of water and sediment in the Yellow River

Since 2000,the middle and upper reaches of the Yellow River show a tendency of clearing during non-flood season,and the Yellow River presents a new water-sand feature of " dry water and dry sand". Based on the actual data of water and sediment measured at 24 major hydrologic control stations in the Yellow River trunk and its tributaries from 1950 to 2016,this paper analyzes the variation trend and influencing factors of water and sediment in the Yellow River trunk and its tributaries over the past 60 years by means of mathematical statistics and trend analysis. The results showed that:( 1) From1950 to 2016,the average annual runoff,average annual sediment transport and average annual sediment content of each station in the Yellow River trunk and tributary decreased with the time,among which the annual annual sediment transport and average annual sediment content of each station decreased the most during 2000-2016( period Ⅲ).( 2) From 1950 to 2016,the mean annual particle size of each station in the middle reaches of the Yellow River decreased with time. The difference of the Yellow River sand status in the dry and peak periods was significant,but it decreased with time.( 3) The Yellow River sediment change is the result of the comprehensive effect of natural factors and human activities,in recent years,the middle reaches of the Yellow River channel clear sediment is caused by a sharp decline,which water conservation measures,reservoir engineering,river sand and sediment diversion basin water diversion sand diversion is the main cause,and the proportion of human activities gradually increased.