1957-2014年信江水沙变化特征分析

利用信江干流3个水文站（上饶站、弋阳站、梅港站）近60年的实测流量、含沙量资料，分析了信江流域年径流、年输沙量的变化特征。结果表明：（1）径流量年际变化较大，1990 s水量异常偏多（+20%），径流序列存在29年、9年的主周期，但未来径流量表现为明显的随机性；（2）输沙量在1990 s起显著减少，导致水沙双累积曲线发生转折，R/S分析表明未来输沙量继续减少；（3）2000 s径流量偏少（-5豫）是输沙量减小的原因之一，1990~2000年间建成的界牌水库、大坳水库、七星水库等大中型水利工程拦截泥沙，是梅港站2000 s输沙量异常偏少的另一个主要因素。由于流域水土流失治理、水利工程建设等，预计今后梅港站输沙量仍将进一步减少。

CHANGING CHARACTERISTIC OF RUNOFF-SEDIMENT OF THE XINJIANG RIVER FROM 1957 TO 2014

In this study we took the variation characteristics of runoff and sediment of the Xinjiang river basin. Studies were based on the long-term measured of discharge and sediment at three hydrological stations,and the data was nearly 60 years. Those stations were Shangrao station,Yiyang station and Meigang station,and they were on the Xinjiang river main stream. The results showed that:1)Creat variability at inter-annual scales on discharge was analyzed at upper three sta-tions. Compared with the average annual flow,the flow in 1990s was increased more than 20%. Therefore,the time in 1990s was abundant of rainfall. The main period of the runoff series was in every 29 years and 9 years,however,the runoff will be fully expressive of randomness in the future. 2)The sediment had reduced significantly since 1990s,which leaded to a turn-ing point on double accumulative curve of runoff and sediment. The R/S analysis of runoff indicate that the sediment will be keep on reducing. 3)One of the reasons for the reduction of sediment load at Meigang station was the less runoff in 2000s, which decreased by 5% compared with the average runoff. Another main factor was that the sediment was intercepted by large and medium reservoirs,which were built between 1990 and 2000 such as Jiepai reservoir,Daao reservoir and Qixing reservoir. Owing to the control of soil erosion and construction of water conservancy projects,it will be expected to reduce the sediment at Meigang station in the future.