信江中下游近60年水沙分配变化特征

针对信江流域水利工程建设以及大规模水土保持工作、河道采砂等人类活动不断增加的现状,为了更好地了解人类活动对信江水沙输移特性的影响,确保对水沙资源的合理开发与利用,基于信江梅港站近60年径流量输沙量实测资料,采用数理统计和Mann-Kendall秩次相关检验法对信江水沙分配变化特征进行分析,探讨人类活动对水沙输移特性的影响。结果表明:梅港站各年代径流量、输沙量年内分配基本呈明显的"单峰型"分布,在6月到达峰值;水沙关系呈现出"大水多沙,小水少沙"的态势,泥沙主要集中在主汛期,月最大输沙量与洪水相对应;汛期与非汛期径流量呈上升趋势、输沙量呈下降趋势,且输沙量下降趋势显著;汛期径流量、输沙量波动较大,明显大于非汛期径流量、输沙量波动幅度;历史上信江流域水沙相关性较稳定,但随着经济社会的发展,大规模水土保持、水利工程建设及河道采砂等人类活动不断增加,对水沙关系造成明显影响。

Variation characteristics of water and sediment distribution of Mid-LowerXinjiang Ｒiver in recent 60 years

t construction as well as large-scale water and soil conservation task， sand mining in river channel， etc. ， the vari-ation characteristics of the water-sediment transport characteristics of Xinjiang Ｒiver is analyzed and then the impacts from humanactivities on water and sediment transport characteristics is discussed by means of mathematical statistics and Mann-Kendall rankcorrelation test in accordance with the measured data of runoff and sediment transport in recent 60 years obtained from MeigangHydrological Station of Xinjiang Ｒiver， so as to better understand the impacts from human activities on the water-sediment trans-port characteristics of Xinjiang Ｒiver for ensuring the reasonable development and utilization of the water and sediment resourcestherein. The result shows that the intra-annual distributions of both the runoffs and sediments within all the years obtained fromMeigang Hydrological Station basically exhibit obvious unimodal distributions， which reach the peaks in June; for which the water-sediment relationship presents a status of rich water with more sediment and less water with less sediment， while sediment ismainly concentrated in main flood period and the maximum monthly sediment transport is corresponded to flood. The runoffs inboth flood period and non-flood period exhibit increasing trends along with a decreasing trend of sediment transport; moreover， the decreasing trend of sediment transport is significant. Both the runoff and the sediment transport in flood period are largelyfluctuated， which are obviously larger than the fluctuating amplitudes of the runoff and the sediment transport in non-flood period.Historically， the water-sediment correlation with Xinjiang Ｒiver Basin is stable， but the water-sediment relationship is obviouslyimpacted along with the socio-economic development and the continuous increases of the human activities， i. e. water conservancyproject construction as well as large-scale water and soil conservation task， sand mining in river channel， etc.