Resear ch on the Dynamics of Tempor al Sediment Tr anspor t in a Gullied Loess Basin: the Lower Chabagou Cr eek on the Loess Plateau
黄土丘陵沟壑区岔巴沟下游泥沙传输 时间尺度动态研究

Suspended sediment dynamics are still imperfectly understood,especially in loess hilly region on the Loess Plateau with strong temporal variability,where few studies heretofore have been conducted.Using the dataset up to eight-year long in the Lower Chabagou Creek,the variability in suspended sediment load at different temporal scales(within-flood variability,monthly-seasonal and annual) were analyzed in this paper.The results show that,within-flood scale,most of the sediment peaks lag behind peak discharges independent of the occurring sequences of the peaks of sediment and discharge,all the events could present anti-clockwise hysteresis loop resulting from the influence of hyperconcentrated flows on suspended sediment concentration.At monthly and seasonal scales,there is a "store-release " process,i.e.sediment is prepared in winter,spring and late autumn,and exported out in summer and early autumn.At the annual scale,the high-variability in concentration and sediment yield are highly correlated with water yield,resulting from the number and magnitude of floods recorded yearly,since almost all the suspended load is transported during these events.