TEMPORAL AND SPATIAL DYNAMICS OF DIFFERENT PARTICLE SIZE OF SUSPENDED SEDIMENT IN THE LIU RIVER CATCHMENTS, CHINA

查看全文 作　　者：Haoming [1,2]FAN;Qiangguo [1]CAI;Chengjiu [1]GUO;Tieliang [1]WANG 机构地区：[1]College of Water Conservancy, Shen Yang Agriculture University, Shenyang 110161, China;[2]Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China 出　　处：《International Journal of Sediment Research》索引2006年第21卷第3期,共11页 基　　金：The research described in this paper was supported by the Foundation of the Department of Education of Liaoning Province (Grant No.05L403);the Youth Science Foundation of Shen Yang Agriculture University;the National Natural Science Foundation of China (Grant No.40235056 and 40271075). 摘　　要：This paper presents information on the particle size characteristics of suspended sediment transported by the Liu River, which has the most serious erosion and sedimentation problems in the northeast of China. The median (d50) particle size for the individual stations on the Liu River ranged from 0.0343 to 0.0588 mm. Particles <0.01 mm ranged from 15.4 to 33.3% and >0.05 mm of ranged from 24.3 to 53.7%. Spatial and temporal variations were noticeable in the particle size composition of suspended sediment within the study basins. At different locations the sediment particles size varies as a result of differences in catchment characteristics. The preferential deposition of the coarser size fractions has resulted in downstream fining of the suspended sediment load. In the flood season the suspended sediment particle size was finer than that in low flow season. The relations among water discharge, suspended sediment concentration, and sediment particle size are complicated. At small water discharge or suspended sediment concentration, with the increase of water discharge or sediment concentration the particle size of suspended sediment decreases to a minimum. However, when the water discharge or sediment concentration exceed certain threshold values (turning points) the particle size increases or remains constant with the increase of water discharge or sediment concentration. The tuning points are different in different rivers. Thus, their relations are double-valued. The negative relation between suspended sediment particle size and flow discharge reflects the importance of supply conditions and the positive relation reflects that the flow and hydraulics take a greater role in sediment transportation. On the whole, variation of the sediment particle size is subject to many factors such as the hydraulic conditions, the type and extent of erosion, human activities, vegetation coverage, hydraulic projects, and sediment supply. The findings reported in this paper have important implications for understanding suspended sediment dynamics and sediment control in river basins. 关 键 词：河流 沉积物 时空变化 粒度 泥沙