欢迎您！东篱公司
退出
-
申报数据库
-
立项数据库
-
成果数据库
-
项目获奖数据库
中文摘要：
河流泥沙管理必须同时考虑河流的产沙量和需沙量。本文从河床演变、河口平衡和人类活动三个方面研究长江的需沙量。长江的需沙量主要包括：1）长江中下游向着最小能耗平衡纵剖面的河床演变所需的泥沙；2）人工采沙量；3）长江口造陆所需泥沙。长江中下游河道横向摆动受到两岸堤防约束，河床演变主要是纵剖面调整。目前中游远未达到最小能耗的平衡纵剖面，长期发展趋势以淤积为主，因此正常情况下中游以淤积为主。三峡水库蓄水暂时改变了这个演变过程。近20年来长江泥沙逐渐减少，水库蓄水拦沙、河道人工采沙等各种人类活动的影响，加剧了长江输沙量的减小。上海市的发展需要在河口创造大片新生陆地，需要大量的泥沙。长江中下游汛期的泥沙主要为冲泻质，非汛期主要为床沙质，输送到河口的泥沙只有大约90％的较粗泥沙可以用于造陆。河口造陆计划的实现需要长江至少来沙超过3亿t才能维持平衡。目前长江每年的缺沙量约为1亿t。
英文摘要：
The river sediment management should take into account simultaneously the sediment yield and the sediment demand. In this paper, the study of the sediment demand of the Yangtze River is carried out, considering the fluvial process, sediment balance in river mouth and the influences of human activities. The sediment demand in the Yangtze River consists of three parts： 1 ） sediment for fluvial processes; 2） sediment for building materials; and 3） sediment for land creation. Constrained by the grand levees, the fluvial process of the middle and lower Yangtze River reaches the equilibrium mainly by adjusting the longitudinal profile defined by the minimum stream power. The present bed profile of the middle reach is lower greatly the equilibrium bed profile. Sedimentation would dominate the fluvial process for a long period of time. But the impoundment of the Three Gorges Reservoir modifies temporarily this process. In recent 20 years, the annual sediment load in the Yangtze River has reduced significantly. Human activities cause further reduction of the sediment load in the river. The land creation project of the Shanghai government needs a large amount of sediment. In the middle and lower Yangtze River, the sediment is mainly wash load in flood reason, and is bed material load in low flow season. Only about 90% of coarser sediment transported to the river mouth can be used for land creation. In order to perform the land creation project and maintain the equilibrium at the Yangtze River mouth, the annual sediment demand is about 300 million tons. Now, there is an annual sediment shortage of about 100 million tons.
同期刊论文项目
同项目期刊论文
Fluvial processes and morphological response in the Yellow and Weihe Rivers to closure and operation
Nonlinear dynamics of nearshore irregular waves: a three-dimensional numerical model and its verific
An analysis of soil composition and mechanical properties of riverbanks in a braided reach of the Lo
Numerical simulation of longitudinal and lateral channel deformations in the braided reach of the Lo
Planar velocity distribution of viscous debris flow at Jiangjia Ravine, Yunnan, China: a field measu
Development of step-pool sequence and its effects in resistance and stream bed stability. Internatio
期刊信息
位置：