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说起“泥沙学”,一定会有很多人感到陌生．尽管该学科体系在二十世纪中期就建立起来．但由于问题的复杂性．泥沙学科仍然是一门不成熟的学科。总得来说．这是一门综合性的基础技术科学,包括泥沙运动、河床演变、工程泥沙、河道整治等专业内容,涉及水力学、地貌学、水土保持学、 相似文献
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母亲河“黄河远上白云间,一片孤城万仞山。”她,绵延5464公里,奔流到海不复回。她,发源于青藏高原巴颜喀拉山北麓的冰峰雪山中。初出冰山,她曾是那么的透明、清彻、清洁。但是,在路过必经之路——黄土高原之后,她变成了一条黄泥河。就是这条黄泥河,孕育了一个黄皮肤的民族,为中华民族的繁衍、兴盛做出了巨大贡献,自古至今,人们称她是——母亲河。 相似文献
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Experimental Study of Sediment Incipience Under Complex Flows 总被引：1，自引：0，他引：1
Sediment incipience under flows passing a backward-facing step was studied. A series of experiments were conducted to measure
scouring depth, probability of sediment incipience, and instantaneous flow velocity field downstream of a backward-facing
step. Instantaneous flow velocity fields were measured by using Particle Image Velocimetry (PIV), and an image processing
method for determining probability of sediment incipience was employed to analyze the experimental data. The experimental
results showed that the probability of sediment incipience was the highest near the reattachment point, even though the near-wall
instantaneous flow velocity and the Reynolds stress were both much higher further downstream of the backward-facing step.
The possible mechanisms are discussed for the sediment incipience near the reattachment point.
Partially supported by National Natural Science Foundation of China (No.10602017), Maritime Research Center and DHI-NTU Center
of Nanyang Technological University, Singapore. 相似文献
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From the group movement of the bed load within the bottom layer, details of the nonlinear dynamic characteristics of bed load movement are discussed in this paper. Whether the sediment is initiated into motion cor-responds to whether the constant term in the equation is equal to zero. If constant term is zero and no dispersive force is considered, the equation represents the traditional Shields initiation curve, and if constant term is zero with-out the dispersive force being considered, then a new Shields curve which is much lower than the traditional one is got, The fixed point of the equation corresponds to the equilibrium sediment transport of bed load. In the mutation analysis, we have found that the inflection point is the demarcation point of breaking. In theory, the breaking point corresponds to the dividing boundary line, across which the bed form changes from flat bed to sand ripple or sand dune. Compared with the experimental data of Chatou Hydraulic Lab in France, the conclusions are verified. 相似文献
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利用多时相的美国Landsat卫星遥感图像对闽江口进行影像分区 ,对其流场、悬浮泥沙流进行动态分析 ,探讨闽江入海泥沙流对闽江口附近海域淤积的影响 ,并对外沙浅滩的形成与变化原因进行探讨 相似文献
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