Braided river physical simulation test system

Abstract

The invention relates to a braided river physical simulation test system comprising a water channel composed of a water channel narrow section and a water channel wide section. The left side of the water channel is provided with a flat pool, a pipe, a gate valve and a flowmeter which are arranged from right to left in sequence; the right side of the water channel is provided with a sand basin, a water delivery pipe and an outlet sump from left to right in sequence; the bottom of the water channel is provided with a fixed support, and the connection position between the water channel narrow section and the water channel wide section is provided with a dump angle adjusting plate; a sand adding device is arranged above the water channel narrow section, and the both sides of the top of the water channel are provided with longitudinal tracks; transverse tracks are provided with testers, and the back side of the sand basin is provided with a water outlet elevation adjusting device; and a camera is installed above the test system. The physical simulation test system provided by the invention is simple in structure and convenient in operation; through the test system, the forming process of a braided river caused by different forms and different factors is simulated successfully; and the reliability and accuracy are provided for exploration, analysis and research on the forming mechanism of the braided river and the retention and start rules of biogenic substances with sediment in the braided river in the development process of mountain rivers.

Description

technical field [0001] The invention relates to a water conservancy and hydropower engineering test system, in particular to a braided river physical simulation test system suitable for mountainous river courses in the water environment protection technology, and belongs to the field of water conservancy and hydropower engineering facilities. Background technique [0002] In mountainous rivers, there is often a phenomenon that the canyon section and the wide valley section alternately appear. For example, the junction of the Yarlung Zangbo Jiangtuo Gorge section and the downstream wide valley section is the confluence of the Lhasa River. When the section enters the wide valley section, the river channel becomes wider, the lateral constraints become smaller, and the water flow begins to expand to both sides of the plane, resulting in a decrease in the velocity of the water flow and a large amount of sediment deposition. Scouring and deposition continue to occur, making the de...

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Problems solved by technology

First of all, there have been disputes about the division of river types at home and abroad. The study of the mechanism of braided rivers will help to further analyze and study the factors that form them, so as to solve the problem of river type attribution; secondly, the development of braided rivers is accompanied by The deposition and erosion of a large amount of sediment means that the biogenic matter attached to the sediment particles will also be retained and activated, and the biogenic matter plays a vital role in the water environment and aquatic organisms, so it is important for braided rivers In addition, braided rivers can hinder navigation and are characterized by curvature and shallow water depth. Due to the lack of knowledge and understanding of the water flow and sediment characteristics of such complex rivers when carrying out channel regulation, it is difficult to It has brought great difficulties to solve the problem of obstructing navigation. These are hot and difficult problems in the study of braided rivers.

[0004] In response to the above problems, various research methods and models have been proposed for riverbed evolution at home and abroad, but most of them are used to study curved, wandering and branched rivers, while there are few studies on braided rivers, and most of them are For braided deltas; in the study of the relationship between biomass and sediment, a large number of experiments are aimed at the adsorption and desorption of nitrogen, phosphorus and other substances by sediment, such as a hydraulic model that dynamically simulates the migration and diffusion of pollutants by sediment (Zhao Lianjun et al., 2015, application publication number CN105178243A), but this hydraulic model ignores the macroscopic impact of changes in water and sediment conditions on the relationship between biogenic matter and sediment, especially in special and complex rivers such as braided rivers , the retention and activation of sediment appear repeatedly, especially in time and space changes are very strong

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