A method to quantitatively define the critical index of non-cohesive bottom sand starting

Abstract

The invention relates to a method for quantitatively defining the start-up critical index of non-sticky bottom sand. Under certain bed bottom sand and changing water flow conditions, a high-speed camera is used to continuously shoot bed surface sediment images, and the color images continuously shot by the high-speed camera are processed. Preprocessing, obtain the movement state of sediment particles in each sub-domain in the imaging area, identify the sub-domains in which movement occurs in the imaging area, clarify the distribution characteristics of sediment movement in the imaging area, and count the area of ​​all sub-domains where sediment movement occurs Sum, calculate the percentage that the subfield that the silt starts takes place accounts for the photographing area, with this, the subfield that takes place the silt starting accounts for the photographing area ratio and is 0 when the water flow intensity is used as the critical hydraulic index that limits the bottom sand starting; The present invention can Accurately and quantitatively defining the start-up critical index of bed surface sediment solves the problem that the critical start-up index of bottom sand is difficult to quantitatively define, and the critical index determined by this method can be easily expanded and applied to bed sand start-up observation under different water and sediment conditions.

Description

technical field [0001] The invention relates to a method for quantitatively defining the start-up critical index of non-cohesive bottom sand, which belongs to the technical field of water conservancy engineering. Background technique [0002] The critical hydraulic index condition of bottom sediment starting is an important part of the research on water and sediment movement in estuaries and coasts, and it is a hot spot of scientific research at the present stage. There are various ways to define the critical hydraulic index for conventional bottom sediment start-up. There are methods of reverse calculation by using the bottom sediment transport rate, and there is also a method of direct monitoring by high-speed camera technology. On the one hand, the measurement of mass and sediment load is difficult, and on the other hand, the accuracy is poor, so higher measurement accuracy can be obtained. However, in field monitoring, on the one hand, due to the complexity of the on-sit...

AI Technical Summary

Problems solved by technology

[0006] The invention provides a method for quantitatively defining the critical index of non-cohesive bottom sand start-up, which is suitable for most water flow conditions, including field surveys or indoor test backgrounds, and solves the difficulty of quantitatively defining non-cohesive sand start-up in complex water flow environments. The problem of critical hydraulic index

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