Vegetation drag force coefficient analysis method and device and storage medium

Abstract

The invention discloses a vegetation drag force coefficient analysis method and device and a storage medium. The method comprises the steps that the vegetation height, the water surface height, the river channel width, the water flow speed, the vegetation height, the vertical projection width and the river channel slope are obtained; according to the vegetation height and the water surface height, the submerging proportion of vegetation relative to water flow is calculated; calculating the waterpower radius of the river channel according to the river channel width and the vegetation height; comprehensive parameters are calculated according to the water flow velocity and the river slope; calculating a vegetation drag force coefficient according to the comprehensive parameters, the vertical projection width of the vegetation, the water flow velocity and the submerging proportion of the vegetation relative to the water flow; the submerging proportion designed in the method can influence the resistance effect of vegetation on water flow, different hydraulic radius values can cause difference of water flow velocity distribution and resistance conditions, factors such as water flow velocity and gradient are comprehensively considered, and the accuracy of final vegetation drag force coefficient calculation is ensured by considering multiple factors; and finally, the precision of vegetation type ecological coast protection effect evaluation is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of vegetation regulation of water flow, and specifically to a vegetation drag force coefficient analysis method, equipment and storage medium. Background Art

[0002] With the development of society and the progress of human cognition of nature, people's requirements for river functions have gradually increased from simple water safety to the trinity of water safety, water ecology and water culture. Aquatic vegetation, as an important part of the river ecosystem, is not only an important source of food and nutrients for river aquatic organisms, but also an important means to protect riverbank soil from soil erosion and achieve beach protection and bank consolidation. Moreover, aquatic plants have good effects on purifying river water, improving water environment and constructing river landscape. However, the existence of aquatic vegetation changes the local flow field structure, increases water flow resistance and affects the transport of sediment, which directly endangers the safety of river flood discharge and becomes an important factor affecting flood discharge safety.

[0003] At present, the study of aquatic vegetation has become a hot issue in river management. In the past, when studying aquatic vegetation, most of the vegetation states were fixed, while the changes in vegetation states under different water flow conditions were ignored. Different types of vegetation drag coefficient expressions may have certain differences in practical application due to different sources and data used. Therefore, how to obtain a more accurate vegetation drag coefficient is what we need to solve. Summary of the invention

[0004] The purpose of this application is to provide a vegetation drag force coefficient analysis method, equipment and storage medium to solve the defect of inaccurate evaluation of ecological coastal protection effect caused by the prior art.

[0005] In order to achieve the above objectives, this application is implemented by adopting the following technical solutions: In the first aspect, the present application discloses a vegetation drag force coefficient analysis method, which includes: Obtain vegetation height, water surface height, river channel width, water flow velocity, vegetation height, vertical projection width, and river channel slope; According to the vegetation height and the water surface height, the submerged ratio of the vegetation relative to the water flow is calculated by a first formula; Calculating the hydraulic radius of the river channel by a second formula according to the river channel width and the vegetation height; Calculating a comprehensive parameter using a third formula according to the water flow velocity, the river channel slope and the river channel hydraulic radius; The vegetation drag coefficient is calculated by the fourth formula according to the comprehensive parameters, the vertical projection width of the vegetation, the water flow velocity and the submergence ratio of the vegetation relative to the water flow.

[0006] In a further solution of the present application, the formula for the submergence ratio of the vegetation relative to the water flow is as follows: ; is the proportion of vegetation submerged relative to water flow, is the vegetation height, is the water surface height.

[0007] In a further solution of the present application, the formula for the hydraulic radius of the river channel is as follows: ; in, is the width of the river, is the vegetation height, is the hydraulic radius of the river channel.

[0008] Further solutions of this application, If the value is greater than the value, the hydraulic radius of the river channel is closer to the true value; If and are close, the value of will vary between to.

[0009] For a further solution, the formula of the comprehensive parameter is as follows: ; in, is the water flow velocity, is the hydraulic radius of the river channel, is the acceleration due to gravity, is the river slope, is a comprehensive parameter.

[0010] In a further solution, the vegetation drag coefficient calculation formula is as follows: ; in, is a comprehensive parameter, is the vertical projection width of vegetation, is the water flow velocity, is the proportion of vegetation submerged relative to water flow, is the vegetation drag coefficient.

[0011] In a second aspect, the present application discloses a vegetation drag force coefficient analysis device, which comprises: Acquisition module for vegetation height, water surface height, river channel width, water flow velocity, vegetation height, vertical projection width, and river channel slope; A submergence ratio module, used to calculate the submergence ratio of vegetation relative to water flow according to the vegetation height and the water surface height; A river hydraulic radius module, used to calculate the river hydraulic radius according to the river width and vegetation height; A comprehensive parameter module calculates comprehensive parameters according to the water flow velocity, the river channel slope and the river channel hydraulic radius; The drag coefficient module calculates the vegetation drag coefficient according to the comprehensive parameters, the vertical projection width of the vegetation, the water flow velocity, and the submergence ratio of the vegetation relative to the water flow.

[0012] In a third aspect, the present application discloses a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the vegetation drag force coefficient analysis method described in any one of claims 1 to 7 when executing the computer program.

[0013] In a fourth aspect, the present application discloses a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the above-mentioned vegetation drag force coefficient analysis method are implemented.

[0014] The beneficial effects of this application are: In this application, the proportion of vegetation submergence relative to water flow is calculated by measuring vegetation height, water surface height, river channel width, water flow velocity, vegetation height, and vertical projection width. The submergence ratio will affect the resistance of vegetation to water flow, and the hydraulic radius of the river channel is calculated. Different hydraulic radius values ​​will lead to different water flow velocity distributions and resistance conditions. Factors such as water flow velocity and slope are also comprehensively considered. Multiple factors are taken into account to ensure the accuracy of the final calculation of the vegetation drag force coefficient, and ultimately ensure the accuracy of the evaluation of the vegetation-based ecological coastal protection effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a flow chart of the vegetation drag force coefficient analysis method in an embodiment of the present application. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its application or use. Embodiment 1

[0017] like Figure 1As shown, the present embodiment discloses a vegetation drag force coefficient analysis method, which includes obtaining vegetation height, water surface height, river channel width, water flow velocity, vegetation height, vertical projection width and river channel slope, and calculating the proportion of vegetation submersion relative to the water flow according to the vegetation height and water surface height; calculating the hydraulic radius of the river channel according to the river channel width and vegetation height; calculating comprehensive parameters according to the water flow velocity, river channel slope and river channel hydraulic radius; calculating the vegetation drag force coefficient according to the comprehensive parameters, vegetation vertical projection width, water flow velocity and the proportion of vegetation submersion relative to the water flow.

[0018] In some embodiments, the vegetation drag force coefficient analysis method is basically implemented as follows: 1) Calculate the basic parameters of the interaction between vegetation and water flow The proportion of vegetation submerged relative to water flow reflects the degree of submergence of vegetation in water flow. , is the vegetation height, is the water surface height. Through this ratio, we can preliminarily understand the relative position relationship between vegetation and water flow. A value close to 1 indicates that most of the vegetation is submerged in water; if A smaller value means that only a small part of the vegetation is underwater, and most of it is above the water surface. This submergence ratio affects the resistance of vegetation to water flow.

[0019] 2) Consider the impact of river channel geometry on water flow Calculate the hydraulic radius of a river channel , the formula is , where The width of the river, is the vegetation height (here it is assumed that the vegetation height is approximately equal to the average water depth of the water flowing through the vegetation area). The hydraulic radius of the river channel is a parameter that comprehensively considers the shape and size of the river cross section. It is very important for describing the flow characteristics of water in the river channel. When it is larger and relatively small, the hydraulic radius of the river channel will be closer; when and When approaching, The value of and Different values ​​of the hydraulic radius of the river channel will result in different water velocity distribution and resistance conditions.

[0020] 3) Comprehensively consider factors such as water flow speed and slope Calculate a composite parameter , the formula is ,in is the water flow velocity, is the hydraulic radius of the river channel calculated in step 2), is the acceleration due to gravity, is the slope (here used to reflect the impact of slope on water flow). This comprehensive parameter combines factors such as water flow velocity, river hydraulic radius and slope. Water flow velocity is the power source of water flow, river hydraulic radius affects the flow characteristics of water flow, and slope causes changes in the gravity component of water flow.

[0021] 4) Calculate vegetation drag coefficient Final vegetation drag coefficient The calculation formula is ,in is the comprehensive parameter calculated in the third step, is the vertical projection width of vegetation, is the water flow velocity, is the proportion of vegetation submerged relative to water flow calculated in step 1).

[0022] The beach protection effect is to reduce the hydrodynamic intensity. On the one hand, it reduces the amount of sediment on the beach that is transported by hydrodynamics, which in turn causes beach erosion. On the other hand, it allows more sediment carried in the water to fall on the bed, which in turn causes siltation on the beach. Therefore, after obtaining the vegetation drag coefficient, the hydrodynamic blocking effect of ecological vegetation beach protection can be judged according to the drag coefficient, and then the degree of weakening of the hydrodynamic effect of sediment transport can be evaluated, thereby evaluating the effect of ecological vegetation beach protection in preventing erosion and promoting sedimentation. Embodiment 2

[0023] This embodiment discloses a vegetation drag force coefficient analysis device, which includes: Acquisition module for vegetation height, water surface height, river channel width, water flow velocity, vegetation height, vertical projection width, and river channel slope; The submergence ratio module is used to calculate the submergence ratio of vegetation relative to water flow based on the vegetation height and water surface height; The river hydraulic radius module is used to calculate the river hydraulic radius based on the river width and vegetation height; Comprehensive parameter module, which calculates comprehensive parameters based on water flow velocity, river slope and river hydraulic radius; The drag coefficient module calculates the vegetation drag coefficient based on comprehensive parameters, vegetation vertical projection width, water flow velocity, and the proportion of vegetation submerged relative to water flow. Embodiment 3

[0024] This embodiment discloses a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the vegetation drag force coefficient analysis method described in the first embodiment are implemented. Embodiment 4

[0025] This embodiment discloses a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the vegetation drag force coefficient analysis method in the first embodiment are implemented.

[0026] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, "multiple" means two or more.

[0027] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood by specific circumstances.

Claims

1. A vegetation drag force coefficient analysis method, characterized in that: include Obtain vegetation height, water surface height, river channel width, water flow velocity, vegetation height, vertical projection width, and river channel slope; Calculating the proportion of vegetation submerged relative to water flow based on the vegetation height and the water surface height; Calculating the hydraulic radius of the river channel according to the river channel width and vegetation height; Calculating comprehensive parameters according to the water flow velocity, the river channel slope and the river channel hydraulic radius; The vegetation drag coefficient is calculated according to the comprehensive parameters, the vertical projection width of the vegetation, the water flow velocity, and the submergence ratio of the vegetation relative to the water flow.

2. The vegetation drag force coefficient analysis method according to claim 1, characterized in that: The formula for the proportion of vegetation submerged relative to water flow is as follows: ； is the proportion of vegetation submerged relative to water flow, is the vegetation height, is the water surface height.

3. The vegetation drag force coefficient analysis method according to claim 1, characterized in that: The formula for the hydraulic radius of the river channel is as follows: ； in, is the width of the river, is the vegetation height, is the hydraulic radius of the river channel.

4. The vegetation drag force coefficient analysis method according to claim 3, characterized in that: The formula for the comprehensive parameters is as follows: ； in, is the water flow velocity, is the hydraulic radius of the river channel, is the acceleration due to gravity, is the river slope, is a comprehensive parameter.

5. The vegetation drag force coefficient analysis method according to claim 4, characterized in that: The calculation formula of the vegetation drag coefficient is as follows: ； in, is a comprehensive parameter, is the vertical projection width of vegetation, is the water flow velocity, is the proportion of vegetation submerged relative to water flow, is the vegetation drag coefficient.

6. A vegetation drag force coefficient analysis device, characterized in that: include: Acquisition module for vegetation height, water surface height, river channel width, water flow velocity, vegetation height, vertical projection width, and river channel slope; A submergence ratio module, used to calculate the submergence ratio of vegetation relative to water flow according to the vegetation height and the water surface height; A river hydraulic radius module, used to calculate the river hydraulic radius according to the river width and vegetation height; A comprehensive parameter module calculates comprehensive parameters according to the water flow velocity, the river channel slope and the river channel hydraulic radius; The drag coefficient module calculates the vegetation drag coefficient according to the comprehensive parameters, the vertical projection width of the vegetation, the water flow velocity, and the submergence ratio of the vegetation relative to the water flow.

7. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the vegetation drag force coefficient analysis method described in any one of claims 1 to 5 are implemented.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the vegetation drag force coefficient analysis method described in any one of claims 1 to 5 are implemented.

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