A method, device, medium and product for reconstructing the flow field of a river cross-section

Abstract

The present application discloses a method, device, medium and product for reconstructing the flow field of a river channel cross-section, which relates to the technical field of hydrological measurement. The method includes determining the entropy parameter of the river channel cross-section according to the historical hydraulic parameters of the river section by using the formula of entropy theory; obtaining the surface velocities at different positions of the river channel cross-section by using non-contact measurement equipment; determining the longitudinal velocity of the river channel cross-section by using the formula of entropy theory velocity distribution according to the entropy parameter of the river channel cross-section and the surface velocity time series data, and solving the equations by using the particle swarm optimization algorithm; obtaining the flow velocity field data of the river channel cross-section by using the two-dimensional interp2 interpolation algorithm; and determining the flow rate of the river channel cross-section by using the velocity-area method. The present application can make full use of the existing non-contact measurement technology to accurately determine the flow velocity field and flow rate of the river channel, greatly improve the measurement efficiency and accuracy, and effectively reduce the consumption of manpower and material resources.

Description

Technical Field

[0001] This application relates to the technical field of hydrological measurement, and particularly to a method, device, medium and product for reconstructing the cross-sectional flow field of a river channel. Background Technique

[0002] The flow velocity and flow rate of rivers are basic monitoring elements in the fields of flood control, water ecology, etc., and are indispensable basic data for water resource management, flood risk control, water environment governance, etc. However, the measurement of river hydrological data often faces major challenges. The traditional method of measuring flow using a moving acoustic Doppler current profiler relies on manual operation and shipborne measurement, which is not only costly and time-consuming, but also poses a major hidden danger to the life and property safety of flow measurement workers, affecting the normal progress of flow measurement during floods. In addition, the discontinuous data obtained by moving measurement cannot continuously monitor the changes in river hydrodynamics, which greatly restricts the construction of digital twin basins. Therefore, there is an urgent need to explore an efficient, low-cost and safe flow measurement method.

[0003] With the continuous development of sensors and embedded systems, non-contact measurement methods for rivers have been successively proposed, and the water measurement technology has been further improved. Based on this development, non-contact flow measurement technologies such as acoustic waves, electromagnetic waves and image processing can remotely measure the surface velocity of water bodies and are gradually becoming important tools for hydrological monitoring. These technologies avoid direct contact with water bodies, improve the safety of measurement work, and show obvious advantages in hydrological monitoring. As two main methods of non-contact flow measurement technology, the radar method and the image method have been widely used in the field of hydrological monitoring. Compared with contact flow measurement technology, non-contact flow measurement technology can complete measurement work that cannot be done manually in harsh field environments and can achieve all-weather real-time online monitoring, greatly ensuring water safety and data integrity.

[0004] Although the current non-contact flow measurement technology can obtain the flow velocity field data on the river surface, how to calculate the flow velocity and flow rate of the cross-section based on this is still a challenge in hydrological monitoring. Most of the existing methods for calculating the cross-sectional flow rate of a river channel are based on statistical analysis methods and use empirical formulas to calculate the cross-sectional flow rate of the entire river channel, such as the index velocity method. This method lacks the support of physical mechanisms, and its empirical coefficients lack applicability in different rivers, with disadvantages such as low calculation accuracy and poor universality. And according to the existing algorithms, the flow velocity field of the river cross-section cannot be effectively calculated. Therefore, there is still room for improvement in the existing calculation methods for cross-sectional flow measurement of river channels, and their accuracy and applicability need to be further improved, and the content needs to be further improved.

[0005] Therefore, in order to overcome the deficiencies of traditional methods for calculating the flow rate of river cross-sections, there is an urgent need to provide a non-contact measurement and precise reconstruction calculation method for river flow fields, which can accurately determine the flow velocity field and flow rate of the river, greatly improve the measurement efficiency and accuracy, and effectively reduce the consumption of human and material resources. Summary of the Invention

[0006] The purpose of this application is to provide a method, device, medium and product for reconstructing the flow field of a river cross-section, which can accurately determine the flow velocity field and flow rate of the river, greatly improve the measurement efficiency and accuracy, and effectively reduce the consumption of human and material resources.

[0007] To achieve the above purpose, this application provides the following solutions:

[0008] In the first aspect, this application provides a method for reconstructing the flow field of a river cross-section. The method for reconstructing the flow field of a river cross-section includes:

[0009] Obtain the topographic data of the river cross-section; determine the three-dimensional cross-section topography and topographic measurement points of the river cross-section according to the topographic data of the river cross-section; and obtain the historical hydraulic parameters of the river section at the topographic measurement points. The topographic data includes: measurement data of the riverbank surface topography and underwater topography obtained at a certain distance in the river cross-section, measuring point coordinates and relative elevation data. The historical hydraulic parameters of the river section include: hydraulic radius of the river cross-section, maximum cross-section velocity and average velocity.

[0010] According to the historical hydraulic parameters of the river section, use the formula of entropy theory to determine the entropy parameter of the river cross-section.

[0011] Use a non-contact measurement device to obtain the surface velocities at different positions in the river cross-section, and obtain the surface velocity time series data of the river cross-section. The non-contact measurement device includes: a radar speed measurement instrument or a large particle image velocimeter.

[0012] According to the entropy parameter of the river cross-section and the surface velocity time series data of the river cross-section, use the formula of entropy theory velocity distribution, and use the particle swarm optimization algorithm to solve the system of equations to determine the longitudinal velocity of the river cross-section. And use the two-dimensional interp2 interpolation algorithm to obtain the velocity field data of the river cross-section.

[0013] According to the velocity field data of the river cross-section, use the velocity-area method to determine the flow rate of the river cross-section.

[0014] Optionally, the obtaining the topographic data of the river cross-section; determining the three-dimensional cross-section topography and topographic measurement points of the river cross-section according to the topographic data of the river cross-section specifically includes:

[0015] Using an ultrasonic detector or an acoustic Doppler current profiler, underwater topography is measured at certain distances across the river channel cross-section to obtain measurement data of the underwater topography;

[0016] Using a level and a rangefinder, along the direction of the river channel cross-section, with the relative elevation zero coordinate point, the relative elevation and distance of both sides of the riverbank are measured up to the fixed columns on both sides, obtaining measurement data of the riverbank surface topography; the relative elevation zero coordinate point is a fixed column on one side of the river channel cross-section;

[0017] Using the relative elevation zero coordinate point to convert the relative elevation data, and determining the three-dimensional cross-sectional topography of the river channel cross-section and the topographic measurement points based on the measurement data of the underwater topography and the measurement data of the riverbank surface topography.

[0018] Optionally, according to the historical hydraulic parameters of the river section, using the formula of entropy theory, the entropy parameter of the river channel cross-section is determined, specifically including:

[0019] If there are historical hydraulic parameters of the river section at the topographic measurement points, then use the formula to determine the entropy parameter M; where Φ(M) is the entropy function, M is the entropy parameter, U m is the average velocity of the river channel cross-section, U max is the maximum velocity of the river channel cross-section;

[0020] If there are no historical hydraulic parameters of the river section at the topographic measurement points, then according to the historical hydraulic parameters of the river section, use the formula to determine the entropy parameter M; where y max is the distance from the maximum velocity U max on the vertical line of the river channel cross-section to the bed surface, y0 is the reference plane where the velocity is assumed to be zero, k is the von Kármán parameter, R is the hydraulic radius, D is the flow depth, h is the distance from the water surface downward of the maximum velocity U max on the vertical line of the river channel cross-section, and g is the acceleration due to gravity.

[0021] Optionally, according to the entropy parameter of the river channel cross-section and the surface velocity time series data of the river channel cross-section, using the formula of entropy theory for velocity distribution, and solving the equations using the particle swarm optimization algorithm to determine the longitudinal velocity of the river channel cross-section; and using the two-dimensional interp2 interpolation algorithm to obtain the velocity field data of the river channel cross-section, specifically including:

[0022] Using the formula to determine the velocity field data of the river channel cross-section at the topographic measurement point (x i , y); ; is the maximum velocity of the vertical line x i on the river channel cross-section, is the vertical line x iWater depth at, M is the entropy parameter, is the vertical line x of the river channel cross-section i The distance by which the maximum flow velocity deviates from the water surface is the point position in the vertical direction is the total number of vertical lines of the river channel cross-section;

[0023] Using the formula Determine the maximum vertical velocity of the vertical line x of the river channel cross-section i on the vertical line ; is the surface velocity value at the vertical line x of the river channel cross-section i ; is the downward shift value of the maximum flow velocity at the vertical line xi of the river channel cross-section is the vertical line x of the river channel cross-section i Water depth at;

[0024] Using the formula Determine the downward shift value of the maximum flow velocity on the vertical line x of the river channel cross-section i on the vertical line ; is the vertical line x of the river channel cross-section i Downward shift value of the maximum flow velocity on the vertical line Correction coefficient;

[0025] Using the formula of entropy theory as a constraint condition, with the difference between the entropy parameter of the river channel cross-section and the theoretical entropy parameter of the river channel cross-section as the objective function value; is the objective function to be optimized is the entropy parameter of the river channel cross-section is the theoretical entropy parameter of the river channel cross-section;

[0026] Using the particle swarm algorithm to solve the minimum value of the objective function value;

[0027] Using the formula Update the particle velocity; is the i-th particle after the k-th update and are the positions of the i-th particle after the k + 1-th and k-th updates respectively is the inertia weight, which controls the ability of the particle to maintain the current flight direction. c1 and c2 are the cognitive constant and the social constant respectively. r1 and r2 are both random numbers, taking values in the range [0, 1]. P b is the historical optimal position of the particle, G b is the global optimal position of the population;

[0028] Using the formula For two-dimensional discrete data points, perform two-dimensional interpolation; x i , yi are the coordinates of the known i-th two-dimensional discrete data point, z i，j is the flow velocity value at the known two-dimensional discrete data point (x i , y i ); z i+1，j is the flow velocity value at (i + 1, j), z i，j+1 is the flow velocity value at (i, j + 1), z i+1，j+1 is the flow velocity value at (i + 1, j + 1); x and y are the coordinates of the two-dimensional discrete data point to be interpolated; z is the flow velocity at the interpolation point, x i+1 , y i+1 are the coordinates of the known (i + 1)-th two-dimensional discrete data point; where i and j are the horizontal and vertical positions on the cross-section respectively.

[0029] Optionally, based on the flow velocity field data of the river channel cross-section, using the velocity-area method to determine the flow rate of the river channel cross-section, specifically including:

[0030] Determine the average flow velocity of the vertical line of the river channel cross-section at the topographic survey point according to the flow velocity field data of the river channel cross-section is the flow velocity at the vertical position 1 of the vertical line x i of the river channel cross-section, V(x i，j ) is the flow velocity at the vertical position j of the vertical line x i of the river channel cross-section;

[0031] According to the average flow velocity V(x i ) between every two adjacent vertical lines x i of the river channel cross-section and the average flow velocity V(x i+1 ) between the vertical lines x i+1 of the river channel cross-section, determine the weighted average flow velocity V(xi) = [V(x i ) + V(x i+1 )] / 2 of the corresponding vertical line of the river channel cross-section;

[0032] Taking the vertical line of the river channel cross-section as the boundary for dividing sub-regions, divide the open channel cross-section into several sub-regions, and determine the local area S i = ∑(b i + 1 - b i ) × (h i + 1 - h i ), where b i is the lateral sub-width between vertical lines, h i is the sub-depth in the vertical direction;

[0033] According to the local area between the vertical lines of the river channel cross-section and the average flow velocity between the vertical lines of the river channel cross-section, use the velocity-area method to determine the flow rate of the river channel cross-section.

[0034] Optionally, according to the local area between vertical lines of the river cross-section and the average flow velocity between vertical lines of the river cross-section, the velocity-area method is adopted to determine the flow rate of the river cross-section, which specifically includes:

[0035] Using the formula Q =∑S i × V (x i ) to determine the flow rate of the river cross-section Q ;

[0036] where S i is the local area between vertical lines, and V(x i ) is the average flow velocity between vertical lines of the river cross-section.

[0037] On the second aspect, the present application provides a device for reconstructing the flow field of a river cross-section. The device for reconstructing the flow field of a river cross-section includes:

[0038] A data acquisition module, configured to acquire the terrain data of the river cross-section; determine the three-dimensional cross-section terrain of the river cross-section and the terrain measurement points according to the terrain data of the river cross-section; and acquire the historical hydraulic parameters of the river section at the terrain measurement points; the terrain data includes: the measurement data of the riverbank surface terrain and the underwater terrain acquired at a certain distance in the river cross-section, the measurement point coordinates and the relative elevation data; the historical hydraulic parameters of the river section include: the hydraulic radius, the maximum cross-section flow velocity and the average flow velocity of the river cross-section;

[0039] An entropy parameter determination module, configured to determine the entropy parameters of the river cross-section according to the historical hydraulic parameters of the river section by using the formula of entropy theory;

[0040] A surface flow velocity determination module, configured to use a non-contact measurement device to acquire the surface flow velocities at different positions in the river cross-section, and obtain the surface flow velocity time series data of the river cross-section; the non-contact measurement device includes: a radar speed measuring instrument or a large particle image velocimeter;

[0041] A flow velocity field data determination module, configured to determine the longitudinal flow velocity of the river cross-section according to the entropy parameters of the river cross-section and the surface flow velocity time series data of the river cross-section by using the formula of entropy theory for flow velocity distribution and solving the equations by using a particle swarm optimization algorithm; and obtain the flow velocity field data of the river cross-section by using a two-dimensional interp2 interpolation algorithm;

[0042] A flow rate determination module of the river cross-section, configured to determine the flow rate of the river cross-section according to the flow velocity field data of the river cross-section by using the velocity-area method.

[0043] In a third aspect, the present application provides a computer device, including: a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor executes the computer program to implement the method for reconstructing the cross-sectional flow field of a river channel as described above.

[0044] In a fourth aspect, the present application provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the method for reconstructing the cross-sectional flow field of a river channel as described above is implemented.

[0045] In a fifth aspect, the present application provides a computer program product, including a computer program, and when the computer program is executed by a processor, the method for reconstructing the cross-sectional flow field of a river channel as described above is implemented.

[0046] According to the specific embodiments provided by the present application, the present application has the following technical effects:

[0047] The present application provides a method, device, medium and product for reconstructing the cross-sectional flow field of a river channel. By using a non-contact measurement device to measure the surface velocity of the river channel cross-section, and using a formula based on entropy theory, combined with the velocity-area method, the problem of accurately calculating the river channel velocity field and flow rate is solved, greatly improving the measurement efficiency and accuracy, and effectively reducing the consumption of human and material resources. This invention will help to improve the comprehensive monitoring, intelligent perception and fine management capabilities of the basin, serve the construction of the digital twin basin, and provide more comprehensive, accurate, perceivable and intelligent information support for improving the level of river basin governance and management; it has important practical value for real-time online monitoring of the river channel flow field under complex water conditions, and provides important support for strengthening water safety guarantee capabilities and water resources management. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0049] Figure 1 It is a schematic flow chart of a method for reconstructing the cross-sectional flow field of a river channel in an embodiment of the present application;

[0050] Figure 2 It is a schematic conceptual diagram of a method for reconstructing the cross-sectional flow field of a river channel in an embodiment of the present application;

[0051] Figure 3 It is a schematic diagram of the flow field data measured by an acoustic Doppler current profiler (ADCP);

[0052] Figure 4Schematic diagram of flow velocity field data calculated by the entropy theory method;

[0053] Figure 5 Comparison diagram of the measured cross-section flow velocity field of the river channel and the calculated flow velocity field of the embodiment of the present application;

[0054] Figure 6 Comparison diagram of the measured vertical flow velocity of the river channel and the calculated vertical flow velocity of the embodiment of the present application;

[0055] Figure 7 Comparison diagram of the measured flow rate of each cross-section of this river channel and the calculated flow rate of the embodiment of the present application. Specific implementation manner

[0056] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0057] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0058] In an exemplary embodiment, as Figure 1 and Figure 2 shown, a method for reconstructing the cross-sectional flow field of a river channel is provided, and this method includes the following S101 to S104. Among them:

[0059] S101, obtaining the topographic data of the river channel cross-section; determining the three-dimensional cross-sectional topography of the river channel cross-section and the topographic measurement points according to the topographic data of the river channel cross-section; and obtaining the historical hydraulic parameters of the river section at the topographic measurement points; the topographic data includes: the measurement data of the river bank surface topography and underwater topography obtained at a certain distance in the river channel cross-section, the measurement point coordinates, and the relative elevation data; the historical hydraulic parameters of the river section include: the hydraulic radius of the river channel cross-section, the maximum cross-sectional flow velocity, and the average flow velocity;

[0060] S101 specifically includes:

[0061] S11, using an ultrasonic sounding instrument or an acoustic Doppler current profiler, etc., to measure the underwater topography at a certain distance in the river channel cross-section and obtain the measurement data of the underwater topography;

[0062] S12. Using a level and a rangefinder, along the cross-section direction of the river channel, with the relative elevation zero coordinate point being a fixed column on one bank of the river channel cross-section, measure the relative elevation and distance of both banks until the fixed columns on both banks are reached, obtaining the measurement data of the riverbank surface topography; the relative elevation zero coordinate point is a fixed column on one bank of the river channel cross-section.

[0063] S13. Use the relative elevation zero coordinate point to convert the relative elevation data, and determine the three-dimensional cross-section topography of the river channel cross-section and the topographic measurement points (X i , Y i , Z i ) based on the measurement data of the underwater topography and the measurement data of the riverbank surface topography.

[0064] S102. According to the historical hydraulic parameters of the river section, use the formula of entropy theory to determine the entropy parameters of the river channel cross-section.

[0065] Classify the topographic measurement points into measured stations and unmeasured stations according to whether there are historical hydraulic parameters of the river section at the topographic measurement points; classify them into erodible river channels and non-erodible river channels according to the soil quality of the river channel cross-section, and conduct a preliminary classification of the measurement cross-section according to the attributes.

[0066] S102 specifically includes:

[0067] If there are historical hydraulic parameters of the river section at the topographic measurement point, use the formula to determine the entropy parameter M; where, Φ(M) is the entropy function, M is the entropy parameter, U m is the average velocity of the river channel cross-section, and U max is the maximum velocity on the vertical line of the river channel cross-section.

[0068] If there are no historical hydraulic parameters of the river section at the topographic measurement point, use the formula to determine the entropy parameter M through parameters such as the hydraulic radius of the river channel; where, y max is the distance from the maximum velocity U max on the vertical line of the river channel cross-section to the bed surface, y0 is the reference plane where the assumed velocity is zero, k is the von Kármán parameter, R is the hydraulic radius, D is the flow depth, and h is the distance from the maximum velocity U max on the vertical line of the river channel cross-section from the water surface downward, and g is the acceleration due to gravity.

[0069] S103. Use a non-contact measurement device to obtain the surface velocities at different positions of the river cross-section, and obtain the time-series data of the surface velocities of the river cross-section. Considering the basic conditions of the river measurement cross-section (such as air visibility, river particle composition, etc.), the difficulty of equipment layout in the measurement area, comprehensively select non-contact velocity measurement instruments such as radar velocity measurement instruments or particle image velocity measurement instruments for the non-contact measurement device. For the selection of the non-contact measurement device, carry out the measurement of the river surface velocity and water level. Use an automatic control device to drive the radar velocity measurement instrument to measure the surface velocity and water level of the river at regular intervals, and record the position and velocity field data (X i , D i , U i );

[0070] S104. According to the entropy parameter of the river cross-section and the time-series data of the surface velocities of the river cross-section, adopt the formula of entropy theory velocity distribution, and use the particle swarm optimization algorithm to solve the equations to determine the longitudinal velocity of the river cross-section; and use the two-dimensional interp2 interpolation algorithm to obtain the velocity field data of the river cross-section;

[0071] S104 specifically includes:

[0072] S41. According to the distance x i of the river cross-section vertical line from the left bank, considering the water depth at the position of this measuring line, determine the basic value of the downward shift of the maximum velocity on this vertical line. The formula is as follows:

[0073] ;

[0074] where, δ(x i ) is the downward shift value of the maximum velocity at the position of the measuring line, is the water depth at the river cross-section vertical line x i , is the correction coefficient of the downward shift value i of the maximum velocity on the river cross-section vertical line x .

[0075] S42. According to the velocity formula of entropy theory, using the surface velocity of the river cross-section, entropy parameter and the downward shift value of the maximum velocity on the vertical line as basic data, obtain the maximum velocity of the vertical line:

[0076] ;

[0077] where, U surf (x i , D(x i )) is the surface velocity value at the measuring line of x i , is the maximum velocity of the vertical line on the river cross-section vertical line x i .

[0078] S43, using the formula of entropy theory as a constraint condition, and taking the difference between the cross-sectional entropy parameter of the river channel and the theoretical cross-sectional entropy parameter of the river channel as the objective function value; is the objective function to be optimized, is the cross-sectional entropy parameter of the river channel, is the theoretical cross-sectional entropy parameter of the river channel;

[0079] Using the particle swarm algorithm, solve the minimum value of the objective function value;

[0080] Using the formula to update the particle velocity; is the i-th particle after the k-th update, and are the positions of the i-th particle after the (k + 1)-th and k-th updates respectively, is the inertia weight, which controls the ability of the particle to maintain the current flight direction. c1 and c2 are the cognitive constant and the social constant respectively. r1 and r2 are both random numbers, taking values between [0, 1]. P b is the historical optimal position of the particle, and G b is the global optimal position of the population;

[0081] Using the formula to perform two-dimensional interpolation on two-dimensional discrete data points; x i , y i is the coordinate of the known i-th two-dimensional discrete data point, and z i，j is the flow velocity value at the known two-dimensional discrete data point (x i , y i ); z i+1，j is the flow velocity value at (i + 1, j), z i，j+1 is the flow velocity value at (i, j + 1), z i+1，j+1 is the flow velocity value at (i + 1, j + 1); x and y are the coordinates of the two-dimensional discrete data point to be interpolated; z is the flow velocity at the interpolation point, x i+1 , y i+1 is the coordinate of the known (i + 1)-th two-dimensional discrete data point; where i and j are the horizontal and vertical positions on the cross-section respectively.

[0082] S44, substituting data such as entropy parameter, maximum velocity of the vertical line, and downward shift value of the maximum velocity into the river channel flow velocity calculation formula, and through the particle swarm optimization solution loop process in S43, obtain the point flow velocity value at the (x, y) position, that is, obtain the flow velocity field data of the river channel cross-section:

[0083] ;

[0084] Among them, is the water depth at the vertical line x of the river channel cross-section, M is the entropy parameter, i is the distance from the maximum flow velocity at the vertical line x of the river channel cross-section to the water surface, i is the position in the vertical direction, is the total number of vertical lines of the river channel cross-section.

[0085] S105. According to the flow velocity field data of the river channel cross-section, the velocity-area method is used to determine the flow rate of the river channel cross-section.

[0086] S105 specifically includes:

[0087] S51. Determine the average flow velocity of the vertical lines of the river channel cross-section at the topographic survey points according to the flow velocity field data of the river channel cross-section;

[0088] Determine the average flow velocity of the vertical lines of the river channel cross-section at the topographic survey points according to the flow velocity field data of the river channel cross-section is the flow velocity at the vertical position of 1 at the vertical line x of the river channel cross-section, V(x i ) is the flow velocity at the vertical position of j at the vertical line x i，j of the river channel cross-section. i

[0089] S52. According to the average flow velocity V(x i ) between every two adjacent vertical lines x of the river channel cross-section and the average flow velocity V(x i ) between the vertical lines x of the river channel cross-section, determine the weighted average flow velocity V(xi) = [V(x i+1 ) + V(x i+1 )] / 2 of the corresponding vertical lines of the river channel cross-section; i ) + V(x i+1 )] / 2;

[0090] S53. Taking the vertical lines of the river channel cross-section as the boundaries for dividing sub-regions, divide the open channel cross-section into several sub-regions, and determine the local area S i = ∑(b i + 1 - b i ) × (h i + 1 - h i ), where b i is the lateral sub-width between the vertical lines, h i is the sub-depth in the vertical direction;

[0091] ​​​S54. Based on the area of the local region between vertical lines in the river cross-section and the average velocity between vertical lines in the river cross-section, the velocity-area method is used to determine the flow rate of the river cross-section. That is, according to the principle of calculating the flow rate of natural river channels in hydraulics, the velocity-area method is utilized. This method first uses the velocity measurement vertical lines as the boundaries for dividing sub-regions, divides the open channel cross-section into several sub-regions, then calculates the cross-sectional area, average velocity, and flow rate of each sub-region based on the measured velocity and water depth, and finally sums up the flow rates of each sub-region to obtain the result.

[0092] Using the formula Q Q = ∑S i × V (x i ) to determine the flow rate of the river cross-section Q ;

[0093] The present application has the following effects:

[0094] (1) The present application provides a method for non-contact measurement and accurate reconstruction calculation of the river flow field, mainly aiming to solve the problems of difficult measurement, high cost, poor accuracy, and difficulty in real-time online monitoring of the flow rate of the river cross-section. The method described in the present application has high accuracy in reconstructing and calculating the flow field of natural rivers, is applicable to different river types of large rivers, medium-sized and small rivers, and can achieve synchronous monitoring of the velocity field and flow rate in real-time online;

[0095] (2) The method provided by the present application has a theoretical basis in hydraulics and probability theory, etc. It can accurately identify the velocity distribution of each vertical line of the river through surface velocity measurement and adaptive adjustment of entropy parameters, is effectively applicable to different river types and river sections. Compared with traditional calculation methods, it has more physical mechanisms, strong interpretability, convenient application, wide applicability, and high accuracy and reliability in calculation;

[0096] (3) The method provided by the present application is based on non-contact measurement of the river channel, has the advantages of high automation degree, strong adaptability to complex environments, and high measurement safety, avoiding potential safety hazards to hydrological measurement personnel. At the same time, it makes full use of surface velocity field data, is applicable to the entire river channel, and is applied to different river types and river sections. Compared with traditional calculation methods, it has hydraulics and river dynamics mechanisms, convenient application, wide applicability, and high accuracy and reliability in calculation;

[0097] (4) The method provided by the present application can perform flow field calculations of multiple cross-sections and flow field modeling of the entire river section. It makes full use of real-time data such as the terrain of the river cross-section and the measured surface velocity, calculates the velocity field of each cross-section of the on-site river through the method provided by the present application, and reconstructs the flow field of the entire river section through interpolation and fitting by computer software. It has high calculation efficiency, can accurately depict the velocity distribution of the river channel, and can describe the hydrological conditions of the river channel in real-time, greatly improving the measurement accuracy of the flow rate of the river cross-section.

[0098] (5) The method provided by this application can not only obtain the flow rate of the river cross-section, but also reconstruct the velocity field of the entire river cross-section, which solves the problems of difficult measurement of the underwater velocity of natural rivers and shortage of continuous data. And it can provide more comprehensive data support for understanding river hydrodynamics. At the same time, the real-time monitoring of the velocity field of the entire cross-section helps to identify adverse flow patterns in a timely manner, evaluate their impacts on river channel evolution, etc., and provide data support for decision-making such as water resource management and river channel governance;

[0099] (6) The precise calculation method provided by this application has strong operability. It can be written into a program, with portability and nesting. Just take the cross-section topography of the measured river channel and the data of the measured velocity field of the river cross-section as input data, and through the built-in model algorithm of this application, it can achieve automatic and rapid precise calculation of the flow field of the river cross-section, and output the real-time online velocity of the entire cross-section and the river channel flow rate. It provides technical support for intelligent perception of rivers and comprehensive detection of river basins, and also helps to improve the fine control ability of rivers and the level of river basin governance and management.

[0100] The following is illustrated by specific examples. The research section of this example belongs to a wide and shallow section, with a straight river channel and a stable riverbed. The surface velocity and water level of the river cross-section are obtained through an automatic control device and a radar flow measurement device; a moving Doppler profiler is used to measure basic data such as the cross-section velocity, flow rate (used for verification), and water depth along the river cross-section; computer software is used to fit the cross-section topography of the river channel with the abscissa as the variable; considering large rivers, the interval of each section of the river width is set to 1.0 m. The attributes of the measurement section are divided into measurement stations with data and erodible soil river channels. The theoretical entropy function value can be calculated through the maximum velocity and average velocity formulas of the cross-section, and the value is 0.591. Combining the on-site situation, a radar velocity measurement instrument is comprehensively selected as a non-contact measurement device to obtain the surface velocity and water level of the river cross-section. Through the entropy theory formula model and the surface velocity field data, the point velocity values of the entire cross-section are calculated by using the operation of the computer particle swarm algorithm. Then, through the hydraulics natural river channel flow calculation method, the flow rate of the entire cross-section is obtained. Figure 3 is the velocity field data measured by ADCP, Figure 4 is the velocity field data calculated based on the entropy theory method, Figure 5 is the comparison between the measured velocity field of the river cross-section and the calculated velocity field of the embodiment of this application. As Figures 3 - 5 shown, the average relative error between the calculated velocity field and the measured velocity field of the entire cross-section is 12.50%. To further verify the accuracy of this invention, the measured velocity vertical distribution on the cross-section is compared and analyzed with the calculated velocity vertical distribution. The result is as Figure 6 . The measured flow rate of the cross-section is compared and analyzed with the calculated flow rate. The calculated flow rate of the river cross-section is 150642 m 3 / s, and the measured flow rate of the river cross-section is 154474 m3 / s, and the relative error is only 2.48%. To further verify the beneficial effects of this application, the measured flow rates and calculated flow rates of each cross-section in the research area were compared and analyzed. During the high flood flow period, the maximum relative error of the flow rate was only 1.36%, and the error of each cross-section was within 10%. The comparison between the measured flow rate and the calculated flow rate of each cross-section is shown in Figure 7 .

[0101] Based on the same inventive concept, the embodiment of this application also provides a cross-sectional flow field reconstruction device for a river channel to implement the cross-sectional flow field reconstruction method of the above-mentioned river channel involved. The solution provided by this device to solve the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more cross-sectional flow field reconstruction device embodiments provided below can refer to the limitations on the cross-sectional flow field reconstruction method of the river channel in the above text, and will not be repeated here.

[0102] In an exemplary embodiment, a cross-sectional flow field reconstruction device for a river channel is provided, including:

[0103] A data acquisition module, configured to acquire the topographic data of the cross-section of the river channel; determine the three-dimensional cross-sectional topography and topographic measurement points of the cross-section of the river channel according to the topographic data of the cross-section of the river channel; and acquire the historical hydraulic parameters of the river section at the topographic measurement points; the topographic data includes: the measurement data of the bank surface topography and underwater topography obtained at a certain distance along the cross-section of the river channel, the measuring point coordinates, and the relative elevation data; the historical hydraulic parameters of the river section include: the hydraulic radius, the maximum cross-sectional velocity, and the average velocity of the cross-section of the river channel;

[0104] An entropy parameter determination module, configured to determine the entropy parameter of the cross-section of the river channel according to the historical hydraulic parameters of the river section and using the formula of entropy theory;

[0105] A surface velocity determination module, configured to use a non-contact measurement device to acquire the surface velocities at different positions of the cross-section of the river channel, and obtain the surface velocity time series data of the cross-section of the river channel; the non-contact measurement device includes: a radar speed measurement instrument or a large particle image velocimeter;

[0106] A velocity field data determination module, configured to determine the longitudinal velocity of the cross-section of the river channel according to the entropy parameter of the cross-section of the river channel and the surface velocity time series data of the cross-section of the river channel, using the formula of entropy theory velocity distribution, and solving the equations using the particle swarm optimization algorithm; and use the two-dimensional interp2 interpolation algorithm to obtain the velocity field data of the cross-section of the river channel;

[0107] A flow rate determination module for the cross-section of the river channel, configured to determine the flow rate of the cross-section of the river channel according to the velocity field data of the cross-section of the river channel using the velocity-area method.

[0108] In an exemplary embodiment, a computer device is provided, which may be a server or a terminal. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store video tag processing data. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with an external terminal through a network connection. The computer program, when executed by the processor, implements a video tag processing method.

[0109] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, which, when executed by a processor, implements the steps in the above method embodiments.

[0110] In an exemplary embodiment, a computer program product is provided, including a computer program, which, when executed by a processor, implements the steps in the above method embodiments.

[0111] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0112] Those of ordinary skill in the art can understand that all or part of the processes of implementing the methods in the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memories. Non-volatile memories can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memories can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0113] The databases involved in the embodiments provided in this application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in this application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logics, data processing logics based on quantum computing, etc., without limitation.

[0114] In this application, all actions of obtaining signals, information, or data are carried out on the premise of complying with the corresponding data protection regulations and policies of the country where the location is, and with the authorization given by the owner of the corresponding device.

[0115] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0116] In this article, specific examples are used to elaborate on the principles and implementation manners of this application. The description of the above embodiments is only used to help understand the method of this application and its core idea. At the same time, for those of ordinary skill in the art, according to the idea of this application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation on this application.

Claims

1. A method for reconstructing the flow field of a river cross section, characterized in that: The river cross-section flow field reconstruction method includes: Obtaining topographic data of a river channel cross section; determining the three-dimensional cross-sectional topography and topographic measurement points of the river channel cross section based on the topographic data of the river channel cross section; and obtaining historical hydraulic parameters of the river section at the topographic measurement points; the topographic data including: measurement data of riverbank surface topography and underwater topography obtained at certain intervals in the river channel cross section, coordinates of measurement points, and relative elevation data; the historical hydraulic parameters of the river section including: the hydraulic radius of the river channel cross section, the maximum flow velocity of the cross section, and the average flow velocity; According to the historical hydraulic parameters of the river section, the entropy parameters of the river cross section are determined using the formula of entropy theory. Using non-contact measurement equipment, the surface flow velocity at different positions of the river cross section is obtained to obtain time series data of the surface flow velocity of the river cross section; the non-contact measurement equipment includes: a radar velocity measuring instrument or a large particle image velocimeter; Based on the entropy parameters of the river cross section and the surface velocity time series data of the river cross section, the particle swarm optimization algorithm is used to solve the equations based on the entropy theory velocity distribution formula to determine the longitudinal velocity of the river cross section; and the two-dimensional interp2 interpolation algorithm is used to obtain the velocity field data of the river cross section; Based on the velocity field data of the river cross section, the velocity area method is used to determine the flow rate of the river cross section.

2. The river cross-section flow field reconstruction method according to claim 1, characterized in that: The obtaining of the topographic data of the river cross section; and determining the three-dimensional topography of the river cross section and the topographic measurement points according to the topographic data of the river cross section, specifically include: Using an ultrasonic sounder or a traveling Doppler profiler, the underwater topography is measured at a certain distance in the cross section of the river to obtain the measurement data of the underwater topography; Using a level and a distance meter, measure the relative elevation and distance of the riverbanks on both sides along the cross section of the river, starting from a relative elevation zero coordinate point, to fixed columns on both sides, to obtain measurement data of the riverbank surface topography; the relative elevation zero coordinate point is a fixed column on the riverbank on one side of the river cross section; The relative elevation zero coordinate point is used to convert the relative elevation data, and the three-dimensional cross-sectional topography of the river channel and the topographic measurement points are determined based on the measurement data of the underwater topography and the river bank surface topography.

3. The river cross-section flow field reconstruction method according to claim 1, characterized in that: The entropy parameters of the river cross section are determined based on the historical hydraulic parameters of the river section using the formula of entropy theory, which specifically includes: If the topographic survey point has the historical hydraulic parameters of the river section, the formula Determine the entropy parameter M; where Φ(M) is the entropy function, M is the entropy parameter, and U m is the average flow velocity of the river cross section, U max is the maximum flow velocity of the river cross section, and e is the natural logarithm; If there is no historical hydraulic parameter of the river section at the topographic measurement point, then the formula Determine the entropy parameter M; where y max is the maximum flow velocity U on the vertical line of the river cross section max The distance from the bed, y0 is the reference plane where the velocity is assumed to be zero, k is the von Karman parameter, R is the hydraulic radius, D is the flow depth, and h is the maximum flow velocity U on the vertical line of the river cross section. max The distance below the water surface, g is the acceleration due to gravity.

4. The river cross-section flow field reconstruction method according to claim 1, characterized in that: The method uses the entropy parameter of the river cross section and the surface velocity time series data of the river cross section, adopts the formula of velocity distribution of entropy theory, uses particle swarm optimization algorithm to solve the equation group, and determines the longitudinal velocity of the river cross section; and uses the two-dimensional interp2 interpolation algorithm to obtain the velocity field data of the river cross section, which specifically includes: Using the formula Determine the topographic measurement point (x i , y) of the river cross section velocity field data ; is the vertical line x of the river cross section i The maximum vertical velocity on is the vertical line x of the river cross section i The water depth at , M is the entropy parameter, is the vertical line x of the river cross section i The distance at which the maximum velocity deviates from the water surface, is the point in the vertical direction, is the total number of vertical lines in the river cross section; Using the formula Determine the vertical line x of the river cross section i Maximum vertical velocity on ; is the vertical line x of the river cross section i The surface velocity value at is the downward displacement value of the maximum flow velocity at the vertical line xi of the river cross section, is the vertical line x of the river cross section i The depth of water; Using the formula Determine the vertical line x of the river cross section i Upper maximum flow rate downward shift value ; is the vertical line x of the river cross section i Upper maximum flow rate downward shift value Correction factor of Using the formula of entropy theory as a constraint condition, the difference between the entropy parameter of the river cross section and the theoretical entropy parameter of the river cross section is used as the constraint condition. As the objective function value; is the objective function to be optimized, is the entropy parameter of the river cross section, is the theoretical river cross-section entropy parameter; Use particle swarm optimization to find the minimum value of the objective function; Using the formula Update particle velocity; is the i-th particle after the k-th update, and are the positions of the i-th particle after the k+1th and kth updates, respectively. is the inertia weight, which controls the ability of the particle to maintain the current flight direction. c1 and c2 are cognitive constants and social constants respectively. r1 and r2 are random numbers with values between [0, 1]. b is the historical optimal position of the particle, G b is the global optimal position of the population; Using the formula Perform two-dimensional interpolation on two-dimensional discrete data points; x i ,y i is the coordinate of the i-th two-dimensional discrete data point, z i，j For a known two-dimensional discrete data point (x i ,y i ) at the flow velocity value; z i+1，j is the velocity value at (i+1, j), z i，j+1 is the velocity value at (i, j+1), z i+1，j+1 is the velocity value at (i+1, j+1); x, y are the coordinates of the two-dimensional discrete data points to be interpolated; z is the velocity of the point to be interpolated, x i+1 ,y i+1 is the coordinate of the known i+1th two-dimensional discrete data point; where i and j are the horizontal and vertical points on the section, respectively.

5. The river cross-section flow field reconstruction method according to claim 1, characterized in that: The method of determining the flow rate of a river cross section by using the velocity area method based on the velocity field data of the river cross section specifically includes: Determine the average flow velocity of the vertical line of the river cross section at the topographic measurement point based on the flow field data of the river cross section is the vertical line x of the river cross section i The velocity at the vertical point is 1, V(x i，j ) is the vertical line x of the river cross section i The flow velocity at the vertical point j; According to the perpendicular line x between each two adjacent river cross sections i The average flow velocity V(x i ) and the vertical line x of the river cross section i+1 The average flow velocity V(x i+1 ) Determine the weighted average velocity V(xi)=[V(x i )+V(x i+1 )] / 2; The vertical line of the river cross section is used as the boundary of the sub-area, and the open channel section is divided into several sub-areas. The area S of the local area between the vertical lines of the river cross section is determined. i =∑(b i +1-b i )×(h i +1-h i ), where b i is the horizontal width between vertical lines, h i is the vertical sub-depth; The velocity-area method is used to determine the flow rate of a river cross section based on the area of the local region between the vertical lines of the river cross section and the average flow velocity between the vertical lines of the river cross section.

6. The river cross-section flow field reconstruction method according to claim 5, characterized in that: The velocity-area method is used to determine the flow rate of a river cross section based on the area of the local region between the vertical lines of the river cross section and the average flow velocity between the vertical lines of the river cross section, specifically including: Using the formula Q =∑S i × V (x i ) Determine the flow rate of a river cross section Q ; Among them, S i is the area of the local region between the vertical lines, V(x i ) is the average flow velocity between perpendicular lines of the river cross section.

7. A river cross-section flow field reconstruction device, characterized in that: The river cross-section flow field reconstruction device includes: A data acquisition module is configured to acquire topographic data of a river channel cross section; determine the three-dimensional cross-sectional topography and topographic measurement points of the river channel cross section based on the topographic data of the river channel cross section; and acquire historical hydraulic parameters of the river section at the topographic measurement points; the topographic data includes: measurement data of the river bank surface topography and underwater topography acquired at a certain distance in the river channel cross section, coordinates of the measurement points, and relative elevation data; the historical hydraulic parameters of the river section include: the hydraulic radius of the river channel cross section, the maximum flow velocity of the cross section, and the average flow velocity; The entropy parameter determination module is used to determine the entropy parameters of the river cross section based on the historical hydraulic parameters of the river section and the formula of the entropy theory; A surface velocity determination module is configured to obtain surface velocity at different locations of a river cross section using a non-contact measurement device, thereby obtaining time series data of the surface velocity of the river cross section; the non-contact measurement device may include a radar velocity measuring instrument or a large particle image velocimeter; The velocity field data determination module is used to determine the longitudinal velocity of the river cross section based on the entropy parameters of the river cross section and the surface velocity time series data of the river cross section, using the formula of the velocity distribution of the entropy theory and the particle swarm optimization algorithm to solve the equation group; and use the two-dimensional interp2 interpolation algorithm to obtain the velocity field data of the river cross section; The flow determination module of the river cross section is used to determine the flow of the river cross section based on the flow velocity field data of the river cross section using the velocity area method.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the river cross-sectional flow field reconstruction method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for reconstructing the river cross-section flow field according to any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the method for reconstructing the river cross-section flow field according to any one of claims 1 to 6 is implemented.

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