Method, system and medium for reconstructing underwater planar terrain of river based on section scouring and silting

Abstract

The present application relates to a method, system and medium for reconstructing the underwater planar topography of a river based on cross-section scouring and silting. The method includes collecting cross-section and planar topography observation data; calculating the scouring and silting thicknesses of each node between cross-sections; regenerating the topographic change background grid between every two cross-sections; and interpolating to form the underwater planar topography of the river. The present application uses multiple survey cross-sections and the underwater topography observation data of a certain survey. Starting from comparing the scouring and silting thicknesses of each node of multiple survey cross-sections, it interpolates the scouring and silting amplitudes of the river cross-sections to form the planar topographic change amount, thereby generating underwater planar topographic data that matches the cross-section data. It can make up for the deficiency of underwater planar topography observation data, and thus more accurately and fully reflect the scouring and silting adjustment and evolution law of the riverbed, providing a basic support for river planning and management.

Description

Technical Field

[0001] The present application relates to the technical field of water conservancy river sediment transport, and in particular to a method, system and medium for reconstructing the underwater plane topography of a river based on cross-section scouring and silting. Background Technique

[0002] The underwater topography of the river plane has always been an important basis for the analysis of riverbed evolution and the numerical simulation calculation of the river. However, due to the large amount of work, long time consumption, high cost, etc. in observing the river topography, the general data frequency is relatively low. For important large rivers such as the Yangtze River and the Yellow River, the frequency can only reach 2 - 3 times per measurement for key river sections and 5 years per measurement for non-key river sections. For small and medium-sized rivers, there is often a lack of observation data on the plane topography of the riverbed. In contrast, fixed cross-section measurement is relatively simple and low-cost. For river sections with large changes, multiple observations can be carried out within 1 year or at least once a year in the same time period by selecting fixed cross-sections at certain intervals. The data has good continuity. However, due to the large interval of fixed cross-sections, it is impossible to fully reflect the changes of the riverbed throughout the process, especially the continuous deformation of some key shoals and troughs, and there are significant shortcomings in the analysis of the plane morphology of the river shoals and troughs.

[0003] In order to master the change characteristics of the plane morphology of river shoals and troughs, enrich the content of riverbed evolution analysis, and comprehensively master the basic laws of river evolution, this application uses the cross-section data of multiple measurement times and the underwater topography observation data of a certain measurement time. Starting from comparing the scouring and silting thicknesses of each node of multiple cross-sections, the change amount of the plane topography is formed by interpolating the scouring and silting amplitude of the river cross-section. Based on the previous topography and the scouring and silting change amount in the time period, underwater plane topography data matching the cross-section data is generated to make up for the deficiency of underwater plane topography observation data, and further more accurately and fully reflect the riverbed scouring and silting adjustment and the evolution law of the shoal and trough pattern of the river, providing a basic support for river planning and management. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a method, system and medium for reconstructing the underwater plane topography of a river based on cross-section scouring and silting, which can be applied to the cross-section topography and plane topography of the first measurement time, and the cross-section data of the second measurement time to construct the plane topography of the second measurement time, providing a basis for the analysis of riverbed evolution when the measured data of the plane topography is scarce.

[0005] To achieve the above purpose, the present application provides the following technical solutions:

[0006] In the first aspect, the embodiments of the present application provide a method for reconstructing the underwater plane topography of a river based on cross-section scouring and silting, including the following steps:

[0007] Step 1. Collect cross-section and plane topography observation data;

[0008] Step 2. Calculate the scouring and silting thickness of each node between cross-sections;

[0009] Step 3. Regenerate the terrain change background grid between two cross-sections.

[0010] Step 4. Interpolate to form the underwater plane terrain of the river channel.

[0011] The implementation method of the above-mentioned Step 1 is as follows.

[0012] Step 11. Collect the cross-section terrain data of the first and second surveys, including the starting distance , elevation :

[0013] ,

[0014] where the subscript represents the measured value, is the number of the measured cross-section, is the number of the measured nodes on the cross-section, is the number of the measured cross-sections, is the number of the measured nodes on the cross-section. The subscripts 1 and 2 represent the first and second surveys respectively.

[0015] Step 12. Collect the plane terrain data of the first survey, including the abscissa , ordinate , elevation :

[0016] ,

[0017] where is the number of the measured points of the plane terrain, is the number of the measured points of the plane terrain.

[0018] The implementation method of the above-mentioned Step 2 is as follows.

[0019] Step 21. Set the number of the new nodes on each cross-section, and its value is the maximum value of the number of the measured nodes of all the cross-section terrains in the cross-section terrain data of the two surveys. The subscript represents the set new nodes.

[0020] Step 22. Determine the minimum value , maximum value of the starting distance of the measured nodes of the cross-section terrains of the two surveys.

[0021] Step 23. Set the starting distance , of the new nodes on the cross-section according to :

[0022] ,

[0023] Step 24. Generate the elevation of each new node on the two survey cross-sections by using the method of linear interpolation:

[0024] ,

[0025] wherein, the th new node on the cross-section is located between the th and the th measured nodes on the cross-section,

[0026] Step 25. Calculate the scouring and silting thickness between the two surveys for each new node on the cross-section:

[0027] .

[0028] The implementation manner of the said Step 3 is as follows,

[0029] Step 31. Calculate the abscissa and the ordinate of each new node on the cross-section:

[0030] ,

[0031] wherein, and respectively represent the abscissa and the ordinate of the cross-section, and the subscript represents the starting point, represents the ending point,

[0032] Step 32. First, connect the th new nodes on two adjacent cross-sections respectively to generate a background grid of a quadrilateral. Secondly, connect the th new node on one cross-section and the th new node on the other cross-section to generate a background grid of a triangle.

[0033] The implementation manner of the said Step 4 is as follows,

[0034] Step 41. Select any triangle in the background grid of the triangle, and apply Heron's formula to calculate the area of this triangle:

[0035] ,

[0036] wherein, are respectively the three side lengths of the triangle, is half of the sum of the three side lengths,

[0037] Step 42. Connect the actually measured points of the planar terrain of the first measurement to any two points of the triangle to form three new triangles, and then apply Heron's formula to calculate the areas of these three new triangles respectively. , , ,

[0038] Step 43. Determine whether it is equal to the sum of , , . If not, then successively select other triangles in the background grid until the triangle where the actually measured points of the planar terrain of the first measurement are located is found.

[0039] Step 44. According to the coordinates of the three vertices of the triangle where the actually measured points of the planar terrain of the first measurement are located and the scouring and silting thickness, use the inverse distance interpolation method to interpolate the scouring and silting thickness of the actually measured points of the planar terrain of the first measurement:

[0040] ,

[0041] wherein, is the scouring and silting thickness of the triangle vertex, is the distance from the actually measured point of the planar terrain of the first measurement to the triangle vertex,

[0042] Step 45. Calculate the terrain elevation of the planar terrain points of the second measurement:

[0043] .

[0044] In a second aspect, an embodiment of the present application provides a river underwater planar terrain reconstruction system based on cross-section scouring and silting, including

[0045] a data collection module for collecting fixed cross-section and underwater terrain observation data of the river section;

[0046] a scouring and silting thickness calculation module for cutting and encrypting cross-sections based on terrain observation data;

[0047] a planar grid regeneration module for regenerating a planar terrain interpolation calculation grid;

[0048] a terrain interpolation calculation module for interpolating and calculating the new planar underwater terrain of the river.

[0049] In a third aspect, an embodiment of the present application provides a computer-readable storage medium. When the program code stored in the computer-readable storage medium is executed by a processor, the steps of the above-mentioned method for reconstructing the river underwater planar terrain based on cross-section scouring and silting are implemented.

[0050] Compared with the prior art, the beneficial effects of the present application are as follows: The present application uses multiple survey cross-sections and underwater topographic observation data of a certain survey to start from comparing the erosion and deposition thicknesses of each node in multiple survey cross-sections, and interpolates the erosion and deposition amplitudes of the river channel cross-section to form the plane topographic change amount, thereby generating underwater plane topographic data that matches the cross-section data, which can make up for the deficiency of underwater plane topographic observation data, and further more accurately and fully reflect the adjustment and evolution law of the riverbed erosion and deposition of the river channel, providing a basic support for river planning and management. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments of the present application. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0052] Figure 1 Flowchart of the method of the embodiment of the present application;

[0053] Figure 2 Cross-section topographic maps of two surveys and a plane topographic map of one survey in a certain reach with both beach and trough in a certain basin of the embodiment of the present application;

[0054] Figure 3 Erosion and deposition distribution maps of two surveys in the embodiment of the present application;

[0055] Figure 4 Background grid map between a certain two cross-sections in the embodiment of the present application;

[0056] Figure 5 Erosion and deposition thickness between two surveys calculated in the embodiment of the present application, the topography of the second survey, and the measured erosion and deposition thickness map;

[0057] Figure 6 System block diagram of the embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0058] The following will describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0059] The term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or apparatus comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or apparatus. Without further limitation, an element qualified by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

[0060] The terms "first", "second", etc. are used only to distinguish one entity or operation from another entity or operation, and cannot be construed as indicating or implying relative importance, nor can it be construed as requiring or implying any such actual relationship or order between these entities or operations.

[0061] Referring Figure 1 , the embodiment of the present application provides a method for reconstructing the underwater planar terrain of a river based on cross-section scouring and silting, including the following steps:

[0062] Step 1. Collect the cross-section terrain and planar terrain data of the first measurement and the cross-section terrain data of the second measurement;

[0063] Step 2. Construct the distribution of new nodes on the cross-section and calculate the scouring and silting thickness between two cross-section terrain measurements of the new nodes on the cross-section;

[0064] Step 3. Generate a background grid based on the distribution of new nodes on the cross-section;

[0065] Step 4. Interpolate the planar terrain of the second measurement based on the scouring and silting thickness of the background grid nodes and the actual measurement points of the planar terrain of the first measurement.

[0066] The implementation manner of the above Step 1 is as follows,

[0067] Step 11. Collect the cross-section terrain data of the first and second measurements, including the starting distance , elevation :

[0068] ,

[0069] where the subscript represents the measured value, is the number of the measured cross-section, is the number of the measured nodes on the cross-section, is the number of measured cross-sections, is the number of measured nodes on the cross-section, and the subscripts 1 and 2 respectively represent the first and second measurements,

[0070] Step 12. Collect the plane terrain data of the first measurement, including the abscissa of the measured points on the plane terrain , ordinate , elevation :

[0071] ,

[0072] wherein, is the number of the measured points on the plane terrain, is the number of the measured points on the plane terrain.

[0073] The implementation method of the said Step 2 is as follows,

[0074] Step 21. Set the number of new nodes on each cross-section , the value of which is the maximum value of the number of measured nodes of all cross-section terrains in the cross-section terrain data of two measurements, and the subscript represents the set new nodes,

[0075] Step 22. Determine the minimum starting distance , maximum value of the measured nodes of the cross-section terrains of two measurements,

[0076] Step 23. Set the starting distance of the new nodes on the cross-section according to , : :

[0077] ,

[0078] Step 24. Generate the elevation of each new node on the cross-sections of two measurements by using the linear interpolation method:

[0079] ,

[0080] wherein, the th new node on the cross-section is located between the th and the th measured nodes on the cross-section,

[0081] Step 25. Calculate the scouring and silting thickness between two measurements of each new node on the cross-section:

[0082] .

[0083] The implementation method of the said Step 3 is as follows,

[0084] Step 31. Calculate the abscissa and ordinate of each new node on the cross-section:

[0085] ,

[0086] Among them, and respectively represent the abscissa and ordinate of the cross-section, and the subscript represents the starting point, represents the ending point.

[0087] Step 32. First, connect the th new nodes on two adjacent cross-sections respectively to generate a quadrilateral background grid. Secondly, connect the th new node on one cross-section and the th new node on the other cross-section to generate a triangular background grid.

[0088] The implementation method of step 4 is as follows.

[0089] Step 41. Select any triangle in the triangular background grid and calculate the area of this triangle using Heron's formula :

[0090] ,

[0091] Among them, are respectively the three side lengths of the triangle, is half of the sum of the three side lengths,

[0092] Step 42. Connect the measured points of the plane terrain of the first measurement to any two points of this triangle to form three new triangles, and then use Heron's formula to calculate the areas of these three new triangles respectively , , ,

[0093] Step 43. Judge whether is equal to the sum of , , . If not, then successively select other triangles in the background grid until the triangle where the measured points of the plane terrain of the first measurement are located is found.

[0094] Step 44. According to the coordinates of the three vertices of the triangle where the measured points of the plane terrain of the first measurement are located and the scouring and silting thickness, use the inverse distance interpolation method to interpolate the scouring and silting thickness of the measured points of the plane terrain of the first measurement:

[0095] ,

[0096] Among them, is the scouring and silting thickness of the triangle vertex, is the distance from the actually measured point of the planar terrain in the first measurement to the vertex of the triangle.

[0097] Step 45. Calculate the terrain elevation of the planar terrain points in the second measurement:

[0098] .

[0099] The specific steps of the embodiment are as follows:

[0100] Step 1. Collect the terrain data of 8 cross-sections in two measurements and the planar terrain data of one measurement in a certain river section with both sandbanks and deep troughs in a certain basin (as Figure 2 shown).

[0101] Step 2. The maximum value of the actually measured node numbers in the cross-section terrains of the two measurements collected is 244. Therefore, the number of new nodes on each cross-section is determined to be 244. Take the maximum and minimum values of the actually measured starting distances of each cross-section, set the nodes to be evenly distributed on the cross-section, and calculate the starting distance of each new node. Using the linear interpolation method, calculate the scouring and silting thickness between the two measurements of each new node on the cross-section as Figure 3 shown.

[0102] Step 3. After calculating the coordinates of the new nodes on the cross-section according to the start and end point coordinates of the cross-section, first connect the th new nodes on two adjacent cross-sections respectively to generate a quadrilateral background grid. Secondly, connect the th new node of one cross-section and the th new node of the other cross-section to generate a triangular background grid. The triangular background grid formed between cross-section 1 and cross-section 2 is as Figure 4 shown.

[0103] Step 4. For the actually measured points of the planar terrain in the first measurement to be interpolated, select any one triangle in the background grid. First, calculate the area of this triangle using Heron's formula , and secondly, calculate the areas of three new triangles formed by this actually measured point of the planar terrain and any two points of this triangle , and judge whether is equal to the sum of

[0104] . If not, then successively select other triangles in the background grid until the triangle where the actually measured point of the planar terrain in the first measurement is located is found. Using the inverse distance interpolation method, interpolate the scouring and silting thickness of the actually measured point of the planar terrain in the first measurement, and finally calculate the terrain elevation of the planar terrain points in the second measurement. The result is as Figure 5As shown, from the comparison with the measured values, it can be seen that the law of the scouring and silting thickness distribution calculated by this method is basically consistent with the measured values, and it can reflect the scouring and silting distribution law between the beach and the trough.

[0105] The embodiment of the present application provides an improved system for calculating the scouring and silting volume of the riverbed based on terrain hierarchical encryption, including

[0106] A data collection module 1 for collecting the observation data of the fixed cross-section and underwater terrain of the river reach;

[0107] A scouring and silting thickness calculation module 2 for cutting and encrypting the cross-section based on the terrain observation data;

[0108] A plane grid regeneration module 3 for regenerating the plane terrain interpolation calculation grid;

[0109] A terrain interpolation calculation module 4 for calculating the new plane underwater terrain of the river channel by interpolation.

[0110] The embodiment of the present application provides a computer-readable storage medium. When the program code stored in the computer-readable storage medium is executed by a processor, the steps of the method for reconstructing the underwater plane terrain of the river channel based on cross-section scouring and silting as described above are implemented.

[0111] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0112] The present application is described with reference to the flowcharts and / or block diagrams of the methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, and the combination of processes and / or blocks in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the specified functions in one Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0113] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including an instruction means that implements the function specified in one or more of the processes and / or blocks Figure 1 in one or more of the processes and / or blocks Figure 1 specified in the block or blocks.

[0114] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, so that the instructions executed on the computer or other programmable apparatus provide steps for implementing the function specified in one or more of the processes and / or blocks Figure 1 in one or more of the processes and / or blocks Figure 1 specified in the block or blocks.

[0115] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and memory.

[0116] The memory may include non-permanent memory in the form of computer-readable media, random access memory (RAM) and / or non-volatile memory such as read only memory (ROM) or flash memory. Memory is an example of computer-readable media.

[0117] Computer-readable media includes both permanent and non-permanent, removable and non-removable media implemented by any method or technology for storage of information such as computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read only memory (ROM), electrically erasable programmable read only memory (EEPROM), flash memory or other memory technologies, compact disc read only memory (CD-ROM), digital versatile discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory media such as modulated data signals and carrier waves.

[0118] The above are only the embodiments of the present application and are not intended to limit the protection scope of the present application. For those skilled in the art, various modifications and changes can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A method for reconstructing underwater plane terrain of a river channel based on cross-section scouring and silting, characterized in that: The following steps are involved: Step 1. Collect cross-sectional and planimetric topographic observation data; Step 2. Calculate the scouring and silting thickness at each node between sections; Step 3. Regenerate the background grid of terrain changes between two sections; Step 4. Interpolate to form the underwater plane terrain of the river channel; The implementation of step 4 is as follows: Step 41. Select any triangle in the triangular background grid and use Heron's formula to calculate the area of ​​the triangle : ， in, are the three side lengths of the triangle, is half the sum of the three sides. Step 42. Connect the measured points of the first survey plane topography with any two points of the triangle to form three new triangles. Apply Heron's formula again to calculate the areas of the three new triangles. , , , Step 43. Judgement Whether , , If the sum is not equal, select other triangles in the background grid in turn until the triangle where the measured point of the plane terrain of the first measurement is located is found. Step 44. Based on the coordinates of the three vertices of the triangle where the measured point of the plane terrain of the first measurement is located and the scouring and silting thickness, the inverse distance interpolation method is used to interpolate the scouring and silting thickness of the measured point of the plane terrain of the first measurement: ， in, is the scouring thickness at the triangle vertex, is the distance from the measured point of the plane terrain to the vertex of the triangle in the first measurement. Step 45. Calculate the terrain elevation of the second measured plane terrain point: 。 2. The method for reconstructing underwater plane terrain of a river channel based on cross-section scouring and silting according to claim 1 is characterized in that: The implementation of step 1 is as follows: Step 11. Collect the cross-sectional terrain data of the first and second measurements, including the starting distance of the measured nodes on the cross-sectional terrain. , Elevation : ， Among them, the subscript Indicates the measured value, is the number of the measured section, is the number of the measured node on the cross section, The number of measured sections, is the number of measured nodes on the cross section, and the subscripts 1 and 2 represent the first and second measurements, respectively. Step 12. Collect the first measurement of plane terrain data, including the horizontal coordinates of the plane terrain measurement points , vertical coordinate , Elevation : ， in, is the number of the measured point of the plane terrain, is the number of measured points of plane terrain.

3. The method for reconstructing underwater plane terrain of a river channel based on cross-section scouring and silting according to claim 1 is characterized in that: The implementation of step 2 is as follows: Step 21. Set the number of new nodes on each section , whose value is the maximum value of the number of measured nodes of all cross-section terrain in the cross-section terrain data of two measurements, subscript Indicates the new node to be set. Step 22. Determine the minimum distance between the starting points of the two measured nodes of the cross-section terrain , maximum value , Step 23. According to , , set the starting distance of the new node on the section : ， Step 24. Use linear interpolation to generate the elevation of each new node on the two measurement sections: ， Among them, the cross section The new node is located on the cross section and Between the measured nodes, Step 25. Calculate the scouring and silting thickness between two measurements for each new node on the cross section: 。 4. The method for reconstructing underwater plane terrain of a river channel based on cross-section scouring and silting according to claim 1 is characterized in that: The implementation of step 3 is as follows: Step 31. Calculate the horizontal coordinates of each new node on the cross section and the vertical coordinate : ， in, and Represent the horizontal and vertical coordinates of the cross section, respectively. Indicates the starting point, Indicates the end point, Step 32. First, connect the first A new node is created to generate a quadrilateral background mesh, and then the first node of one of the sections is connected. A new node and another section A new node is created to generate a triangular background mesh.

5. A river underwater plane terrain reconstruction system based on cross-section scouring and silting, used to implement any method of claims 1-4, characterized in that: include, Data collection module, used to collect observation data of fixed sections of river sections and underwater topography; Scouring and silting thickness calculation module, used to cut encrypted sections based on terrain observation data; Plane mesh regeneration module, used to regenerate plane terrain interpolation calculation mesh; The terrain interpolation calculation module is used to calculate the new planar underwater terrain of the river by difference.

6. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores program codes, and when the program codes are executed by a processor, the steps of the method for reconstructing underwater planar terrain of a river channel based on cross-section scouring and silting are implemented as described in any one of claims 1 to 4.

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