Method and system for generating river topography based on measured cross-sections and hydraulic elements

Abstract

The present invention provides a method and system for generating river channel topography based on measured sections and hydraulic elements, which relates to the technical field of water conservancy projects, including: constructing a one-dimensional hydrodynamic model based on data of measured sections; taking hydraulic elements as hydrological boundaries, and obtaining water surface lines of each hydraulic element based on the one-dimensional hydrodynamic model; obtaining water edge lines of each hydraulic element according to intersection points of each water surface line with the river channel section; gridding the river channel based on boundary lines and control lines to obtain two-dimensional plane grids; and generating a river channel topography model by interpolating and solving along the two-dimensional plane grid according to measured section data, thereby achieving the technical effect that while reducing the cost of river channel topography measurement, the generated river channel can fully reflect the river hydraulic elements and more accurately reflect the actual river channel morphology, thereby improving the scientificity and accuracy of water conservancy numerical simulation calculations.

Description

Technical Field

[0001] The present invention relates to the technical field of water conservancy engineering, and in particular to a method and system for generating river channel topography based on measured cross sections and hydraulic elements. Background Art

[0002] River topography is the basis of water conservancy numerical simulation calculations. The degree of refinement of the terrain is the key factor that determines the accuracy of water conservancy numerical simulation calculations. Its high-precision water conservancy numerical simulation calculations have increasingly higher requirements on the accuracy and construction efficiency of river topography. However, in the actual field measurement process, due to the limitations of manpower, material resources, financial resources and technical conditions, it is difficult to achieve high-precision full coverage measurement of river topography. In order to save time and economic costs, cross-sections with representative features are selected for large-section measurement, and then the refined river topography is obtained through terrain interpolation algorithms, which has become the technical key to water conservancy numerical simulation calculations.

[0003] Existing interpolation algorithms include Kriging interpolation, cubic spline interpolation and other algorithms. These algorithms have disadvantages in river channel interpolation applications, such as large errors and inability to reflect river morphological characteristics.

[0004] An existing patent with publication number CN109960838A discloses a method for automatically generating river channel topography that reflects the basic characteristics of a river. The method obtains the river channel topography through a river channel interpolation algorithm based on measured sections. In the algorithm, the left and right bank boundary lines and the river channel deep line that reflect the basic characteristics of the river are extracted, and the middle line between the left and right bank boundary lines and the deep line of the river channel is encrypted, and intersected with the measured section line of the river channel to form a directional interpolation line segment of the river channel. Directional interpolation generates river channel elevation points that reflect the three basic characteristics of the river line, thereby realizing automatic generation of river channel topography; an existing patent with publication number CN103425856A discloses a method for automatically generating river channel topography based on river channel measurement section data. The method uses a spline interpolation method to add logical sections between fixed sections, and adds longitudinal lines along the river channel direction to form a grid. According to the fixed section measurement data of the river channel, the elevation of the grid points in the fixed section is interpolated using the Kriging interpolation algorithm.

[0005] Although the existing river channel interpolation algorithm based on measured sections has some improvements compared to the traditional interpolation algorithm, the river channel morphology is not taken into account during the interpolation calculation, or only the left and right bank lines and deep channels in the river channel morphology are taken into account. There are still large errors and it cannot meet the requirements of high-precision hydraulic numerical simulation calculations for terrain refinement when generating complex river channel terrain. Summary of the invention

[0006] The purpose of the present invention is to provide a method and system for generating river channel topography based on measured sections and hydraulic elements, so as to alleviate the technical problem of large errors in the interpolation calculation of topography for complex rivers existing in the prior art.

[0007] In a first aspect, the present invention provides a method for generating river topography based on measured cross sections and hydraulic elements, comprising:

[0008] Based on the data of the measured cross section, a one-dimensional hydrodynamic model is constructed;

[0009] Taking hydraulic elements as hydrological boundaries, based on the one-dimensional hydrodynamic model, obtaining the water surface line of each hydraulic element;

[0010] According to the intersection points of the water surface lines and the river section, the water edge lines of the hydraulic elements are obtained;

[0011] Based on the boundary lines and control lines, the river channel is meshed to obtain a two-dimensional plane grid;

[0012] The river terrain model is generated by interpolating and solving along the two-dimensional plane grid according to the measured cross-section data.

[0013] In an optional embodiment, the one-dimensional hydrodynamic model is constructed based on the measured cross-section data, including:

[0014] Construct a one-dimensional river network file based on the measured cross-section locations and river centerlines;

[0015] Construct cross-section terrain files based on measured cross-section elevation data;

[0016] Set the model boundary conditions and model parameters to obtain a one-dimensional hydrodynamic model;

[0017] The one-dimensional hydrodynamic model is calibrated and verified based on measured flood data.

[0018] In an optional embodiment, the hydraulic elements include large-scale floods, medium-scale floods and small-scale floods.

[0019] In an optional embodiment, taking hydraulic elements as hydrological boundaries, based on the one-dimensional hydrodynamic model, obtaining water surface lines under each hydraulic element includes:

[0020] Taking the flow rate as the upper hydrological boundary and the water level as the lower hydrological boundary, based on the upper hydrological boundary, the lower hydrological boundary and the one-dimensional hydrodynamic model, the water surface lines corresponding to large-scale floods, medium-scale floods and small-scale floods are calculated.

[0021] In an optional embodiment, the waterside line of each hydraulic element is obtained according to the intersection point of each water surface line and the river section, including:

[0022] Based on the location of the river section, determining a deep point in the river section;

[0023] Based on the deep point, performing a point-by-point analysis operation to determine a first intersection point and a second intersection point between the river section and the river bank;

[0024] According to the point-by-point analysis operation, all the river sections are traversed in a loop to obtain all the first intersection points and the second intersection points of the river sections;

[0025] Based on all the first intersection points and the second intersection points of the river section of each hydraulic element, the waterside line of each hydraulic element is obtained.

[0026] In an optional embodiment, the point-by-point analysis operation includes:

[0027] Taking the deep gulf point as the dividing point, based on the deep gulf point, along the left bank direction, determine a first elevation point greater than the water level of the river section and a second elevation point adjacent to the first elevation point, the second elevation point is lower than the first elevation point of the water level of the river section, and perform linear interpolation based on the first elevation point and the second elevation point to obtain a first intersection point;

[0028] Based on the deep point, along the right bank direction, determine a third elevation point greater than the water level of the river section and a fourth elevation point adjacent to the third elevation point, the fourth elevation point is lower than the third elevation point of the river section water level, and linear interpolation is performed based on the third elevation point and the fourth elevation point to obtain the second intersection point.

[0029] In an optional embodiment, the river channel is meshed based on the boundary line and the control line to obtain a two-dimensional plane mesh, including:

[0030] The left and right bank lines of the river are used as grid boundaries;

[0031] The waterside line and the deep channel line of each hydraulic element are used as the longitudinal control line;

[0032] Based on the subdivision rules, meshing is performed between two adjacent longitudinal control lines to obtain a two-dimensional plane orthogonal curve mesh.

[0033] In a second aspect, the present invention provides a system for generating river topography based on measured cross sections and hydraulic elements, comprising:

[0034] A construction module, used for constructing a one-dimensional hydrodynamic model based on the data of the measured section;

[0035] A calculation module, for obtaining the water surface line of each hydraulic element based on the one-dimensional hydrodynamic model by taking the hydraulic element as the hydrological boundary; and obtaining the water edge line of each hydraulic element according to the intersection point of each water surface line with the river section;

[0036] A partitioning module is used to partition the river channel into grids based on boundary lines and control lines to obtain a two-dimensional plane grid;

[0037] The generation module is used to generate a river terrain model by performing interpolation and solving along the two-dimensional plane grid according to the measured cross-section data.

[0038] In a third aspect, the present invention further provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any one of the methods described in the first aspect when executing the computer program.

[0039] In a fourth aspect, the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores machine-executable instructions. When the machine-executable instructions are called and executed by a processor, the machine-executable instructions prompt the processor to execute any of the methods described in the first aspect above.

[0040] The present invention provides a method and system for generating river channel topography based on measured cross-sections and hydraulic elements. A one-dimensional hydrodynamic model is constructed based on the data of the measured cross-section; the water surface line of each hydraulic element is obtained based on the one-dimensional hydrodynamic model, using the hydraulic element as the hydrological boundary; the water edge line of each hydraulic element is obtained according to the intersection point of each water surface line with the river channel cross-section; the river channel is gridded based on the boundary line and the control line to obtain a two-dimensional plane grid; and the river channel topography model is generated by interpolating and solving along the two-dimensional plane grid according to the measured cross-section data. Thus, the cost of river channel topography measurement can be reduced, and the generated river channel can fully reflect the hydraulic elements of the river, and can also more accurately reflect the actual river channel morphology, thereby improving the scientificity and accuracy of hydraulic numerical simulation calculations. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 A schematic flow chart of a method for generating river topography based on measured cross-sections and hydraulic elements provided in an embodiment of the present invention;

[0043] Figure 2 A schematic diagram of a river network of a one-dimensional hydrodynamic model provided by an embodiment of the present invention;

[0044] Figure 3A schematic diagram of the measured cross-sectional water surface curve at different flow levels provided by an embodiment of the present invention;

[0045] Figure 4 A schematic diagram of the intersection of the water surface of a river section and a river bank provided by an embodiment of the present invention;

[0046] Figure 5 A schematic diagram of a river waterside line at different flow levels provided by an embodiment of the present invention;

[0047] Figure 6 A schematic diagram of a river channel mesh subdivision based on a longitudinal control line provided in an embodiment of the present invention;

[0048] Figure 7 A schematic diagram of generating river terrain based on measured cross-sections and hydraulic elements provided by an embodiment of the present invention;

[0049] Figure 8 A schematic diagram of the river terrain is generated by using interpolation method without considering hydraulic elements;

[0050] Fig. 9 A schematic diagram of a system for generating river terrain based on measured cross-sections and hydraulic elements provided in an embodiment of the present invention;

[0051] Fig.10 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0053] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] The current existing river terrain interpolation algorithm does not take the river morphology into consideration when constructing the grid. Even if the river morphology is taken into consideration, it only considers the left and right bank lines and the deep channel. However, the algorithm still cannot meet the requirements of high-precision hydraulic numerical simulation calculations for the refinement of terrain for complex river terrain generation, and there are still large errors. Based on this, the present invention provides a method and system for generating river terrain based on measured sections and hydraulic elements, by constructing a one-dimensional hydrodynamic model based on measured section data, and obtaining the waterside line of the hydraulic element according to the hydraulic element, and constructing a two-dimensional plane grid with the waterside line and the deep channel line as the control line. The river terrain is generated by interpolating the measured section along the two-dimensional plane grid in the horizontal and vertical directions. It can reduce the cost of river terrain measurement while generating a more accurate river morphology, and improve the scientificity and accuracy of hydraulic numerical simulation calculations.

[0055] Figure 1 The present invention provides a flow chart of a method for generating river terrain based on measured cross-sections and hydraulic elements. The execution subject of the method can be a server, and a relatively complex river terrain model can be generated by the method. The method mainly includes the following steps:

[0056] S100. Construct a one-dimensional hydrodynamic model based on the measured cross-section data.

[0057] The measured cross-section data include riverbed elevation, water depth, riverbank shape, cross-sectional area and location information, etc. These measured cross-section data can be obtained through professional measuring equipment.

[0058] It should be noted that one-dimensional hydrodynamic models can enable users to better understand the behavior of water bodies, predict flood events, and conduct water resources planning.

[0059] In a possible embodiment, a one-dimensional hydrodynamic model may be constructed by the following steps:

[0060] Step 1: Construct a one-dimensional river network file based on the measured cross-section location and river centerline;

[0061] Step 2: Construct the cross-section terrain file based on the measured cross-section elevation data;

[0062] Step 3: Set the model boundary conditions and model parameters to obtain a one-dimensional hydrodynamic model;

[0063] Step 4: Calibrate and verify the one-dimensional hydrodynamic model based on measured flood data.

[0064] In order to determine the specific flow conditions in the river channel and the transmission path and connectivity of the water flow in the river channel, a one-dimensional river network file is constructed according to the position of the measured section and the center line of the river channel, and the river section information is input and edited. It is necessary to first determine the center line of the river channel, and determine the section position according to the measured section data. The position of each section is usually marked by its distance along the river. Through the center line data of the river channel, the sections are arranged on the center line according to the measured data or design requirements to obtain a one-dimensional river network file. Then, in the one-dimensional river network file, the information of each river section is input and edited, where the river section information specifically includes the geometric characteristics of each section of the river channel such as length, flow direction, etc., connection information such as the connection relationship between upstream and downstream sections, and river section attributes such as whether water is allowed to flow in and out.

[0065] The purpose of constructing the cross-sectional terrain file is to provide the cross-sectional information of the river, such as the riverbed depth, width, and riverbank shape, so it is based on the measured elevation data of the cross-sectional area. Specifically, the elevation data of the measured cross-sectional area can be processed by software to produce files describing the cross-sectional terrain of each cross-sectional area.

[0066] In setting the model boundary conditions and model parameters, the model boundary conditions include upper and lower boundaries, inner and outer boundaries, etc. The upper boundary can be an inflow condition such as reservoir water release, runoff generated by rainfall, etc. The lower boundary can be an outflow condition such as sea tide, the water level of another reservoir, etc. The inner boundary condition can be related to the confluence of tributaries, diversion or river crossing, etc. The outer boundary can be water exchange with the atmosphere or groundwater, etc. The model parameters include initial conditions, riverbed roughness, etc. The initial conditions describe the water flow state in the river channel when the model starts to simulate, such as water level, flow, etc. The riverbed roughness is a parameter that reflects the resistance of the riverbed to the water flow;

[0067] After obtaining the one-dimensional hydrodynamic model through the above steps, the measured data of historical flood events, such as the curves of water level and flow change over time, are used as the input of the model. The model parameters are adjusted so that the water level, flow, etc. output by the model are consistent with the actual data to the highest degree. The one-dimensional hydrodynamic model is calibrated and verified to ensure the accuracy of the model and to ensure that the model has a reliable scientific basis for application in the fields of water management, flood control planning, environmental impact assessment, etc.

[0068] In this application, the principle of the one-dimensional hydrodynamic model is as follows:

[0069] 1. Governing equations

[0070] The control equations in the one-dimensional unsteady flow mathematical model can be expressed as the Saint-Venant equations:

[0071]

[0072] Where F is the area of ​​the flow cross section, in m 2 , Q is the flow rate, unit is m3 / s, t is the time, x is the ordinate along the river, in m, q is the lateral inflow, in m 3 / s, u is the average flow velocity of the section, the singular is m / s, g is the acceleration due to gravity, generally g = 9.8m 2 / s, Z is the water level, unit is m, u qx is the component velocity of the average lateral inflow velocity in the x direction, in m / s, c is the Xie Cai coefficient, and R is the hydraulic radius, in m.

[0073] 2. Equation Discretization and Solution Methods

[0074] B represents the width of the water surface, We can get:

[0075]

[0076] In order to reduce the impact of the wider channel on the calculation results, for the compound section with obvious main channel and side beach, the flow modulus K of the main channel F and the side beach are calculated respectively, and then the hydraulic radius R of the whole section is calculated. Assuming that the roughness of the main channel and the side beach is the same, the hydraulic radius is converted using the following formula:

[0077]

[0078] In the formula, K zhu The flow modulus of the main tank, in m 3 / s·km 2 , F zhu is the cross-sectional area of ​​the main slot, in m 2 , R zhu is the hydraulic radius of the main tank, in m, K bian is the flow modulus of the beach, in m 3 / s·km 2 , F bian is the cross-sectional area of ​​the main slot, in m 2 , R bian It is the hydraulic radius of the main tank, in m.

[0079] If the main channel and the side beach are not divided, the hydraulic radius of the cross section is calculated according to the general hydraulic method. When Z and Q are used as basic unknowns and the momentum change of the lateral inflow along the x direction is ignored, the above Saint-Venant equations can be rewritten as:

[0080]

[0081] The above two expressions describe the flow movement method in a straight river section. For a river network composed of straight river sections, the branching needs to be processed. For a branch connecting k straight river sections, the connection equation is:

[0082] Z1=Z2=...=Z k

[0083]

[0084] The rewritten expressions and connection equations constitute the basic equations of one-dimensional unsteady flow in the river network. The above equations are numerically solved by the finite difference method, and the difference format adopts the four-point weighted average implicit format. The internal section equations and connection equations can form a quasi-linear equation system equal to the unknown number, which is solved by Gaussian elimination method.

[0085] S200, taking hydraulic elements as hydrological boundaries and obtaining the water surface line of each hydraulic element based on the one-dimensional hydrodynamic model.

[0086] Among them, hydraulic elements are various characteristic values ​​of water flow and its boundaries at different flow levels, such as water level, flow velocity, flow direction, flow rate, etc. In this application, hydraulic elements are water depth values ​​at different flow levels in the same large section, where different flow levels include large-scale floods, medium-scale floods, and small-scale floods.

[0087] In a possible embodiment, step S200 further includes the following steps:

[0088] Taking the flow rate as the upper hydrological boundary and the water level as the lower hydrological boundary, based on the upper hydrological boundary, the lower hydrological boundary and the one-dimensional hydrodynamic model, the water surface lines corresponding to large-scale floods, medium-scale floods and small-scale floods are calculated.

[0089] Specifically, in the present application, constant flow rates of large, medium and small magnitudes are used as the upper hydrological boundaries, and the corresponding water levels are used as the lower hydrological boundaries. Based on the one-dimensional hydrodynamic model constructed in the above steps, the water surface lines of the river channel under flood conditions of different flow levels can be calculated respectively.

[0090] S300, obtaining the waterside line of each hydraulic element according to the intersection points of each water surface line and the river section.

[0091] Among them, the waterside line refers to the dividing line between the land and the water surface. In a river, the waterside line is related to the water level, and the waterside line changes with the flow rate and riverbed topography.

[0092] In a possible embodiment, in step S300, the waterside line of each hydraulic element is obtained according to the intersection point of each water surface line and the river section, including:

[0093] Step S310, determining a deep point in the river section based on the river section position;

[0094] Step S320: Based on the deep point, perform a point-by-point analysis operation to determine a first intersection point and a second intersection point between the river section and the river bank;

[0095] Step S330: According to the point-by-point analysis operation, all river sections are traversed in a loop to obtain all the first intersection points and the second intersection points of the river sections.

[0096] Step S340: obtaining the waterside line of each hydraulic element based on all the first intersection points and the second intersection points of the river section of each hydraulic element.

[0097] In a possible embodiment, the point-by-point analysis operation includes the following steps:

[0098] Taking the deep gulf point as the dividing point, based on the deep gulf point, along the left bank direction, determine a first elevation point greater than the water level of the river section and a second elevation point adjacent to the first elevation point, the second elevation point is lower than the first elevation point of the water level of the river section, and perform linear interpolation based on the first elevation point and the second elevation point to obtain a first intersection point;

[0099] Based on the deep point, along the right bank direction, determine a third elevation point greater than the water level of the river section and a fourth elevation point adjacent to the third elevation point, the fourth elevation point is lower than the third elevation point of the river section water level, and linear interpolation is performed based on the third elevation point and the fourth elevation point to obtain the second intersection point.

[0100] Specifically, the method for solving the intersection point between the water surface line and the river section of different river sections is:

[0101] Based on the measured cross-sectional data of the river section, that is, the elevation data of the measured cross-sectional data, first determine the deep point in the river section. The deep point is the point with the deepest water depth on the river section. The deep point has the lowest elevation and the largest water depth. The position of the deep point can be determined by traversing all points on the river section and comparing the elevation values ​​of all points.

[0102] Then, the channel section is divided into two parts, the left and the right, based on the position of the deep fen. The left side of the deep fen to the left bank of the channel is the left part, and the right side of the deep fen to the right bank of the channel is the right part.

[0103] Then, based on the position of the deep gulf point, along the left bank direction, find the first elevation point greater than the water level of the river section and the second elevation point adjacent to the first elevation point, and the second elevation point is smaller than the first elevation point, and a linear interpolation algorithm is performed based on the first elevation point and the second elevation point to obtain a first intersection point, which is the intersection point of the river section and the left bank of the river; using the same method, based on the position of the deep gulf point, along the right bank direction, find the third elevation point greater than the water level of the river section and the fourth elevation point adjacent to the third elevation point, and the fourth elevation point is smaller than the third elevation point, and a linear interpolation algorithm is performed based on the third elevation point and the fourth elevation point to obtain a second intersection point, which is the intersection point of the river section and the right bank of the river. Through the above method, the intersection points of the river section and both sides of the river bank, that is, the first intersection point and the second intersection point, can be obtained;

[0104] Then, using the above method, the intersection points of different river sections and both sides of the river bank under the same magnitude of flood are obtained, and the intersection points of different river sections and both sides of the river bank under the same magnitude of flood are connected to obtain the water edge line under the same magnitude of flood;

[0105] Finally, using the above method, we can get the waterside line under each hydraulic element, that is, the waterside line corresponding to floods of different magnitudes.

[0106] S400, gridding the river channel based on the boundary lines and the control lines to obtain a two-dimensional plane grid.

[0107] Among them, control lines are used to divide the river into grids, and the grid division follows the rule of dense grids in key areas and appropriately sparse grids in non-key areas, thus forming a complete two-dimensional plane grid, which can more accurately simulate and analyze the river flow process, and provide strong support for water resources management, river governance, flood risk assessment, etc.

[0108] In a possible embodiment, step S400 further includes the following contents:

[0109] The left and right bank lines of the river are used as grid boundaries;

[0110] The waterside line and the deep channel line of each hydraulic element are used as the longitudinal control line;

[0111] Based on the subdivision rules, meshing is performed between two adjacent longitudinal control lines to obtain a two-dimensional plane orthogonal curve mesh.

[0112] Specifically, before constructing a two-dimensional plane grid, it is necessary to first determine the fixed boundaries of the grid. In this application, the boundary lines of the grid are determined by the left and right bank lines of the river channel, and then the water edge lines and sump lines at different flow levels are used as longitudinal control lines. The longitudinal control lines are used to ensure the rationality and accuracy of the grid division. Finally, the orthogonal curve grids are sequentially divided between every two longitudinal control lines (such as adjacent water edge lines or sump lines) to obtain a two-dimensional plane grid.

[0113] Furthermore, the division by orthogonal curve grid can better adapt to the irregular shape of the river channel, while maintaining the orthogonality of the grid, which is convenient for calculation and analysis.

[0114] Furthermore, the orthogonal curve grids are sequentially divided between each two longitudinal control lines based on the division rules, and the division rules are to encrypt the grids in the key areas and appropriately sparse the grids in the non-key areas. In other words, the grid division density can be adjusted as needed, for example, the grid density can be increased in areas where the river is curved, the water flow is complex, or high-precision simulation is required.

[0115] In a possible embodiment, after meshing the river channel based on the boundary line and the control line to obtain a two-dimensional plane mesh, the method further includes:

[0116] The grid can be optimized as needed to ensure that the grid shape can better fit the river channel morphology, hydraulic elements, i.e. the longitudinal control line morphology such as the deep pool. The optimization method can be achieved by adjusting the position of the grid nodes, merging or subdividing the grid units, etc.

[0117] It should be noted that the grid division in the present application may also adopt other types of grids, such as unstructured grids or adaptive grids.

[0118] S500, generating a river terrain model by performing interpolation along the two-dimensional plane grid according to the measured cross-section data.

[0119] The specific process of interpolating and solving the river terrain model along the two-dimensional plane grid based on the measured cross-section data is as follows:

[0120] First, it is necessary to obtain the measured cross-sectional data, which includes the coordinates of the data points and the corresponding function values. These data constitute a known data set on a two-dimensional plane.

[0121] Then, according to the nature, distribution and accuracy requirements of the data, select a suitable interpolation method. Common two-dimensional interpolation methods include bilinear interpolation, DIS (using spline interpolation), etc. The bilinear interpolation method is used in this application;

[0122] Finally, the elevation points on the longitudinal control line are interpolated based on the points on both sides of the longitudinal control line in each measured section, and then the elevation points on the grid nodes are interpolated along the longitudinal control line to complete the interpolation solution and generate the river terrain model.

[0123] In this application, a river section can be selected as a research example, and the river topography can be generated by interpolation based on measured cross-section data and hydraulic elements. The specific implementation process is as follows:

[0124] Step 1. Collect measured cross-section data, build a one-dimensional hydrodynamic model based on the measured cross-section data, and set up the river network file and cross-section layout, such as Figure 2 As shown;

[0125] Step 2. Take the hydraulic elements of different flow levels, large, medium and small, as the hydrological boundaries, and calculate the water surface lines at different flow levels according to the one-dimensional hydrodynamic model, such as Figure 3 As shown;

[0126] Step 3. Based on the intersection points of the water surface line and the river section at different flow levels, the water edge lines at different flow levels are obtained, such as Figure 4 and Figure 5 As shown;

[0127] Step 4. Take the left and right bank lines of the river, the water edge lines at different flow levels, and the deep water lines as the longitudinal control lines, and encrypt the two-dimensional plane grid between every two control lines. The grid generation results are as follows: Figure 6 As shown;

[0128] Step 5. Generate the river terrain model based on the measured cross section by interpolation along the grid, such as Figure 7 shown.

[0129] Figure 8 is the terrain interpolation result without considering hydraulic elements. Figure 7 and Figure 8 By comparison, it can be clearly seen from the figure that the interpolation results taking into account hydraulic elements can better reflect the morphological characteristics of the river channel and the results are more refined.

[0130] In summary, the method and system for generating river topography based on measured cross-sections and hydraulic elements provided in the embodiments of the present invention have the following innovative features:

[0131] 1. By constructing a two-dimensional plane grid to reflect the river morphology, hydraulic elements and longitudinal interpolation lines of the deep, the interpolation lines can more accurately reflect the longitudinal changes of the river, including the ups and downs, curvature of the riverbed and changes in hydraulic characteristics.

[0132] 2. When collecting elevation data of the measured section, a certain number of points are selected for data collection. These points are distributed along the cross section of the river. Therefore, these points need to be intersected with the longitudinal interpolation line. The elevation of the corresponding intersection on the interpolation line can be interpolated to ensure the longitudinal continuity and accuracy of the river terrain.

[0133] 3. After determining the elevation of the intersection points on the longitudinal interpolation lines of the river channel, each measured cross section and these intersection points can be used as control points. Then, along the longitudinal interpolation lines of the river channel, the elevation of the grid nodes on each longitudinal interpolation line is calculated using the interpolation algorithm, thus forming river channel terrain elevation points that can reflect the hydraulic elements and river channel morphology of the river channel.

[0134] Fig. 9 A schematic diagram of a system structure for generating river topography based on measured cross-sections and hydraulic elements provided in an embodiment of the present application. Fig. 9 As shown, the system includes:

[0135] A construction module 910 is used to construct a one-dimensional hydrodynamic model based on the data of the measured section;

[0136] The calculation module 920 is used to obtain the water surface line of each hydraulic element based on the one-dimensional hydrodynamic model by taking the hydraulic element as the hydrological boundary; and to obtain the water edge line of each hydraulic element according to the intersection point of each water surface line with the river section;

[0137] A division module 930 is used to divide the river channel into grids based on the boundary lines and the control lines to obtain a two-dimensional plane grid;

[0138] The generation module 940 is used to generate a river terrain model by performing interpolation and solving along the two-dimensional plane grid according to the measured cross-section data.

[0139] In a possible embodiment, the building module 910 is further configured to:

[0140] Construct a one-dimensional river network file based on the measured cross-section locations and river centerlines;

[0141] Construct cross-section terrain files based on measured cross-section elevation data;

[0142] Set the model boundary conditions and model parameters to obtain a one-dimensional hydrodynamic model;

[0143] The one-dimensional hydrodynamic model is calibrated and verified based on measured flood data.

[0144] In a possible embodiment, the hydraulic elements include large-scale floods, medium-scale floods and small-scale floods.

[0145] In a possible embodiment, the calculation module 920 is further configured to:

[0146] Taking the flow rate as the upper hydrological boundary and the water level as the lower hydrological boundary, based on the upper hydrological boundary, the lower hydrological boundary and the one-dimensional hydrodynamic model, the water surface lines corresponding to large-scale floods, medium-scale floods and small-scale floods are calculated.

[0147] In a possible embodiment, the calculation module 920 is further configured to:

[0148] Based on the location of the river section, determining a deep point in the river section;

[0149] Based on the deep point, performing a point-by-point analysis operation to determine a first intersection point and a second intersection point between the river section and the river bank;

[0150] According to the point-by-point analysis operation, all the river sections are traversed in a loop to obtain all the first intersection points and the second intersection points of the river sections;

[0151] Based on all the first intersection points and the second intersection points of the river section of each hydraulic element, the waterside line of each hydraulic element is obtained.

[0152] In a possible embodiment, the point-by-point analysis operation includes:

[0153] Taking the deep gulf point as the dividing point, based on the deep gulf point, along the left bank direction, determine a first elevation point greater than the water level of the river section and a second elevation point adjacent to the first elevation point, the second elevation point is lower than the first elevation point of the water level of the river section, and perform linear interpolation based on the first elevation point and the second elevation point to obtain a first intersection point;

[0154] Based on the deep point, along the right bank direction, determine a third elevation point greater than the water level of the river section and a fourth elevation point adjacent to the third elevation point, the fourth elevation point is lower than the third elevation point of the river section water level, and linear interpolation is performed based on the third elevation point and the fourth elevation point to obtain the second intersection point.

[0155] In a possible embodiment, the partitioning module 930 is further configured to:

[0156] The left and right bank lines of the river are used as grid boundaries;

[0157] The waterside line and the deep channel line of each hydraulic element are used as the longitudinal control line;

[0158] Based on the subdivision rules, meshing is performed between two adjacent longitudinal control lines to obtain a two-dimensional plane orthogonal curve mesh.

[0159] In a possible embodiment, the generating module 940 is further configured to:

[0160] The river topography is generated based on the measured cross-section and the horizontal and vertical interpolation along the grid, and the topographic data or graphics are output to the interactive device. The final river topographic data and graphics can be displayed on the monitor or written into an Excel spreadsheet for storage.

[0161] The implementation principle and technical effects of the system provided in the embodiment of the present application are the same as those of the aforementioned method embodiment. For the sake of brief description, for matters not mentioned in the system embodiment, reference may be made to the corresponding contents in the aforementioned method embodiment.

[0162] like Fig.10 As shown, an electronic device 600 provided in an embodiment of the present application includes: a processor 601, a memory 602 and a bus, the memory 602 stores machine-readable instructions executable by the processor 601, when the electronic device is running, the processor 601 and the memory 602 communicate through the bus, and the processor 601 executes the machine-readable instructions to perform the steps of the method for generating river topography based on measured sections and hydraulic elements as described above.

[0163] Specifically, the above-mentioned memory 602 and processor 601 can be general-purpose memory and processor, which are not specifically limited here. When the processor 601 runs the computer program stored in the memory 602, it can execute the above-mentioned method of generating river topography based on measured sections and hydraulic elements.

[0164] The processor 601 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the hardware integrated logic circuit or software instructions in the processor 601. The above processor 601 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiments of the present application can be directly embodied as a hardware decoding processor for execution, or a combination of hardware and software modules in the decoding processor for execution. The software module may be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 602, and the processor 601 reads the information in the memory 602 and completes the steps of the above method in combination with its hardware.

[0165] Corresponding to the above-mentioned method for generating river channel topography based on measured sections and hydraulic elements, an embodiment of the present application also provides a computer-readable storage medium, which stores machine-executable instructions. When the computer-executable instructions are called and executed by the processor, the computer-executable instructions prompt the processor to execute the steps of the above-mentioned method for generating river channel topography based on measured sections and hydraulic elements.

[0166] The system for generating river topography based on measured cross-sections and hydraulic elements provided in the embodiments of the present application can be specific hardware on the device or software or firmware installed on the device. The device provided in the embodiments of the present application, its implementation principle and the technical effect produced are the same as those in the aforementioned method embodiments. For the sake of brief description, for the parts not mentioned in the device embodiment, reference can be made to the corresponding contents in the aforementioned method embodiments. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, devices and units described above can all refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here.

[0167] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0168] For another example, the flowchart and block diagram in the accompanying drawings show the possible architecture, functions and operations of the device, method and computer program product according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and a part of the module, program segment or code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of the boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0169] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0170] In addition, each functional unit in the embodiments provided in the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0171] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can essentially or in other words, the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including a number of instructions for an electronic device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, referred to as ROM), random access memory (Random Access Memory, referred to as RAM), disk or optical disk and other media that can store program codes.

[0172] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0173] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0174] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for generating river topography based on measured cross sections and hydraulic elements, characterized in that: include: Based on the data of the measured cross section, a one-dimensional hydrodynamic model is constructed; Taking hydraulic elements as hydrological boundaries, based on the one-dimensional hydrodynamic model, the water surface line of each hydraulic element is obtained; wherein, the hydraulic elements are taken as the hydrological upper boundary with flow rates of different magnitudes, and the water level corresponding to different flow rates is taken as the hydrological lower boundary; According to the intersection points of each water surface line and the river section, the waterside line of each hydraulic element is obtained; wherein, according to the intersection points of each water surface line and the river section, the waterside line of each hydraulic element is obtained, including: based on the position of the river section, determining the deep point in the river section; based on the deep point, performing a point-by-point analysis operation to determine the first intersection point and the second intersection point of the water surface line and the river bank; according to the point-by-point analysis operation, looping through all river sections to obtain all the first intersection points and the second intersection points of the river section; based on all the first intersection points and the second intersection points of the river section of each hydraulic element, the waterside line of each hydraulic element is obtained; wherein, The point-by-point analysis operation includes: taking the deep gulf point as a dividing point, based on the deep gulf point, along the left bank direction, determining a first elevation point greater than the water level of the river section and a second elevation point adjacent to the first elevation point, the second elevation point being lower than the first elevation point of the river section water level, and performing linear interpolation based on the first elevation point and the second elevation point to obtain a first intersection point; based on the deep gulf point, along the right bank direction, determining a third elevation point greater than the water level of the river section and a fourth elevation point adjacent to the third elevation point, the fourth elevation point being lower than the third elevation point of the river section water level, and performing linear interpolation based on the third elevation point and the fourth elevation point to obtain a second intersection point; Based on the boundary lines and the control lines, the river channel is meshed to obtain a two-dimensional plane grid; wherein, based on the boundary lines and the control lines, the river channel is meshed to obtain a two-dimensional plane grid, including: using the left and right bank lines of the river channel as grid boundary lines; using the water edge line and the deep channel line of each hydraulic element as longitudinal control lines; based on the segmentation rule, meshing is performed between two adjacent longitudinal control lines to obtain a two-dimensional plane orthogonal curve grid; The river terrain model is generated by interpolating and solving along the two-dimensional plane grid according to the measured cross-section data.

2. The method according to claim 1, characterized in that The one-dimensional hydrodynamic model is constructed based on the measured cross-section data, including: Construct a one-dimensional river network file based on the measured cross-section locations and river centerlines; Construct cross-section terrain files based on measured cross-section elevation data; Set the model boundary conditions and model parameters to obtain a one-dimensional hydrodynamic model; The one-dimensional hydrodynamic model is calibrated and verified based on measured flood data.

3. The method according to claim 1, characterized in that The hydraulic elements include large-scale floods, medium-scale floods and small-scale floods.

4. The method according to claim 3, characterized in that Taking hydraulic elements as hydrological boundaries and based on the one-dimensional hydrodynamic model, the water surface lines under each hydraulic element are obtained, including: Taking the flow rate as the upper hydrological boundary and the water level as the lower hydrological boundary, based on the upper hydrological boundary, the lower hydrological boundary and the one-dimensional hydrodynamic model, the water surface lines corresponding to large-scale floods, medium-scale floods and small-scale floods are calculated.

5. A system for generating river topography based on measured cross sections and hydraulic elements, characterized in that: include: A construction module is used to construct a one-dimensional hydrodynamic model based on the data of the measured section; A calculation module is used to use hydraulic elements as hydrological boundaries, and based on the one-dimensional hydrodynamic model, obtain the water surface line of each hydraulic element; and obtain the water edge line of each hydraulic element according to the intersection point of each water surface line with the river section; wherein, the hydraulic element is used as the hydrological upper boundary with different magnitudes of flow, and the water level corresponding to different flow rates is the hydrological lower boundary; wherein, according to the intersection point of each water surface line with the river section, the water edge line of each hydraulic element is obtained, including: based on the position of the river section, determining the deep point in the river section; based on the deep point, performing a point-by-point analysis operation to determine the first intersection point and the second intersection point of the water surface line with the river bank; according to the point-by-point analysis operation, looping through all river sections to obtain all the first intersection points and the second intersection points of the river section; based on All the first intersection points and the second intersection points of the river section of each hydraulic element are determined to obtain the waterside line of each hydraulic element; wherein the point-by-point analysis operation includes: taking the deep trough point as the dividing point, based on the deep trough point, along the left bank direction, determining a first elevation point greater than the water level of the river section and a second elevation point adjacent to the first elevation point, the second elevation point is lower than the first elevation point of the river section water level, and performing linear interpolation based on the first elevation point and the second elevation point to obtain the first intersection point; based on the deep trough point, along the right bank direction, determining a third elevation point greater than the water level of the river section and a fourth elevation point adjacent to the third elevation point, the fourth elevation point is lower than the third elevation point of the river section water level, and performing linear interpolation based on the third elevation point and the fourth elevation point to obtain the second intersection point; A division module is used to divide the river channel into grids based on the boundary lines and the control lines to obtain a two-dimensional plane grid; wherein, the river channel is divided into grids based on the boundary lines and the control lines to obtain a two-dimensional plane grid, including: using the left and right bank lines of the river channel as grid boundary lines; using the water edge line and the deep channel line of each hydraulic element as longitudinal control lines; based on the division rule, dividing the grid between two adjacent longitudinal control lines to obtain a two-dimensional plane orthogonal curve grid; The generation module is used to generate a river terrain model by performing interpolation and solving along the two-dimensional plane grid according to the measured cross-section data.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 4 are implemented.

7. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores machine-executable instructions. When the machine-executable instructions are called and executed by a processor, the machine-executable instructions cause the processor to execute the method according to any one of claims 1 to 4.

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