A river section extraction method, device, equipment, medium and product

Abstract

The application discloses a river section extraction method, device, equipment, medium and product, and relates to the hydrological technology field. The method comprises the following steps: dividing a river section based on the equidistance of the river axis of a target river, and obtaining the river section bending coefficient of each river section; adjusting the river section extraction interval of the target river based on the river section bending coefficient of each river section, and obtaining a first section extraction interval with different values; determining the water depth sudden change coefficient in the first section extraction interval, and adjusting the first section extraction interval based on the water depth sudden change coefficient, thereby obtaining a second section extraction interval with different values; determining the measuring point of the river section in the second section extraction interval based on the grid interval of the underwater topographic data; and generating the river section of the target river based on the second section extraction interval with different values and the measuring point of the river section. The application can improve the data precision of the river section and provide data support for establishing a one-dimensional hydrodynamic model.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrology, in particular to a river section extraction method, device, equipment, medium and product. BACKGROUND

[0002] The section of a river is a surface elevation profile of a river cross section. The information of the section of a river is key information used by waterway surveying. For example, the information of the section can be used to establish a one-dimensional hydrodynamic (river) model.

[0003] At present, the method for extracting the section of a river usually draws a section line of the section of a river based on the contour lines of the location where the river is located, and generates a profile drawing of the section by using the contour lines and the section line. That is, the section line is first drawn on a topographic map, then the intersection points of the section line and characteristic contour lines such as the ordinate curve and the abscissa curve are captured by using VBA programming, and finally the elevation values of the intersection points are extracted according to the elevation values of the characteristic contour lines. However, when the above method is used to extract the section of a river, if the contour lines in the topographic map of the river are sparse or do not exist, the contour section line needs to be extended to obtain a self-drawn contour section line, which will result in low data precision of the extracted section of a river and cannot establish a one-dimensional hydrodynamic (river) model with high precision. SUMMARY

[0004] In view of the above defects or shortcomings in the related art, the purpose of the present application is to provide a river section extraction method, device, equipment, medium and product, which can improve the data precision of the section of a river and provide data support for establishing a one-dimensional hydrodynamic (river) model.

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

[0006] In a first aspect, the present application provides a river section extraction method, which comprises: dividing river reaches at equal intervals based on a river axis of a target river, and obtaining a river reach curvature coefficient of each river reach; adjusting a river section extraction interval of the target river based on the river reach curvature coefficient of each river reach to obtain a first section extraction interval with different values; determining a water depth sudden change coefficient within the first section extraction interval, and adjusting the first section extraction interval based on the water depth sudden change coefficient to obtain a second section extraction interval with different values; determining a measurement point of a river section within the second section extraction interval based on a grid interval of underwater topographic data; and generating a river section of the target river based on the second section extraction interval with different values and the measurement point of the river section.

[0007] Optionally, the equal interval division of the river axis of the target river and obtaining the river section bending coefficient of each river section include: dividing the river axis of the target river into a plurality of river sections according to a preset length; obtaining a straight-line distance and an actual distance between start and end points of each river section; and obtaining the river section bending coefficient of each river section based on the straight-line distance and the actual distance of each river section.

[0008] Optionally, the adjusting of the river cross-section extraction interval of the target river based on the river section bending coefficient of each river section and obtaining the first cross-section extraction interval of different values include: if the river section bending coefficient S1 of any river section of the equal interval division is less than a first threshold value, marking the corresponding river section as a straight section and determining the first cross-section extraction interval of the straight section as a first value; if the river section bending coefficient S1 of any river section of the equal interval division is greater than or equal to the first threshold value and less than or equal to a second threshold value, marking the corresponding river section as a curved section and determining the first cross-section extraction interval of the curved section as a second value; if the river section bending coefficient S1 of any river section of the equal interval division is greater than the second threshold value, marking the corresponding river section as a sharp bend section and determining the first cross-section extraction interval of the sharp bend section as a third value; or, in the case that the first cross-section extraction interval is the third value, if the river section bending coefficient S2 of any river section within the first cross-section extraction interval is greater than the first threshold value or the bending angle between adjacent river sections is less than 90 degrees, marking the corresponding river section as a sharp bend section and determining the first cross-section extraction interval of the sharp bend section as a fourth value.

[0009] Optionally, the determining of the water depth sudden change coefficient within the first cross-section extraction interval include: obtaining a maximum elevation and a minimum elevation within the first cross-section extraction interval of different values; and obtaining the difference between the maximum elevation and the minimum elevation within the first cross-section extraction interval of different values to obtain the water depth sudden change coefficient within the first cross-section extraction interval of different values.

[0010] Optionally, the adjusting of the first cross-section extraction interval based on the water depth sudden change coefficient and obtaining the second cross-section extraction interval of different values include: if the water depth sudden change coefficient within any first cross-section extraction interval is greater than a third threshold value in a plain area, the river section corresponding to the first cross-section extraction interval is a water depth sudden change zone, and the second cross-section extraction interval is a fifth value; and if the water depth sudden change coefficient within any first cross-section extraction interval is greater than a fourth threshold value in a mountainous area, the river section corresponding to the first cross-section extraction interval is a water depth sudden change zone, and the second cross-section extraction interval is a fifth value.

[0011] Optionally, the determining the measuring points of the river section within the second cross-section extraction interval based on the grid spacing of the underwater topographic data comprises: if the grid spacing of the underwater topographic data is less than or equal to a fifth threshold value, determining the measuring point spacing of the river section within the second cross-section extraction interval as a sixth numerical value; and if the grid spacing of the underwater topographic data is greater than the fifth threshold value, determining the measuring point spacing of the river section within the second cross-section extraction interval as a seventh numerical value.

[0012] In a second aspect, the present application provides a river section extraction device, comprising:

[0013] a river section dividing module, configured to divide a river section based on equal spacing of a river axis of a target river, and obtain a river section bending coefficient of each river section;

[0014] a first adjusting module, configured to adjust a river section cross-section extraction interval of the target river based on the river section bending coefficient of each river section, to obtain a first cross-section extraction interval with different numerical values;

[0015] a second adjusting module, configured to determine a water depth sudden change coefficient within the first cross-section extraction interval, and adjust the first cross-section extraction interval based on the water depth sudden change coefficient, to obtain a second cross-section extraction interval with different numerical values;

[0016] a measuring point determining module, configured to determine measuring points of a river section within the second cross-section extraction interval based on a grid spacing of underwater topographic data;

[0017] a cross-section generating module, configured to generate a river section of the target river based on the second cross-section extraction interval with different numerical values and the measuring points of the river section.

[0018] In a third aspect, the present application provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the river section extraction method according to any one of the above embodiments.

[0019] In a fourth aspect, the present application provides a computer readable storage medium, having a computer program stored thereon, wherein the computer program is executable by a processor to implement the steps of the river section extraction method according to any one of the above embodiments.

[0020] In a fifth aspect, the present application provides a computer program product, comprising a computer program executable by a processor to implement the steps of the river section extraction method according to any one of the above embodiments.

[0021] According to the embodiments of the present application, the following technical effects are achieved:

[0022] The application provides a river section extraction method, device, equipment, medium and product. A plurality of river sections are obtained by equally spacing the river axis of a target river, the river section extraction interval of the target river is adjusted by obtaining the river section bending coefficient of each river section, and a first section extraction interval with different values is obtained. The first section extraction interval is adjusted by the water depth sudden change coefficient in the first section extraction interval with different values, and a second section extraction interval with different values is obtained. The measuring points of the river section in the second section extraction interval with different values are determined by the grid interval of the underwater topographic data. The river section of the target river is generated by the measuring points of the river section and the second section extraction interval with different values. On the one hand, the river section of the target river is extracted on the basis of the traditional equal-interval section extraction method in combination with the river section bending coefficient, the water depth sudden change coefficient and the grid interval of the underwater topographic data, the data precision of the river section is effectively improved, and data support is provided for establishing a one-dimensional hydrodynamic (river) model. On the other hand, the river section extraction interval is adjusted twice, which can adapt to the river conditions of different river basins of the target river, so that the generated river section of the target river can better reflect the real situation of the target river, thereby supporting more accurate flood prediction and other water conservancy management activities. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0024] Figure 1 The application environment diagram of a river section extraction method in an embodiment of the present application;

[0025] Figure 2 The flowchart of a river section extraction method provided by an embodiment of the present application;

[0026] Figure 3 The flowchart of a river section extraction method provided by another embodiment of the present application;

[0027] Figure 4 The functional module diagram of a river section extraction device provided by an embodiment of the present application;

[0028] Figure 5 The structural diagram of a computer device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0030] The above purposes, features and advantages of the present application can be more apparent and easy to understand. The solutions described in the present application are further described below with reference to the drawings and specific embodiments.

[0031] The river cross section extraction method provided by the embodiments of the present application can be applied in an application environment as shown in the figure. Figure 1 The terminal 102 communicates with the server 104 through a network. The data storage system can store the data required by the server 104 for processing. The data storage system can be separately arranged, integrated on the server 104, or placed on the cloud or other servers. The terminal 102 can send the river axis length of the target river and the grid spacing of the underwater topographic data to the server 104. After receiving the river axis length and the grid spacing of the underwater topographic data, the server 104 equally divides the river section based on the river axis of the target river for the river axis length and the grid spacing of the underwater topographic data, and obtains the river section bending coefficient of each river section. The server 104 adjusts the river cross section extraction interval of the target river based on the river section bending coefficient of each river section, and obtains the first cross section extraction interval with different values. The server 104 determines the water depth sudden change coefficient within the first cross section extraction interval, and adjusts the first cross section extraction interval based on the water depth sudden change coefficient, and obtains the second cross section extraction interval with different values. Based on the grid spacing of the underwater topographic data, the server 104 determines the measuring point of the river cross section within the second cross section extraction interval. Based on the second cross section extraction interval with different values and the measuring point of the river cross section, the server 104 generates the river cross section of the target river. The server 104 can feed back the obtained river cross section of the target river to the terminal 102. In addition, in some embodiments, the river cross section extraction method can also be realized by the server 104 or the terminal 102 alone, for example, the terminal 102 can directly extract the river cross section for the river axis length and the grid spacing of the underwater topographic data, or the server 104 can obtain the river axis length and the grid spacing of the underwater topographic data from the data storage system, and extract the river cross section for the river axis length and the grid spacing of the underwater topographic data.

[0032] The terminal 102 can be, but is not limited to, various desktop computers, notebook computers, smart phones, tablet computers and the like. The server 104 can be realized by an independent server or a server cluster composed of multiple servers, and can also be a cloud server.

[0033] In one example embodiment, as shown in Figure 2 A river cross-section extraction method is provided, which is executed by a computer device, specifically, can be executed by a terminal or a server, or both, in the embodiments of the present application, the method is applied to the server 104 in Figure 1 The following steps S201 to S205 are included. Wherein:

[0034] Step S201, divide the river section according to the equal spacing of the river axis of the target river, and obtain the river section bending coefficient of each river section.

[0035] In the example embodiment, the river axis refers to a virtual line along the center line of the river, which is usually used to represent the main flow direction and morphology of the river. This line runs through the entire river, from upstream to downstream, basically representing the longest path or the direction of the main flow of the river. In technical documents or engineering drawings, the river axis is the basis for analyzing the structure of the river, designing bridges and other hydraulic structures, and simulating river dynamics. In the embodiments of the present application, the river axis is the basis for calculating the river section bending degree, identifying the sharp bend area and analyzing the sudden change of water depth.

[0036] Wherein, the flowing area of the target river from upstream to downstream generally includes straight area, curved area and sharp bend area; straight area refers to the target river channel which presents a relatively straight, single morphology in the plane, without obvious bending or winding; the river boundary is smooth and the shape is straight. The curved area refers to the river channel which presents a significant bending or winding morphology in the plane; the main flow line of such a river channel is no longer a straight line or an approximate straight line, but flows along a complex and variable curve. The sharp bend area refers to the area where the flow direction of the river changes significantly, usually formed due to the sudden change of the river direction.

[0037] Optionally, the above step S201 can include: dividing the river axis of the target river into a plurality of river sections according to a preset length; obtaining the straight line distance and the actual distance between the starting and ending points of each river section; based on the straight line distance and the actual distance of each river section, obtaining the river section bending coefficient of each river section.

[0038] It can be understood that, for example, the river axis is divided into a section every 10 kilometers based on the river axis, each section is called a river section, and the river section bending coefficient S1 of each river section is calculated by formula (1):

[0039]

[0040] Wherein, L R is the actual length of the corresponding river section, and L is the straight line distance between the starting and ending points of the corresponding river section.

[0041] It should be noted that the embodiments of the present application take 10 as an example of equal interval, and the river bend coefficient of each river section of the target river is described. In other embodiments, the equal interval division distance can be appropriately set according to the actual length of the target river.

[0042] In step S202, the river channel section extraction interval of the target river is adjusted based on the river bend coefficient of each river section, and a first section extraction interval with different values is obtained.

[0043] As can be seen from the above example embodiments, the flowing area of the target river from the upstream to the downstream generally includes a straight area, a curved area and a sharp bend area. If the river axis of the river section of the straight area, the curved area and the sharp bend area is equal, it will cause a larger section extraction error. Therefore, the section extraction interval of the river section of the straight area, the curved area and the sharp bend area needs to be adjusted according to the different river bend coefficients of the corresponding straight area, curved area and sharp bend area, so as to improve the data precision of the river channel section.

[0044] Optionally, the above step S202 can include: if the river bend coefficient S1 of any river section divided by equal interval is less than a first threshold value, the corresponding river section is marked as a straight area, and the first section extraction interval of the straight area is determined as a first value; if the river bend coefficient S1 of any river section divided by equal interval is greater than or equal to the first threshold value and less than or equal to a second threshold value, the corresponding river section is marked as a curved area, and the first section extraction interval of the curved area is determined as a second value; if the river bend coefficient S1 of any river section divided by equal interval is greater than the second threshold value, the corresponding river section is marked as a sharp bend area, and the first section extraction interval of the sharp bend area is determined as a third value; or, in the case where the first section extraction interval is the third value, if the river bend coefficient S2 of any river section within the first section extraction interval is greater than the first threshold value or the bending angle between adjacent river sections is less than 90 degrees, the corresponding river section is marked as a sharp bend area, and the first section extraction interval of the sharp bend area is determined as a fourth value.

[0045] As can be understood, for example, as shown in Table 1 below:

[0046] Table 1

[0047]

[0048] If the first threshold value is 1.2, the second threshold value is 1.5, the first value is 1000 meters, the second value is 500 meters, the third value is 200 meters, and the fourth value is 50 meters, then:

[0049] When the river section bending coefficient S1 is less than 1.2, the river section is straight, and the first cross section extraction interval is 1000 meters. When the river section bending coefficient S1 is greater than or equal to 1.2 and less than or equal to 1.5, the river section is curved, and the first cross section extraction interval is 500 meters. When the river section bending coefficient S1 is greater than 1.5, the river section is sharp curved, and the first cross section extraction interval is 200 meters.

[0050] After the river section extraction, that is, the first cross section extraction interval is determined, first, the river section bending coefficient S2 of each river section in the first cross section extraction interval of different numerical values is calculated by formula (2);

[0051]

[0052] wherein, L d is the first cross section extraction interval, L n is the straight line distance between the start and end points of the river section in the first cross section extraction interval.

[0053] Secondly, the bending angle L θ between adjacent river sections (that is, the straight line angle between the start and end points of adjacent river sections) is calculated by formula (3);

[0054]

[0055] wherein, k AB is the slope of the straight line AB between the start and end points of the nth river section in the first cross section extraction interval, k BC is the slope of the straight line BC between the start and end points of the n+1th river section in the first cross section extraction interval, L θ is the angle between adjacent river sections L n , L n+1 in the first cross section extraction interval; 180 represents 180 degrees.

[0056] In the case where the first cross section extraction interval is 200 meters, when the river section bending coefficient S2 of any river section in the first cross section extraction interval is greater than 1.2 or L θ is less than 90 degrees, it is determined that the river section is a sharp curved section, and the river channel cross section interval needs to be set to 50 meters.

[0057] It should be noted that in the case of determining any river section as a sharp bend area, the river section in the sharp bend area is divided into multiple sections, and the adjacent river section angles and the river section bending coefficients in the sharp bend area are used to determine the river shape in the sharp bend area again, mainly to make up for the judgment defects when the river section is in some special positions (for example, at the arc of a large bend or across multiple small bends). That is, when determining the river shape in the sharp bend area, in the case that any river section is at the arc of a large bend, the river section bending coefficient cannot completely reflect the river shape of the river section, and the adjacent river section angle can be used to represent it; in the case that any river section is in a narrow river channel and crosses multiple small bends, at this time, the adjacent river section angle cannot reflect the real river shape in the sharp bend area, and the river section bending coefficient needs to be used to represent it. In the present application, the large bend refers to the adjacent river section angle being less than 90 degrees, and the small bend refers to the adjacent river section angle being greater than or equal to 90 degrees.

[0058] By re-determining the river shape of the river section in the sharp bend area, the distance between the adjacent river sections in the sharp bend area can be further adjusted, and the data accuracy of the river cross section can be further improved.

[0059] In step S203, the water depth sudden change coefficient in the first cross section extraction interval is determined, and the first cross section extraction interval is adjusted based on the water depth sudden change coefficient to obtain a second cross section extraction interval with different values.

[0060] In an example embodiment, the water depth sudden change coefficient is a parameter used to describe a water depth sudden change zone in a river or a channel. The water depth sudden change zone refers to a region in a river where the water depth or the river elevation changes significantly within a relatively short spatial range due to sudden changes in riverbed topography, flow conditions or other natural factors. This region can be regarded as a belt-shaped region because the changes in water depth or river elevation are often not isolated but continuously spread along a certain river section.

[0061] Optionally, the determination of the water depth sudden change coefficient in the first cross section extraction interval in step S203 can include: obtaining the maximum elevation and the minimum elevation in the first cross section extraction interval with different values; calculating the difference between the maximum elevation and the minimum elevation in the first cross section extraction interval with different values to obtain the water depth sudden change coefficient in the first cross section extraction interval with different values.

[0062] It can be understood that the water depth sudden change coefficient Δh in the first cross section extraction interval with different values is calculated by formula (4);

[0063] Δh = H max -H min (4);

[0064] wherein H max is the maximum elevation of the river section in the first cross section extraction interval, and H minextract the minimum elevation of the river section within the first section extraction interval.

[0065] It should be noted that the maximum elevation refers to the height of the highest point of the river section within the first section extraction interval; the minimum elevation refers to the height of the lowest point of the river section within the first section extraction interval.

[0066] Further, the step S203 of adjusting the first section extraction interval based on the water depth sudden change coefficient to obtain a second section extraction interval with different values can include: if the water depth sudden change coefficient within any first section extraction interval in the plain area is greater than a third threshold value, the river section corresponding to the first section extraction interval is a water depth sudden change zone, and the second section extraction interval is a fifth value; if the water depth sudden change coefficient within any first section extraction interval in the mountainous area is greater than a fourth threshold value, the river section corresponding to the first section extraction interval is a water depth sudden change zone, and the second section extraction interval is a fifth value.

[0067] It can be understood that, for example, if the third threshold value is 5 meters, the fourth threshold value is 50 meters, and the fifth value is 100 meters, then: when the water depth sudden change coefficient within a first section extraction interval in the mountainous area is greater than 50 meters, it is determined to be a water depth sudden change zone. When the water depth sudden change coefficient within a first section extraction interval in the plain area is greater than 5 meters, it is determined to be a water depth sudden change zone. At this time, the first section extraction interval is set to 100 meters.

[0068] In step S204, based on the grid interval of the underwater topographic data, the measuring points of the river section within the second section extraction interval are determined.

[0069] In an example embodiment, the grid of underwater topographic data generally refers to the application of a digital elevation model (Digital Elevation Model, DEM) in a water environment, i.e., a digital bathymetric model (Digital Bathymetric Model, DBM) or a seabed topographic model. The grid of underwater topographic data in the embodiment of the application mainly refers to the digital bathymetric model DBM, which uses regular or irregular grids to represent the height (actually the depth relative to a certain reference surface) information of the seabed topography.

[0070] The grid of underwater topographic data uses regular grid to represent the river water terrain in the plain area, i.e., all grid points are arranged according to fixed intervals to form a rectangular grid; each grid point represents the water depth value at a specific geographic coordinate. The grid of underwater topographic data uses irregular grid to represent the river water terrain in the mountainous area, i.e., the river terrain is decomposed into a series of connected triangles, each vertex corresponding to an actually measured data point; the sampling density can be adjusted according to the complexity of the terrain change.

[0071] In the process of river cross-section measurement, in order to accurately describe the shape and characteristics of the river cross-section, the points with representative topographic features selected on the river bottom (river bottom line), water surface or river cross-section side slope are called measuring points. In the river cross-section measurement, the projection distance between adjacent two measuring points in the horizontal direction (i.e. perpendicular to the main flow direction of the river) is called the measuring point spacing. The density of the measuring points can directly reflect the shape accuracy of the river cross-section. In the embodiments of the present application, the setting of the measuring point spacing mainly refers to the grid spacing of the underwater topographic data. In other embodiments, the setting of the measuring point spacing can refer to the grid spacing of the underwater topographic data and the design accuracy of the one-dimensional hydrodynamic model.

[0072] Optionally, the above step S204 can include: if the grid spacing of the underwater topographic data is less than or equal to the fifth threshold value, determining the measuring point spacing of the river cross-section within the second cross-section extraction spacing to be a sixth value; and if the grid spacing of the underwater topographic data is greater than the fifth threshold value, determining the measuring point spacing of the river cross-section within the second cross-section extraction spacing to be a seventh value.

[0073] It can be understood that, for example, when the fifth threshold value is 5 meters, the sixth value is 3 meters, and the seventh value is 10 meters, then when the grid spacing of the underwater topographic data is less than or equal to 5 meters, the measuring point spacing of the river cross-section within the second cross-section extraction spacing is 3 meters. When the underwater topographic grid spacing is greater than 5 meters, the measuring point spacing of the river cross-section within the second cross-section extraction spacing is 10 meters.

[0074] Step S205, generating the river cross-section of the target river based on the second cross-section extraction spacing with different values and the measuring points of the river cross-section.

[0075] It should be noted that the river cross-section of the target river generated by the second cross-section extraction spacing with different values and the measuring points of the river cross-section has a larger density in the area with a sharp change in topography or a special important area (such as a sharp bend area or a water depth sudden change belt), and a smaller density in the area with relatively flat topography (such as a straight area).

[0076] The steps S201 to S205 are implemented, a plurality of river sections are obtained by equally spacing the river axis of the target river, the river channel section extraction interval of the target river is adjusted by obtaining the river section bending coefficient of each river section, and different values of the first section extraction interval are obtained; the first section extraction interval is adjusted by the water depth sudden change coefficient in the different values of the first section extraction interval, and different values of the second section extraction interval are obtained; the river channel section in the different values of the second section extraction interval is determined by the grid interval of the underwater topographic data; the river channel section of the target river is generated by the measuring points of the river channel section and the different values of the second section extraction interval; on the one hand, on the basis of the traditional equal-interval section extraction method, the river channel section of the target river is extracted in combination with the river section bending coefficient, the water depth sudden change coefficient, and the grid interval of the underwater topographic data, the data precision of the river channel section is effectively improved, and data support is provided for establishing a one-dimensional hydrodynamic (river) model; on the other hand, by adjusting the river channel section extraction interval twice, the river channel condition of different river basins of the target river can be adapted, so that the generated river channel section of the target river can better reflect the real situation of the target river, thereby supporting more accurate flood forecasting and other water conservancy management activities.

[0077] In another exemplary embodiment of the present application, in order to further comprehensively understand the generation process of the river channel section of the target river, as shown in Figure 3 The river channel section extraction method includes steps S1 to S6, specifically:

[0078] Step S1: equally spacing the river axis of the target river to obtain a plurality of river sections with equal length of the river axis. In this embodiment, the river axis of the target river can be divided into a plurality of river sections with equal interval of 10 kilometers.

[0079] Step S2: judging the river section bending degree S1 of each river section, if S1>1.5, executing step S21 to adjust the section extraction interval of the 10-kilometer river section to 200 meters to generate the river channel section with an interval of 200 meters; if 1.2≤S1≤1.5, executing step S22 to adjust the section extraction interval of the 10-kilometer river section to 500 meters to generate the river channel section with an interval of 500 meters; if S1<1.2, executing step S23 to adjust the section extraction interval of the 10-kilometer river section to 1000 meters to generate the river channel section with an interval of 1000 meters.

[0080] Step S3: in the case of the section extraction interval of 200 meters and 500 meters, judging the adjacent river section included angle L θ and the water depth sudden change coefficient Δh in each river section, or judging the water depth sudden change coefficient Δh in each river section.

[0081] That is, in the case of the section extraction interval of 200 meters, judging the adjacent river section included angle Lθ and the water depth sudden change coefficient Ah in each river section, if L θ <90 degrees or S2>1.2, step S31 is executed, the cross section extraction interval of 200 meters is adjusted to 50 meters, the river section cross section of 50 meters interval is generated, if L θ ≥90 degrees and Ah>50 meters, step 32 is executed, the cross section extraction interval of 200 meters is adjusted to 100 meters, the river section cross section of 100 meters interval is generated; if L θ ≥90 degrees and Ah≤50 meters, the cross section extraction interval is not adjusted, the cross section extraction interval of 200 meters is maintained.

[0082] In the case of the cross section extraction interval of 500 meters, if Ah>50 meters, step S32 is executed, the cross section extraction interval of 500 meters is adjusted to 100 meters, the river section cross section of 100 meters interval is generated; if Ah≤50 meters, the cross section extraction interval is not adjusted, the cross section extraction interval of 500 meters is maintained; or, if Ah>5 meters, step S32 is executed, the cross section extraction interval of 500 meters is adjusted to 100 meters, the river section cross section of 100 meters interval is generated; if Ah≤5 meters, the cross section extraction interval is not adjusted, the cross section extraction interval of 500 meters is maintained.

[0083] Step S4: merging all river section cross sections in the upstream and downstream order to generate a cross section file. That is, the generated river cross section of 1000 meters interval, 200 meters interval, 100 meters interval and 50 meters interval are merged in the upstream and downstream order to generate a cross section file.

[0084] Step S5: judging the resolution of the grid of the underwater topographic data, if the resolution of the grid of the underwater topographic data is greater than 5, step S51 is executed, the extraction interval of the cross section file in step S4 is adjusted, the river section cross section of 10 meters interval is generated; if the resolution of the grid of the underwater topographic data is less than or equal to 5, step S52 is executed, the extraction interval of the cross section file in step S4 is adjusted, the river section cross section of 3 meters interval is generated.

[0085] Step S6: generating the cross section elevation point file shp or the cross section elevation point file GeoJSON of the target river according to the river section cross section of 10 meters interval in step S51; or generating the cross section elevation point file shp or the cross section elevation point file GeoJSON of the target river according to the river section cross section of 3 meters interval in step S52.

[0086] It should be noted that the river section curvature S, the adjacent river section angle L θ The calculation methods of the river section curvature S, the adjacent river section angle L

[0087] Based on the same inventive concept, the embodiments of the present application also provide a river cross-section extraction device for implementing the above-mentioned river cross-section extraction method. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme described in the above method, and therefore the specific limitations in one or more river cross-section extraction device embodiments provided below can refer to the limitations of the river cross-section extraction method described above, which will not be repeated here.

[0088] In an exemplary embodiment, as shown in Figure 4 A river cross-section extraction device 400 is provided, which includes a river section division module 401, a first adjustment module 402, a second adjustment module 403, a measuring point determination module 404, and a cross-section generation module 405, wherein,

[0089] The river section division module 401 is configured to divide the river sections based on the equidistant river axis of the target river, and obtain the river section bending coefficient of each river section;

[0090] The first adjustment module 402 is configured to adjust the river cross-section extraction interval of the target river based on the river section bending coefficient of each river section, to obtain different numerical values of the first cross-section extraction interval;

[0091] The second adjustment module 403 is configured to determine the water depth sudden change coefficient within the first cross-section extraction interval, and adjust the first cross-section extraction interval based on the water depth sudden change coefficient, to obtain different numerical values of the second cross-section extraction interval;

[0092] The measuring point determination module 404 is configured to determine the measuring points of the river cross-section within the second cross-section extraction interval based on the grid interval of the underwater topographic data;

[0093] The cross-section generation module 405 is configured to generate the river cross-section of the target river based on the different numerical values of the second cross-section extraction interval and the measuring points of the river cross-section.

[0094] As an optional implementation, the above river section division module 401 is specifically configured to divide the river axis of the target river into a plurality of river sections according to a preset length; obtain the straight-line distance and the actual distance between the start and end points of each river section; and obtain the river section bending coefficient of each river section based on the straight-line distance and the actual distance of each river section.

[0095] As an optional implementation, the first adjustment module 402 is specifically configured to: if the river section curvature coefficient S1 of any river section divided at equal intervals is less than a first threshold value, mark the corresponding river section as a straight section and determine the first cross section extraction interval of the straight section as a first value; if the river section curvature coefficient S1 of any river section divided at equal intervals is greater than or equal to the first threshold value and less than or equal to a second threshold value, mark the corresponding river section as a curved section and determine the first cross section extraction interval of the curved section as a second value; if the river section curvature coefficient S1 of any river section divided at equal intervals is greater than the second threshold value, mark the corresponding river section as a sharp bend section and determine the first cross section extraction interval of the sharp bend section as a third value; or, in the case where the first cross section extraction interval is the third value, if the river section curvature coefficient S2 of any river section within the first cross section extraction interval is greater than the first threshold value or the bending angle between adjacent river sections is less than 90 degrees, mark the corresponding river section as a sharp bend section and determine the first cross section extraction interval of the sharp bend section as a fourth value.

[0096] As an optional implementation, the second adjustment module 403 is specifically configured to: obtain the maximum elevation and the minimum elevation within the first cross section extraction interval of different values; and obtain the difference between the maximum elevation and the minimum elevation within the first cross section extraction interval of different values to obtain the water depth sudden change coefficient within the first cross section extraction interval of different values.

[0097] As an optional implementation, the second adjustment module 403 is further specifically configured to: if in a plain area and the water depth sudden change coefficient within any first cross section extraction interval is greater than a third threshold value, the river section corresponding to the first cross section extraction interval is a water depth sudden change zone, and the second cross section extraction interval is a fifth value; if in a mountainous area and the water depth sudden change coefficient within any first cross section extraction interval is greater than a fourth threshold value, the river section corresponding to the first cross section extraction interval is a water depth sudden change zone, and the second cross section extraction interval is a fifth value.

[0098] As an optional implementation, the measuring point determination module 404 is specifically configured to: if the grid interval of the underwater topographic data is less than or equal to a fifth threshold value, determine the measuring point interval of the river cross section within the second cross section extraction interval as a sixth value; and if the grid interval of the underwater topographic data is greater than the fifth threshold value, determine the measuring point interval of the river cross section within the second cross section extraction interval as a seventh value.

[0099] In the implementation, the river axis of the target river is divided into a plurality of reaches by equal intervals, the river cross section extraction interval of the target river is adjusted by obtaining the reach bending coefficient of each reach, and a plurality of first cross section extraction intervals with different values are obtained; the first cross section extraction interval is adjusted by the water depth sudden change coefficient in the first cross section extraction interval, and a plurality of second cross section extraction intervals with different values are obtained; the river cross section in the plurality of second cross section extraction intervals with different values is determined by the grid interval of the underwater topographic data; the river cross section of the target river is generated by the measuring points of the river cross section and the plurality of second cross section extraction intervals with different values; on the one hand, the river cross section of the target river is extracted based on the traditional equal-interval cross section extraction method, combined with the reach bending coefficient, the water depth sudden change coefficient and the grid interval of the underwater topographic data, the data precision of the river cross section is effectively improved, and data support is provided for establishing a one-dimensional hydrodynamic (river) model; on the other hand, the river cross section extraction interval is adjusted twice, which can adapt to the river conditions of different river basins of the target river, so that the generated river cross section of the target river can better reflect the real situation of the target river, thereby supporting more accurate flood forecasting and other water conservancy management activities.

[0100] In an exemplary embodiment, a computer device, which can be a server or a terminal, has an internal structure as shown in Figure 5 The computer device includes a processor, a memory, an input / output interface (I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The database of the computer device is configured to store river cross section extraction data. The input / output interface of the computer device is configured to exchange information between the processor and external devices. The communication interface of the computer device is configured to communicate with external terminals through network connection. The computer program is executed by the processor to implement a river cross section extraction method.

[0101] Those skilled in the art can understand that Figure 5 The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. The specific computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0102] In an example embodiment, a computer device is also provided, including a memory and a processor, the memory storing a computer program, and the processor implementing the steps in the above method embodiments when executing the computer program.

[0103] In an example embodiment, a computer readable storage medium is provided, storing a computer program, which, when executed by a processor, implements the steps in the above method embodiments.

[0104] In an example embodiment, a computer program product is provided, including a computer program, which, when executed by a processor, implements the steps in the above method embodiments.

[0105] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data agreed by the user or agreed by all parties, and the collection, use and processing of related data need to comply with relevant regulations.

[0106] It can be understood by those skilled in the art that all or part of the processes in the above method embodiments can be completed by a computer program instructing related hardware, and the computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the above method embodiments. Any reference to the memory, database or other medium used in the embodiments provided by the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0107] The database involved in each embodiment provided by the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a blockchain, and the like, without being limited thereto. The processor involved in each embodiment provided by the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a data processing logic of a programmable logic device, and the like, without being limited thereto.

[0108] The technical features of the above embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above embodiments are not described, but it should be considered that any combination of the technical features is within the scope of the present disclosure, as long as the combination does not result in contradictions.

[0109] The principles and implementation modes of the present application are described by applying specific examples herein, and the above embodiments are only used to help understand the method of the present application and its core idea. Meanwhile, for those skilled in the art, the specific implementation modes and application ranges will be changed according to the idea of the present application. In conclusion, the content of the present description should not be understood as a limitation of the present application.

Claims

1. A river cross-section extraction method characterized by, The method comprises the following steps: dividing the river section along the river axis of the target river at equal intervals to obtain a river section bending coefficient of each river section; Adjust the river section extraction interval based on the river section bending coefficient to obtain a first section extraction interval with different numerical values; wherein if the river section bending coefficient S1 of any river section divided by equal intervals is less than a first threshold value, the corresponding river section is marked as a straight section and the first section extraction interval is determined as a first numerical value; the river section bending coefficient S1 is the actual length L of the corresponding river section after the river section is divided by equal intervals R The ratio of the straight-line distance between the start and end points of the river section L to the actual length L of the corresponding river section if the river section bending coefficient S1 of any river section divided at equal intervals is greater than or equal to the first threshold value and less than or equal to the second threshold value, the corresponding river section is marked as a bending area and the first cross-section extraction interval is determined as a second value; if the river section bending coefficient S1 of any river section divided at equal intervals is greater than the second threshold value, the corresponding river section is marked as a sharp bending area and the first cross-section extraction interval is determined as a third value; or When the extraction interval of the first cross section is the third value, if the river segment curvature coefficient S2 of any river segment within the extraction interval of the first cross section is greater than the first threshold or the curvature angle L between adjacent river segments is greater than the first threshold, then... θ For bends less than 90 degrees, the corresponding river section is marked as a sharp bend area, and the extraction spacing of the first cross-section is determined to be the fourth value; the river section bend coefficient S2 is the extraction spacing L of the first cross-section. d With the corresponding river section L n The ratio of the straight-line distances between the starting and ending points; the bend angle L between adjacent river segments is determined by the following formula. θ ; ； wherein k AB is the slope of the straight line AB between the start and end points of the nth river section within the first cross-section extraction interval, k BC is the slope of the straight line BC between the start and end points of the n+1th river section within the first cross-section extraction interval, L θ is the included angle between adjacent river sections L n , L n+1 within the first cross-section extraction interval; and 180 represents 180 degrees. obtaining the maximum elevation and the minimum elevation within the first cross-section extraction interval of different values; calculating the difference between the maximum elevation and the minimum elevation within the first cross-section extraction interval of different values to obtain a water depth sudden change coefficient within the first cross-section extraction interval of different values; adjusting the first cross-section extraction interval based on the water depth sudden change coefficient to obtain a second cross-section extraction interval of different values; determining the measuring points of the river cross-section within the second cross-section extraction interval based on the grid interval of the underwater topographic data; generating the river cross-section based on the second cross-section extraction interval of different values and the measuring points of the river cross-section.

2. The river cross-section extraction method according to claim 1, characterized by, The method comprises the following steps: dividing the river section along the river axis of the target river at equal intervals to obtain a river section bending coefficient of each river section; obtaining the straight-line distance and the actual distance between the starting point and the ending point of each river section; obtaining the river section bending coefficient of each river section based on the straight-line distance and the actual distance of each river section.

3. The river cross-section extraction method according to claim 1, characterized by, The method comprises the following steps: if the water depth sudden change coefficient within any first cross-section extraction interval is greater than a third threshold value in a plain area, the river section corresponding to the first cross-section extraction interval is a water depth sudden change zone, and the second cross-section extraction interval is a fifth value; if the water depth sudden change coefficient within any first cross-section extraction interval is greater than a fourth threshold value in a mountainous area, the river section corresponding to the first cross-section extraction interval is a water depth sudden change zone, and the second cross-section extraction interval is a fifth value.

4. The river cross-section extraction method according to claim 1, characterized by, The method comprises the following steps: if the grid interval of the underwater topographic data is less than or equal to a fifth threshold value, the measuring point interval of the river cross-section within the second cross-section extraction interval is determined as a sixth value; if the grid interval of the underwater topographic data is greater than a fifth threshold value, the measuring point interval of the river cross-section within the second cross-section extraction interval is determined as a seventh value.

5. A river cross-section extraction apparatus characterized by comprising: The method comprises the following steps: a river section dividing module is configured to divide the river section along the river axis of the target river at equal intervals to obtain a river section bending coefficient of each river section; The first adjusting module is configured to adjust the riverway cross section extraction interval based on the river section bending coefficient to obtain a first cross section extraction interval with different values; wherein, if the river section bending coefficient S1 of any river section divided at equal intervals is less than a first threshold value, the corresponding river section is marked as a straight section and the first cross section extraction interval is determined as a first value; the river section bending coefficient S1 is the ratio of the actual length L of the corresponding river section after the river section is divided at equal intervals to the straight line distance between the start and end points of the river section L R If the river section bending coefficient S1 of any river section divided at equal intervals is greater than or equal to the first threshold value and less than or equal to a second threshold value, the corresponding river section is marked as a curved section and the first cross section extraction interval is determined as a second value; if the river section bending coefficient S1 of any river section divided at equal intervals is greater than the second threshold value, the corresponding river section is marked as a sharp bend section and the first cross section extraction interval is determined as a third value; or, in the case that the first cross section extraction interval is the third value, if the river section bending coefficient S2 of any river section within the first cross section extraction interval is greater than the first threshold value or the bending angle L θ between adjacent river sections is less than 90 degrees, the corresponding river section is marked as a sharp bend section and the first cross section extraction interval is determined as a fourth value; the river section bending coefficient S2 is the ratio of the actual length L of the corresponding river section within the first cross section extraction interval to the straight line distance between the start and end points of the corresponding river section L d The first cross section extraction interval is determined as the first value, the second value, the third value or the fourth value. n The bending angle L between adjacent river sections is determined by the following formula: θ ​ ； wherein k AB is the slope of the straight line AB between the start and end points of the nth river section within the first cross-section extraction interval, k BC is the slope of the straight line BC between the start and end points of the (n+1)th river section within the first cross-section extraction interval, L θ is the included angle between adjacent river sections L n , L n+1 within the first cross-section extraction interval; and 180 represents 180 degrees. a second adjusting module is configured to obtain the maximum elevation and the minimum elevation within the first cross-section extraction interval of different values, calculate the difference between the maximum elevation and the minimum elevation within the first cross-section extraction interval of different values to obtain a water depth sudden change coefficient within the first cross-section extraction interval of different values, and adjust the first cross-section extraction interval based on the water depth sudden change coefficient to obtain a second cross-section extraction interval of different values. a point determination module configured to determine points of the river section within the second section extraction interval based on a grid interval of the underwater topographic data; a section generation module configured to generate the river section based on the points of the river section and the second section extraction interval with different numerical values.

6. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the river section extraction method according to any one of claims 1-4.

7. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the river section extraction method according to any one of claims 1-4.

8. A computer program product comprising a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the river section extraction method according to any one of claims 1-4.

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