River section extraction method, device, equipment, medium and product

Abstract

The invention discloses a river section extraction method, device, equipment, medium and product, and relates to the technical field of hydrology, and the method comprises the steps: dividing river reaches at equal intervals based on the river axis of a target river, and obtaining the river reach bending coefficient of each river reach; adjusting the river section extraction spacing of the target river based on the river reach bending coefficient of each river reach to obtain first section extraction spacing with different values; determining a 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 to obtain second section extraction intervals with different values; based on the grid spacing of the underwater topographic data, determining the measuring points of the river channel section in the second section extraction spacing; and generating the river channel section of the target river based on the second section extraction spacing and the measuring points of the river channel section with different values. According to the method, the data precision of the river section can be improved, and data support is provided for establishing a one-dimensional hydrodynamic model.

Description

Technical Field

[0001] This application relates to the field of hydrological technologies, and particularly to a method, device, equipment, medium and product for extracting river channel cross-sections. Background Art

[0002] The cross-section of a river channel is the surface elevation profile of the river channel's cross-section. The information of the river channel's cross-section is key information used in hydrographic surveys. For example, the cross-section information can be used to establish a one-dimensional hydrodynamic (river channel) model.

[0003] Currently, the method for extracting river channel cross-sections is usually to draw a cross-section line of the river channel based on the topographic contour lines at the location of the river channel, and use the topographic contour lines and the cross-section line to generate a cross-section profile. That is, first draw a cross-section line on the topographic map, then use VBA programming to capture the intersection points of the cross-section line and characteristic contour lines such as index contours and primary contours, and finally extract the elevation values of the intersection points according to the elevation values of the characteristic contour lines. However, when using the above method to extract river channel cross-sections, if the contour lines in the river channel topographic map are sparse or there are no contour lines, it is necessary to extend the contour line cross-section line to obtain a self-drawn contour line cross-section line, which will result in low accuracy of the extracted river channel cross-section data and cannot establish a one-dimensional hydrodynamic (river channel) model with high accuracy. Summary of the Invention

[0004] In view of the above defects or deficiencies in the related art, the purpose of this application is to provide a method, device, equipment, medium and product for extracting river channel cross-sections, which can improve the data accuracy of river channel cross-sections and provide data support for establishing a one-dimensional hydrodynamic (river channel) model.

[0005] To achieve the above purpose, this application provides the following solutions: In a first aspect, this application provides a method for extracting a river channel cross-section. The method for extracting a river channel cross-section includes: equally spacing the river reaches based on the river axis of the target river and obtaining the river reach bending coefficient of each river reach; adjusting the river channel cross-section extraction spacing of the target river based on the river reach bending coefficient of each river reach to obtain first cross-section extraction spacings with different values; determining the sudden change coefficient of water depth within the first cross-section extraction spacing and adjusting the first cross-section extraction spacing based on the sudden change coefficient of water depth to obtain second cross-section extraction spacings with different values; determining the measuring points of the river channel cross-section within the second cross-section extraction spacing based on the grid spacing of the underwater terrain data; and generating the river channel cross-section of the target river based on the second cross-section extraction spacings with different values and the measuring points of the river channel cross-section.

[0006] Optionally, the steps of equally spacing the river axis of the target river to divide river reaches and obtaining the bend coefficient of each river reach include: dividing the river axis of the target river into multiple river reaches according to a preset length; obtaining the straight-line distance and the actual distance between the starting and ending points of each river reach; and obtaining the bend coefficient of each river reach based on the straight-line distance and the actual distance of each river reach.

[0007] Optionally, the steps of adjusting the cross-section extraction spacing of the target river based on the bend coefficient of each river reach to obtain first cross-section extraction spacings with different values include: if the bend coefficient of any river reach is less than a first threshold, marking the corresponding river reach as a straight section and determining the first cross-section extraction spacing of the straight section as a first value; if the bend coefficient of any river reach is greater than or equal to the first threshold and less than or equal to a second threshold, marking the corresponding river reach as a bend section and determining the first cross-section extraction spacing of the bend section as a second value; if the bend coefficient of any river reach is greater than the second threshold, marking the corresponding river reach as a sharp bend section and determining the first cross-section extraction spacing of the sharp bend section as a third value; or, in the case where the first cross-section extraction spacing is the third value, if the bend coefficient of any river reach is greater than the first threshold or the bending angle between adjacent river reaches is less than 90 degrees, marking the corresponding river reach as a sharp bend section and determining the first cross-section extraction spacing of the sharp bend section as a fourth value.

[0008] Optionally, the steps of determining the water depth abrupt change coefficient within the first cross-section extraction spacing include: obtaining the maximum elevation and the minimum elevation within the first cross-section extraction spacings with different values; and obtaining the difference between the maximum elevation and the minimum elevation within the first cross-section extraction spacings with different values to obtain the water depth abrupt change coefficient within the first cross-section extraction spacings with different values.

[0009] Optionally, the steps of adjusting the first cross-section extraction spacing based on the water depth abrupt change coefficient to obtain second cross-section extraction spacings with different values include: if in a plain area and the water depth abrupt change coefficient within any first cross-section extraction spacing is greater than a third threshold, the river reach corresponding to the first cross-section extraction spacing is a water depth abrupt change zone, and the second cross-section extraction spacing is a fifth value; if in a mountainous area and the water depth abrupt change coefficient within any first cross-section extraction spacing is greater than a fourth threshold, the river reach corresponding to the first cross-section extraction spacing is a water depth abrupt change zone, and the second cross-section extraction spacing is a fifth value.

[0010] Optionally, determining the measuring points of the river channel cross-section within the second cross-section extraction interval based on the grid interval of the underwater terrain data includes: if the grid interval of the underwater terrain data is less than or equal to a fifth threshold, determining that the measuring point interval of the river channel cross-section within the second cross-section extraction interval is a sixth value; if the grid interval of the underwater terrain data is greater than the fifth threshold, determining that the measuring point interval of the river channel cross-section within the second cross-section extraction interval is a seventh value.

[0011] In a second aspect, the present application provides a river channel cross-section extraction device, where the river channel cross-section extraction device includes: A river section division module, configured to equally divide river sections based on the river axis of the target river and obtain the river section bending coefficient of each river section; A first adjustment module, configured to adjust the river channel cross-section extraction interval of the target river based on the river section bending coefficient of each river section to obtain first cross-section extraction intervals with different values; A second adjustment module, configured to determine the rapid change coefficient of water depth within the first cross-section extraction interval and adjust the first cross-section extraction interval based on the rapid change coefficient of water depth to obtain second cross-section extraction intervals with different values; A measuring point determination module, configured to determine the measuring points of the river channel cross-section within the second cross-section extraction interval based on the grid interval of the underwater terrain data; A cross-section generation module, configured to generate the river channel cross-section of the target river based on the second cross-section extraction intervals with different values and the measuring points of the river channel cross-section.

[0012] In a third aspect, the present application provides a computer device, including: a memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor executes the computer program to implement the steps of the river channel cross-section extraction method described in any one of the above.

[0013] In a fourth aspect, the present application provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the steps of the river channel cross-section extraction method described in any one of the above.

[0014] In a fifth aspect, the present application provides a computer program product, including a computer program, and when the computer program is executed by a processor, it implements the steps of the river channel cross-section extraction method described in any one of the above.

[0015] According to the specific embodiments provided by the present application, the following technical effects are disclosed in the present application: The present application provides a method, apparatus, device, medium and product for extracting a river channel cross-section. By equally spacing the river axis of a target river, a plurality of river reaches are obtained. The extraction spacing of the river channel cross-section of the target river is adjusted by obtaining the bending coefficient of each river reach, and first cross-section extraction spacings with different values are obtained. The first cross-section extraction spacings are adjusted by the rapid change coefficient of water depth within the first cross-section extraction spacings with different values, and second cross-section extraction spacings with different values are obtained. The measuring points of the river channel cross-section within the second cross-section extraction spacings with different values are determined by the grid spacing of the underwater terrain data. The river channel cross-section of the target river is generated by the measuring points of the river channel cross-section and the second cross-section extraction spacings with different values. On the one hand, on the basis of adopting the traditional equal-spacing cross-section extraction method, the river channel cross-section of the target river is extracted by combining the bending coefficient of the river reach, the rapid change coefficient of water depth and the grid spacing of the underwater terrain data, effectively improving the data accuracy of the river channel cross-section and providing data support for establishing a one-dimensional hydrodynamic (river channel) model. On the other hand, by adjusting the river channel cross-section extraction spacing twice, the river channel conditions of different basins of the target river can be adapted, so that the generated river channel cross-section of the target river can better reflect the real situation of the target river, thus supporting more accurate flood forecasting and other water conservancy management activities. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0017] Figure 1 It is an application environment diagram of a method for extracting a river channel cross-section in an embodiment of the present application; Figure 2 It is a schematic flowchart of a method for extracting a river channel cross-section provided in an embodiment of the present application; Figure 3 It is a flowchart of a method for extracting a river channel cross-section provided in another embodiment of the present application; Figure 4 It is a schematic diagram of the functional modules of a device for extracting a river channel cross-section provided in an embodiment of the present application; Figure 5 It is a schematic diagram of the structure of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0019] To make the above objects, features, and advantages of the present application more obvious and understandable, the solutions described in the present application will be further described below with reference to the accompanying drawings and specific embodiments.

[0020] The river cross-section extraction method provided by the embodiments of the present application can be applied to an application environment as Figure 1 shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be set up separately, integrated on the server 104, 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 terrain data to the server 104. After receiving the river axis length and the grid spacing of the underwater terrain data, for the river axis length and the grid spacing of the underwater terrain data, the server 104 equally divides the river sections based on the river axis of the target river and obtains the river section bending coefficient of each river section; adjusts the river cross-section extraction spacing of the target river based on the river section bending coefficient of each river section to obtain the first cross-section extraction spacing with different values; determines the sudden change coefficient of water depth within the first cross-section extraction spacing and adjusts the first cross-section extraction spacing based on the sudden change coefficient of water depth to obtain the second cross-section extraction spacing with different values; determines the measuring points of the river cross-section within the second cross-section extraction spacing based on the grid spacing of the underwater terrain data; generates 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. The server 104 can feedback 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 implemented independently by the server 104 or the terminal 102. For example, the terminal 102 can directly perform river cross-section extraction for the river axis length and the grid spacing of the underwater terrain data, or the server 104 can obtain the river axis length and the grid spacing of the underwater terrain data from the data storage system and perform river cross-section extraction for the river axis length and the grid spacing of the underwater terrain data.

[0021] Among them, the terminal 102 can be, but is not limited to, various desktop computers, laptop computers, smart phones, tablet computers, etc. The server 104 can be implemented by an independent server or a server cluster composed of multiple servers, and can also be a cloud server.

[0022] In an exemplary embodiment, Figure 2 As shown, a river section extraction method is provided. The method is executed by a computer device, and can be executed by a computer device such as a terminal or a server alone, or by a terminal and a server together. In the embodiment of the present application, the method is applied to Figure 1 The server 104 in the example is used as an example to illustrate the method, which includes the following steps S201 to S205. Among them: Step S201, dividing the river sections at equal intervals based on the river axis of the target river, and obtaining the river section curvature coefficient of each river section.

[0023] 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, extending from upstream to downstream, and basically represents the longest path or mainstream direction of the river. In technical documents or engineering drawings, the river axis is the basis for analyzing river structures, designing bridges and other hydraulic structures, and performing river dynamics simulations. In the embodiment of the present application, the river axis is the basis for calculating the curvature of river sections, identifying sharp bends, and analyzing sudden changes in water depth.

[0024] Among them, the flow area of ​​the target river from upstream to downstream generally includes straight areas, curved areas and sharp bend areas; the straight area refers to the target river channel presenting a relatively straight and single shape on the plane, without obvious bends or meanders; the river channel boundary is smooth and the shape is straight. The curved area refers to the river channel presenting a significant bend or meander shape on the plane; in this form of river channel, its mainstream line no longer remains straight or approximately straight, but flows along a complex and changeable curve. The sharp bend area refers to the area in the river channel where the flow direction of the water changes significantly, which is usually caused by a sudden change in the direction of the river channel.

[0025] Optionally, the above step S201 may include: dividing the river axis of the target river into multiple river sections according to preset lengths; obtaining the straight-line distance and actual distance between the starting and ending points of each river section; and obtaining the river section curvature coefficient of each river section based on the straight-line distance and actual distance of each river section.

[0026] It can be understood that, for example, based on the river axis, the river axis is divided into sections of 10 kilometers each, each section is called a river section, and the section curvature coefficient S of each river section is calculated by formula (1): (1) Among them, 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.

[0027] It should be noted that in the embodiments of the present application, taking the equal interval of 10 as an example, the river section bending coefficient of each river section of the target river is described. In other embodiments, the equal interval division distance can also be appropriately set according to the actual length of the target river.

[0028] Step S202: Adjust the cross-section extraction interval of the target river based on the river section bending coefficient of each river section to obtain the first cross-section extraction intervals with different values.

[0029] Combined with the above example embodiments, it can be seen that the flowing area of the target river from upstream to downstream generally includes a straight section, a bending section, and a sharp bend section. If the river axes of the river sections in the straight section, the bending section, and the sharp bend section are equal, it will cause a large cross-section extraction error. Therefore, it is necessary to adjust the cross-section extraction intervals of the river sections in the straight section, the bending section, and the sharp bend section according to the different river section bending coefficients of the corresponding straight section, bending section, and sharp bend section to improve the data accuracy of the river cross-section.

[0030] Optionally, the above step S202 may include: if the river section bending coefficient of any river section is less than the first threshold, mark the corresponding river section as a straight section and determine the first cross-section extraction interval of the straight section as the first value; if the river section bending coefficient of any river section is greater than or equal to the first threshold and less than or equal to the second threshold, mark the corresponding river section as a bending section and determine the first cross-section extraction interval of the bending section as the second value; if the river section bending coefficient of any river section is greater than the second threshold, mark the corresponding river section as a sharp bend section and determine the first cross-section extraction interval of the sharp bend section as the third value; or, in the case where the first cross-section extraction interval is the third value, if the river section bending coefficient of any river section is greater than the first threshold 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 the fourth value.

[0031] It can be understood that, for example, as shown in Table 1 below: Table 1

[0032] If the first threshold is 1.2, the second threshold 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: When the river section bending coefficient S is less than 1.2, then the river section is a straight section, and the first cross-section extraction interval is 1000 meters. When the river section bending coefficient S is greater than or equal to 1.2 and less than or equal to 1.5, then the river section is a bending section, and the first cross-section extraction interval is 500 meters. When the river section bending coefficient S is greater than 1.5, then the river section is a sharp bend section, and the first cross-section extraction interval is 200 meters.

[0033] After the extraction of the river section spacing, that is, after the determination of the extraction spacing of the first cross-section, first, calculate the river section bending coefficient S of each river section within the extraction spacing of the first cross-section with different values through formula (2); (2); Wherein, L d is the extraction spacing of the first cross-section, and L n is the straight-line distance between the starting and ending points of the river section within the extraction spacing of the first cross-section.

[0034] Secondly, calculate the bending angle L between adjacent river sections through formula (3) θ (that is, the straight-line included angle between the starting and ending points of adjacent river sections); (3); Wherein, k AB is the slope of the straight line AB between the starting and ending points of the nth river section within the extraction spacing of the first cross-section, and k BC is the slope of the straight line BC between the starting and ending points of the (n + 1)th river section within the extraction spacing of the first cross-section, and L θ is the included angle between adjacent river sections L n and L n+1 within the extraction spacing of the first cross-section; 180 represents 180 degrees.

[0035] When the extraction spacing of the first cross-section is 200 meters, when the river section bending coefficient S of any river section within the extraction spacing of the first cross-section is greater than 1.2 or L θ is less than 90 degrees, it is determined that the river section is a sharp bend area, and the river channel cross-section spacing needs to be set to 50 meters.

[0036] It should be noted that in the case of determining that any river section is a sharp bend area, the river section in the sharp bend area is divided into multiple sections, and the river form in the sharp bend area is judged again through the included angle between adjacent river sections and the river section bending coefficient, 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 judging the river form in the sharp bend area, when any river section is at the arc of a large bend, the river section bending coefficient cannot fully reflect the river form of the river section, and the included angle between adjacent river sections can be used for representation; when any river section is in a narrow river channel and across multiple small bends, at this time, the included angle between adjacent river sections cannot reflect the true river form in the sharp bend area, and the river section bending coefficient needs to be used for representation. Among them, the large bend involved in the embodiments of the present application refers to an included angle between adjacent river sections less than 90 degrees, and the small bend refers to an included angle between adjacent river sections greater than or equal to 90 degrees.

[0037] By judging the river form of the river section in the sharp bend area again, the spacing between adjacent river sections in the sharp bend area can be further adjusted, and the data accuracy of the river channel cross-section can be further improved.

[0038] Step S203: Determine the water depth abrupt change coefficient within the first cross-section extraction interval, and adjust the first cross-section extraction interval based on the water depth abrupt change coefficient to obtain second cross-section extraction intervals with different values.

[0039] In the exemplary embodiment, the water depth abrupt change coefficient is a parameter used to describe the water depth abrupt change zone in a river or a channel. The water depth abrupt change zone refers to the area in a river where, due to sudden changes in the riverbed topography, water flow conditions, or other natural factors, the water depth or the river elevation changes significantly within a relatively short spatial range. This area can be regarded as a belt-shaped area because the changes in water depth or river elevation often do not occur in isolation but continuously along a certain river section.

[0040] Optionally, determining the water depth abrupt change coefficient within the first cross-section extraction interval in step S203 above may include: obtaining the maximum elevation and the minimum elevation within the first cross-section extraction interval with different values; calculating the difference between the maximum elevation and the minimum elevation within the first cross-section extraction interval with different values to obtain the water depth abrupt change coefficient within the first cross-section extraction interval with different values.

[0041] It can be understood that the water depth abrupt change coefficient within the first cross-section extraction interval with different values is calculated through formula (4) ; (4); where, H max is the maximum elevation of the river section within the first cross-section extraction interval, and H min is the minimum elevation of the river section within the first cross-section extraction interval.

[0042] It should be noted that the maximum elevation refers to the height of the highest point of the river section within the first cross-section extraction interval; the minimum elevation refers to the height of the lowest point of the river section within the first cross-section extraction interval.

[0043] Furthermore, adjusting the first cross-section extraction interval based on the water depth abrupt change coefficient in step S203 above to obtain second cross-section extraction intervals with different values may include: if in a plain area and the water depth abrupt change coefficient within any first cross-section extraction interval is greater than a third threshold, the river section corresponding to the first cross-section extraction interval is a water depth abrupt change zone, and the second cross-section extraction interval is a fifth value; if in a mountainous area and the water depth abrupt change coefficient within any first cross-section extraction interval is greater than a fourth threshold, the river section corresponding to the first cross-section extraction interval is a water depth abrupt change zone, and the second cross-section extraction interval is a fifth value.

[0044] It is understandable that, for example, when the third threshold is 5 meters, the fourth threshold is 50 meters, and the fifth value is 100 meters, then: when the water depth abrupt change coefficient within a first cross-section extraction interval in the mountainous area is greater than 50 meters, it is determined as a water depth abrupt change zone. When the water depth abrupt change coefficient within a first cross-section extraction interval in the plain area is greater than 5 meters, it is determined as a water depth abrupt change zone. At this time, the first cross-section extraction interval is set to 100 meters.

[0045] Step S204: Determine the measuring points of the river channel cross-section within the second cross-section extraction interval based on the grid interval of the underwater terrain data.

[0046] In the exemplary embodiment, the grid of the underwater terrain data generally refers to the application of the Digital Elevation Model (DEM) in the water environment, that is, the Digital Bathymetric Model (DBM), or also known as the seabed terrain model. In the embodiments of the present application, the grid of the underwater terrain data mainly refers to the Digital Bathymetric Model DBM. This model uses regular or irregular grids to represent the height (actually the depth relative to a certain reference plane) information of the seabed terrain.

[0047] The grid of the underwater terrain data uses regular grids to represent the river water body terrain in the plain area, that is, all grid points are arranged at fixed intervals to form a rectangular grid; each grid point represents the water depth value at a specific geographical coordinate. The grid of the underwater terrain data uses irregular grids to represent the river water body terrain in the mountainous area, that is, the river terrain is decomposed into a series of interconnected triangles, and each vertex corresponds to an actually measured data point; the sampling density can be adjusted according to the complexity of the terrain change.

[0048] During the river channel cross-section measurement process, in order to accurately describe the shape and characteristics of the river channel cross-section, the points with representative terrain features selected on the river bottom (river bottom line), water surface, or the side slopes of both sides of the river channel cross-section are called measuring points. In the river channel cross-section measurement, the projected distance between two adjacent measuring points along 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 morphological accuracy of the river channel cross-section. In the embodiments of the present application, the setting of the measuring point spacing mainly refers to the grid interval of the underwater terrain data. In other embodiments, the setting of the measuring point spacing can refer to the grid interval of the underwater terrain data and the design accuracy of the one-dimensional hydrodynamic model.

[0049] Optionally, the above step S204 may include: if the grid interval of the underwater terrain data is less than or equal to the fifth threshold, determine that the measuring point spacing of the river channel cross-section within the second cross-section extraction interval is the sixth value; if the grid interval of the underwater terrain data is greater than the fifth threshold, determine that the measuring point spacing of the river channel cross-section within the second cross-section extraction interval is the seventh value.

[0050] It is understandable that, for example, when the fifth threshold is 5 meters, the sixth value is 3 meters, and the seventh value is 10 meters, then when the grid spacing of the underwater terrain data is less than or equal to 5 meters, the measurement point spacing of the river channel section within the second section extraction spacing is 3 meters. When the underwater terrain grid spacing is greater than 5 meters, the measurement point spacing of the river channel section within the second section extraction spacing is 10 meters.

[0051] Step S205: Generate the river channel section of the target river based on the second section extraction spacings with different values and the measurement points of the river channel section.

[0052] It should be noted that the river channel section of the target river generated by the second section extraction spacings with different values and the measurement points of the river channel section has a relatively large density in areas with drastic terrain changes or special importance (such as sharp bend areas and sudden water depth change zones), and a relatively small density in areas with relatively flat terrain (such as straight sections).

[0053] By implementing the above steps S201 to S205, multiple river reaches are obtained by equally spacing the river axis of the target river. The extraction spacing of the river channel section of the target river is adjusted by obtaining the reach bending coefficient of each river reach to obtain the first section extraction spacings with different values; the first section extraction spacing is adjusted by the sudden water depth change coefficient within the first section extraction spacings with different values to obtain the second section extraction spacings with different values; the measurement points of the river channel section within the second section extraction spacings with different values are determined by the grid spacing of the underwater terrain data; the river channel section of the target river is generated by the measurement points of the river channel section and the second section extraction spacings with different values. On the one hand, on the basis of the traditional equal-spacing section extraction method, the river channel section of the target river is extracted by combining the reach bending coefficient, the sudden water depth change coefficient, and the grid spacing of the underwater terrain data, effectively improving the data accuracy of the river channel section and providing data support for establishing a one-dimensional hydrodynamic (river channel) model. On the other hand, by adjusting the river channel section extraction spacing twice, it can adapt to the river channel conditions in different basins of the target river, so that the generated river channel section of the target river can better reflect the real situation of the target river, thus supporting more accurate flood forecasting and other water conservancy management activities.

[0054] 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 Figure 3 shown, the river channel section extraction method includes steps S1 to S6, specifically: Step S1: Equally space the river axis of the target river to obtain several river reaches with equal lengths of the river axis. In this embodiment, the river axis of the target river can be divided into several river reaches according to a length of 10 kilometers at equal intervals.

[0055] Step S2: Determine the river bend degree S of each river section. If S > 1.5, execute Step S21, adjust the cross-section extraction interval of a 10-kilometer river section to 200 meters, and generate river channel cross-sections at 200-meter intervals; if 1.2 ≤ S ≤ 1.5, execute Step S22, adjust the cross-section extraction interval of a 10-kilometer river section to 500 meters, and generate river channel cross-sections at 500-meter intervals; if S < 1.2, execute Step S23, adjust the cross-section extraction interval of a 10-kilometer river section to 1000 meters, and generate river channel cross-sections at 1000-meter intervals.

[0056] Step S3: When the cross-section extraction interval is 200 meters and 500 meters, determine the included angle L between adjacent river sections θ and the sudden change coefficient of water depth within each river section , or determine the sudden change coefficient of water depth within each river section .

[0057] That is, when the cross-section extraction interval is 200 meters, determine the included angle L between adjacent river sections θ and the sudden change coefficient of water depth within each river section . If L θ < 90 degrees or S > 1.2, execute Step S31, adjust the 200-meter cross-section extraction interval to 50 meters, and generate river section cross-sections at 50-meter intervals; if L θ ≥ 90 degrees and > 50 meters, execute Step 32, adjust the 200-meter cross-section extraction interval to 100 meters, and generate river section cross-sections at 100-meter intervals; if L θ ≥ 90 degrees and ≤ 50 meters, do not adjust the cross-section extraction interval and keep the 200-meter cross-section extraction interval.

[0058] When the cross-section extraction interval is 500 meters, if > 50 meters, execute Step S32, adjust the 500-meter cross-section extraction interval to 100 meters, and generate river section cross-sections at 100-meter intervals; if ≤ 50 meters, do not adjust the cross-section extraction interval and keep the 500-meter cross-section extraction interval; or, if > 5 meters, execute Step S32, adjust the 500-meter cross-section extraction interval to 100 meters, and generate river section cross-sections at 100-meter intervals; if ≤ 5 meters, do not adjust the cross-section extraction interval and keep the 500-meter cross-section extraction interval.

[0059] Step S4: Merge all river section cross-sections in the upstream-downstream order to generate a cross-section file. That is, merge the generated river channel cross-sections at 1000-meter intervals, 200-meter intervals, 100-meter intervals, and 50-meter intervals in the upstream-downstream order to generate a cross-section file.

[0060] Step S5: Determine the resolution of the grid of the underwater terrain data. If the resolution of the grid of the underwater terrain data is greater than 5, then execute Step S51 to adjust the extraction interval of the cross-section file in Step S4 and generate a river cross-section with an interval of 10 meters. If the resolution of the grid of the underwater terrain data is less than or equal to 5, then execute Step S52 to adjust the extraction interval of the cross-section file in Step S4 and generate a river cross-section with an interval of 3 meters.

[0061] Step S6: Generate a cross-section elevation point file shp or a cross-section elevation point file GeoJSON of the target river based on the river cross-section with an interval of 10 meters in Step S51; or generate a cross-section elevation point file shp or a cross-section elevation point file GeoJSON of the target river based on the river cross-section with an interval of 3 meters in Step S52.

[0062] It should be noted that in the embodiments of the present application, the river bend degree S and the included angle L between adjacent river reaches θ and the sudden change coefficient of water depth within each river reach are all described in detail in the above embodiments. For specific details, please refer to the corresponding content of the above embodiments, and the embodiments of the present application will not be elaborated herein.

[0063] 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 solution provided by this device to solve the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the river cross-section extraction device provided below can refer to the limitations on the river cross-section extraction method in the above text, and will not be elaborated herein.

[0064] In an exemplary embodiment, as Figure 4 shown, a river cross-section extraction device is provided. The river cross-section extraction device 400 includes: a river reach 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, where the river reach division module 401 is used to equally divide river reaches based on the river axis of the target river and obtain the river bend coefficient of each river reach; the first adjustment module 402 is used to adjust the river cross-section extraction interval of the target river based on the river bend coefficient of each river reach to obtain different values of the first cross-section extraction interval; the second adjustment module 403 is used to determine the sudden change coefficient of water depth within the first cross-section extraction interval and adjust the first cross-section extraction interval based on the sudden change coefficient of water depth to obtain different values of the second cross-section extraction interval; the measuring point determination module 404 is used 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 terrain data. The cross-section generation module 405 is used to generate the river channel cross-section of the target river based on the second cross-section extraction intervals with different values and the measuring points of the river channel cross-section.

[0065] As an alternative implementation, the above-mentioned river section division module 401 is specifically configured to divide the river axis of the target river into multiple river sections according to a preset length; obtain the straight-line distance and the actual distance between the starting and ending 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.

[0066] As an alternative implementation, the above-mentioned first adjustment module 402 is specifically configured to, if the river section bending coefficient of any river section is less than the first threshold, mark the corresponding river section as a straight section and determine that the first cross-section extraction interval of the straight section is the first value; if the river section bending coefficient of any river section is greater than or equal to the first threshold and less than or equal to the second threshold, mark the corresponding river section as a bending section and determine that the first cross-section extraction interval of the bending section is the second value; if the river section bending coefficient of any river section is greater than the second threshold, mark the corresponding river section as a sharp bend section and determine that the first cross-section extraction interval of the sharp bend section is the third value; or, in the case where the first cross-section extraction interval is the third value, if the river section bending coefficient of any river section is greater than the first threshold 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 that the first cross-section extraction interval of the sharp bend section is the fourth value.

[0067] As an alternative implementation, the above-mentioned second adjustment module 403 is specifically configured to obtain the maximum elevation and the minimum elevation within the first cross-section extraction intervals with different values; calculate the difference between the maximum elevation and the minimum elevation within the first cross-section extraction intervals with different values to obtain the water depth sudden change coefficient within the first cross-section extraction intervals with different values.

[0068] As an alternative implementation, the above-mentioned second adjustment module 403 is also 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 the third threshold, 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 the fifth value; if in a mountainous area and the water depth sudden change coefficient within any first cross-section extraction interval is greater than the fourth threshold, 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 the fifth value.

[0069] As an alternative implementation, the above-mentioned measuring point determination module 404 is specifically configured to, if the grid spacing of the underwater terrain data is less than or equal to the fifth threshold, determine that the measuring point spacing of the river channel cross-section within the second cross-section extraction interval is the sixth value; if the grid spacing of the underwater terrain data is greater than the fifth threshold, determine that the measuring point spacing of the river channel cross-section within the second cross-section extraction interval is the seventh value.

[0070] Among them, when implementing this implementation method, multiple river sections are obtained by equally spacing the river axis of the target river. The cross-section extraction spacing of the target river is adjusted by obtaining the bending coefficient of each river section, and the first cross-section extraction spacing with different values is obtained. The first cross-section extraction spacing is adjusted by the sudden change coefficient of water depth within the first cross-section extraction spacing with different values, and the second cross-section extraction spacing with different values is obtained. The measuring points of the river channel cross-section within the second cross-section extraction spacing with different values are determined by the grid spacing of the underwater terrain data. The river channel cross-section of the target river is generated by the measuring points of the river channel cross-section and the second cross-section extraction spacing with different values. On the one hand, on the basis of adopting the traditional equal-spacing cross-section extraction method, the river channel cross-section of the target river is extracted by combining the bending coefficient of the river section, the sudden change coefficient of water depth, and the grid spacing of the underwater terrain data, effectively improving the data accuracy of the river channel cross-section and providing data support for establishing a one-dimensional hydrodynamic (river channel) model. On the other hand, by adjusting the cross-section extraction spacing of the river channel twice, it can adapt to the river channel conditions of different basins of the target river, so that the generated river channel cross-section of the target river can better reflect the real situation of the target river, thus supporting more accurate flood forecasting and other water conservancy management activities.

[0071] In an exemplary embodiment, a computer device is provided. The computer device can be a server or a terminal, and its internal structure diagram can be as Figure 5 shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store river channel cross-section extraction data. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals through a network connection. When the computer program is executed by the processor, it implements a river channel cross-section extraction method.

[0072] Those skilled in the art can understand that Figure 5 the structure shown in

[0073] In an exemplary embodiment, a computer device is further provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, the steps in the above method embodiments are implemented.

[0074] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0075] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0076] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data that have been consented to by the user or fully consented to by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0077] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to the memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memories. 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. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0078] The databases involved in the embodiments provided in this application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in this application can be general-purpose processors, central processors, graphics processors, digital signal processors, data processing logics of programmable logics, etc., without limitation.

[0079] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0080] In this text, specific examples are used to illustrate the principles and implementation manners of the present application. The descriptions of the above embodiments are only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A method for extracting river cross-sections, characterized in that, The described river cross-section extraction method includes: Dividing the river reaches at equal intervals based on the river axis of the target river, and obtaining the river bend coefficient of each river reach; Adjusting the river cross-section extraction interval of the target river based on the river bend coefficient of each river reach to obtain the first cross-section extraction intervals with different values; Determining the rapid water depth change coefficient within the first cross-section extraction interval, and adjusting the first cross-section extraction interval based on the rapid water depth change coefficient to obtain the second cross-section extraction intervals with 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 terrain data; Generating the river cross-section of the target river based on the second cross-section extraction intervals with different values and the measuring points of the river cross-section.

2. The river channel cross-section extraction method according to claim 1, characterized in that The dividing the river reaches at equal intervals based on the river axis of the target river and obtaining the river bend coefficient of each river reach includes: Dividing the river axis of the target river into multiple river reaches according to a preset length; Obtaining the straight-line distance and the actual distance between the starting and ending points of each river reach; Obtaining the river bend coefficient of each river reach based on the straight-line distance and the actual distance of each river reach.

3. The river channel cross-section extraction method according to claim 1, characterized in that, The adjusting the river cross-section extraction interval of the target river based on the river bend coefficient of each river reach to obtain the first cross-section extraction intervals with different values includes: If the river bend coefficient of any river reach is less than the first threshold, marking the corresponding river reach as a straight section and determining the first cross-section extraction interval of the straight section as the first value; If the river bend coefficient of any river reach is greater than or equal to the first threshold and less than or equal to the second threshold, marking the corresponding river reach as a bending section and determining the first cross-section extraction interval of the bending section as the second value; If the river bend coefficient of any river reach is greater than the second threshold, marking the corresponding river reach as a sharp bend section and determining the first cross-section extraction interval of the sharp bend section as the third value; or, In the case where the first cross-section extraction interval is the third value, if the river bend coefficient of any river reach is greater than the first threshold or the bending angle between adjacent river reaches is less than 90 degrees, marking the corresponding river reach as a sharp bend section and determining the first cross-section extraction interval of the sharp bend section as the fourth value.

4. The river channel cross-section extraction method according to claim 1, characterized in that The determining the rapid water depth change coefficient within the first cross-section extraction interval includes: Obtaining the maximum elevation and the minimum elevation within the first cross-section extraction intervals with different values; Calculating the difference between the maximum elevation and the minimum elevation within the first cross-section extraction intervals with different values to obtain the rapid water depth change coefficient within the first cross-section extraction intervals with different values.

5. The river channel cross-section extraction method according to claim 1, characterized in that, The adjusting the first cross-section extraction interval based on the rapid water depth change coefficient to obtain the second cross-section extraction intervals with different values includes: If in a plain area and the rapid water depth change coefficient within any of the first cross-section extraction intervals is greater than the third threshold, the river reach corresponding to the first cross-section extraction interval is a rapid water depth change zone, and the second cross-section extraction interval is the fifth value; If in a mountainous area and the rapid water depth change coefficient within any of the first cross-section extraction intervals is greater than the fourth threshold, the river reach corresponding to the first cross-section extraction interval is a rapid water depth change zone, and the second cross-section extraction interval is the fifth value.

6. The river channel cross-section extraction method according to claim 1, characterized in that, Determining the measuring points of the river channel cross-section within the second cross-section extraction interval based on the grid interval of the underwater terrain data includes: If the grid interval of the underwater terrain data is less than or equal to the fifth threshold, determining that the measuring point interval of the river channel cross-section within the second cross-section extraction interval is the sixth value; If the grid interval of the underwater terrain data is greater than the fifth threshold, determining that the measuring point interval of the river channel cross-section within the second cross-section extraction interval is the seventh value.

7. A river channel cross-section extraction device, characterized in that The river channel cross-section extraction device includes: A river section division module, configured to equally divide river sections based on the river axis of the target river and obtain the river section bending coefficient of each river section; A first adjustment module, configured to adjust the river channel cross-section extraction interval of the target river based on the river section bending coefficient of each river section to obtain first cross-section extraction intervals with different values; A second adjustment module, configured to determine the sudden change coefficient of water depth within the first cross-section extraction interval and adjust the first cross-section extraction interval based on the sudden change coefficient of water depth to obtain second cross-section extraction intervals with different values; A measuring point determination module, configured to determine the measuring points of the river channel cross-section within the second cross-section extraction interval based on the grid interval of the underwater terrain data; A cross-section generation module, configured to generate the river channel cross-section of the target river based on the second cross-section extraction intervals with different values and the measuring points of the river channel cross-section.

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

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the river channel cross-section extraction method according to any one of claims 1-6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the river channel cross-section extraction method according to any one of claims 1-6.

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