DEM-based riverway water surface width acquisition method and system, storage medium and computer equipment
By obtaining the river surface width using a DEM-based method, the problems of large calculation errors and high computational cost in existing technologies are solved, enabling faster and more accurate solution of the water surface width parameter and improving the computational accuracy and applicability of distributed watershed hydrological models.
Patent Information
- Application Number
- CN202411164111.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-23
- Publication Date
- 2024-12-17
AI Technical Summary
Existing technologies suffer from large errors and computational burdens when solving for river surface width in distributed watershed hydrological models, especially during low water periods. Nonlinear solutions also suffer from excessive computational burdens and limited accuracy improvements.
A DEM-based method is adopted to determine the river topology by acquiring DEM data, measured cross-sectional data and measured water level information of the river area, interpolating the river DEM water level information, correcting the DEM cross-sectional position and flow direction, and calculating the river water surface width by combining the river DEM cross-sectional data.
It enables faster and more accurate solutions to the river surface width parameters of distributed watershed hydrological models, improving computational accuracy and applicability.
Smart Images
Figure CN119150405A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method, system, storage medium and computer equipment for obtaining river water surface width based on DEM, and belongs to the technical field of hydrological models. Background Art
[0002] Distributed basin hydrological model, i.e., distributed physical model, describes the basin hydrological process through the dynamic mechanism of water cycle. The model parameters can be determined according to the physical properties of water medium movement, which is conducive to analyzing the change law of runoff after the change of basin underlying surface. Compared with conceptual model, distributed hydrological model uses strict mathematical and physical equations to describe each sub-process of hydrological cycle. It fully considers the spatial heterogeneity of parameters and variables, and focuses on the connection between different hydrological units. It uses partial differential equations to simulate water volume and energy processes, which provides a powerful tool for realistically simulating the physical process of basin rainfall runoff formation. Therefore, it has a wide range of applications in many fields such as simulating hydrological responses of various change processes such as land use, land cover, soil erosion, non-point source pollution, land surface process, climate change impact assessment, etc. The parameters of distributed hydrological model have a clear physical meaning, which solves the problems of non-independence and uncertainty between parameters, and is convenient for promotion and application in areas without measured hydrological data.
[0003] In the process of model confluence, when solving the parameter of river channel water surface width, it can be solved through hydraulics. There are two methods of solution: linear and nonlinear. In the linear solution, it is assumed that the ratio of the parameter tank storage to the reference flow K and the flow weight factor X of each river section are time-invariant constants, and the river channel water surface width is the corresponding reference stable water surface width under a certain reference stable flow state of the river section. In the nonlinear solution, the parameters K and X are recalculated according to the known water flow conditions in each calculation period, and the river channel water surface width is further calculated. The linear solution has higher accuracy during high floods, but in the low water part, there is often a certain error due to the large difference between the parameters and the actual situation; in comparison, the nonlinear solution is more reasonable, but the nonlinear solution greatly increases the amount of calculation, and the improvement of the accuracy of flood peak simulation is relatively limited. Summary of the invention
[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a method, system, storage medium and computer equipment for obtaining river water surface width based on DEM. The method can more quickly and accurately solve the water surface width of the river section of the distributed watershed hydrological model.
[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions: In a first aspect, the present invention provides a method for obtaining a river water surface width based on a DEM, comprising: Obtain DEM data within the river area, river measured large-section data and river measured water level information; Determine the topological relationship of the river channel based on the measured large-section data of the river channel; Based on the topological relationship of the river channel and the DEM data in the river channel area, the DEM large-section data of the river channel is obtained; Combine the measured water level information of the river channel, the DEM large-section data of the river channel and the measured large-section data of the river channel to obtain the preliminary DEM water level information of the river channel, and interpolate the preliminary DEM water level information of the river channel to obtain the DEM water level information of the river channel; Based on the large-section DEM data of the river and the DEM water level information of the river, the left and right bank positions of each section of the river are obtained, and the water surface width of the river is obtained using the left and right bank positions of each section of the river.
[0006] Optionally, the DEM data in the river channel area includes: elevation information and flow direction information in the river channel area; the measured large-section data of the river channel includes: the position of each measured section of the river channel and the information of each measured section of the river channel.
[0007] Optionally, determining the topological relationship of the river channel according to the measured large-section data of the river channel includes: According to the measured cross-section information of the river channel, the lowest point of each measured cross-section is obtained; Based on the positions of each measured section of the river and the lowest point of each measured section, the path of the measured river channel mid-channel line is obtained; By using the measured mid-channel path of the river, the river nodes and upstream and downstream relationships, that is, the topological relationship of the river, are determined.
[0008] Optionally, based on the topological relationship of the river channel and the DEM data in the river channel area, obtain the river channel DEM large section data, including: Obtain the preset interval lengths between each DEM river section, and obtain the position of each DEM river section according to the preset interval lengths between each DEM river section; Based on the elevation information in the river area and the location of each DEM river section, the information of each DEM river section is obtained; Based on the information of each DEM river section, the lowest point of each DEM river section is obtained to determine whether the lowest point of each DEM river section is close to the shore. If it is close to the shore, the DEM river section is an unreasonable section. Combined with the measured large-section data of the river channel, the unreasonable section positions are corrected to obtain the corrected positions of each DEM river channel section; Based on the elevation information in the river area and the positions of the corrected DEM river sections, the corrected DEM river section information is obtained; Using the corrected DEM river section information, the elevation change and morphological change of two adjacent DEM river sections are obtained, and the flow direction information in the river area is corrected according to the elevation change and morphological change to obtain the DEM river flow direction information; The DEM large-section river data is obtained by combining the DEM river flow direction information, the corrected positions of each DEM river section and the corrected DEM river section information.
[0009] Optionally, the measured water level information of the river channel, the DEM large-section data of the river channel and the measured large-section data of the river channel are combined to obtain preliminary DEM water level information of the river channel, and the preliminary DEM water level information of the river channel is interpolated to obtain the DEM water level information of the river channel, including: According to the measured cross-section information of the river channel and the measured water level information of the river channel, the measured water surface width information of the river channel section is obtained; Based on the measured water surface width information of the river section and the large-section DEM data of the river, the matching value of the measured water level of the river section is obtained; Combine the matching value of the measured water level of the river section with the DEM large section data of the river to obtain the preliminary DEM water level information of the river; The preliminary DEM water level information of the river is sequentially interpolated from upstream to downstream to obtain the DEM water level information of the river.
[0010] Optionally, if there is a reservoir in the river, update the river DEM water level information, including: Obtain the location of the reservoir dam, and obtain the DEM river section information at the dam based on the location of the reservoir dam and the DEM large section data; Based on the DEM river section information at the dam, the riverbed elevation and river section area at the dam are obtained; Obtain the discharge flow at the dam; The water level upstream of the reservoir dam is obtained based on the riverbed elevation at the dam, the discharge at the dam, and the cross-sectional area of the river at the dam. Based on the water level upstream of the reservoir dam, the water level of the reservoir section is obtained, and the water level of the reservoir section is updated to the river channel DEM water level information.
[0011] Optionally, the water level upstream of the reservoir dam is calculated as follows:
[0012] in, Z 2 represents the water level upstream of the reservoir dam; Z 1 represents the river bottom elevation at the reservoir dam; Q Indicates the discharge flow at the reservoir dam; α represents the kinetic energy correction factor; β represents the local head loss coefficient; A1 represents the cross-sectional area of the river at the reservoir dam.
[0013] In a second aspect, the present invention provides a river water surface width acquisition system based on DEM, comprising: Data acquisition module, used to obtain DEM data in the river area, river measured large section data and river measured water level information; The data processing module is used to determine the topological relationship of the river channel based on the measured large-section data of the river channel; to obtain the large-section DEM data of the river channel based on the topological relationship of the river channel and the DEM data in the river channel area; to obtain the preliminary DEM water level information of the river channel by combining the measured water level information of the river channel, the large-section DEM data of the river channel and the measured large-section data of the river channel, and to interpolate the preliminary DEM water level information of the river channel to obtain the DEM water level information of the river channel; to obtain the left and right bank positions of each section of the river channel based on the large-section DEM data of the river channel and the DEM water level information of the river channel, and to obtain the water surface width of the river channel using the left and right bank positions of each section of the river channel.
[0014] In a third aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for obtaining the river water surface width based on DEM as described in the first aspect.
[0015] In a fourth aspect, the present invention provides a computer device, comprising: A memory for storing instructions; The processor is used to execute the instructions so that the device performs operations to implement the method for obtaining the river water surface width based on DEM as described in the first aspect.
[0016] Compared with the prior art, the present invention has the following beneficial effects: The DEM-based river water surface width acquisition method proposed in the present invention utilizes DEM (digital elevation model) data, measured large-section data of the river and measured water level information of the river to obtain the DEM large-section data of the river and the DEM water level information of the river, and based on the DEM large-section data of the river and the DEM water level information of the river, obtains the left and right bank positions of each section of the river, thereby obtaining the water surface width of the river, and can more quickly and accurately solve the water surface width parameters of the water-passing section of the river in the distributed watershed hydrological model, and can improve the accuracy and applicability of calculating the water surface width. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor, among which: Figure 1 The flowchart of the method for obtaining the river water surface width based on DEM in an embodiment of the present invention is shown; Figure 2 The schematic diagram of the river section information of the upstream node in the embodiment of the present invention is shown; FIG3 (a) is a schematic diagram showing the topological relationship of a level 1+level 2+level 3 river section in an embodiment of the present invention; FIG3 (b) is a schematic diagram showing the topological relationship of a 2nd level + 3rd level river section in an embodiment of the present invention; FIG3 (c) is a schematic diagram showing the topological relationship of three-level river sections in an embodiment of the present invention; FIG. 4 (a) shows a satellite image of a river section in Guangxi Zhuang Autonomous Region according to an embodiment of the present invention; FIG. 4( b ) shows a water surface map of a certain section of a river in Guangxi Zhuang Autonomous Region according to an embodiment of the present invention. DETAILED DESCRIPTION
[0018] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.
[0019] The application principle of the present invention is described in detail below in conjunction with the accompanying drawings.
[0020] Example 1 like Figure 1 As shown, an embodiment of the present invention provides a method for obtaining a river water surface width based on a DEM, comprising the following steps: S01: obtaining DEM data, river channel measured large-section data, and river channel measured water level information within a river channel area; S02: Determine the topological relationship of the river channel based on the measured large-section data of the river channel; S03: Based on the topological relationship of the river channel and the DEM data in the river channel area, obtain the DEM large section data of the river channel; S04: combining the measured water level information of the river channel, the DEM large-section data of the river channel and the measured large-section data of the river channel to obtain preliminary DEM water level information of the river channel, and interpolating the preliminary DEM water level information of the river channel to obtain DEM water level information of the river channel; S05: Based on the large-section DEM data of the river channel and the DEM water level information of the river channel, the left and right bank positions of each section of the river channel are obtained, and the water surface width of the river channel is obtained by using the left and right bank positions of each section of the river channel.
[0021] The river water surface width obtained in step S05 is the river water surface width parameter of the distributed watershed hydrological model.
[0022] The DEM-based river water surface width acquisition method proposed in the present invention utilizes DEM data, measured large-section data of the river and measured water level information of the river to obtain the DEM large-section data of the river and the DEM water level information of the river, and based on the DEM large-section data of the river and the DEM water level information of the river, obtains the left and right bank positions of each section of the river, thereby obtaining the water surface width of the river, which can realize the solution of the water surface width parameters of the river in the distributed watershed hydrological model more quickly and accurately, and can improve the accuracy and applicability of calculating the water surface width.
[0023] In this embodiment, the specific method for obtaining the DEM data, the measured large-section data of the river channel and the measured water level information of the river channel in step S01 includes: 1) DEM data in the river area; Obtain a national digital elevation model (DEM) with a spatial resolution of 30 meters; Based on the national digital elevation model with a spatial resolution of 30 meters, ArcGIS tools were used to generate elevation data, flow direction data, and catchment area data in the area to be studied; The DEM data in the river area is obtained by using the elevation data, flow direction data and catchment area data in the area to be studied; the DEM data in the river area includes: elevation information and flow direction information in the river area; 2) Measured large-section data of the river and measured water level information of the river The measured large-section data of the river channel are usually collected through acoustic measurement, GPS measurement, traditional measuring chains and level rulers and other tools and technologies. Here we can directly obtain the existing measured large-section data of the river channel and the measured water level information of the river channel. The measured large-section data of the river channel includes: the position of each measured section of the river channel and the measured section information of each measured section of the river channel; among them, the section information of the upstream node (a certain upstream section of the river channel) is referenced Figure 2 shown.
[0024] In this embodiment, in step S02, the topological relationship of the river channel is determined based on the measured large-section data of the river channel, which specifically includes: According to the measured cross-section information of the river channel, the lowest point of each measured cross-section is obtained, such as Figure 2 Point A in is the lowest point of the section; Based on the positions of each measured section of the river and the lowest point of each measured section, the lowest point of each section is connected to obtain the path of the measured river channel midline; According to the measured river channel mid-line path, the river channel nodes (the confluence of the river section) and the upstream and downstream relationships of the river channel, the confluence relationship between sub-basins, that is, the topological relationship of the river channel are determined. As shown in Figure 3, Figure 3 (a) is a 1st level + 2nd level + 3rd level river section, Figure 3 (b) is a 2nd level + 3rd level river section, and Figure 3 (c) is a 3rd level river section, where the 2nd level river section is formed by the confluence of the 1st level river section, and the 3rd level river section is formed by the confluence of the 2nd level river section.
[0025] In this embodiment, in step S03, based on the topological relationship of the river channel and the DEM data in the river channel area, the river channel DEM large section data is obtained, which specifically includes: S031: Obtain the location and information of each DEM river section in the river area; Get the interval length between each preset DEM river section; According to the preset interval lengths between the DEM river sections, the positions of the DEM river sections are obtained; specifically, based on the DEM, the river is divided into different sections using the topological relationship of the river; the interval lengths of the river sections on different sections are set as needed to confirm the positions of the DEM river sections; the interval length can be adjusted according to the tortuosity of the river, for example, more DEM river sections are divided in the more tortuous sections of the river, which is conducive to improving the accuracy of obtaining the large-section DEM data of the river; Based on the elevation information in the river area and the location of each DEM river section, the information of each DEM river section in the river area is obtained; S032: Correct the position and information of each DEM river section in the river area; According to the DEM river section information obtained in S032, the lowest point of each DEM river section is obtained to determine whether the lowest point of each DEM river section is close to the bank (left / right bank of the river). If it is close to the bank, the DEM river section is an unreasonable section. Specifically, the lowest point of some DEM river sections is too close to the bank and cannot be used as the DEM river channel midline position (the lowest point of the DEM river section). By comparing with the measured river data, the river section position is corrected. Combined with the measured river section positions in the previously obtained river channel measured large section data, the unreasonable section positions are corrected to obtain the corrected positions of each DEM river channel section; Based on the elevation information in the river area and the positions of the corrected DEM river sections, the corrected DEM river section information is obtained; S033: Obtain DEM river flow information; Using the corrected DEM river section information, the elevation change and morphological change of two adjacent DEM river sections are obtained, and the flow direction information in the river area is corrected according to the elevation change and morphological change to obtain the DEM river flow direction information; specifically, the river flows from the place with high riverbed elevation to the place with low riverbed elevation; The DEM large-section data of the river channel is obtained by combining the DEM river channel flow direction information, the corrected positions of each DEM river channel section and the corrected DEM river channel section information; the DEM large-section data of the river channel includes: the DEM river channel flow direction information, the corrected positions of each DEM river channel section and the corrected DEM river channel section information.
[0026] In this embodiment, in step S04, the measured water level information of the river channel, the DEM large section data of the river channel and the measured large section data of the river channel are combined to obtain preliminary DEM water level information of the river channel, and the preliminary DEM water level information of the river channel is interpolated to obtain the DEM water level information of the river channel, which specifically includes: Since the DEM river section information does not match the measured river section information, and the two use different coordinate systems, the measured water level information cannot be directly used for water level interpolation); based on the measured section information and the measured water level information, the measured section water surface width is obtained; Based on the measured water surface width of the section, combined with the DEM river section information corresponding to the measured section, the water level at the corresponding DEM section is obtained, and the water level is used as the matching value of the measured water level to obtain the preliminary DEM water level information of the river; According to the preliminary DEM water level information of the river channel, the DEM water level information of the river channel is interpolated in order from upstream to downstream; considering the input water level data error and DEM elevation accuracy, 2m is set as the default water depth. When the interpolated water level is not higher than the riverbed elevation of 2m, the corrected water level meets the 2m default water depth; Specifically, there may be a reservoir in the river area. If there is a reservoir in the river, the river DEM water level information needs to be updated, including: Obtain the location of the reservoir dam, and obtain the DEM river section information at the dam based on the location of the reservoir dam and the DEM large section data; Based on the DEM river section information at the dam, the riverbed elevation and river section area at the dam are obtained; Obtain the discharge flow at the dam; The water level upstream of the reservoir dam is obtained based on the riverbed elevation at the dam, the discharge at the dam, and the cross-sectional area of the river at the dam. Based on the water level upstream of the reservoir dam, the water level of the reservoir section is obtained, and the water level of the reservoir section is updated to the river channel DEM water level information.
[0027] Specifically, the hydraulic method is used to calculate the water level upstream of the reservoir dam, and the basic equation is as follows:
[0028] In the formula, Z 1 is the water level at the downstream section, m; Z 2 is the water level of the upstream section, m; is the kinetic energy correction coefficient, which is related to the uneven distribution of flow velocity on the cross section. It is 1.12 to 1.5 for plain rivers and 1.5 to 2.0 for mountain rivers; is the local head loss coefficient, which is -0.33 ~ -0.55 for a gradually expanding section and -0.55 ~ -1.0 for a rapidly expanding section; g is the acceleration due to gravity, m / s 2 ; Q is the reservoir discharge, m 3 / s; Q 1 is the flow rate downstream of the reservoir, m 3 / s; Q 2 is the upstream flow of the reservoir, m 3 / s; A is the area of a single gate hole, m 2 ; A 1 is the downstream cross-sectional area, m 2 ; A 2 is the upstream cross-sectional area, m 2 ; R is the hydraulic radius, m; ∆ L is the distance between upstream and downstream sections; n is the number of gate holes.
[0029] Based on the above basic equation, it is assumed that at the dam site, the reservoir is stationary and the flow upstream of the reservoir is Q 2 and reservoir discharge Q If is 0, The calculation formula of the water level downstream of the reservoir dam is as follows:
[0030] in, Z 2 represents the water level at the upstream section, where the water level at the reservoir dam is taken; Z 1 represents the water level at the downstream section, where the river bottom elevation at the reservoir dam is taken; Q 1 is the flow rate downstream of the reservoir, which is the flow rate at the dam site of the reservoir; A 1 represents the downstream cross-sectional area, which is the cross-sectional area of the river at the reservoir dam; α represents the kinetic energy correction factor; β Represents the local head loss coefficient.
[0031] In this embodiment, in step S05, based on the river channel DEM large section data and the river channel DEM water level information, the left and right bank positions of each section of the river channel are obtained, and the river channel water surface width is obtained by using the left and right bank positions of each section of the river channel, which specifically includes: Through the cross-section information in the river DEM large cross-section data and the river DEM water level information, the left and right bank positions of each DEM cross-section in the river area are obtained; According to the left and right bank positions of each DEM section in the river area, the water surface map of the entire river is generated, and based on the generated river water surface map, the river water surface width (the water surface width of the required section corresponding to the water level) is obtained to realize the solution of the river water surface width parameters of the distributed basin hydrological model.
[0032] Example 2 Referring to the DEM-based river water surface width acquisition method in Example 1, the water surface width of a certain river section in Guangxi Zhuang Autonomous Region was solved; finally, a water surface map of a certain river section in Guangxi Zhuang Autonomous Region was obtained as shown in Figure 4 (b). Compared with the river satellite image of the area shown in Figure 4 (a), it was found that this method can determine the accurate water surface width.
[0033] Example 3 The present invention provides a river water surface width acquisition system based on DEM, comprising: Data acquisition module, used to obtain DEM data in the river area, river measured large section data and river measured water level information; The data processing module is used to determine the topological relationship of the river channel based on the measured large-section data of the river channel; to obtain the large-section DEM data of the river channel based on the topological relationship of the river channel and the DEM data in the river channel area; to obtain the preliminary DEM water level information of the river channel by combining the measured water level information of the river channel, the large-section DEM data of the river channel and the measured large-section data of the river channel, and to interpolate the preliminary DEM water level information of the river channel to obtain the DEM water level information of the river channel; to obtain the left and right bank positions of each section of the river channel based on the large-section DEM data of the river channel and the DEM water level information of the river channel, and to obtain the water surface width of the river channel using the left and right bank positions of each section of the river channel. Example 4 The present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the method for obtaining the river water surface width based on DEM as described in Example 1 are implemented.
[0034] Example 5 The present invention provides a computer device, comprising: A memory for storing instructions; The processor is used to execute the instructions so that the device performs the operations of implementing the method for obtaining the river water surface width based on DEM as described in Example 1.
[0035] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0036] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.
[0037] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.
[0038] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.
[0039] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.
Claims
1. A method for obtaining river surface width based on DEM. It is characterized in that include: Obtain DEM data within the river area, river measured large-section data and river measured water level information; Determine the topological relationship of the river channel based on the measured large-section data of the river channel; Based on the topological relationship of the river channel and the DEM data in the river channel area, the DEM large-section data of the river channel is obtained; Combine the measured water level information of the river channel, the DEM large-section data of the river channel and the measured large-section data of the river channel to obtain the preliminary DEM water level information of the river channel, and interpolate the preliminary DEM water level information of the river channel to obtain the DEM water level information of the river channel; Based on the large-section DEM data of the river and the DEM water level information of the river, the left and right bank positions of each section of the river are obtained, and the water surface width of the river is obtained using the left and right bank positions of each section of the river.
2. The method for obtaining river water surface width based on DEM according to claim 1, It is characterized in that The DEM data in the river area includes: elevation information and flow direction information in the river area; the measured large-section data of the river includes: the position of each measured section of the river and the information of each measured section of the river.
3. The method for obtaining river water surface width based on DEM according to claim 2, It is characterized in that Determining the topological relationship of the river channel based on the measured large-section data of the river channel includes: According to the measured cross-section information of the river channel, the lowest point of each measured cross-section is obtained; Based on the positions of each measured section of the river and the lowest point of each measured section, the path of the measured river channel mid-channel line is obtained; By using the measured mid-channel path of the river, the river nodes and upstream and downstream relationships, that is, the topological relationship of the river, are determined.
4. The method for obtaining river water surface width based on DEM according to claim 3, It is characterized in that Based on the topological relationship of the river and the DEM data in the river area, the river DEM large section data is obtained, including: Obtain the preset interval lengths between each DEM river section, and obtain the position of each DEM river section according to the preset interval lengths between each DEM river section; Based on the elevation information in the river area and the location of each DEM river section, the information of each DEM river section is obtained; Based on the information of each DEM river section, the lowest point of each DEM river section is obtained to determine whether the lowest point of each DEM river section is close to the shore. If it is close to the shore, the DEM river section is an unreasonable section. Combined with the measured large-section data of the river channel, the unreasonable section positions are corrected to obtain the corrected positions of each DEM river channel section; Based on the elevation information in the river area and the positions of the corrected DEM river sections, the corrected DEM river section information is obtained; Using the corrected DEM river section information, the elevation change and morphological change of two adjacent DEM river sections are obtained, and the flow direction information in the river area is corrected according to the elevation change and morphological change to obtain the DEM river flow direction information; The DEM large-section river data is obtained by combining the DEM river flow direction information, the corrected positions of each DEM river section and the corrected DEM river section information.
5. The method for obtaining river water surface width based on DEM according to claim 4, It is characterized in that Combine the measured water level information of the river channel, the DEM large section data of the river channel and the measured large section data of the river channel to obtain the preliminary DEM water level information of the river channel, and interpolate the preliminary DEM water level information of the river channel to obtain the DEM water level information of the river channel, including: According to the measured cross-section information of the river channel and the measured water level information of the river channel, the measured water surface width information of the river channel section is obtained; Based on the measured water surface width information of the river section and the large-section DEM data of the river, the matching value of the measured water level of the river section is obtained; Combine the matching value of the measured water level of the river section with the DEM large section data of the river to obtain the preliminary DEM water level information of the river; The preliminary DEM water level information of the river is sequentially interpolated from upstream to downstream to obtain the DEM water level information of the river.
6. The method for obtaining river water surface width based on DEM according to claim 5, It is characterized in that If there is a reservoir in the river, update the river DEM water level information, including: Obtain the location of the reservoir dam, and obtain the DEM river section information at the dam based on the location of the reservoir dam and the DEM large section data; Based on the DEM river section information at the dam, the riverbed elevation and river section area at the dam are obtained; Obtain the discharge flow at the dam; The water level upstream of the reservoir dam is obtained based on the riverbed elevation at the dam, the discharge at the dam, and the cross-sectional area of the river at the dam. Based on the water level upstream of the reservoir dam, the water level of the reservoir section is obtained, and the water level of the reservoir section is updated to the river channel DEM water level information.
7. The method for obtaining river water surface width based on DEM according to claim 6, It is characterized in that The calculation formula of the water level upstream of the reservoir dam is as follows: in, Z 2 Indicates the water level upstream of the reservoir dam; Z 1 Indicates the river bottom elevation at the reservoir dam; Q 1 Indicates the discharge flow at the reservoir dam; α represents the kinetic energy correction factor; β represents the local head loss coefficient; A 1 It indicates the cross-sectional area of the river at the reservoir dam.
8. A river surface width acquisition system based on DEM, It is characterized in that include: Data acquisition module, used to obtain DEM data in the river area, river measured large section data and river measured water level information; The data processing module is used to determine the topological relationship of the river channel based on the measured large-section data of the river channel; to obtain the large-section DEM data of the river channel based on the topological relationship of the river channel and the DEM data in the river channel area; to obtain the preliminary DEM water level information of the river channel by combining the measured water level information of the river channel, the large-section DEM data of the river channel and the measured large-section data of the river channel, and to interpolate the preliminary DEM water level information of the river channel to obtain the DEM water level information of the river channel; to obtain the left and right bank positions of each section of the river channel based on the large-section DEM data of the river channel and the DEM water level information of the river channel, and to obtain the water surface width of the river channel using the left and right bank positions of each section of the river channel.
9. A computer-readable storage medium having a computer program stored thereon, It is characterized in that When the computer program is executed by a processor, the steps of the method for obtaining the river water surface width based on DEM as described in any one of claims 1 to 7 are implemented.
10. A computer device, It is characterized in that include: A memory for storing instructions; A processor is used to execute the instruction so that the device performs the operation of implementing the method for obtaining the river water surface width based on DEM as described in any one of claims 1 to 7.