River channel longitudinal section determination method based on river channel section terrain and related equipment

Abstract

The invention discloses a riverway longitudinal section determination method based on a riverway section terrain and related equipment. The method comprises the following steps: acquiring main groove section data of a plurality of sections in a target river reach, wherein the main groove section data comprises a main groove section area of each section under a corresponding section flat beach water level; for each section, a target water level value is determined from a plurality of preset water level values larger than the thalweg point elevation of the section, the channel range interval where the thalweg point of the section under the target water level value is located is a target interval, and the channel section area in the target interval is larger than or equal to the product of the main channel section area and a preset proportion value; taking the target water level value as the deep groove elevation of the corresponding section; and determining the longitudinal section of the river channel of the target river reach by utilizing the deep groove elevations of the multiple sections in the target river reach. Sawteeth in the longitudinal section of the riverway can be reduced, so that the longitudinal adjustment rule of the riverway can be accurately identified, and the level requirement on related technicians is reduced.

Description

Technical Field

[0001] This application relates to the fields of river evolution simulation, river regulation and protection, and specifically relates to a method for determining a river longitudinal profile based on river cross-section topography and related equipment. Background Art

[0002] The longitudinal profile of an alluvial river is an important tool for studying the morphology of river thalwegs and their dynamic evolution, and is an important research content in river regulation and protection work. As an important index for judging the stability of a river channel and its longitudinal evolution trend, the morphological characteristics of the longitudinal profile of an alluvial river directly affect the hydrodynamic characteristics of the water flow, can effectively display the process of riverbed erosion and deposition, and mastering its dynamic change law has important application value for revealing the evolution of river thalweg morphology, river (navigation) channel design and maintenance, flood prediction, etc.

[0003] In related technologies, a thalweg longitudinal profile can be drawn through cross-section drawing software to reflect the longitudinal changes of the river channel. However, due to the large variation in the elevation of thalweg points in the cross-section, the obtained thalweg longitudinal profile is mostly significantly serrated, which interferes with accurately identifying the longitudinal adjustment law of the river channel and requires a relatively high level of relevant technical personnel. Summary of the Invention

[0004] Embodiments of this application provide a method for determining a river longitudinal profile based on river cross-section topography and related equipment, which can reduce the serrations in the river longitudinal profile, facilitate accurately identifying the longitudinal adjustment law of the river channel, and reduce the level requirement for relevant technical personnel.

[0005] On the one hand, this application provides a method for determining a river longitudinal profile based on river cross-section topography, and the method includes: Obtain the main channel cross-section data of multiple cross-sections in the target river reach, where the main channel cross-section data includes the main channel cross-section area of each cross-section at the corresponding cross-section floodplain water level; For each cross-section, determine a target water level value among multiple preset water level values greater than the elevation of the thalweg point of the cross-section. Wherein, the river channel range interval where the thalweg point of the cross-section is located at the target water level value is the target interval, and the cross-section area of the river channel within the target interval is greater than or equal to the product of the main channel cross-section area and a preset proportional value; Take the target water level value as the thalweg elevation of the corresponding cross-section; Use the thalweg elevations of multiple cross-sections in the target river reach to determine the river longitudinal profile of the target river reach.

[0006] In some embodiments, the obtaining of the main channel cross-section data of multiple cross-sections in the target river reach includes: For each cross-section, obtain the main channel range interval of the cross-section; Determine the area of the section within the corresponding main channel range interval at the flat flood level of the corresponding section, and use it as the main channel section area of the section at the flat flood level of the corresponding section.

[0007] In some embodiments, obtaining the main channel range interval of the section includes: Obtain the observation data of the section, where the observation data includes the starting distances and riverbed elevations of multiple observation points in the section; Based on the riverbed elevation, determine the thalweg points among the multiple observation points; Use the low water level of the section to divide the multiple observation points sorted in sequence according to the starting distance, and obtain multiple first observation point intervals; Take the first observation point interval where the thalweg point is located as the low water channel range interval of the section; Based on the low water channel range interval, determine the main channel range interval of the section.

[0008] In some embodiments, based on the low water channel range interval, determining the main channel range interval of the section includes: Among the starting distances of the multiple observation points in the low water channel range interval, determine the maximum starting distance and the minimum starting distance; Among the multiple observation points sorted in sequence according to the starting distance, detect whether there is a target observation point that satisfies the first preset condition or the second preset condition. Among them, the first preset condition includes that the target observation point does not exist in the low water channel range interval, the target observation point is adjacent to the observation point where the maximum starting distance is located among the multiple observation points sorted in sequence according to the starting distance, and the riverbed elevation of the target observation point and the riverbed elevation of the observation point where the maximum starting distance is located satisfy the first preset size relationship. The second preset condition includes that the target observation point does not exist in the low water channel range interval, the target observation point is adjacent to the observation point where the minimum starting distance is located among the multiple observation points sorted in sequence according to the starting distance, and the riverbed elevation of the target observation point and the riverbed elevation of the observation point where the minimum starting distance is located satisfy the second preset size relationship; If there is the target observation point, add the target observation point to the low water channel range interval to obtain an expanded low water channel range interval; Based on the expanded low water channel range interval, determine the main channel range interval of the section.

[0009] In some embodiments, the observation data of the section includes the starting distances and riverbed elevations of multiple observation points in the section. Among the multiple observation points, there is a thalweg point, which is determined based on the riverbed elevation. Before determining the target water level value among the multiple preset water level values greater than the elevation of the thalweg point of the section, it further includes: For each of the preset water level values, using the preset water level value, divide a plurality of observation points sorted in sequence according to the starting distance to obtain a plurality of second observation point intervals; Take the second observation point interval where the thalweg point is located as the river channel range interval where the thalweg point of the cross-section is located under the preset water level value.

[0010] In some embodiments, a plurality of preset water level values greater than the thalweg elevation of the cross-section are determined through the following steps: Determine the sum of the thalweg elevation and the preset elevation to obtain the target elevation; Increase the target elevation in sequence according to the preset step size to obtain a plurality of the preset water level values.

[0011] In some embodiments, the determining the longitudinal profile of the river channel of the target river section by using the thalweg elevations of a plurality of cross-sections in the target river section includes: Perform a moving average process on the thalweg elevations of a plurality of cross-sections in the target river section in sequence according to the cross-section distance from the dam to obtain the processed thalweg elevations of a plurality of cross-sections; Connect the processed thalweg elevations of a plurality of cross-sections according to the cross-section distance from the dam to obtain the longitudinal profile of the river channel of the target river section.

[0012] In some embodiments, the cross-section floodplain water level is determined through the following steps: Obtain the measured historical floodplain water levels of a plurality of target hydrological stations in the target river section; Perform linear interpolation processing on the measured historical floodplain water levels of a plurality of the target hydrological stations to obtain the cross-section floodplain water level of each cross-section in the target river section.

[0013] On the other hand, an embodiment of the present application provides a device for determining the longitudinal profile of a river channel based on the river channel cross-section topography, including: A first acquisition module, configured to acquire the main channel cross-section data of a plurality of cross-sections in the target river section, where the main channel cross-section data includes the main channel cross-section area of each cross-section at the corresponding cross-section floodplain water level; A first determination module, configured to, for each cross-section, determine a target water level value from a plurality of preset water level values greater than the thalweg elevation of the cross-section, where the river channel range interval where the thalweg point of the cross-section is located under the target water level value is the target interval, and the river channel cross-section area within the target interval is greater than or equal to the product of the main channel cross-section area and the preset ratio value; A second determination module, configured to use the target water level value as the thalweg elevation of the corresponding cross-section; A third determination module, configured to determine the longitudinal profile of the river channel of the target river section by using the thalweg elevations of a plurality of cross-sections in the target river section.

[0014] On the other hand, the present application also provides a computer device, which includes: One or more processors; A memory; and One or more applications, wherein the one or more applications are stored in the memory and are configured to be executed by the processor to implement the steps in any one of the methods for determining the longitudinal profile of a river channel based on the cross-sectional topography of the river channel.

[0015] On the other hand, the present application also provides a computer-readable storage medium, on which a computer program is stored, and the computer program is loaded by a processor to execute the steps in any one of the methods for determining the longitudinal profile of a river channel based on the cross-sectional topography of the river channel.

[0016] On the other hand, an embodiment of the present application provides a computer program product, including a computer program or instruction, and the computer program or instruction is executed by a processor to implement the method for determining the longitudinal profile of a river channel based on the cross-sectional topography of the river channel as described in any one of the above.

[0017] The method for determining the longitudinal profile of a river channel based on the cross-sectional topography of the river channel and related devices provided by the embodiments of the present application obtain the main channel cross-section data of multiple cross-sections in a target river reach. The main channel cross-section data includes the main channel cross-sectional area of each cross-section at the corresponding cross-section floodplain water level; for each cross-section, among multiple preset water level values greater than the thalweg elevation of the cross-section, a target water level value is determined, wherein the river channel range interval where the thalweg is located at the target water level value of the cross-section is the target interval, and the river channel cross-sectional area within the target interval is greater than or equal to the product of the main channel cross-sectional area and a preset ratio value; the target water level value is used as the deep trough elevation of the corresponding cross-section; the longitudinal profile of the target river reach is determined by using the deep trough elevations of multiple cross-sections in the target river reach. The embodiments of the present application determine the target water level value with the corresponding river channel cross-sectional area based on the product of the main channel cross-sectional area of the cross-section at the corresponding cross-section floodplain water level and the preset ratio value, and use it as the deep trough elevation of the corresponding cross-section, and then determine the longitudinal profile of the target river reach. Compared with the thalweg longitudinal profile drawn based on the thalweg elevation of the cross-section, the sawtooth shape in the longitudinal profile of the river channel is less, which is convenient for accurately identifying the longitudinal adjustment law of the river channel and reducing the level requirements for relevant technical personnel. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0019] Figure 1It is a schematic diagram of an embodiment of the method for determining the longitudinal profile of a river based on the river cross-section topography provided in the embodiments of the present application; Figure 2 It is a schematic diagram of the thalweg elevation and deep trough elevation of the cross-sections at different cross-section distances from the dam in the target river section provided in the embodiments of the present application; Figure 3 It is a schematic diagram of the longitudinal profile of the river in the target river section at different survey times provided in the embodiments of the present application; Figure 4 It is a schematic structural diagram of an embodiment of the device for determining the longitudinal profile of a river based on the river cross-section topography provided in the embodiments of the present application; Figure 5 It is a schematic terminal structure diagram of an embodiment of the computer device provided in the embodiments of the present application.

[0020] Among them, Figure 2 and 3 are color pictures to facilitate the distinction of different objects in the same picture. Detailed implementation manners

[0021] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with 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. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0022] In the description of the present application, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0023] In the present application, the phrase "in some embodiments" is used to mean "serving as an example, illustration, or description". Any embodiment described as "in some embodiments" in the present application is not necessarily construed as being more preferred or having more advantages than other embodiments. In order for any person skilled in the art to implement and use the present application, the following description is given. In the following description, details are set forth for the purpose of explanation. It should be understood that those skilled in the art can recognize that the present application can be implemented without using these specific details. In other instances, well-known structures and processes are not elaborated in detail to avoid obscuring the description of the present application with unnecessary details. Therefore, the present application is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

[0024] It should be noted that since the system of the embodiments of the present application is executed in a computer device, the processing objects of each computer device exist in the form of data or information. For example, time, which is actually time information. It can be understood that in subsequent embodiments, if dimensions, quantities, positions, etc. are mentioned, they are all corresponding data existences for the computer device to process, and specific details will not be elaborated here.

[0025] The embodiments of the present application provide a method for determining the longitudinal profile of a river channel based on the cross-sectional topography of the river channel and related devices. The aim is to determine a target water level value with a corresponding river channel cross-sectional area based on the product of the main channel cross-sectional area of the cross-section at the corresponding cross-sectional floodplain water level and a preset ratio value, and use it as the deep channel elevation of the corresponding cross-section. Connect the deep channel elevations of each cross-section along the target river section as the longitudinal profile line of the river channel, and realize the automatic recognition of the deep channel elevation of the cross-section and the automatic drawing of the longitudinal profile line through programs such as MATLAB, which can efficiently, quickly and simply identify the temporal variation law of the longitudinal profile of the alluvial river channel. The following will be described in detail respectively.

[0026] In one embodiment, referring to Figure 1 , the method for determining the longitudinal profile of a river channel based on the cross-sectional topography of the river channel includes: 101. Obtain the main channel cross-sectional data of multiple cross-sections in the target river section, where the main channel cross-sectional data includes the main channel cross-sectional area of each cross-section at the corresponding cross-sectional floodplain water level.

[0027] In the embodiments of the present application, the target river section is a specified river section, and the target river section includes multiple cross-sections of the river channel. In the main channel cross-sectional data, each cross-section corresponds to a main channel cross-sectional area at the corresponding cross-sectional floodplain water level. Among them, since each cross-section has a river channel main channel, and the main channel has a certain width, the corresponding main channel cross-sectional area can be determined by combining the corresponding cross-sectional floodplain water level of the cross-section.

[0028] In some embodiments of the present application, step 101 may include: for each cross-section, obtain the main channel range interval of the cross-section. Among them, the cross-section may include multiple observation points, and each observation point has a corresponding starting distance and riverbed elevation. The maximum value of the main channel range interval may be the maximum value of the starting distances of multiple observation points in the main channel, and the minimum value of the main channel range interval may be the minimum value of the starting distances of multiple observation points in the main channel. At this time, the main channel range interval is the starting distance range of the main channel of the cross-section; determine the area of the region of the cross-section within the corresponding main channel range interval and at the corresponding cross-sectional floodplain water level, and use it as the main channel cross-sectional area of the cross-section at the corresponding cross-sectional floodplain water level, where the main channel cross-sectional area can be calculated by the trapezoidal area summation method of adjacent observation points.

[0029] In some embodiments of the present application, obtaining the main channel range interval of a cross-section may include: obtaining the observation data of the cross-section, where the observation data includes the starting distances and riverbed elevations of multiple observation points in the cross-section, and the starting distances and riverbed elevations can be obtained based on the actual measurement of the observation points; based on the riverbed elevation, determining the thalweg point among the multiple observation points. For example, the observation point with the deepest riverbed elevation among the multiple observation points can be used as the thalweg point; using the low water level of the cross-section, dividing the multiple observation points sorted in ascending order of starting distance to obtain multiple first observation point intervals. For example, the multiple observation points sorted in ascending order of starting distance can be used as an observation point sequence, and then the riverbed elevations of the multiple observation points in the observation point sequence are successively compared with the low water level of the cross-section to obtain multiple subsequences. The riverbed elevation of each observation point in each subsequence is deeper than the low water level of the cross-section, and each subsequence is a first observation point interval; taking the first observation point interval where the thalweg point is located as the low water channel range interval of the cross-section, that is, the starting distance range of the low water channel of the cross-section; based on the low water channel range interval, determining the main channel range interval of the cross-section.

[0030] In some embodiments of the present application, the low water level is determined through the following steps: obtaining the measured historical low water levels of multiple target hydrological stations in the target river reach; assuming that the water surface slope between the hydrological stations remains unchanged, performing linear interpolation processing on the measured historical low water levels of the multiple target hydrological stations to obtain the low water level of each cross-section in the target river reach, so as to make the determination of the low water level more convenient and rapid.

[0031] In some embodiments of the present application, based on the low water channel range interval, determining the main channel range interval of the cross-section may include: determining the maximum starting distance and the minimum starting distance among the starting distances of the multiple observation points in the low water channel range interval; detecting whether there are target observation points that meet the first preset condition or the second preset condition among the multiple observation points sorted in order of starting distance; if there are target observation points, adding the target observation points to the low water channel range interval to obtain an expanded low water channel range interval; based on the expanded low water channel range interval, determining the main channel range interval of the cross-section. For example, the expanded low water channel range interval can be directly used as the main channel range interval of the cross-section, so that the determined main channel range interval is more accurate.

[0032] Among them, based on the characteristic that the riverbed elevations on both banks increase in the area outside the dry river channel range within the main channel range interval, the first preset condition is set as follows: The first preset condition includes that the target observation point does not exist in the dry river channel range interval, the target observation point is adjacent to the observation point with the maximum starting distance among multiple observation points sorted in sequence according to the starting distance, and a first preset size relationship is satisfied between the riverbed elevation of the target observation point and the riverbed elevation of the observation point with the maximum starting distance. The first preset size relationship can be, for example, that the riverbed elevation of the target observation point is greater than the riverbed elevation of the observation point with the maximum starting distance, that is, it conforms to the above characteristics (within the main channel range interval, the riverbed elevation on the right bank in the area outside the dry river channel range interval increases). Therefore, the target observation point can be added to the dry river channel range interval to obtain a more accurate main channel range interval.

[0033] Similarly, the second preset condition includes that the target observation point does not exist in the dry river channel range interval, the target observation point is adjacent to the observation point with the minimum starting distance among multiple observation points sorted in sequence according to the starting distance, and a second preset size relationship is satisfied between the riverbed elevation of the target observation point and the riverbed elevation of the observation point with the minimum starting distance. The second preset size relationship can be, for example, that the riverbed elevation of the target observation point is greater than the riverbed elevation of the observation point with the minimum starting distance, that is, it conforms to the above characteristics (within the main channel range interval, the riverbed elevation on the left bank in the area outside the dry river channel range interval increases). Therefore, the target observation point can be added to the dry river channel range interval to obtain a more accurate main channel range interval.

[0034] After adding the target observation point to the dry river channel range interval, the starting distances of multiple observation points in the expanded dry river channel range interval still satisfy the ascending order.

[0035] In some embodiments of the present application, the cross-section flat pool water level is determined through the following steps: Obtain the measured historical flat pool water levels of multiple target hydrological stations in the target river section; assuming that the water surface slope between hydrological stations remains unchanged, perform linear interpolation processing on the measured historical flat pool water levels of multiple target hydrological stations to obtain the cross-section flat pool water level of each cross-section in the target river section, so as to make the determination of the cross-section flat pool water level more convenient and fast.

[0036] In some embodiments of the present application, an example is given to illustrate the refinement content of step 101. Specifically, step 101 may include: Step 1, standardize the long-sequence observation data of the measured large cross-section to form a data set including the starting distance X, the riverbed elevation Y, and the mileage L from the dam.

[0037] 1.1, sort out the long-time sequence measured large cross-section observation data of the target river section. For the data of a certain measurement, assuming the number of cross-sections is mm and the number of cross-section observation points is dd, the river channel cross-section topography X and Y are two-dimensional arrays: X(i, j), Y(i, j), L(i) In the formula, X is the distance of the observation point from the starting point of the cross-section (i.e., the starting distance); Y is the measured riverbed elevation of the observation point; L is the distance of the measured large cross-section from the dam site (i.e., the mileage from the dam); i is the measurement cross-section number; j is the maximum value of the number of observation points for each cross-section. Where i = 1, 2, …, mm; j = 1, 2, …, dd.

[0038] 1.2. Standardize the topographic data of the measured large cross-section. Store the data of different cross-sections in the same measurement in the same Excel file in the format of the starting distance X and the riverbed elevation Y. At the same time, store the mileage L from the dam of different cross-sections in the same measurement in different worksheets (sheets) of the above Excel file, and name the data of different measurements by the measurement time and store them in different Excel files.

[0039] Step 2. Determine the typical water level data set of the measured large cross-section.

[0040] 2.1. Collect and sort out the measured historical low water level and floodplain water level data of the target hydrological station in the target river section. 2.2. Assume that the water surface slope between hydrological stations remains unchanged, and use linear interpolation to obtain the characteristic water levels of the measured large cross-section, forming a data set including the cross-section name, the mileage L from the dam, the low water level Z_low and the floodplain water level Z_bankfull.

[0041] Step 3. Identify the main channel range of the measured large cross-section.

[0042] 3.1. Use the find statement in software such as MATLAB to determine the lowest riverbed elevation and location of the measured large cross-section. The lowest riverbed elevation is the thalweg elevation, denoted as Z. The cross-section node where the thalweg is located is denoted as d_thaw, i.e., Z = min(Y), d_thaw = find(Y = min(Y)).

[0043] 3.2. Extract the area where the cross-section riverbed elevation is less than the low water level Z_low of the cross-section. According to the continuity of the cross-section nodes, divide the area where the cross-section riverbed elevation is less than the low water level Z_low into different sub-intervals, and then determine the interval where the thalweg is located as the range of the low-flow river channel.

[0044] 3.3. Based on the characteristics of the increasing elevation of the left and right banks of the area outside the low-flow river channel within the main channel range, use the while conditional statement in software such as MATLAB. In the order of increasing starting distance, with the increase of the elevation of the adjacent nodes on the left and right sides of the low-flow river channel as the standard, expand the range of the low-flow river channel determined in step 3.2 until the elevation of the left and right banks decreases, and determine the range between the left and right nodes at this time as the main channel range.

[0045] 3.4. Calculate the cross-sectional area A of the main channel under the flood-level by using the trapezoidal area summation method for adjacent observation points.

[0046] 102. For each cross-section, among multiple preset water level values greater than the elevation of the thalweg point of the cross-section, determine the target water level value. Wherein, the river channel range interval where the thalweg point of the cross-section is located under the target water level value is the target interval, and the cross-sectional area of the river channel within the target interval is greater than or equal to the product of the cross-sectional area of the main channel and the preset ratio value.

[0047] 103. Take the target water level value as the thalweg elevation of the corresponding cross-section.

[0048] In the embodiments of the present application, the elevation of the thalweg point refers to the riverbed elevation of the thalweg point. Multiple preset water level values greater than the elevation of the thalweg point of the cross-section can be set based on actual needs. In order to make the determined longitudinal profile of the river channel more accurate, it is necessary to determine the target water level value that can reflect the actual characteristics of the longitudinal profile of the river channel among multiple preset water level values greater than the elevation of the thalweg point of the cross-section. For example, the river channel range interval where the thalweg point of the cross-section is located under the target water level value can be used as the target interval. At this time, the cross-sectional area of the river channel within the target interval needs to be greater than or equal to the product of the cross-sectional area of the main channel and the preset ratio value, so that the target water level value can better represent the actual characteristics of the longitudinal profile of the river channel. The preset ratio value can be, for example, 10%. In addition, if there are multiple preset water level values that meet the above conditions (the cross-sectional area of the river channel within the target interval is greater than or equal to the product of the cross-sectional area of the main channel and the preset ratio value), the minimum value of the multiple preset water level values that meet the above conditions is taken as the target water level value.

[0049] In some embodiments of the present application, before determining the target water level value among multiple preset water level values greater than the elevation of the thalweg point of the cross-section, it may further include: for each preset water level value, use the preset water level value to divide multiple observation points sorted in order of starting distance to obtain multiple second observation point intervals. The division method of the multiple second observation point intervals is similar to the division method of the multiple first observation point intervals, which will not be elaborated here; take the second observation point interval where the thalweg point is located as the river channel range interval where the thalweg point of the cross-section is located under the preset water level value. The determination method of the river channel range interval where the thalweg point is located is similar to the determination method of the dry-season river channel range interval, which will not be elaborated here. And the determination method of the cross-sectional area of the river channel within the river channel range interval where the thalweg point of the cross-section is located under the preset water level value is similar to the determination method of the cross-sectional area of the main channel of the corresponding cross-section under the flood-level of the cross-section, which will not be elaborated here.

[0050] In some embodiments of the present application, multiple preset water level values greater than the elevation of the thalweg point of the cross-section can be determined through the following steps: determine the sum of the elevation of the thalweg point and the preset elevation to obtain the target elevation. The preset elevation can be, for example, 0.5 meters; increase the target elevation in sequence according to the preset step size to obtain multiple preset water level values.

[0051] In a further embodiment, by increasing the target elevation step by step according to a preset step size, a plurality of preset water level values can be obtained, which may include: since the number of nodes in the cross-section within the preset elevation range above the thalweg elevation is too small to effectively smooth the longitudinal profile of the river channel, first, a new target elevation is quickly searched above the target elevation according to a first preset step size (e.g., 0.1 m), where the number of consecutive nodes near the cross-section where the thalweg is located is greater than a preset number (e.g., 6); then, according to a second preset step size (e.g., 0.02 m), the new target elevation is increased step by step to obtain a plurality of preset water level values. Here, the second preset step size is smaller than the first preset step size to facilitate accurately finding the target water level value that meets the area condition.

[0052] In some embodiments of the present application, the refined content of steps 102 and 103 is illustrated by examples. Specifically, steps 102 and 103 may include: Step 4, identifying the elevation of the deep trough of the measured large cross-section.

[0053] 4.1, Using the while conditional statement in software such as MATLAB, the cross-sectional area ans_A of the interval where the thalweg is located is calculated by the trapezoidal area summation method of adjacent observation points at different preset water levels ans_Z. Here, the initial water level of ans_Z is 0.5 m above the thalweg elevation, i.e., ans_Z = Z + 0.5 m, and the step size is 0.02 m. It continues until the cross-sectional area of the interval where the thalweg is located at ans_Z is greater than or equal to 10% of the cross-sectional area A of the main channel at the floodplain water level, i.e., ans_A ≥ 0.1 A, and the preset water level at this time is determined as the elevation of the deep trough of the measured large cross-section.

[0054] 4.2, Using the for loop statement in MATLAB software, calculate the elevations of the deep troughs of different cross-sections in the same measurement.

[0055] 104. Determine the longitudinal profile of the river channel of the target reach using the elevations of the deep troughs of multiple cross-sections in the target reach.

[0056] In the embodiments of the present application, taking the target water level value as the elevation of the deep trough of the corresponding cross-section means taking the target water level value as the depth characteristic value of the main channel of the corresponding cross-section. Using the elevations of the deep troughs of multiple cross-sections in the target reach, the longitudinal profile of the river channel of the target reach can be drawn.

[0057] In some embodiments of the present application, step 104 may include: performing a moving average process on the thalweg elevations of multiple cross-sections in the target river reach in sequence according to the mileage of the cross-section from the dam, to obtain the processed thalweg elevations of the multiple cross-sections, so that the transition between the thalweg elevations of the multiple cross-sections can be smoother. Herein, the mileage of the cross-section from the dam refers to the distance of the cross-section relative to the target dam site. It can be understood that the distances of different cross-sections in the target river reach relative to the target dam site are different, so different cross-sections can be distinguished by the mileage of the cross-section from the dam; connecting the processed thalweg elevations of the multiple cross-sections according to the mileage of the cross-section from the dam to obtain the longitudinal profile of the river channel of the target river reach, so that there are fewer sawteeth in the longitudinal profile of the river channel. Based on the longitudinal profile of the river channel, the thalweg depths and the changes in thalweg depths of different cross-sections in the target river reach can be known, thereby efficiently, quickly and simply identifying the temporal variation law of the longitudinal profile of the alluvial river channel.

[0058] In some embodiments of the present application, an example is given to illustrate the refined content of step 104. Specifically, step 104 may include: Step 5, draw the longitudinal profile of the river channel for the same measurement.

[0059] 5.1, based on the calculation results in step 4.2, perform a smoothing process on the thalweg elevations of adjacent cross-sections along the way by using the moving average method.

[0060] 5.2, use the plot function in software such as MATLAB to draw the relationship diagram between the thalweg elevation of the measured large cross-section and the mileage L from the dam for the same measurement, that is, the longitudinal profile of the river channel.

[0061] In some embodiments of the present application, after step 104, it may further include: Step 6, determine the variation law of the longitudinal profile of the river channel.

[0062] 6.1, use the for loop statement in software such as MATLAB to calculate the longitudinal profiles of the river channel for different measurements; 6.2, use the plot function in software such as MATLAB to draw the longitudinal profiles of the river channel for different measurements on the same graph to obtain the variation law of the longitudinal profile of the river channel.

[0063] In the technical solution disclosed in this embodiment, based on the product of the main channel cross-section area at the corresponding cross-section's flat flood water level and the preset ratio value, the target water level value with the corresponding river channel cross-section area is determined and used as the thalweg elevation of the corresponding cross-section, and then the longitudinal profile of the river channel of the target river reach is determined. Compared with the thalweg longitudinal profile drawn based on the elevation of the thalweg point of the cross-section, there are fewer sawteeth in the longitudinal profile of the river channel, so as to accurately identify the longitudinal adjustment law of the river channel and reduce the level requirements for relevant technical personnel.

[0064] Next, with reference to Figure 1, an example is given to illustrate the method for determining the longitudinal profile of a river based on the cross-sectional topography. Specifically, the variation law of the longitudinal profile of the target river reach is identified, including the following steps: Step 1: Standardize the long-term observational data of the measured large cross-sections to form a dataset including the starting distance X, the riverbed elevation Y, and the mileage L from the dam.

[0065] Collect and organize the long-term historical observational data of the measured large cross-sections of the target river reach. Store the data of different cross-sections in the same measurement in the same Excel file in the format of the starting distance X and the elevation Y, as shown in Table 1 below. At the same time, sort out the cross-sectional data of all measurements, store the mileage L from the dam of different cross-sections in the same measurement in different sheets of the above Excel file, and name the data of different measurements according to the measurement time and store them in different Excel files.

[0066] Table 1 Standardized dataset of different cross-sections in the same measurement

[0067] Step 2: Determine the dataset of typical water levels of the measured large cross-sections.

[0068] Collect and organize the low water level and bankfull water level data of typical hydrological stations or typical cross-sections in the target river reach. Assume that the water surface slope between hydrological stations or typical cross-sections remains unchanged, and use linear interpolation to obtain the characteristic water levels of the measured large cross-sections to form a dataset including the cross-section name, the mileage L from the dam, the low water level Z_low, and the bankfull water level Z_bankfull, as shown in Table 2 below.

[0069] Table 2 Dataset of characteristic parameters of the measured large cross-sections

[0070] Step 3: Identify the main channel range of the measured large cross-sections.

[0071] Taking cross-section 66 in 2001 as an example, an example is given to illustrate the identification process of the main channel range of the cross-sectional data. Use the find statement in MATLAB to determine the lowest elevation of the cross-section (i.e., the thalweg elevation Z = 28.1m), and the serial number d_thaw of the cross-section node where the thalweg is located is 48. Use the find statement in MATLAB to extract the area where the riverbed elevation of the cross-section is less than the low water level Z_low = 36.84m of the cross-section. The continuous node range of this area is [13, 50], including the cross-section node 48 where the thalweg is located, and then determine this area as the range of the low-flow river channel.

[0072] Then, based on the characteristics of the increasing elevation on both the left and right banks of the area outside the dry river channel within the main channel range, using the while conditional statement in MATLAB, in ascending order of the starting distance, with the increase in elevation between adjacent nodes on both the left and right sides as the criterion, the range of the dry river channel is expanded until the elevation on both the left and right banks decreases. And the range between the left and right nodes at this time is determined as the main channel range. The continuous node range of the main channel area of this cross-section is [3, 53].

[0073] Step 4: Identification of the elevation of the deep trough in the measured large cross-section.

[0074] The trapezoidal area summation method of adjacent observation points is used to calculate the cross-sectional area A of the main channel within the node range [3, 53] where the water level at the floodplain Z_bankfull = 42.82m.

[0075] Considering that 0.5m above the elevation of the thalweg point Z = 28.1m, the number of nodes in the cross-section is too small to effectively smooth the longitudinal profile of the river channel. Therefore, first, using the while conditional statement in MATLAB, with a step size of 0.1m, search for a preset water level (i.e., ans_Z1 = 32.3m) where the number of consecutive nodes near the cross-section node 48 where the elevation is 0.5m above the thalweg point (i.e., above the elevation of ans_Z = 28.6m) is greater than the preset number (for example, 6) to facilitate subsequent smoothing of the longitudinal profile of the river channel. Then, using the while conditional statement in MATLAB with a step size of 0.02m, the trapezoidal area summation method of adjacent observation points is used to calculate the cross-sectional area ans_A of the interval where the thalweg point is located at different preset water levels until the cross-sectional area of the interval where the thalweg point is located at the preset water level is greater than or equal to 10% of the cross-sectional area A of the main channel at the floodplain water level (i.e., ans_A ≥ 0.1 A). And the preset water level at this time is determined as the elevation of the deep trough in the measured large cross-section. That is, the elevation of the deep trough of cross-section 66 in 2001 is 32.50m.

[0076] Then, using the for loop statement in MATLAB, calculate the elevation of the thalweg point and the elevation of the deep trough of different cross-sections in the same measurement. The calculation results of the elevation of the thalweg point and the elevation of the deep trough of multiple cross-sections in the target river reach in 2003 are as Figure 2 shown.

[0077] Step 5: Draw the longitudinal profile of the river channel for the same measurement.

[0078] To better display the variation law of the longitudinal profile of the river channel, based on the calculation results of the elevation of the deep trough of different cross-sections in the same measurement obtained in Step 4, the sliding average method is used to smooth the elevation of the deep trough of adjacent cross-sections along the way. Then, using the plot function in MATLAB, draw the relationship diagram between the elevation of the deep trough of the cross-section and the mileage L from the dam in the target river reach, that is, the longitudinal profile of the river channel.

[0079] Step 6: Determine the variation law of the river channel longitudinal profile.

[0080] Using the for loop statement in MATLAB and adopting the above steps, calculate the longitudinal profiles of the river channel at different measurement times in the target river reach. Then, using the plot function in MATLAB, plot the longitudinal profiles of the river channel at different measurement times in the target river reach on the same graph. For example, the longitudinal profiles of the river channel at different measurement times (such as the two measurement times in 2001 and 2021) in the target river reach are as Figure 3 shown.

[0081] It can be seen that based on the measured large cross-section data of a long time series, the present invention uses the preset water level corresponding to the preset proportion value (such as 10%) of the floodplain area within the main channel of the river as the elevation of the deep trough of the cross-section, and takes the connection line of the deep trough elevations of each cross-section along the way as the longitudinal profile line of the river channel, which can effectively reduce the serrated volatility of the longitudinal profile of the thalweg of the river channel, and realize the automatic identification of the elevation of the deep trough of the cross-section and the automatic drawing of the longitudinal profile line through software such as MATLAB. This technology is based on the measured large cross-section data, with less difficulty in obtaining data, lower cost, and high accuracy, and can efficiently, quickly, and simply identify the temporal variation law of the longitudinal profile of alluvial river channels, which is of great significance for predicting the characteristics of river channel evolution, formulating appropriate river (navigation) regulation plans, and flood prediction.

[0082] In order to better implement the method for determining the longitudinal profile of a river channel based on the river channel cross-section topography in the embodiments of the present application, on the basis of the method for determining the longitudinal profile of a river channel based on the river channel cross-section topography, an apparatus for determining the longitudinal profile of a river channel based on the river channel cross-section topography is further provided in the embodiments of the present application, as Figure 4 shown. The apparatus 400 for determining the longitudinal profile of a river channel based on the river channel cross-section topography includes: A first acquisition module 401, configured to acquire the main channel cross-section data of multiple cross-sections in the target river reach, where the main channel cross-section data includes the main channel cross-section area of each cross-section at the floodplain water level corresponding to the cross-section; A first determination module 402, configured to determine, for each cross-section, a target water level value from multiple preset water level values greater than the elevation of the thalweg point of the cross-section, where the river channel range interval where the thalweg point of the cross-section is located at the target water level value is the target interval, and the river channel cross-section area within the target interval is greater than or equal to the product of the main channel cross-section area and the preset proportion value; A second determination module 403, configured to use the target water level value as the elevation of the deep trough of the corresponding cross-section; A third determination module 404, configured to determine the longitudinal profile of the target river reach by using the elevations of the deep troughs of multiple cross-sections in the target river reach.

[0083] The embodiments of the present application further provide a computer device, which integrates any one of the river channel longitudinal profile determination devices based on the river channel cross-section topography provided by the embodiments of the present application. As Figure 5 shown, it shows a schematic structural diagram of the computer device involved in the embodiments of the present application. Specifically: The computer device may include components such as a processor 501 with one or more processing cores, a memory 502 with one or more computer-readable storage media, a power supply 503, and an input unit 504. Those skilled in the art can understand that Figure 5 the computer device structure shown in does not limit the computer device, and may include more or fewer components than shown, or combine certain components, or have different component arrangements. Among them: The processor 501 is the control center of the computer device, connecting various parts of the entire computer device through various interfaces and lines. By running or executing software programs and / or modules stored in the memory 502, and calling the data stored in the memory 502, it executes various functions of the computer device and processes data, thereby monitoring the computer device as a whole. Optionally, the processor 501 may include one or more processing cores; preferably, the processor 501 may integrate an application processor and a modem processor. Among them, the application processor mainly processes the operating system, user interface, application programs, etc., and the modem processor mainly processes wireless communication. It can be understood that the above modem processor may not be integrated into the processor 501.

[0084] The memory 502 can be used to store software programs and modules. The processor 501 executes various functional applications and data processing by running the software programs and modules stored in the memory 502. The memory 502 may mainly include a program storage area and a data storage area. Among them, the program storage area may store an operating system, application programs required for at least one function (such as a sound playback function, an image playback function, etc.); the data storage area may store data created according to the use of the computer device. In addition, the memory 502 may include high-speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other volatile solid-state storage devices. Correspondingly, the memory 502 may also include a memory controller to provide the processor 501 with access to the memory 502.

[0085] The computer device further includes a power supply 503 for powering each component. Preferably, the power supply 503 can be logically connected to the processor 501 through a power management system, so as to manage functions such as charging, discharging, and power consumption management through the power management system. The power supply 503 can also include any components such as one or more DC or AC power supplies, a recharge system, a power failure detection circuit, a power converter or inverter, and a power status indicator.

[0086] The computer device may further include an input unit 504, which can be used to receive input digital or character information, and generate keyboard, mouse, joystick, optical or trackball signal inputs related to user settings and function controls.

[0087] Although not shown, the computer device may further include a display unit, etc., which will not be elaborated here. Specifically, in this embodiment, the processor 501 in the computer device will load the executable files corresponding to the processes of one or more application programs into the memory 502 according to the following instructions, and the processor 501 will run the application programs stored in the memory 502 to implement various functions as follows: Obtain the main channel cross-section data of multiple cross-sections in the target river section. The main channel cross-section data includes the main channel cross-section area of each cross-section at the corresponding cross-section's floodplain water level; for each cross-section, determine a target water level value among multiple preset water level values greater than the thalweg elevation of the cross-section. The river channel range interval where the thalweg is located at the target water level value of the cross-section is the target interval, and the cross-section area of the river channel within the target interval is greater than or equal to the product of the main channel cross-section area and a preset ratio value; use the target water level value as the deep channel elevation of the corresponding cross-section; use the deep channel elevations of multiple cross-sections in the target river section to determine the longitudinal profile of the river channel of the target river section.

[0088] Those of ordinary skill in the art can understand that all or part of the steps in the above various methods of the embodiments can be completed by instructions, or by controlling related hardware through instructions. The instructions can be stored in a computer-readable storage medium and loaded and executed by the processor.

[0089] Therefore, an embodiment of the present application provides a computer-readable storage medium, which may include: a read-only memory (ROM, Read Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disc, etc. A computer program is stored thereon, and the computer program is loaded by the processor to execute the steps in any one of the methods for determining the longitudinal profile of a river channel based on the river channel cross-section topography provided by the embodiments of the present application. For example, when the computer program is loaded by the processor, the following steps can be executed: Obtain the main channel cross-section data of multiple cross-sections in the target river reach. The main channel cross-section data includes the main channel cross-sectional area of each cross-section at the corresponding cross-section floodplain water level. For each cross-section, determine a target water level value among multiple preset water level values greater than the thalweg elevation of the cross-section. Wherein, the river channel range interval where the thalweg is located at the target water level value of the cross-section is the target interval, and the cross-sectional area of the river channel within the target interval is greater than or equal to the product of the main channel cross-sectional area and the preset ratio value. Take the target water level value as the thalweg elevation of the corresponding cross-section. Use the thalweg elevations of multiple cross-sections in the target river reach to determine the longitudinal profile of the river channel of the target river reach.

[0090] An embodiment of the present application also provides a computer program product or a computer program. The computer program product or the computer program includes computer instructions, and the computer instructions are stored in a computer-readable storage medium. The processor of the electronic device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions to enable the electronic device to execute to implement the method for determining the longitudinal profile of a river channel based on the river channel cross-section topography as described in any one of the above, for example: Obtain the main channel cross-section data of multiple cross-sections in the target river reach. The main channel cross-section data includes the main channel cross-sectional area of each cross-section at the corresponding cross-section floodplain water level. For each cross-section, determine a target water level value among multiple preset water level values greater than the thalweg elevation of the cross-section. Wherein, the river channel range interval where the thalweg is located at the target water level value of the cross-section is the target interval, and the cross-sectional area of the river channel within the target interval is greater than or equal to the product of the main channel cross-sectional area and the preset ratio value. Take the target water level value as the thalweg elevation of the corresponding cross-section. Use the thalweg elevations of multiple cross-sections in the target river reach to determine the longitudinal profile of the river channel of the target river reach.

[0091] In the above embodiments, the descriptions of each embodiment have their own emphases. For parts not detailed in a certain embodiment, reference can be made to the detailed descriptions of other embodiments above, and details will not be repeated here.

[0092] In specific implementation, the above-mentioned each unit or structure can be implemented as an independent entity, or can be combined arbitrarily to be implemented as the same or several entities. The specific implementation of the above-mentioned each unit or structure can refer to the method embodiments above, and details will not be repeated here.

[0093] The specific implementation of each of the above operations can refer to the previous embodiments, and details will not be repeated here.

[0094] The above has introduced in detail a method for determining the longitudinal profile of a river channel based on the cross-sectional topography of the river channel and related devices. Specific examples are used in this article to elaborate on the principle and implementation manner of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application; at the same time, for those skilled in the art, according to the idea of this application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

1. A method for determining the longitudinal profile of a river channel based on the cross-sectional topography of the river channel, characterized in that, The method includes: Obtaining the main channel cross-section data of multiple cross-sections in the target river reach, where the main channel cross-section data includes the main channel cross-sectional area of each cross-section at the corresponding cross-section floodplain water level; For each cross-section, determining a target water level value from multiple preset water level values greater than the thalweg elevation of the cross-section. Wherein, the river channel range interval where the thalweg is located at the target water level value of the cross-section is the target interval, and the river channel cross-sectional area within the target interval is greater than or equal to the product of the main channel cross-sectional area and a preset ratio value; Taking the target water level value as the thalweg elevation of the corresponding cross-section; Using the thalweg elevations of multiple cross-sections in the target river reach to determine the longitudinal profile of the river channel of the target river reach.

2. The method for determining the longitudinal profile of a river channel based on the cross-sectional topography of the river channel according to claim 1, wherein The obtaining of the main channel cross-section data of multiple cross-sections in the target river reach includes: For each cross-section, obtaining the main channel range interval of the cross-section; Determining the area of the region of the cross-section within the corresponding main channel range interval and at the corresponding cross-section floodplain water level, and taking it as the main channel cross-sectional area of the cross-section at the corresponding cross-section floodplain water level.

3. The method for determining the longitudinal profile of a river channel based on the cross-sectional topography of the river channel according to claim 2, wherein The obtaining of the main channel range interval of the cross-section includes: Obtaining the observation data of the cross-section, where the observation data includes the starting distances and riverbed elevations of multiple observation points in the cross-section; Based on the riverbed elevation, determining the thalweg among the multiple observation points; Using the low water level of the cross-section to divide the multiple observation points sorted in sequence according to the starting distance, obtaining multiple first observation point intervals; Taking the first observation point interval where the thalweg is located as the dry river channel range interval of the cross-section; Based on the dry river channel range interval, determining the main channel range interval of the cross-section.

4. The method for determining the longitudinal profile of a river channel based on the cross-sectional topography of the river channel according to claim 3, wherein The determining of the main channel range interval of the cross-section based on the dry river channel range interval includes: Determining the maximum starting distance and the minimum starting distance among the starting distances of multiple observation points in the dry river channel range interval; Detecting whether there is a target observation point that satisfies the first preset condition or the second preset condition among the multiple observation points sorted in sequence according to the starting distance. Wherein, the first preset condition includes that the target observation point does not exist in the dry river channel range interval, the target observation point is adjacent to the observation point where the maximum starting distance is located among the multiple observation points sorted in sequence according to the starting distance, and there is a first preset size relationship between the riverbed elevation of the target observation point and the riverbed elevation of the observation point where the maximum starting distance is located. The second preset condition includes that the target observation point does not exist in the dry river channel range interval, the target observation point is adjacent to the observation point where the minimum starting distance is located among the multiple observation points sorted in sequence according to the starting distance, and there is a second preset size relationship between the riverbed elevation of the target observation point and the riverbed elevation of the observation point where the minimum starting distance is located; If there is the target observation point, adding the target observation point to the dry river channel range interval to obtain an expanded dry river channel range interval; Based on the expanded dry river channel range interval, determining the main channel range interval of the cross-section.

5. The method for determining the longitudinal profile of a river channel based on the cross-sectional topography of the river channel according to claim 1, wherein The observation data of the cross-section includes the starting distances and riverbed elevations of multiple observation points in the cross-section. Among the multiple observation points, there is a thalweg point, which is determined based on the riverbed elevation. Before determining the target water level value among multiple preset water level values greater than the elevation of the thalweg point of the cross-section, it further includes: For each of the preset water level values, using the preset water level value, divide the multiple observation points sorted in sequence according to the starting distance to obtain multiple second observation point intervals; Take the second observation point interval where the thalweg point is located as the river channel range interval where the thalweg point of the cross-section is located under the preset water level value.

6. The method for determining the longitudinal profile of a river channel based on the cross-sectional topography of the river channel according to claim 1 or 5, characterized in that The multiple preset water level values greater than the elevation of the thalweg point of the cross-section are determined through the following steps: Determine the sum of the elevation of the thalweg point and the preset elevation to obtain the target elevation; Increase the target elevation sequentially according to the preset step size to obtain the multiple preset water level values.

7. The method for determining the longitudinal profile of a river channel based on the cross-sectional topography of the river channel according to claim 1, wherein The method of determining the longitudinal profile of the river channel using the thalweg elevations of multiple cross-sections in the target river reach includes: Perform moving average processing on the thalweg elevations of multiple cross-sections in the target river reach in sequence according to the cross-section distance from the dam to obtain the processed thalweg elevations of multiple cross-sections; Connect the processed thalweg elevations of multiple cross-sections according to the cross-section distance from the dam to obtain the longitudinal profile of the river channel of the target river reach.

8. The method for determining the longitudinal profile of a river channel based on the cross-sectional topography of the river channel according to claim 1, characterized in that The cross-section flat pool water level is determined through the following steps: Obtain the measured historical flat pool water levels of multiple target hydrological stations in the target river reach; Perform linear interpolation processing on the measured historical flat pool water levels of multiple target hydrological stations to obtain the cross-section flat pool water level of each cross-section in the target river reach.

9. A computer device, characterized in that, The computer device includes: One or more processors; A memory; And one or more applications, where the one or more applications are stored in the memory and are configured to be executed by the processor to implement the steps in the method for determining the longitudinal profile of the river channel based on the river channel cross-section topography according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that, A computer program is stored thereon, and the computer program is loaded by the processor to execute the steps in the method for determining the longitudinal profile of the river channel based on the river channel cross-section topography according to any one of claims 1 to 8.

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