CN115309199B - The basic flow control method and system of the downstream channel of the hub based on the channel scale - Google Patents

Abstract

The invention provides a method and system for controlling the basic flow rate of the downstream channel of a hub based on the channel scale, wherein the method includes determining the target channel section scale parameter; obtaining the riverbed gradient of the target channel; calculating the flow rate of the target channel; calculating the downstream outlet water level of the hub; and obtaining the downstream of the hub Depth distribution along the target channel to obtain the minimum water depth of the target channel downstream of the hub; determine whether the absolute value of the difference between the minimum water depth and the channel water depth under the target channel level exceeds the preset water depth threshold; if not, determine the flow rate of the target channel as the target channel Basic flow; if yes, judge whether the minimum water depth is greater than the channel water depth under the target channel level; if yes, calculate the upstream inflow flow of the hub and the downstream outlet water level of the hub to be reduced; if not, calculate the upstream inflow flow of the hub and The outlet water level downstream of the hub. The invention directly calculates the flow rate of the target waterway through the formula, shortens the adjustment range of the waterway flow rate, and improves the calculation efficiency of the basic flow rate of the waterway.

Description

The basic flow control method and system of the downstream channel of the hub based on the channel scale

technical field

The invention belongs to the technical field of water resources management, and in particular relates to a method and system for controlling the basic flow of a waterway downstream of a hub based on the waterway scale.

Background technique

In the tributaries of the river basin, there are often pivotal projects to control the discharge flow process. The discharge flow of the hub meets the basic water demand of the downstream channel, which is the basic premise of the development, construction and protection of the downstream channel of the hub. However, the basic water demand of the channel varies with different channel grades and different channel characteristics. The monitoring of channel flow is the basis for dispatching and making full use of water resources, and is the basis for implementing a strict water resources management system.

Traditional waterway flow measurement methods include manual ship survey, bridge survey, cableway survey and wading survey, etc. The basic principle is to lay out multiple vertical lines on the flow measurement section, measure the water depth on each vertical line and measure the flow velocity at one to several points with a current meter, so as to obtain the average flow velocity of the vertical line, and then obtain the cross-sectional area and cross-sectional average flow velocity, and the flow rate is It is obtained by the product of the cross-sectional area and the average velocity of the cross-section. However, in the traditional method, the representativeness of the flow at the measurement point is low, and the adjustment range of the channel flow is relatively large, and a large number of flow measurements and adjustments are required to make the discharge flow of the hub meet the basic water demand of the current channel. This traditional method Time-consuming and labor-intensive, the efficiency is low.

Contents of the invention

Aiming at the deficiencies in the prior art, the present invention provides a method and system for controlling the basic flow of a channel downstream of a hub based on channel scale.

In the first aspect, the present invention provides a basic flow control method for the downstream channel of a hub based on the channel scale, including:

S1, according to the grade of the target channel downstream of the hub, determine the target channel section scale parameters; the target channel section scale parameters include channel water depth, channel bottom width and channel slope slope;

S2, obtaining the riverbed gradient of the target channel;

S3, calculate the discharge of the target channel according to the riverbed gradient and section scale parameters of the target channel;

S4. Construct a two-dimensional water flow model of the channel downstream of the hub;

S5, according to the two-dimensional water flow model of the channel plane, taking the flow rate of the target channel as the upstream water flow of the hub, and calculating the downstream outlet water level of the hub;

S6. According to the two-dimensional water flow model of the channel plane, the water depth distribution along the target channel downstream of the hub is obtained, and the minimum water depth of the target channel downstream of the hub is obtained;

S7, judging whether the absolute value of the difference between the minimum water depth of the target channel and the water depth of the channel under the target channel level exceeds a preset water depth threshold;

S8, if not, determine that the flow of the target channel is the basic flow of the target channel;

S9, if yes, judging whether the minimum water depth of the target channel is greater than the water depth of the target channel level;

S10, if yes, calculate the upstream inflow of the hub and the downstream outlet water level of the hub that need to be reduced according to the two-dimensional water flow model of the channel plane, and return to the operation of step S6;

S11, if not, calculate the upstream inflow flow of the hub and the downstream outlet water level of the hub to be increased according to the two-dimensional water flow model of the channel plane, and return to the operation of step S6.

Further, the calculation of the flow rate of the target channel according to the riverbed gradient and section scale parameters of the target channel includes:

Calculate the flow rate of the target channel according to the following formula:

Among them, Q is the channel flow rate under the target channel level; _n1 is the comprehensive roughness of the target channel; J is the riverbed gradient of the target channel; H is the water depth under the target channel level; B is the channel bottom width under the target channel level; m is the channel slope slope under the target channel level.

Further, the construction of the two-dimensional water flow model of the channel downstream of the hub includes:

Construct the two-dimensional water flow model of the channel downstream of the hub according to the following formula:

Among them, x and y are the coordinates of the Cartesian coordinate system; t is the time variable; Z is the outlet water level downstream of the hub; M=uh, N=vh, u is the flow velocity in the x direction, v is the flow velocity in the y direction, and h is the water depth; n ₂ is the Manning roughness coefficient; D is the turbulent viscosity coefficient; Q is the channel flow rate under the target channel level; u ₀ is the flow velocity in the x direction when the source-sink enters or exits the channel; v ₀ is y when the source-sink enters or exits the channel The flow velocity in the direction; g is the acceleration due to gravity.

In the second aspect, the present invention provides a basic flow control system for the downstream channel of the hub based on the channel scale, including:

The channel parameter determination module is used to determine the target channel section scale parameter according to the level of the target channel downstream of the hub; the target channel section scale parameter includes channel water depth, channel bottom width and channel slope;

The first obtaining module is used to obtain the riverbed gradient of the target channel;

The first calculation module is used to calculate the flow rate of the target channel according to the riverbed gradient and section scale parameters of the target channel;

Building blocks, used to construct the two-dimensional water flow model of the channel downstream of the hub;

The second calculation module is used to calculate the downstream outlet water level of the hub according to the two-dimensional water flow model of the channel plane, taking the flow rate of the target channel as the upstream water flow of the hub;

The second acquisition module is used to obtain the water depth distribution along the target channel downstream of the hub according to the two-dimensional water flow model of the channel plane, and obtain the minimum water depth of the target channel downstream of the hub;

The first judging module is used to judge whether the absolute value of the difference between the minimum water depth of the target waterway and the water depth of the waterway under the target waterway level exceeds the preset water depth threshold;

The channel basic flow determination module is used to determine the flow rate of the target channel as the target channel when the absolute value of the difference between the minimum water depth of the target channel and the channel water depth under the target channel level does not exceed the preset water depth threshold as determined by the first judgment module basic flow;

The second judgment module is used to determine whether the minimum water depth of the target waterway is greater than the target waterway level when the absolute value of the difference between the minimum water depth of the target waterway and the water depth of the waterway under the target waterway level exceeds the preset water depth threshold as determined by the first judgment module The depth of the channel below;

The third calculation module is used to calculate the upstream inflow of the hub and the downstream outlet water level of the hub that need to be reduced according to the two-dimensional water flow model of the channel plane when the second judging module determines that the minimum water depth of the target channel is greater than the water depth of the target channel level , return to execute the operation of the second acquisition module;

The fourth calculation module is used to calculate the upstream inflow of the hub and the downstream outlet water level of the hub to be increased according to the two-dimensional water flow model of the channel plane when the minimum water depth of the target channel is determined by the second judgment module to be less than the water depth of the target channel level , return to execute the operation of the second acquisition module.

Further, the first computing module includes:

Calculation unit, used to calculate the flow of the target channel according to the following formula:

Among them, Q is the channel flow rate under the target channel level; _n1 is the comprehensive roughness of the target channel; J is the riverbed gradient of the target channel; H is the water depth under the target channel level; B is the channel bottom width under the target channel level; m is the channel slope slope under the target channel level.

Further, the building blocks include:

The construction unit is used to construct the two-dimensional water flow model of the channel downstream of the hub according to the following formula:

Among them, x and y are the coordinates of the Cartesian coordinate system; t is the time variable; Z is the outlet water level downstream of the hub; M=uh, N=vh, u is the flow velocity in the x direction, v is the flow velocity in the y direction, and h is the water depth; n ₂ is the Manning roughness coefficient; D is the turbulent viscosity coefficient; Q is the channel flow rate under the target channel level; u ₀ is the flow velocity in the x direction when the source-sink enters or exits the channel; v ₀ is y when the source-sink enters or exits the channel The flow velocity in the direction; g is the acceleration due to gravity.

The present invention provides a basic flow control method and system for the downstream waterway of a hub based on the waterway scale, wherein the method calculates the flow rate of the target waterway according to the target waterway section scale parameter determined by the level of the downstream target waterway of the hub and the riverbed gradient of the target waterway, avoiding relying on More times of flow measurement and adjustment, so that the discharge flow of the hub can meet the basic water demand of the current channel. The invention directly calculates the flow rate of the target waterway through the formula, shortens the adjustment range of the waterway flow rate, and improves the calculation efficiency of the basic flow rate of the waterway.

Description of drawings

In order to illustrate the technical solution of the present invention more clearly, the accompanying drawings that need to be used in the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, on the premise of not paying creative work, they can also Additional figures can be derived from these figures.

Fig. 1 is a flowchart of a basic flow control method for a channel downstream of a hub based on channel scale provided by an embodiment of the present invention;

Fig. 2 is a schematic diagram of the scale structure of the waterway section provided by the embodiment of the present invention;

Fig. 3 is a schematic structural diagram of a basic flow control system for a channel downstream of a hub based on channel scale provided by an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

As shown in Figure 1, the embodiment of the present invention provides a basic flow control method for the downstream channel of the hub based on the channel scale, including:

Step S1, according to the level of the target channel downstream of the hub, determine the target channel section scale parameters; as shown in Figure 2, the target channel section scale parameters include channel water depth, channel bottom width and channel slope slope.

Step S2, obtaining the river bed gradient of the target channel.

Step S3, calculating the discharge of the target channel according to the river bed gradient and section scale parameters of the target channel.

In this step, the flow rate of the target channel is calculated according to the following formula:

Among them, Q is the channel flow rate under the target channel level; _n1 is the comprehensive roughness of the target channel; J is the riverbed gradient of the target channel; H is the water depth under the target channel level; B is the channel bottom width under the target channel level; m is the channel slope slope under the target channel level.

Step S4, constructing a two-dimensional water flow model of the channel downstream of the hub.

In this step, the two-dimensional water flow model of the channel downstream of the hub is constructed according to the following formula:

Among them, x and y are the coordinates of the Cartesian coordinate system; t is the time variable; Z is the outlet water level downstream of the hub; M=uh, N=vh, u is the flow velocity in the x direction, v is the flow velocity in the y direction, and h is the water depth; n ₂ is the Manning roughness coefficient; D is the turbulent viscosity coefficient; u ₀ is the flow velocity in the x direction when the source sink enters or exits the channel; v ₀ is the flow velocity in the y direction when the source sink enters or exits the channel; g is the gravitational acceleration.

In step S5, according to the two-dimensional water flow model of the channel plane, the outlet water level of the downstream of the hub is calculated by taking the flow rate of the target channel as the inflow upstream of the hub.

Step S6, according to the two-dimensional water flow model of the channel plane, the water depth distribution along the target channel downstream of the hub is obtained, and the minimum water depth of the target channel downstream of the hub is obtained.

Step S7, judging whether the absolute value of the difference between the minimum water depth of the target channel and the water depth of the target channel level exceeds a preset water depth threshold.

Step S8, if not, determine the flow of the target channel as the basic flow of the target channel.

Step S9, if yes, judge whether the minimum water depth of the target channel is greater than the water depth of the target channel level.

Step S10, if yes, calculate the upstream inflow flow of the hub and the outlet water level downstream of the hub to be reduced according to the two-dimensional water flow model on the channel plane, and return to step S6.

Step S11, if not, calculate the upstream inflow flow of the hub and the outlet water level downstream of the hub to be increased according to the two-dimensional water flow model on the channel plane, and return to step S6.

Steps S6-S11, if the minimum water depth is greater than the channel water depth under the target channel level, reduce the upstream flow Q of the hub, and the rate of flow reduction is ΔQ, and reduce the downstream outlet water level Z of the hub according to the relationship between the downstream outlet water level Z of the hub and the upstream flow Q of the hub, and reduce The range of water level is ΔH, and the range of water level reduction ΔH and flow reduction range ΔQ correspond to the relationship between the downstream outlet water level Z of the hub and the upstream flow Q of the hub. Recalculate the minimum water depth of the target channel according to the plane two-dimensional water flow model and judge whether the absolute value of the difference between the minimum water depth of the target channel and the channel water depth under the target channel level exceeds the preset water depth threshold.

If the minimum water depth is less than the water depth of the channel under the target channel level, increase the upstream flow Q of the hub, and the flow increase range is ΔQ. According to the relationship between the downstream outlet water level Z of the hub and the upstream flow Q of the hub, increase the downstream outlet water level Z of the hub, and increase the water level by ΔH. The water level increase range ΔH and the flow rate increase range ΔQ correspond to the relationship between the downstream outlet water level Z of the hub and the upstream flow Q of the hub. Recalculate the minimum water depth of the target channel according to the plane two-dimensional water flow model and judge whether the absolute value of the difference between the minimum water depth of the target channel and the channel water depth under the target channel level exceeds the preset water depth threshold.

In order to make the solutions of the present invention clearer, the embodiments of the present invention further disclose specific examples.

1) The grade of the target channel downstream of the hub is a fourth-level channel, and the cross-sectional scale of the target channel is determined: the water depth H of the channel is 2.4m, the bottom width B of the channel is 50m, and the slope of the channel is 1:5.

2) After the target waterway is dredged, the riverbed gradient is 0.0001, and the calculated discharge that meets the target waterway scale is:

3) According to the terrain data and channel construction data of the downstream channel of the hub, construct the two-dimensional water flow model of the downstream channel of the hub. The initially determined flow rate of 133m ³ /s is used as the upstream inlet flow of the model. According to the relationship between the downstream outlet water level Z and the flow Q, determine the downstream The outlet water level is 58.0m. Calculate the water depth along the channel and obtain the water depth distribution along the channel. The minimum water depth H _min of the channel is 2.38m.

4) Based on the calculation result of step 3), judge whether the flow meets the water depth requirement of the channel: |H _min -H|=|2.38-2.40|=0.02m≤H _{allowable deviation} =0.05m, that is, the flow Q=133m ³ / s is the basic flow that can meet the channel scale.

Based on the same inventive idea, the embodiment of the present invention also provides a basic flow control system for the downstream waterway of a hub based on the waterway scale. Therefore, the implementation of this system can refer to the implementation of the basic flow control method for the downstream channel of the hub based on the channel scale, and the repetition will not be repeated.

A basic flow control system for the downstream channel of a hub based on the channel scale provided by the embodiment of the present invention, as shown in Figure 3, includes:

The channel parameter determination module 10 is used to determine the target channel section scale parameters according to the level of the target channel downstream of the hub; the target channel section scale parameters include channel water depth, channel bottom width and channel slope gradient.

The first obtaining module 20 is used to obtain the river bed gradient of the target channel.

The first calculation module 30 is used to calculate the flow rate of the target channel according to the river bed gradient and section scale parameters of the target channel;

The construction module 40 is used to construct the two-dimensional water flow model of the channel downstream of the hub.

The second calculation module 50 is used to calculate the downstream outlet water level of the hub according to the two-dimensional water flow model of the channel plane, taking the flow rate of the target channel as the inflow upstream of the hub.

The second acquisition module 60 is used to obtain the water depth distribution along the target channel downstream of the hub according to the two-dimensional water flow model of the channel plane, and obtain the minimum water depth of the target channel downstream of the hub.

The first judging module 70 is configured to judge whether the absolute value of the difference between the minimum water depth of the target channel and the water depth of the target channel level exceeds a preset water depth threshold.

The channel basic flow determination module 80 is used to determine that the flow rate of the target channel is the target when the absolute value of the difference between the minimum water depth of the target channel and the channel water depth under the target channel level does not exceed the preset water depth threshold as determined by the first judging module Channel basic flow.

The second judging module 90 is used for judging whether the minimum water depth of the target waterway is greater than the target waterway when the absolute value of the difference between the minimum water depth of the target waterway and the water depth of the waterway under the target waterway level exceeds the preset water depth threshold as determined by the first judgment module Channel water depth under grade.

The third calculation module 100 is used to calculate the upstream inflow flow of the hub and the downstream outlet of the hub that need to be reduced according to the two-dimensional water flow model of the channel plane when the second judgment module determines that the minimum water depth of the target channel is greater than the channel water depth at the target channel level Water level, return to execute the operation of the second acquisition module 60 .

The fourth calculation module 110 is used to calculate the upstream inflow of the hub and the downstream outlet of the hub that need to be increased according to the two-dimensional water flow model of the channel plane when the minimum water depth of the target channel is determined by the second judgment module to be less than the water depth of the target channel level. Water level, return to execute the operation of the second acquisition module 60 .

Optionally, the first calculation module includes:

Calculation unit, used to calculate the flow of the target channel according to the following formula:

Among them, Q is the channel flow rate under the target channel level; _n1 is the comprehensive roughness of the target channel; J is the riverbed gradient of the target channel; H is the water depth under the target channel level; B is the channel bottom width under the target channel level; m is the channel slope slope under the target channel level.

Optionally, the building blocks include:

The construction unit is used to construct the two-dimensional water flow model of the channel downstream of the hub according to the following formula:

Among them, x and y are the coordinates of the Cartesian coordinate system; t is the time variable; Z is the outlet water level downstream of the hub; M=uh, N=vh, u is the flow velocity in the x direction, v is the flow velocity in the y direction, and h is the water depth; n ₂ is the Manning roughness coefficient; D is the turbulent viscosity coefficient; u ₀ is the flow velocity in the x direction when the source sink enters or exits the channel; v ₀ is the flow velocity in the y direction when the source sink enters or exits the channel; g is the gravitational acceleration.

For the more specific working process of each of the above modules, reference may be made to the corresponding content disclosed in the foregoing embodiments, which will not be repeated here.

Correspondingly, an embodiment of the present invention also provides a computer device, including a processor and a memory; wherein, when the processor executes the computer program stored in the memory, the basic flow control method for the downstream channel of the hub based on the channel scale disclosed in the foregoing embodiments is realized .

For a more specific process of the above method, reference may be made to the corresponding content disclosed in the foregoing embodiments, and details are not repeated here.

Furthermore, an embodiment of the present invention also provides a computer-readable storage medium for storing a computer program; when the computer program is executed by a processor, the above-mentioned basic flow control method for the downstream channel of a hub based on the channel scale is realized.

For a more specific process of the above method, reference may be made to the corresponding content disclosed in the foregoing embodiments, and details are not repeated here.

Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same or similar parts of each embodiment can be referred to each other. As for the systems, devices, and storage media disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and for relevant details, please refer to the description of the methods.

Those skilled in the art can clearly understand that the technologies in the embodiments of the present invention can be implemented by means of software plus a necessary general-purpose hardware platform. Based on this understanding, the essence of the technical solutions in the embodiments of the present invention or the part that contributes to the prior art can be embodied in the form of software products, and the computer software products can be stored in storage media, such as ROM/RAM , magnetic disk, optical disk, etc., including several instructions to enable a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of the present invention.

The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions should not be construed as limiting the present invention. Those skilled in the art understand that without departing from the spirit and scope of the present invention, various equivalent replacements, modifications or improvements can be made to the technical solutions and implementations of the present invention, all of which fall within the scope of the present invention. The protection scope of the present invention shall be determined by the appended claims.

Claims (2)

1. A basic flow control method for the downstream waterway of a hub based on the waterway scale, characterized in that it includes: S1, according to the grade of the target channel downstream of the hub, determine the target channel section scale parameters; the target channel section scale parameters include channel water depth, channel bottom width and channel slope slope; S2, obtaining the riverbed gradient of the target channel; S3, calculate the discharge of the target channel according to the riverbed gradient and section scale parameters of the target channel; S4. Construct a two-dimensional water flow model of the channel downstream of the hub; S5, according to the two-dimensional water flow model of the channel plane, taking the flow rate of the target channel as the upstream water flow of the hub, and calculating the downstream outlet water level of the hub; S6. According to the two-dimensional water flow model of the channel plane, the water depth distribution along the target channel downstream of the hub is obtained, and the minimum water depth of the target channel downstream of the hub is obtained; S7, judging whether the absolute value of the difference between the minimum water depth of the target channel and the water depth of the channel under the target channel level exceeds a preset water depth threshold; S8, if not, determine that the flow of the target channel is the basic flow of the target channel; S9, if yes, judging whether the minimum water depth of the target channel is greater than the water depth of the target channel level; S10, if yes, calculate the upstream inflow of the hub and the downstream outlet water level of the hub that need to be reduced according to the two-dimensional water flow model of the channel plane, and return to the operation of step S6; S11, if not, calculate the required increase of the upstream water flow of the hub and the downstream outlet water level of the hub according to the two-dimensional water flow model of the channel plane, and return to the operation of step S6; Among them, the flow rate of the target channel is calculated according to the following formula:

Among them, Q is the channel flow rate under the target channel level; _n1 is the comprehensive roughness of the target channel; J is the riverbed gradient of the target channel; H is the water depth under the target channel level; B is the channel bottom width under the target channel level; m is the channel slope slope under the target channel level; Construct the two-dimensional water flow model of the channel downstream of the hub according to the following formula:

Among them, x and y are the coordinates of the Cartesian coordinate system; t is the time variable; Z is the outlet water level downstream of the hub; M=uh, N=vh, u is the flow velocity in the x direction, v is the flow velocity in the y direction, and h is the water depth; n ₂ is the Manning roughness coefficient; D is the turbulent viscosity coefficient; u ₀ is the flow velocity in the x direction when the source sink enters or exits the channel; v ₀ is the flow velocity in the y direction when the source sink enters or exits the channel; g is the gravitational acceleration. 2. A basic flow control system for the downstream channel of a hub based on the channel scale, characterized in that it includes: The channel parameter determination module is used to determine the target channel section scale parameter according to the level of the target channel downstream of the hub; the target channel section scale parameter includes channel water depth, channel bottom width and channel slope; The first obtaining module is used to obtain the river bed gradient of the target channel; The first calculation module is used to calculate the flow rate of the target channel according to the riverbed gradient and section scale parameters of the target channel; Building blocks, used to construct the two-dimensional water flow model of the channel downstream of the hub; The second calculation module is used to calculate the downstream outlet water level of the hub according to the two-dimensional water flow model of the channel plane, taking the flow rate of the target channel as the upstream water flow of the hub; The second acquisition module is used to obtain the water depth distribution along the target channel downstream of the hub according to the two-dimensional water flow model of the channel plane, and obtain the minimum water depth of the target channel downstream of the hub; The first judging module is used to judge whether the absolute value of the difference between the minimum water depth of the target waterway and the water depth of the waterway under the target waterway level exceeds the preset water depth threshold; The channel basic flow determination module is used to determine the flow rate of the target channel as the target channel when the absolute value of the difference between the minimum water depth of the target channel and the channel water depth under the target channel level does not exceed the preset water depth threshold as determined by the first judgment module basic flow; The second judgment module is used to determine whether the minimum water depth of the target waterway is greater than the target waterway level when the absolute value of the difference between the minimum water depth of the target waterway and the water depth of the waterway under the target waterway level exceeds the preset water depth threshold as determined by the first judgment module The depth of the channel below; The third calculation module is used to calculate the upstream inflow of the hub and the downstream outlet water level of the hub that need to be reduced according to the two-dimensional water flow model of the channel plane when the second judging module determines that the minimum water depth of the target channel is greater than the water depth of the target channel level , return to execute the operation of the second acquisition module; The fourth calculation module is used to calculate the upstream inflow of the hub and the downstream outlet water level of the hub to be increased according to the two-dimensional water flow model of the channel plane when the minimum water depth of the target channel is determined by the second judgment module to be less than the water depth of the target channel level , return to execute the operation of the second acquisition module; Wherein, the first calculation module includes: Calculation unit, used to calculate the flow of the target channel according to the following formula:

Among them, Q is the channel flow rate under the target channel level; _n1 is the comprehensive roughness of the target channel; J is the riverbed gradient of the target channel; H is the water depth under the target channel level; B is the channel bottom width under the target channel level; m is the channel slope slope under the target channel level; The building blocks include: The construction unit is used to construct the two-dimensional water flow model of the channel downstream of the hub according to the following formula:

Among them, x and y are the coordinates of the Cartesian coordinate system; t is the time variable; Z is the outlet water level downstream of the hub; M=uh, N=vh, u is the flow velocity in the x direction, v is the flow velocity in the y direction, and h is the water depth; n ₂ is the Manning roughness coefficient; D is the turbulent viscosity coefficient; u ₀ is the flow velocity in the x direction when the source sink enters or exits the channel; v ₀ is the flow velocity in the y direction when the source sink enters or exits the channel; g is the acceleration of gravity.

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