Digital twinborn basin water environment arbitrary pollution scene simulation method and system

Abstract

The invention belongs to the related technical field of digital twin basin water environment simulation, and discloses a method and a system for simulating any pollution scene of a digital twin basin water environment. The method comprises the following steps: setting pollutant concentration and flow of each grid unit at t0 moment in a digital twin basin water environment model; pollution occurs at the t1 moment; setting pollution treatment modes for the input pollution position, and solving the pollutant concentration and flow of the pollution position according to different pollution treatment modes; and for the non-input pollution position, updating the pollutant concentration and flow of the non-pollution position by using the hydrodynamic pollutant migration model, thereby obtaining the pollutant concentration and flow of each position after pollution in the digital twin basin water environment model. According to the invention, the influence of the treatment mode without considering pollution on pollution diffusion after pollution occurs in the drainage basin is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field related to digital twin river basin water environment simulation, and more specifically, relates to a method and system for simulating arbitrary pollution scenarios in a digital twin river basin water environment. Background Art

[0002] The construction of digital twin river basins should be based on river basin characteristics and practical needs. As a complex open system, river basins are complexly interwoven with lakes, reservoirs, and rivers, which are highly uncertain. Existing model technologies cannot respond to water pollution problems such as sudden water pollution in real time.

[0003] Journal of Environmental Management, 2024, No. 354, Article 120294, "Adaptive reservoir operation considering water quantity and quality objectives: Application of parallel cellular automata and sub-seasonal streamflow forecasts", linked the adaptive optimization model with the CE-QUAL-W2 water quality simulation model to evaluate the water quality of the reservoir and the water quality out of the reservoir. Water Science and Technology, 2024, No. 89, Volume 3, "Water quality's responses to water energy variability of the Yangtze River", used Mike21 to construct a hydrodynamic and water quality model of the Yangtze River mainstream to evaluate the impact of changes in water quality in the basin. The model constructed by the above method cannot respond to sudden water pollution problems in real time and does not consider the impact of different pollution treatment methods on pollution diffusion after pollution, which makes it difficult to meet the requirements of digital twin basin construction.

[0004] Therefore, this study aims to address the challenge of the difficulty of real-time simulation and disposal of pollution in the construction of digital twin river basins, and to provide a theoretical basis and technical support for the construction of digital twin river basins. Summary of the invention

[0005] In response to the above defects or improvement needs of the prior art, the present invention provides a method and system for simulating arbitrary pollution scenarios in the water environment of a digital twin river basin, which solves the problems of not being able to perform real-time pollutant diffusion analysis in the river basin and not considering the impact of pollution treatment methods on pollution diffusion after pollution occurs.

[0006] To achieve the above object, according to one aspect of the present invention, a method for simulating arbitrary pollution scenarios of water environment in a digital twin river basin is provided, and the method comprises the following steps:

[0007] Set the pollutant concentration and sewage flow rate of each grid unit at time t0 in the digital twin watershed water environment model; input pollutants into the digital twin watershed water environment model at time t1;

[0008] For the location where pollutants are input, a pollution treatment method is set, and the pollutant concentration and flow rate at the location where the pollution occurs are solved according to different pollution treatment methods, wherein the pollution treatment methods include pollutant dilution and pollutant interception;

[0009] For locations where no pollutants are input, the pollutant concentration and flow of the locations where pollution is input, as well as the pollutant concentration and flow of the locations where pollution is not input at time t0, are updated using the hydrodynamic pollutant migration model. Thus, the pollutant concentration and flow of each location after pollution occurs in the digital twin river basin water environment model are obtained.

[0010] Further preferably, when the pollution treatment method is pollutant dilution, the pollutant concentration and flow rate at the pollutant dilution position are calculated according to the following formula:

[0011]

[0012] in, is the grid pollutant concentration after dilution, is the pollutant concentration of the grid before dilution, is the flow rate of the diluted grid, is the flow rate of the grid before dilution, C k is the dilution concentration, q m is the diluent flow rate and K is the diffusion coefficient.

[0013] Further preferably, the concentration C of the input pollutant is k The formula is as follows:

[0014]

[0015] Where v is the pollutant dilution factor.

[0016] Further preferably, when the pollution treatment method is the interception of pollutants, the pollutant concentration and flow rate at the location where the pollutant interception occurs are calculated according to the following formula:

[0017]

[0018] Where C is the pollutant concentration, Q lis the pollutant flow rate, K x , K y , K z are the diffusion coefficients in the x, y, and z directions respectively, u, v, and w are the velocity components in the x, y, and z directions respectively, and S c is the source and sink term entering or leaving the unit water body, h min and h max are the minimum water depth and the maximum water depth, respectively, and b e is the intercept width.

[0019] Further preferably, the minimum water depth h min and maximum water depth h max The formula is as follows:

[0020] h max =max(Z r ,Z c )-Z e

[0021] h min =min(Z r ,Z c )-Z e

[0022] Among them, Z r and Z c are the upstream and downstream water levels of the interception point, Z e They are intercept elevation.

[0023] Further preferably, the formula of the hydrodynamic migration model is as follows:

[0024]

[0025]

[0026] Among them, z is the vertical σ coordinate, u, v, w are the velocity components in the x, y, and z directions respectively, t is the time, m x and m y is the horizontal coordinate transformation scale factor, Q H is the source and sink term of the continuity equation, Q u and Q v is the source and sink term of the momentum equation, f e is the correlation coefficient of the Coriolis force, ρ0 is the reference density of the water body; ρ is the water body density; P is the additional hydrostatic pressure, g is the gravitational acceleration, w* is the vertical flow velocity in the Cartesian coordinate system, and A v is the vertical eddy viscosity coefficient, C is the water quality index concentration, K x , K y , K z are the diffusion coefficients in the x, y, and z directions, respectively, and Sc It is the source or sink term entering or leaving a unit water body.

[0027] Further preferably, when calculating the pollutant concentration and flow rate at the location where the pollution occurs, the location where the pollution occurs is projected onto the grid cells in the digital twin watershed water environment model, so as to obtain the grid cells corresponding to the location where the pollution occurs in the digital twin watershed water environment model.

[0028] Further preferably, the grid unit corresponding to the pollution occurrence location in the digital twin watershed water environment model is calculated using the pre-calibrated correspondence between the pollution occurrence location and the grid unit.

[0029] According to another aspect of the present invention, a digital twin watershed water environment arbitrary pollution scene simulation system is provided, the system includes an actuator, and the actuator is used to execute the above-mentioned digital twin watershed water environment arbitrary pollution scene simulation method.

[0030] According to another aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the method for simulating arbitrary pollution scenarios in the water environment of a digital twin river basin as described above is implemented.

[0031] In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art:

[0032] 1. In the case of pollution in the water environment of the digital twin river basin, the present invention divides the pollution treatment methods into two types: pollutant dilution and interception. Different pollutant concentration and flow calculations are used for different pollution treatment methods, which is highly targeted and accurate;

[0033] 2. The present invention updates the initial pollutant concentration and flow rate at the pollution site according to the input pollutant concentration and flow rate for pollutant dilution. The original data and external disturbance data are combined to calculate the concentration at the pollution site after the pollution occurs. At the same time, the pollutant concentration and flow rate of other grid cells in the digital twin watershed water environment are updated according to the change of the concentration at the pollution site, so as to realize the real-time update of the pollutant concentration and flow rate in the digital twin watershed water environment.

[0034] 3. The present invention further sets the height and width of pollution interception, updates the pollutant concentration and flow rate at the pollution occurrence site, and then updates the pollutant concentration and flow rate of other grids in the digital twin watershed water environment according to the pollutant concentration and flow rate of the grid unit at the pollution occurrence site, and updates the changes in pollutant concentration and flow rate after pollutant interception in real time in combination with actual conditions, with strong real-time performance;

[0035] 4. The present invention adopts a hydrodynamic migration model to update the pollutant concentration and flow rate at locations other than where the pollution occurs. It not only considers the impact of the pollutant concentration and flow rate at the pollution occurrence site on other grid units, but also combines the current pollutant concentration and flow rate of other grid units themselves, and has high calculation accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a flow chart of a method for simulating arbitrary pollution scenarios of a digital twin watershed water environment constructed according to a preferred embodiment of the present invention;

[0037] Figure 2 Schematic diagram of pollutant flow and digital twin watershed water environment model of Danjiangkou according to preferred embodiment 1 of the present invention, wherein (a) is a schematic diagram of pollutant flow at the inflow of Danjiangkou Dam changing with time, and (b) is a schematic diagram of digital twin watershed water environment model of Danjiangkou;

[0038] Figure 3 The pollutant flow rate of the grid at Danjiangkou Dam in the digital twin watershed water environment model constructed according to the preferred embodiment of the present invention is set to 3000m at time t1. 3 Schematic diagram of simulation results of pollutant flow rates of all grids obtained by simulation after / s;

[0039] Figure 4 The pollutant flow rate of the grid at Danjiangkou Dam in the digital twin watershed water environment model constructed according to the preferred embodiment of the present invention is set to 5000m at time t1. 3 Schematic diagram of simulation results of pollutant concentrations of all grids obtained by simulation after / s;

[0040] Figure 5 The pollutant flow rate of the grid at Danjiangkou Dam in the digital twin watershed water environment model constructed according to the preferred embodiment of the present invention is set to 7000m at time t1. 3 Schematic diagram of simulation results of pollutant concentrations of all grids obtained by simulation after / s;

[0041] Figure 6 The pollutant flow rate of the grid at Danjiangkou Dam in the digital twin watershed water environment model constructed according to the preferred embodiment of the present invention is set to 9000m at time t1. 3 Schematic diagram of simulation results of pollutant concentrations of all grids obtained by simulation after / s;

[0042] Figure 7 The pollutant flow rate of the grid at Danjiangkou Dam in the digital twin watershed water environment model constructed according to the preferred embodiment of the present invention is set to 11000m at time t1. 3Schematic diagram of simulation results of pollutant concentrations of all grids obtained by simulation after / s;

[0043] Figure 8 It is a schematic diagram of a digital twin watershed water environment model of a tributary of Laoguan River in Danjiangkou Reservoir constructed according to the preferred embodiment 2 of the present invention;

[0044] Fig. 9 It is the migration of pollutants in the next month if no measures are taken according to the preferred embodiment 2 of the present invention;

[0045] Fig.10 It is the simulation result of the pollutant concentration and flow after being intercepted by the four-stage rubber dam constructed according to the preferred embodiment 2 of the present invention;

[0046] Fig.11 It is the simulation result of the pollutant concentration and flow after adding the polyferric sulfate dilution constructed according to the preferred embodiment 2 of the present invention. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0048] like Figure 1 As shown, the present invention provides a method for simulating any pollution scenario in a digital twin watershed water environment, which can quickly construct a corresponding pollution scenario based on the pollution input location, pollutant concentration, sewage flow, and pollution disposal method of the pollution event, and establish a pollutant simulation model for any pollution scenario based on the digital twin watershed, so as to simulate pollutants in different pollution scenarios and provide support for pollution event warning, rehearsal, and emergency plans for the digital twin watershed system. The specific implementation steps of this method are:

[0049] (1) Location of input pollutants

[0050] Based on the location of the pollution point or the pollution situation, the pollution treatment method and pollution input point are preliminarily determined, and different sudden pollution simulation scenarios are quickly constructed, including pollution input location, pollutant concentration, sewage flow and pollution disposal method.

[0051] Pollution input locations include pollution input points or pollution disposal points, which can be selected and set in the digital twin watershed system by clicking. The points are geographic coordinates (x, y). In order to facilitate model calculation, before model simulation, the coordinate attribute table corresponding to the geographic coordinates of the grid number is called to quickly convert the geographic coordinates and model grid number, and the geographic coordinates (x, y) are converted to the model grid number (i, j).

[0052] The pollutant concentration settings for different pollution scenarios include the pollutant concentration time series C k =(c1,c2,…,c t ,…,c T ), the sewage flow setting includes the dilution flow time series q m =(q1,q2,…,q t ,…,q T ). Where k = 1, 2, ... represents the number of different pollutant concentration scenarios, and T represents the simulation time step.

[0053] There are two types of pollution disposal methods for pollution scenarios: pollution dilution and pollution interception. The two methods can also be used in combination.

[0054] (a) Pollution dilution

[0055] According to the chemical reaction of the pollutant, determine the dilution factor v of the reactant, thereby determining the concentration and dosage of the reactant, and then set the dilution concentration C k And simulated input flow q m For any point, the pollutant concentration calculation formula of its dosing grid is:

[0056]

[0057]

[0058] in, is the concentration after dilution, is the concentration before dilution. is the flow rate after dilution, is the flow rate before dilution. K is the diffusion coefficient.

[0059] (b) Pollution Interception

[0060] Set any point as a weir flow or other form as a boundary point to simulate the interception effect in pollution disposal. Suppose the flow rate of the upstream and downstream of the river channel with an interception dam at a certain time is Q l , the method of using the weir flow formula to approximate the exchange flow is as follows:

[0061]

[0062] Where: hmin and h max The following formulas are used for calculation:

[0063] h max =max(Z r ,Z c )-Z e

[0064] h min =min(Z r ,Z c )-Z e

[0065] Where: Z r and Z c is the water level upstream and downstream of the setting point, Z e Set the elevation for the intercept, b e is the intercept width.

[0066] The concentration of pollutants is calculated using the following formula:

[0067]

[0068] Where: C is the pollutant concentration; K x , K y , K z are the diffusion coefficients in the x, y, and z directions respectively; u, v, and w are the flow velocities in the x, y, and z directions respectively; S c It is the source or sink term entering or leaving a unit water body.

[0069] (2) For locations where no pollutants are input

[0070] Constructing a simulation model of arbitrary pollution scenarios for the digital twin river basin water environment can simulate one or more combined pollution scenarios such as different pollution input locations, different pollutant concentrations, different sewage flows and pollution disposal methods.

[0071] The simulation model of arbitrary pollution scenarios of the digital twin watershed water environment is constructed based on the hydrodynamic equation and the pollutant migration and transformation equation. The hydrodynamic equation adopts the motion equation of momentum conservation of incompressible fluid. The transport of pollutants in the water body and the physical, chemical and biological transformation processes adopt the mass conservation equation group. The mass conservation equation group is:

[0072]

[0073] Where: C is the pollutant concentration; K x , K y , K z are the diffusion coefficients in the x, y, and z directions respectively; u, v, and w are the flow velocities in the x, y, and z directions respectively; S cIt is the source or sink term entering or leaving a unit water body.

[0074] The arbitrary pollution scenario simulation model of the digital twin river basin water environment is used to simulate pollutants in different pollution scenarios. The simulation results of different pollution scenarios are analyzed, and the diffusion direction, speed, impact range and impact degree of pollutants are compared to provide early warning, rehearsal and plan support for the digital twin river basin system.

[0075] The hydrodynamic control equations of the model are as follows:

[0076]

[0077] Where z is the vertical σ coordinate, u, v, w are the velocity components in the x, y, and z directions respectively; t is time; m x and m y is the horizontal coordinate transformation scale factor; Q H is the source and sink term of the continuity equation; Q u and Q v is the source and sink term of the momentum equation; f e is the correlation coefficient of the Coriolis force; ρ0 is the reference density of water (1×10 3 kg / m 3 ) ; ρ is the water density; P is the additional hydrostatic pressure; g is the acceleration due to gravity (9.81 N / kg); w* is the vertical velocity in the Cartesian coordinate system (true vertical velocity); A v is the vertical eddy viscosity coefficient.

[0078] The present invention is further described in detail below with reference to examples.

[0079] Embodiment 1:

[0080] This example assumes that the Danjiangkou Bridge is suddenly polluted and uses pollution treatment simulation technology to model it. Set the pollution source location and concentration by clicking the Danjiangkou Bridge location. The task is to determine the pollution arrival location and pollution duration under different reservoir scheduling schemes based on the Hanjiang River flow in 2021 and considering the most unfavorable hydrological characteristics. Figure 2 The figure is a schematic diagram of the configuration according to the preferred embodiment of the present invention, wherein (a) is a schematic diagram of the pollutant flow rate at the inlet of Danjiangkou Dam changing with time, and (b) is a schematic diagram of the digital twin watershed water environment model of Danjiangkou. In order to simulate the impact of the Hanjiang River pollution incident on the Danjiangkou Reservoir, especially Taocha (the water intake of the middle route of the South-to-North Water Diversion Project), a 3000m 3 / s、5000m 3 / s、7000m 3 / s、9000m 3 / s and 11100m 3 / sFive types of Danjiangkou Dam outflows, Figure 3 to Figure 7 Set 3000m respectively 3 / s、5000m 3 / s、7000m 3 / s、9000m 3 / s and 11100m 3 / sSimulation results of pollutant concentration of Danjiangkou Dam flow.

[0081] The simulation results show that a larger outflow can more effectively and quickly remove pollutants. October is when the inflow is the largest, and pollutants are brought into the Danjiangkou area. Increasing the downstream dispatch flow can speed up the removal of pollutants in the area and ensure the safety of Taocha.

[0082] Embodiment 2:

[0083] This example simulates and evaluates an accidental water pollution incident in a tributary of the Laogan River in the Danjiangkou Reservoir. The study includes simulating response plans such as dam interception and coagulant injection to quickly evaluate their effectiveness in controlling pollution. The simulation results are used to automatically generate an emergency monitoring plan and evaluate the effectiveness of implementing strategies such as dam interception, coagulant injection, and emergency plans.

[0084] In the digital twin watershed system, real-time on-site monitoring data will be fed back to the model, triggering an alarm for sudden water pollution incidents, thereby calling the arbitrary point pollution disposal simulation technology based on the digital twin watershed. In the absence of action, a one-dimensional model is used to predict the migration of pollutants within one month. The pollutant concentration at Guanyintang is used as the inlet concentration of Danjiangkou Reservoir to observe the changes in pollutant concentration. After evaluating future risks, combined with the actual situation of Laoguan River, the setting of a four-level rubber dam at Fanqiao to intercept pollutants and release iron sulfate solvent was simulated.

[0085] Figure 8 This is the setup diagram for the second case of sudden pollution simulation. Figures 9 to 11 The simulation results are as follows: no measures, four-level rubber dam interception, and polyferric sulfate dilution release. It can be seen that the rubber dam reduces the impact of pollutants on the downstream, and combined with the injection of coagulants, the pollutants are reduced to an acceptable level before entering the reservoir.

[0086] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for simulating arbitrary pollution scenarios of water environment in a digital twin watershed, characterized in that: The method comprises the following steps: Set the pollutant concentration and sewage flow rate of each grid unit at time t0 in the digital twin watershed water environment model; input pollutants into the digital twin watershed water environment model at time t1; For the location where pollutants are input, a pollution treatment method is set, and the pollutant concentration and flow rate at the location where the pollution occurs are solved according to different pollution treatment methods, wherein the pollution treatment methods include pollutant dilution and pollutant interception; For locations where no pollutants are input, the pollutant concentration and flow of the locations where pollution is input, as well as the pollutant concentration and flow of the locations where pollution is not input at time t0, are updated using the hydrodynamic pollutant migration model. Thus, the pollutant concentration and flow of each location after pollution occurs in the digital twin river basin water environment model are obtained.

2. A method for simulating arbitrary pollution scenarios of a digital twin watershed water environment as claimed in claim 1, characterized in that: When the pollution treatment method is pollutant dilution, the pollutant concentration and flow rate at the pollutant dilution position are calculated according to the following formula: in, is the grid pollutant concentration after dilution, is the pollutant concentration of the grid before dilution, is the flow rate of the diluted grid, is the flow rate of the grid before dilution, C k is the dilution concentration, q m is the diluent flow rate and K is the diffusion coefficient.

3. A method for simulating arbitrary pollution scenarios of a digital twin watershed water environment as claimed in claim 2, characterized in that: The concentration of the input pollutant C k The formula is as follows: Where v is the pollutant dilution factor.

4. A method for simulating arbitrary pollution scenarios of a digital twin watershed water environment as claimed in claim 1 or 3, characterized in that: When the pollution treatment method is the interception of pollutants, the pollutant concentration and flow rate at the location where the pollutants are intercepted are calculated according to the following formula: Where C is the pollutant concentration, Q l is the pollutant flow rate, K x , K y , K z are the diffusion coefficients in the x, y, and z directions respectively, u, v, and w are the velocity components in the x, y, and z directions respectively, and S c is the source and sink term entering or leaving the unit water body, h min and h max are the minimum water depth and the maximum water depth, respectively, and b e is the intercept width.

5. A method for simulating arbitrary pollution scenarios of a digital twin watershed water environment as claimed in claim 4, characterized in that: The minimum water depth h min and maximum water depth h max The formula is as follows: h max =max(Z r ,Z c )-Z e h min =min(Z r ,WITH c )-WITH e Among them, Z r and Z c are the upstream and downstream water levels of the interception point, Z e They are intercept elevation.

6. A method for simulating arbitrary pollution scenarios of a digital twin watershed water environment as claimed in claim 4, characterized in that: The formula of the hydrodynamic migration model is as follows: Among them, z is the vertical σ coordinate, u, v, w are the velocity components in the x, y, and z directions respectively, t is the time, m x and m y is the horizontal coordinate transformation scale factor, Q H is the source and sink term of the continuity equation, Q u and Q v is the source and sink term of the momentum equation, f e is the correlation coefficient of the Coriolis force, ρ0 is the reference density of the water body; ρ is the water body density; P is the additional hydrostatic pressure, g is the gravitational acceleration, w* is the vertical flow velocity in the Cartesian coordinate system, and A v is the vertical eddy viscosity coefficient, C is the water quality index concentration, K x , K y , K z are the diffusion coefficients in the x, y, and z directions, respectively, and S c It is the source or sink term entering or leaving a unit water body.

7. A method for simulating arbitrary pollution scenarios of a digital twin watershed water environment as claimed in claim 1, characterized in that: When calculating the pollutant concentration and flow rate at the location where pollution occurs, the location where pollution occurs is projected onto the grid cells in the digital twin watershed water environment model to obtain the grid cells corresponding to the location where pollution occurs in the digital twin watershed water environment model.

8. A method for simulating arbitrary pollution scenarios of a digital twin watershed water environment as claimed in claim 7, characterized in that: The grid unit corresponding to the pollution occurrence location in the digital twin watershed water environment model is calculated using the pre-calibrated correspondence between the pollution occurrence location and the grid unit.

9. A digital twin watershed water environment arbitrary pollution scene simulation system, characterized in that: The system includes an actuator, which is used to execute a method for simulating arbitrary pollution scenarios in a digital twin river basin water environment as described in any one of claims 1-8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, it implements a method for simulating arbitrary pollution scenarios in a digital twin river basin water environment as described in any one of claims 1 to 8.

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