Beach shallow sea oil spill rapid numerical forecasting method

Abstract

The invention provides a beach shallow sea oil spill rapid numerical forecasting method, and belongs to the field of oil spill algorithms. According to the technical scheme, rapid numerical forecasting of oil spill of the beach and the shallow sea is finally achieved through rapid forecasting of ocean currents of an intertidal zone and calculation of the gravity expansion process after oil spill of the beach and the shallow sea, the adhesion process of the spill oil and the scouring and resuspension process of the spill oil. The method has the beneficial effects that the expansion of the spilled oil under the oil spilling condition of the beach shallow sea, the migration and diffusion process of the spilled oil in the water, and the conditions that the oil film is stranded and adsorbed in the intertidal zone again and is scoured into the water by the seawater can be quickly calculated by utilizing the type of the surrounding coastal zone; adsorption and scouring processes of spilled oil in the beach and shallow sea are quantified, a prediction and early warning tool can be provided for coastal zone oil spilling accident emergency, an optimal strategy is provided for coastal spilled oil removal, the pollution length and the pollution area of spilled oil on a shoreline can be provided, and technical support is provided for evaluating the influence of spilled oil on the ecological environment.

Description

Technical Field

[0001] The present invention relates to the field of oil spill algorithms, in particular to a rapid numerical prediction method for oil spills in shallow waters. Background Art

[0002] Since the 20th century, numerous large-scale oil spills have occurred worldwide, severely impacting the marine and coastal ecosystems affected by the incidents. Numerical models can effectively predict the trajectory and property changes of spilled oil following an incident. After years of development, numerous numerical models for marine oil spill modeling have been established. One approach to modeling oil spill trajectories is to treat the oil film as a whole and derive the oil film deformation equation, exemplified by Fay theory. Another approach is to represent the oil film as a swarm of moving particles, a Lagrangian particle model that has become the mainstream approach in marine oil spills.

[0003] The fate of an oil spill includes processes such as weathering, emulsification, and sedimentation, which are currently incorporated into most ocean models. However, most models either ignore or simplify the process of oil adhesion and scouring. Early models assumed that the oil film completely adhered to the shore and ceased its motion. Recent models, such as COZOIL, have categorized oil spills by coastal type. However, these models are complex and require a high level of basic topographical data, making them difficult to use for rapid forecasting in areas where data is relatively scarce.

[0004] The oil film washout model, in contrast to the oil film adhesion process model, describes the process by which oil films on the coast are washed away by ocean currents. Currently, the most widely used model is the semi-life cycle conceptual model, which describes the mass decay of adsorbed oil films on the coast. This process is difficult to integrate with the oil particle model approach during shallow-water oil spills, meaning that individual "oil particles" remain in the intertidal zone (completely adsorbed) or are carried into the water by the current (unadsorbed).

[0005] Currently, mature and representative oil spill models include the GNOME model developed by the National Oceanic and Atmospheric Administration of the United States, which uses particle tracking technology based on the Lagrangian method to predict the spread and impact range of oil spills. MEDSLIK-II, developed by the Italian National Research Council, is a three-dimensional oil spill model based on the Euler method that can simulate processes such as evaporation, dispersion, emulsification, and biodegradation of oil spilled substances. The OILMAP model established by the US RPS company is a numerical software for simulating marine oil spills. It can predict the movement trajectory of oil spills and their interactions with coastlines, ice layers, etc. These numerical models can simulate the movement and distribution of oil spills in offshore waters, simulate the expansion and propagation of oil films, and take into account multiple influencing factors, including wind, tides, waves, and hydrodynamics.

[0006] Current marine oil spill models are all targeted at marine oil spill accidents, and they mainly consider the migration, diffusion and return of spilled oil in seawater. The coastline is used as the boundary condition of the oil spill model, and the expansion process in shallow waters is not considered. The process of spilled oil dissolving in water is mainly the emulsification and dissolution of the lower layer of the oil film, which cannot describe the process of the upper oil film of the shallow water oil spill being washed away by the ocean current. Therefore, the existing marine oil spill models cannot accurately describe the behavior of oil spills in shallow waters or intertidal zones, nor are they suitable for oil spills occurring in shallow waters. In view of the fact that there is currently no algorithm that is fully targeted at shallow water oil spills, the present invention provides an oil spill algorithm that is suitable for shallow waters based on the combination of an "oil particle" method and oil film expansion, thereby achieving rapid prediction of shallow water oil spills. Summary of the Invention

[0007] When an oil spill occurs in shallow waters, its behavior differs significantly from that of an oil spill on the sea surface. This is primarily manifested in the following ways: Initially, in shallow waters, the spill expands under the influence of gravity. At high tide, the upper oil film is washed away by the seawater and suspended. In contrast, when an oil spill occurs on the sea surface, the oil film floats on the water surface, while the lower film emulsifies, disperses, and dissolves into the water. The two differ significantly in their expansion and oil-water interactions. This paper aims to address the impact of intertidal topography on oil spill scenarios in shallow waters, deriving a formula for the expansion of intertidal oil spills under the influence of gravity. Furthermore, it considers the probability of oil spill retention or resuspension for different coastal types, and designs a rapid forecasting method for shallow waters based on the "oil particle" approach.

[0008] The present invention is achieved by the following measures:

[0009] A rapid numerical prediction method for oil spills in shallow waters, characterized in that the steps of the preparation method are specifically as follows:

[0010] S1. Calculate the expansion of oil spills under the action of gravity at the beginning of the spill, referring to the Fay theory of oil spill expansion on a still sea surface.

[0011] S2. Calculate the relevant information of the oil spilled into the water body;

[0012] S3. Use oil particle model to calculate the movement of spilled oil in water;

[0013] S4. Calculate the amount of oil adsorbed on the coast, and the reduction in the number of particles is calculated based on the reduced amount of oil spilled;

[0014] S5. Calculate the amount of oil spill resuspended after flushing, and recount the number of particles entering the water after flushing to perform particle trajectory tracking calculation.

[0015] The specific features of the present invention also include:

[0016] The calculation of S1 is as follows:

[0017] The Fay theory is an extended three-stage model. Considering the slope of the intertidal zone, after an oil spill occurs, the oil film is subjected to a downward gravity component along the slope, and there is a stretching along the slope. That is, the oil film expands in the intertidal zone in the form of an ellipse rather than a circle, and its long axis is consistent with the slope. The expansion is improved as follows:

[0018]

[0019]

[0020] Where: L min is the minor axis, L max is the semi-major axis, g is the acceleration of gravity, α is the inclination angle between the intertidal zone and the sea level, μ is the viscosity of the oil spill, V is the volume of the oil spill, and t is the time after the oil spill.

[0021] The calculation of S2 is as follows:

[0022] S21. Judgment of stranded oil particles in the intertidal zone:

[0023] A tidal current model including the intertidal zone is constructed. The water level is predicted by the tidal harmonic constant at the open boundary. A two-dimensional ocean hydrodynamic model is used, and the grid "dry and wet point" algorithm is used to quickly simulate the flooding and drying process of the intertidal zone. The open boundary water level prediction formula is as follows:

[0024]

[0025] i represents the M2 (main semidiurnal equinoctial tide), S2 (main semidiurnal equinoctial tide), K1 (lunar-solar declination diurnal equinoctial tide), and O1 (lunar declination diurnal equinoctial tide);

[0026] Hi is the amplitude of the i-th tidal harmonic constant; gi is the phase of the i-th tidal harmonic constant; σ i The angular frequency of the i-th partial tide; vi is the initial phase of the i-th partial tide; f i ,u i The i-th tidal intersection factor and the correction angle of the intersection;

[0027] S22. Determination of dry and wet points in the intertidal zone:

[0028] Assume that the total water depth of (i, j) is D i,j ,

[0029] D i,j =H i,j +η i,j (4)

[0030] η i,j is the water level at the grid point, H i,j is the water depth from mean sea level, D i,j>0.05m, the grid point is considered a wet point, D i,j When ≤0.05m, the grid point is a dry point;

[0031] S23. Judgment of oil particle stranding:

[0032] Assume the oil film thickness is H oil ;

[0033] When D i,j >H oil , it is judged that the oil particles are located in the water body; when D i,j ≤H oil Oil particles are stranded, determine whether oil particles are stranded.

[0034] The calculation of S3 is as follows:

[0035] The velocity equation of oil particles can be expressed as: U t =C w U w +U s (5)

[0036] The position change of oil particles during the Δt period can be expressed as:

[0037] X=X0+uΔt+C w U w sinθΔt (6)

[0038] Y=Y0+vΔt+C w V w cosθΔt (7)

[0039] Where X0 and Y0 are the initial positions of the oil film; U t is the total speed of drift motion; U s is the surface velocity; u and v are the east and north components of the tidal velocity; U w 、V w are the east and north components of the wind speed at 10 m above the sea surface; θ is the wind direction angle; C w is the wind drift coefficient, which is generally taken as 0.03;

[0040] Random diffusion distance S of oil particles per unit time α The calculation formula is as follows:

[0041]

[0042] Where D α is the diffusion coefficient in the α direction, α represents the x and y directions, and R is a random number between -1 and 1.

[0043] The calculation of S4 is as follows:

[0044] When the oil spill in the seawater is stranded and adsorbed on the coast, the adsorption amount is determined by the Torgrimson formula.

[0045] V2=V1e -kΔt (8)

[0046] V1, V2 are the amount of oil spilled on the coast at t1 and t2, and the attenuation coefficient λ is the half-life.

[0047] Table 1 Reference values ​​of oil spill half-life for different coastal types

[0048]

[0049]

[0050] The calculation of S5 is as follows:

[0051] The resuspension process of oil spills refers to the process by which oil that has been deposited on the bottom of the water or in the sediment is resuspended in the water body. This process occurs when the intertidal land is re-inundated by seawater at high tide. The resuspension process is relatively complex because it is affected by multiple factors: waves and currents are one of the main driving factors for resuspension. Under the influence of wind, waves and currents, oil spills stranded in the intertidal zone are washed back into the water. The formula for the amount of water washed back into the water used in this invention is as follows:

[0052]

[0053] in: is the adsorption amount of coastal oil spill, The amount of water entering the flushing tank.

[0054] The beneficial effects of this invention include: It can utilize the surrounding coastal zone type to rapidly calculate the spread of oil spills in shallow waters, the migration and diffusion of oil in the water after entering the water, and the re-adsorption and scouring of the oil film in the intertidal zone. By quantifying the adsorption and scouring processes of oil spills in shallow waters, this invention can provide a predictive and early warning tool for coastal oil spill emergency response and an optimal strategy for coastal oil spill cleanup. It can also provide information on the length and area of ​​shoreline contamination, providing technical support for assessing the ecological and environmental impacts of oil spills. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 Schematic diagram of the expansion of intertidal oil spill in an embodiment of the present invention.

[0056] Figure 2 Schematic diagram of resuspension of intertidal deposited oil in an embodiment of the present invention. DETAILED DESCRIPTION

[0057] In order to clearly illustrate the technical features of this solution, this solution is described below through specific implementation methods.

[0058] Example 1

[0059] A method for rapid numerical prediction of oil spills in shallow waters, wherein the steps of the preparatory method are as follows:

[0060] S1. Calculate the expansion of oil spills under the action of gravity at the beginning of the spill, referring to the Fay theory of oil spill expansion on a still sea surface.

[0061] S2. Calculate the relevant information of the oil spilled into the water body;

[0062] S3. Use oil particle model to calculate the movement of spilled oil in water;

[0063] S4. Calculate the amount of oil adsorbed on the coast, and the reduction in the number of particles is calculated based on the reduced amount of oil spilled;

[0064] S5. Calculate the amount of oil spill resuspended after flushing, and recount the number of particles entering the water after flushing to perform particle trajectory tracking calculation.

[0065] The calculation of S1 is as follows:

[0066] See also Figure 1 The Fay theory is an extended three-stage model. Considering the slope of the intertidal zone, after an oil spill occurs, the oil film is subjected to a downward gravity component along the slope, and there is a stretch along the slope. That is, the oil film expands in the intertidal zone in the form of an ellipse rather than a circle, and its long axis is consistent with the slope. The expansion is improved as follows:

[0067]

[0068]

[0069] Where: L min is the minor axis, L max is the semi-major axis, g is the acceleration of gravity, α is the inclination angle between the intertidal zone and the sea level, μ is the viscosity of the oil spill, V is the volume of the oil spill, and t is the time after the oil spill.

[0070] The calculation of S2 is as follows:

[0071] S21. Judgment of stranded oil particles in the intertidal zone:

[0072] A tidal current model including the intertidal zone is constructed. The water level is predicted by the tidal harmonic constant at the open boundary. A two-dimensional ocean hydrodynamic model is used, and the grid "dry and wet point" algorithm is used to quickly simulate the flooding and drying process of the intertidal zone. The open boundary water level prediction formula is as follows:

[0073]

[0074] i represents the M2 (main semidiurnal equinoctial tide), S2 (main semidiurnal equinoctial tide), K1 (lunar-solar declination diurnal equinoctial tide), and O1 (lunar declination diurnal equinoctial tide);

[0075] H i The amplitude of the i-th tidal harmonic constant; g i The i-th tidal harmonic constant phase; σ i The ith tidal angular frequency; v i The initial phase of the i-th tidal component; f i ,u i The i-th tidal intersection factor and the correction angle of the intersection;

[0076] S22. Determination of dry and wet points in the intertidal zone:

[0077] Assume that the total water depth of (i, j) is D i,j ,

[0078] D i,j =H i,j +η i,j (4)

[0079] η i,j is the water level at the grid point, H i,j is the water depth from mean sea level, D i,j >0.05m, the grid point is considered a wet point, D i,j When ≤0.05m, the grid point is a dry point;

[0080] S23. Judgment of oil particle stranding:

[0081] Assume the oil film thickness is H oil ;

[0082] When D i,j >H oil , it is judged that the oil particles are located in the water body; when D i,j ≤H oil Oil particles are stranded, determine whether oil particles are stranded.

[0083] The calculation of S3 is as follows:

[0084] The velocity equation of oil particles can be expressed as: U t =C w U w +U s (5)

[0085] The position change of oil particles during the Δt period can be expressed as:

[0086] X=X0+uΔt+C w Uw sinθΔt (6)

[0087] Y=Y0+vΔt+C w V w cosθΔt (7)

[0088] Where X0 and Y0 are the initial positions of the oil film; U t is the total speed of drift motion; U s is the surface velocity; u and v are the east and north components of the tidal velocity; U w 、V w are the east and north components of the wind speed at 10 m above the sea surface; θ is the wind direction angle; C w is the wind drift coefficient, which is generally taken as 0.03;

[0089] Random diffusion distance S of oil particles per unit time α The calculation formula is as follows:

[0090]

[0091] Where D α is the diffusion coefficient in the α direction, α represents the x and y directions, and R is a random number between -1 and 1.

[0092] The calculation of S4 is as follows:

[0093] When the oil spill in the seawater is stranded and adsorbed on the coast, the adsorption amount is determined by the Torgrimson formula.

[0094] V2=V1e -kΔt (8)

[0095] V1, V2 are the amount of oil spilled on the coast at t1 and t2, and the attenuation coefficient λ is the half-life.

[0096] Table 1 Reference values ​​of oil spill half-life for different coastal types

[0097] Serial number Coastal type Oil spill half-life (h) 1 Exposed headland 1 2 Sea erosion platform 1 3 Bag Beach 24 4 beach 24 5 gravel beach 24 6 Pebble Beach 8760 7 Exposed tidal flats 1 8 Sheltered rocky coast 8760 9 Sheltered tidal flats 8760 10 Sheltered swamp wetlands 8760

[0098] The calculation of S5 is as follows:

[0099] See also Figure 2 The resuspension process of oil spills refers to the process by which oil that has been deposited on the bottom of the water or in the sediment is resuspended in the water body. This process occurs when the intertidal land is re-inundated by seawater during high tide. The resuspension process is relatively complex because it is affected by multiple factors: waves and currents are one of the main driving factors for resuspension. Under the influence of wind, waves and currents, oil spills stranded in the intertidal zone are washed back into the water. The formula for the amount of water washed back into the water used in this invention is as follows:

[0100]

[0101] in: is the adsorption amount of coastal oil spill, The amount of water entering the flushing tank.

[0102] Example 2

[0103] A method for rapid numerical prediction of oil spills in shallow waters, wherein the steps of the preparatory method are as follows:

[0104] S1. Calculate the expansion of oil spills under the action of gravity at the beginning of the spill, referring to the Fay theory of oil spill expansion on a still sea surface.

[0105] S2. Calculate the relevant information of the oil spilled into the water body;

[0106] S3. Use oil particle model to calculate the movement of spilled oil in water;

[0107] S4. Calculate the amount of oil adsorbed on the coast, and the reduction in the number of particles is calculated based on the reduced amount of oil spilled;

[0108] S5. Calculate the amount of oil spill resuspended after flushing, and recount the number of particles entering the water after flushing to perform particle trajectory tracking calculation.

[0109] The calculation of S1 is as follows:

[0110] See also Figure 1 The Fay theory is an extended three-stage model. Considering the slope of the intertidal zone, after an oil spill occurs, the oil film is subjected to a downward gravity component along the slope, and there is a stretch along the slope. That is, the oil film expands in the intertidal zone in the form of an ellipse rather than a circle, and its long axis is consistent with the slope. The expansion is improved as follows:

[0111]

[0112]

[0113] Where: L min is the minor axis, L max is the semi-major axis, g is the acceleration of gravity, α is the inclination angle between the intertidal zone and the sea level, μ is the viscosity of the oil spill, V is the volume of the oil spill, and t is the time after the oil spill.

[0114] The calculation of S2 is as follows:

[0115] S21. Judgment of stranded oil particles in the intertidal zone:

[0116] A tidal current model including the intertidal zone is constructed. The water level is predicted by the tidal harmonic constant at the open boundary. A two-dimensional ocean hydrodynamic model is used, and the grid "dry and wet point" algorithm is used to quickly simulate the flooding and drying process of the intertidal zone. The open boundary water level prediction formula is as follows:

[0117]

[0118] i represents the M2 (main semidiurnal equinoctial tide), S2 (main semidiurnal equinoctial tide), K1 (lunar-solar declination diurnal equinoctial tide), and O1 (lunar declination diurnal equinoctial tide);

[0119] H i The amplitude of the i-th tidal harmonic constant; g i The i-th tidal harmonic constant phase; σ i The ith tidal angular frequency; v i The initial phase of the i-th tidal component; f i ,u i The i-th tidal intersection factor and the correction angle of the intersection;

[0120] S22. Determination of dry and wet points in the intertidal zone:

[0121] Assume that the total water depth of (i, j) is D i,j ,

[0122] D i,j =H i,j +η i,j (4)

[0123] η i,j is the water level at the grid point, H i,j is the water depth from mean sea level, D i,j >0.05m, the grid point is considered a wet point, D i,j When ≤0.05m, the grid point is a dry point;

[0124] S23. Judgment of oil particle stranding:

[0125] Assume the oil film thickness is H oil ;

[0126] When D i,j >H oil , it is judged that the oil particles are located in the water body; when D i,j ≤H oil Oil particles are stranded, determine whether oil particles are stranded.

[0127] The calculation of S3 is as follows:

[0128] The velocity equation of oil particles can be expressed as: U t =C w U w +Us (5)

[0129] The position change of oil particles during the Δt period can be expressed as:

[0130] X=X0+uΔt+C w U w sinθΔt (6)

[0131] Y=Y0+vΔt+C w V w cosθΔt (7)

[0132] Where X0 and Y0 are the initial positions of the oil film; U t is the total speed of drift motion; U s is the surface velocity; u and v are the east and north components of the tidal velocity; U w 、V w are the east and north components of the wind speed at 10 m above the sea surface; θ is the wind direction angle; C w is the wind drift coefficient, which is generally taken as 0.03;

[0133] Random diffusion distance S of oil particles per unit time α The calculation formula is as follows:

[0134]

[0135] Where D α is the diffusion coefficient in the α direction, α represents the x and y directions, and R is a random number between -1 and 1.

[0136] The calculation of S4 is as follows:

[0137] When the oil spill in the seawater is stranded and adsorbed on the coast, the adsorption amount is determined by the Torgrimson formula.

[0138] V2=V1e -kΔt (8)

[0139] V1, V2 are the amount of oil spilled on the coast at t1 and t2, and the attenuation coefficient λ is the half-life.

[0140] Table 1 Reference values ​​of oil spill half-life for different coastal types

[0141] Serial number Coastal type Oil spill half-life (h) 1 Exposed headland 1 2 Sea erosion platform 1 3 Bag Beach 24 4 beach 24 5 gravel beach 24 6 Pebble Beach 8760 7 Exposed tidal flats 1 8 Sheltered rocky coast 8760 9 Sheltered tidal flats 8760 10 Sheltered swamp wetlands 8760

[0142] The calculation of S5 is as follows:

[0143] See also Figure 2The resuspension process of oil spills refers to the process by which oil that has been deposited on the bottom of the water or in the sediment is resuspended in the water body. This process occurs when the intertidal land is re-inundated by seawater during high tide. The resuspension process is relatively complex because it is affected by multiple factors: waves and currents are one of the main driving factors for resuspension. Under the influence of wind, waves and currents, oil spills stranded in the intertidal zone are washed back into the water. The formula for the amount of water washed back into the water used in this invention is as follows:

[0144]

[0145] in: is the adsorption amount of coastal oil spill, The amount of water entering for flushing.

[0146] The resuspension process of oil spill refers to the process in which oil that has been deposited on the bottom of the water or in the sediment is resuspended in the water body.

[0147] The resuspension process of oil spills occurs when the intertidal land is re-inundated by seawater during high tide. The resuspension process is affected by many factors and is therefore complex.

[0148] Example 3

[0149] To predict the distribution of oil spills along the coastline and intertidal zone, this paper provides a test case. A hydrodynamic model of the study area is constructed to simulate the hydrodynamic field in the oil spill area. The adsorption and flushing process of oil spills in shallow waters simulates the adsorption and flushing process of oil spills in shallow waters, and the oil particle module simulates the migration and diffusion of oil spills in the water body. The details are as follows:

[0150] This aspect is aimed at oil spills in shallow waters. At the beginning of the spill, the oil spreads under the action of gravity.

[0151]

[0152]

[0153] The movement of spilled oil in water is calculated using the oil particle model:

[0154] U t =C w U w +U s

[0155] X=X0+uΔt+C w U w sinθΔt

[0156] Y=Y0+vΔt+C w V w cosθΔt

[0157] Random diffusion distance S of oil particles per unit time α The calculation formula is as follows:

[0158]

[0159] The number of particles entering the water after flushing was recounted and particle trajectory tracking was calculated. The oil spill spread 2.5 km in 12 hours.

[0160] Technical features not described in the present invention can be achieved through or by adopting existing technologies and will not be described in detail here. Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention should also fall within the scope of protection of the present invention.

Claims

1. A rapid numerical prediction method for oil spills in shallow waters, characterized in that: The steps of the preparation method are as follows: S1. Calculate the expansion of oil spills under the action of gravity at the beginning of the spill, referring to the Fay theory of oil spill expansion on a still sea surface. S2. Calculate the relevant information of the oil spilled into the water body; S3. Use oil particle model to calculate the movement of spilled oil in water; S4. Calculate the amount of oil adsorbed on the coast, and the reduction in the number of particles is calculated based on the reduced amount of oil spilled; S5. Calculate the amount of oil spill resuspended after flushing, and recount the number of particles entering the water after flushing to perform particle trajectory tracking calculation.

2. The rapid numerical prediction method for shallow sea oil spill according to claim 1, characterized in that: The calculation of S1 is as follows: The Fay theory is an extended three-stage model. Considering the slope of the intertidal zone, after an oil spill occurs, the oil film is subjected to a downward gravity component along the slope, and there is a stretching along the slope. That is, the oil film expands in the intertidal zone in the form of an ellipse rather than a circle, and its long axis is consistent with the slope. The expansion is improved as follows: Where: L min is the minor axis, L max is the semi-major axis, g is the acceleration of gravity, α is the inclination angle between the intertidal zone and the sea level, μ is the viscosity of the oil spill, V is the volume of the oil spill, and t is the time after the oil spill.

3. The rapid numerical prediction method for shallow sea oil spill according to claim 1, characterized in that: The calculation of S2 is as follows: S21. Judgment of stranded oil particles in the intertidal zone: A tidal current model including the intertidal zone is constructed. The water level is predicted by the tidal harmonic constant at the open boundary. A two-dimensional ocean hydrodynamic model is used, and a grid "dry and wet point" algorithm is used to quickly simulate the flooding and drying process of the intertidal zone. The open boundary water level prediction formula is as follows: i represents the M2 (main semidiurnal equinoctial tide), S2 (main semidiurnal equinoctial tide), K1 (lunar-solar declination diurnal equinoctial tide), and O1 (lunar declination diurnal equinoctial tide); H i The amplitude of the i-th tidal harmonic constant; g i The i-th tidal harmonic constant phase; σ i The ith tidal angular frequency; v i The initial phase of the i-th tidal component; f i ,u i The i-th tidal intersection factor and the correction angle of the intersection; S22. Determination of dry and wet points in the intertidal zone: Assume that the total water depth of (i, j) is D i,j , D i,j =H i,j +n i,j (4) η i,j is the water level at the grid point, H i,j is the water depth from mean sea level, D i,j >0.05m, the grid point is considered a wet point, D i,j When ≤0.05m, the grid point is a dry point; S23. Judgment of oil particle stranding: Assume the oil film thickness is H oil ; When D i,j >H oil , it is judged that the oil particles are located in the water body; when D i,j ≤H oil , determine that the oil particles are stranded.

4. The rapid numerical prediction method for shallow sea oil spills according to claim 1 is characterized in that: The calculation of S3 is as follows: The velocity equation of oil particles can be expressed as: U t =C w I w +U s (5) The position change of oil particles during the Δt period can be expressed as: X=X0+uΔt+C w U w sinθΔt (6) Y=Y0+vΔt+C w V w cosθΔt (7) Where X0 and Y0 are the initial positions of the oil film; U t is the total speed of drift motion; U s is the surface velocity; u and v are the east and north components of the tidal velocity; U w 、V w are the east and north components of the wind speed at 10 m above the sea surface; θ is the wind direction angle; C w is the wind drift coefficient, which is generally taken as 0.03; Random diffusion distance S of oil particles per unit time α The calculation formula is as follows: Where D α is the diffusion coefficient in the α direction, α represents the x and y directions, and R is a random number between -1 and 1.

5. The rapid numerical prediction method for shallow sea oil spill according to claim 1 is characterized in that: The adsorption amount of the stranded oil in S4 on the coast is determined by the Torgrimson formula, which is: <h2 style=";text-align:left;direction:ltr">V2=V1e<h2 style=";text-align:left;direction:ltr"> -kΔt <h2 style=";text-align:left;direction:ltr"> (8) V1, V2 are the amount of oil spilled on the coast at t1 and t2, and the attenuation coefficient λ is the half-life.

6. The rapid numerical prediction method for shallow sea oil spills according to claim 1 is characterized in that: The flushing water volume formula used by S5 is as follows: in: is the adsorption amount of coastal oil spill, The amount of water entering the flushing tank.

7. The rapid numerical prediction method for shallow sea oil spills according to claim 5 is characterized in that: The resuspension process of oil spill refers to the process in which oil that has been deposited on the bottom of the water or in the sediment is resuspended in the water body.

8. The rapid numerical prediction method for shallow sea oil spills according to claim 7 is characterized in that: The resuspension process of oil spills occurs when the intertidal land is re-inundated by seawater during high tide. The resuspension process is affected by many factors and is therefore complex.

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