A method for compiling and using a full-tide tidal current forecast table along a sea channel

Abstract

The present invention discloses a method for compiling and using a full-tide tidal forecast table along a sea channel. The method uses a three-dimensional tidal numerical model to simulate and calculate hourly tidal data along the channel under different tidal ranges in the sea area where the channel is located, and compiles a tidal forecast table along the channel. This facilitates linear interpolation based on the predicted tidal range in the tidal forecast table, and quickly obtains hourly navigation flow conditions along the channel, including data such as the vertical average flow velocity, vertical average flow direction, and vertical average crossflow within the full-load draft depth of the designed ship type, providing a basis for the formulation of ship maneuvering and pilotage plans. The present invention overcomes the shortcomings of existing tidal forecast tables that only have average flow velocity and average flow direction data within the entire water depth range of the channel obtained based on two-dimensional numerical models. It has the advantages of being more consistent with the actual flow field, more adaptable to actual navigation, and easy to use.

Description

Technical Field

[0001] The present invention belongs to the fields of construction, maintenance and operation of water transport engineering industry, as well as navigation and ocean forecasting, and relates to the preparation and use of a full-tide tidal current forecast table based on a three-dimensional tidal current numerical model along a sea channel. Background Art

[0002] The channel width required for safe navigation is closely related to the velocity, direction, and cross-current along the channel. These are not only affected by topography—for example, near breakwater openings, remediation structures, or islands, the velocity and cross-current may be significantly greater than in normal sections—but are also closely related to the tide time (e.g., high tide, low tide, low tide) and the tidal range, which in turn is closely related to the tidal type (spring tide, moderate tide, neap tide).

[0003] The tide forecast tables currently released publicly in the industry (such as the tide table compiled by the China National Marine Information Center) use a two-dimensional tidal model based on the influence of astronomical factors on tides. They provide annual tide level forecasts for some long-term tide stations along the coast of China, as well as annual tidal forecasts for stations in important sea areas. The tidal forecasts are divided into two categories:

[0004] ① Reciprocating flow site

[0005] The tide forecast table includes the daily turning time, maximum flow speed and the time of occurrence.

[0006] ② Rotating flow property site

[0007] The tide forecast table includes the two maximum flow velocities and directions and the two minimum flow velocities and directions and the times of their occurrence during the process of one tide rotation (approximately one tidal cycle) (tide by tide).

[0008] The current forecast in the existing tide forecast table has the following deficiencies:

[0009] ①Tidal current forecast stations usually have only one forecast point in a certain sea area, located on the public shipping lanes in the open sea, far away from the waterways of various ports, with poor representativeness and no coverage along the shipping lanes, which obviously cannot meet the needs of navigation;

[0010] ② Although daily or tide-by-tide tidal data are given, only the flow velocity and direction at the time of rapids and turning currents are given. The total flow velocity, direction and cross-current data during the entire navigation period are not given, which obviously cannot meet the needs of navigation.

[0011] ③ The flow velocity and direction data are for the entire water depth range of the channel, and there is a lack of flow velocity, direction and cross-flow data within the full-load draft depth range of the designed ship type.

[0012] ④ The flow velocity and direction data are based on the two-dimensional tidal current model, not the three-dimensional tidal current model, and cannot reflect the distribution of flow velocity and direction in the vertical direction.

[0013] In addition, the existing three-dimensional tidal numerical model has technically reached the level of "accurately simulating and calculating, and giving hourly flow velocity, flow direction and cross-current data along the waterway in future years based on the tide data in the tide forecast table." However, if it is implemented in this way, the amount of calculation will be huge, and a large number of tables will be generated, which will be very inconvenient for guiding navigation. Summary of the Invention

[0014] In order to solve the above problems, the present invention discloses a method for compiling and using a full-tide tidal current forecast table along a sea channel based on a three-dimensional tidal current numerical model.

[0015] Previous two-dimensional numerical modeling studies have shown that the maximum crosscurrent at the entrance of certain ports, such as the Qitai estuary of Lianyungang Port, is positively correlated with the tidal range. This is because the waters of these ports are not affected by runoff and are completely controlled by the tides, so the magnitude of the crosscurrent at the entrance is completely determined by the tidal range.

[0016] Therefore, the present invention proposes to calculate the hourly tidal current along the waterway under the graded tidal ranges (e.g., tidal ranges of 5.5m, 5.0m, 4.5m, 4.0m, 3.5m, 3.0m, 2.5m, 2.0m, 1.5m, and 1.0m, covering astronomical spring tides, astronomical moderate tides, and astronomical neap tides, hence the term "full-tide type") at the tidal stations in the sea area where the waterway is located, obtain navigable flow condition data, including flow velocity, flow direction, and crossflow, and compile a waterway (hourly) tidal current forecast table under different graded tidal ranges. When used, linear interpolation is performed based on the predicted tidal range for the tidal station given in the tidal forecast table by querying the tidal current data given in the waterway (hourly) tidal current forecast table under adjacent graded tidal ranges, thereby quickly determining the hourly navigable flow conditions along the waterway. This provides a basis for the advance formulation of ship maneuvers and pilotage plans. This method can meet accuracy requirements while greatly reducing the amount of calculation and the number of generated tables, making it easier to use.

[0017] Specifically, the technical solution of the present invention includes the following steps:

[0018] S1. Establish a three-dimensional tidal numerical model of the waterway and the sea area in which it is located;

[0019] S2. Use the measured tide level, current velocity, and flow direction data of the sea area where the channel is located to verify the three-dimensional tidal numerical model and determine the calculation parameters;

[0020] S3. Using a validated three-dimensional tidal numerical model, simulate and calculate the hourly (based on the time from the tidal station to high and low tide, for example, 3 hours before high and low tide to 3 hours after high and low tide, with an interval of 1 hour, 30 minutes, or 15 minutes, the same below) tide level, vertical flow velocity, and flow direction at different tidal ranges (generally, the tidal range is 0.5 m, such as 5.5 m, 5.0 m, 4.5 m, 4.0 m, 3.5 m, 3.0 m, 2.5 m, 2.0 m, 1.5 m, and 1.0 m, with the maximum and minimum tidal ranges covering all historical astronomical spring tides, moderate tides, and neap tides, hence the term "full tide model") along the waterway.

[0021] S4. Based on the numerical model calculation results of S3, calculate the hourly tide level at each characteristic point along the channel under different tidal ranges, the vertical average flow velocity within the full-load draft range of the designed ship type, the vertical average flow direction, and the vertical average crossflow;

[0022] S5. Based on the calculation results of S4, prepare a tidal current forecast table along the waterway, including the hourly tide level at each characteristic point along the waterway, the vertical average flow velocity within the full-load draft range of the designed ship type, the vertical average flow direction and the vertical average cross flow.

[0023] In some embodiments, the S1 may include:

[0024] S1a. Determine the calculation range and open boundary settings of the three-dimensional tidal numerical model based on the topographic characteristics of the sea area where the waterway is located, as well as the tidal wave propagation characteristics and tidal current movement characteristics;

[0025] S1b. Plane meshing of the 3D tidal numerical model should be performed based on the design dimensions and layout of the waterway, as well as the terrain characteristics along the waterway. The mesh density should be sufficient to outline the boundaries between the land coastline and underwater terrain, the waterway, and surrounding structures. Grid density should be increased for key research areas.

[0026] S1c. Determine the number of vertical calculation layers in the three-dimensional tidal numerical model based on the fully loaded draft of the designed channel ship type and the tidal range in the area. The number of layers should be able to accurately reflect the changes in flow velocity and direction within the fully loaded draft range of the designed channel ship type during the tidal cycle.

[0027] In some embodiments, S3 may include:

[0028] S3a. Based on the measured tidal range at the tidal stations in the sea area where the waterway is located, determine the tidal range levels required for the compilation of tidal forecast tables and the flow field calculations required for the three-dimensional tidal numerical model;

[0029] S3b. Adjust the open boundary input conditions of the three-dimensional tidal numerical model so that the calculated values of the tidal ranges of each level at the tidal station in the sea area where the waterway is located obtained by the numerical model are the same as the tidal ranges of each level required for the compilation of the tidal forecast table;

[0030] S3c. Using a three-dimensional tidal numerical model, based on the open boundary input conditions corresponding to each tidal range, simulate the hourly tide level, flow velocity and direction of each vertical layer along the waterway under each tidal range.

[0031] In some embodiments, the S4 may include:

[0032] S4a. Based on the waterway's plan layout, the placement of buildings or structures along the waterway, and the flow characteristics along the waterway, determine the locations of characteristic points along the waterway that need to be included in the tidal current forecast table.

[0033] S4b. For each characteristic point along the channel included in the tidal forecast table, calculate the hourly tide level, vertical stratified flow velocity and flow direction of each characteristic point along the channel based on the three-dimensional tidal numerical model, and calculate its full-load draft depth range H of the designed ship type. m The hourly vertical average flow velocity V m , flow to α m , which is calculated as follows:

[0034]

[0035] In formula (1), i is the i-th layer number of the three-dimensional tidal numerical model, i=1 is the surface layer, i=n is the bottom layer, and n is the total number of vertical layers of the three-dimensional tidal numerical model; V i With α i is the flow velocity and direction of a certain layer at a certain feature point; k is the number of layers of the three-dimensional tidal current numerical model within the full-load draft depth range of the designed ship type at that point, and its value is The calculation result is rounded, k≤n; H is the still water depth of the feature point that does not change with the tide level; ζ is the hourly tide level of the point.

[0036]

[0037] In formula (2), arctan2() is the four-quadrant inverse tangent function; if the calculated α m If it is less than 0°, add 360°.

[0038] S4c calculates the hourly vertical average crossflow V within the full-load draft range of the designed ship type at each characteristic point along the channel based on the calculation results of S4b c , which is calculated as follows:

[0039] V c =|V m sin(αm -α c )|Formula (3)

[0040] In formula (3), α c is the channel strike angle of the feature point.

[0041] In some embodiments, the S5 may include:

[0042] S5a. Prepare a separate table of tidal current forecasts along the waterway for each tidal range classification, including the hourly tide levels at each characteristic point along the waterway, the vertical average current velocity within the full-load draft range of the designed ship type, the vertical average current direction, and the vertical average crosscurrent;

[0043] S5b. Gather the separate tables of tidal current forecast along the waterway under different tidal ranges to form a complete table of tidal current forecast along the waterway.

[0044] The method for using the above-mentioned full-tide tidal current forecast table along the sea channel is to perform linear interpolation based on the predicted tidal range of the tide station given by the tidal forecast table, by querying the tidal data given by the hourly tidal current forecast table along the channel under adjacent graded tidal ranges, and quickly determine the hourly navigation water flow conditions along the channel, providing a basis for the early formulation of ship maneuvering and pilotage plans.

[0045] In some embodiments, the following steps may be included:

[0046] (1) Based on the predicted tidal range of a certain tidal process given in the tidal forecast table, query the tidal data given in the tidal forecast table along the channel under the adjacent graded tidal range;

[0047] (2) Linear interpolation is performed based on the tidal range to obtain the hourly navigation flow conditions at each characteristic point along the channel, including the tidal level, the vertical average flow velocity within the range of the designed ship's full-load draft, the vertical average flow direction and the vertical average crossflow.

[0048] In one embodiment, based on the predicted tidal range (e.g., 4.9 m) of a certain tidal process (e.g., the daily tide on September 18th of the lunar calendar) given in the tidal forecast table, the tidal data given in the tidal forecast table along the waterway under adjacent graded tidal ranges (tidal range of 5 m and tidal range of 4.5 m) are queried, and linear interpolation is performed based on the tidal range to obtain the hourly navigation flow conditions at each characteristic point along the waterway, including the tidal level, the vertical average flow velocity within the range of the designed ship's full-load draft, the vertical average flow direction, and the vertical average crossflow.

[0049] Applications:

[0050] It should be noted that the present invention is suitable for the preparation and use of tidal forecasts along all tidal navigation periods along sea channels, particularly under normal weather conditions where tidal influences dominate. In high winds or at estuaries, actual flow velocity, direction, and crossflow may be affected by strong winds or runoff, resulting in deviations. This requires careful consideration when using the present invention.

[0051] Beneficial effects:

[0052] The present invention provides a method for compiling a tidal current forecast table for a sea area channel based on a three-dimensional tidal current numerical model, which has the following beneficial effects:

[0053] ① The hourly vertical average velocity, vertical average flow direction and vertical average cross-flow data of each characteristic point along the sea channel and within the range of the fully loaded draft of the designed ship type under different tidal conditions can be given. In this way, when designing the overall waterway project, the determination of the waterway operation standard and the number of waterway navigable times can further consider the influence of the combination of cross-flow and tide level, and determine the waterway operation standard and navigation guarantee rate more comprehensively and reasonably, overcoming the shortcomings of the current waterway operation standard in which the cross-flow limit is based on the maximum cross-flow calculated by actual measurement or numerical simulation, the number of waterway navigable times is calculated based on the number of wind, wave, fog and thunder days, and the default cross-flow of the waterway does not exceed the design operation standard.

[0054] ② It can provide hourly vertical average velocity, vertical average flow direction, and vertical average crossflow data for each characteristic point along the sea channel under different tidal range conditions within the range of the designed ship's full-load draft. This allows the hourly navigation flow conditions along the channel to be quickly determined through linear interpolation based on the tidal range given in the sea area tide forecast table, including the vertical average velocity, vertical average flow direction, and vertical average crossflow within the range of the tidal level and the designed ship's full-load draft, providing a basis for the early formulation of ship maneuvering and pilotage plans. This not only meets accuracy requirements, but also greatly reduces the amount of calculations and the generated tables, making it easier to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 :A flow chart of the preparation and use of a full-tide tidal current forecast table along a sea channel.

[0056] Figure 2 : Schematic diagram of the waterway plan layout of an embodiment of the present invention.

[0057] Figure 3 : Calculation range and grid division diagram of the three-dimensional tidal numerical model according to the embodiment of the present invention.

[0058] Figure 4 : Calculation results of the rapid surface flow field according to an embodiment of the present invention.

[0059] Figure 5: Schematic diagram of the locations of characteristic points within a waterway according to an embodiment of the present invention.

[0060] Figure 6 : Schematic diagram of vertical flow velocity distribution at feature point C5 2 hours before high tide under 5.0m graded tidal range according to an embodiment of the present invention. DETAILED DESCRIPTION

[0061] The present invention will be described in detail below with reference to the embodiments and drawings.

[0062] A certain port on the coast of my country has a 300,000-ton channel and a long-term tide station. The layout of the port area and channel is shown in Figure 2 The 300,000-ton channel is designed for 300,000-ton bulk carriers, whose fully loaded draft is 23.0m and the designed bottom elevation of the channel is -22.6m (the local theoretical lowest tide level). When fully loaded, 300,000-ton bulk carriers enter the port and need to sail with the tide in the WY section of the channel, which is 2 hours before high tide to 2 hours after high tide.

[0063] The preparation and use of the full tide type tidal current forecast table for the WY section of the waterway includes the following steps:

[0064] Step 1: Establish a three-dimensional tidal numerical model of the waterway and the sea area where it is located.

[0065] Firstly, the calculation range and opening boundary position of the three-dimensional tidal numerical model are determined according to the tidal and current characteristics and terrain characteristics of the sea area where the channel is located. Figure 3 .

[0066] Then, the computational domain is divided into grids using unstructured grids. To ensure the accuracy of flow field simulation in the waters of the WY section of the waterway, the local grids are encrypted, and the plane scale of the minimum grid is about 20m.

[0067] Finally, considering the large tidal range near the shore of the waterway (typically exceeding 5.0m during high tides), the flow velocity and direction at different water depths in the waterway will vary significantly with tide level. To more accurately reflect the changing total water depth of the waterway during the tidal cycle at different tidal ranges, the flow velocity, direction, and crossflow variations within the fully loaded draft range of the ship (from the water surface to 23.0m underwater) were designed, ensuring that the water layer thickness of each calculation layer did not exceed 1m. The number of vertical stratification layers in the three-dimensional tidal numerical model was determined to be 30.

[0068] Step 2: Use the measured tide level, flow velocity, and flow direction data of the sea area where the channel is located to verify the three-dimensional tidal numerical model and determine the calculation parameters.

[0069] The model's calculations were compared and validated using large-scale, fixed-point hydrological survey data from April and September 2023 in the waters surrounding the channel, as well as ADCP flow field monitoring data from September and October 2023 at the mouth of the channel. Calculation parameters were adjusted to ensure that the tidal level, current velocity, and flow direction at the measurement points met the accuracy requirements specified in the "Technical Specifications for Simulation Testing of Water Transport Engineering" (JTS / T 231-2021). After verification and debugging using measured data, the model's bed Manning roughness coefficient was determined to be 0.015-0.025, and the vertical eddy viscosity coefficient was determined to be 1.2.

[0070] Step 3: Use the verified three-dimensional tidal numerical model to simulate and calculate the hourly tide level, stratified flow velocity and flow direction under different tidal ranges in the sea area where the waterway is located.

[0071] First, according to the analysis results of the measured tidal range at the long-term tide station from 2013 to 2022, the tidal range on the nearshore side of this sea area is generally between 2.0m and 5.5m. Therefore, 2.0m, 2.5m, 3.0m, 3.5m, 4.0m, 4.5m, 5.0m, and 5.5m are determined as the graded tidal ranges for the three-dimensional flow field calculation.

[0072] Then, the open boundary input conditions of the three-dimensional tidal numerical model (the water level at the open boundary of the model in this embodiment) are adjusted so that the calculated tidal range values of each level of the tidal station calculated by the three-dimensional tidal numerical model are the same as the aforementioned graded tidal ranges.

[0073] Finally, using the three-dimensional tidal numerical model verified in step 2, based on the open boundary input conditions corresponding to each graded tidal range, the hourly three-dimensional flow field under each tidal range in the sea area where the channel is located is calculated, including the hourly tide level, the flow velocity and direction of each vertical layer. Among them, under the condition of a tidal range of 5.0m at the tide station, the rising and falling surface flow field in the waters of the WY section of the channel is shown in Figure 2. Figure 4 .

[0074] Step 4: Based on the calculation results of hourly tide level, stratified flow velocity and flow direction under different tidal ranges of the three-dimensional tidal numerical model, the hourly vertical average flow velocity, vertical average flow direction and vertical average cross flow within the full load draft range of the design ship type at each characteristic point along the channel are calculated.

[0075] According to the calculation results of the flow field, in the waterway's mouth section, due to the effect of the breakwater diversion, the flow velocity is high and the flow state is complex. The tidal flow direction and the direction of the WY section of the waterway have a large intersection angle, which makes it more likely to have a large cross current than other sections, and requires special attention. Therefore, when determining the characteristic points to be included in the tidal forecast table, a characteristic point is arranged every 1 km near the port area of the WY section (2 km from the mouth to the outside of the mouth), and a characteristic point is arranged every 2 km in the other sections. They are numbered C1 to C10 from west to east. Figure 5 .

[0076] For the characteristic points of the channel included in the compilation of the tide forecast table, the hourly tide level, layered flow velocity and flow direction of the point under different tidal ranges are calculated based on the three-dimensional tidal numerical model. Formulas (1) and (2) are used to calculate the hourly vertical average flow velocity and vertical average flow direction of the point under different tidal ranges and within the range of the designed ship's full-load draft. Among them, the vertical flow field of the C5 characteristic point 2 hours before the high tide is shown under the condition that the tidal range of the tide station is 5.0m. Figure 6 At this time, the number of calculation layers of the three-dimensional tidal numerical model within the full-load draft depth range of the designed ship is 28, and it is necessary to calculate the vertical average flow velocity and flow direction of the 1st to 28th layers, that is, k in formula (1) and formula (2) is taken as 28.

[0077] Based on the calculation results of the hourly vertical average flow velocity and vertical average flow direction at characteristic points C1 to C10 under different tidal ranges and within the range of the designed ship's full-load draft, combined with the channel strike angle of the WY section of the channel (63° to 243°), formula (3) is used to calculate the hourly vertical average crossflow at each characteristic point under different tidal ranges and within the range of the designed ship's full-load draft.

[0078] Step 5: Based on the calculation results of step 4, prepare a tidal current forecast table along the waterway.

[0079] Based on the long-term tide station reaching the aforementioned tidal range of 2.0m, 2.5m, 3.0m, 3.5m, 4.0m, 4.5m, 5.0m and 5.5m as the benchmark, the compilation of each sub-table of the tidal forecast table is carried out, that is, a sub-table is a tidal forecast table along the WY section of the waterway under a certain graded tidal range at the long-term tide station.

[0080] The navigation period for the WY section of the waterway is from 2 hours before high tide to 2 hours after high tide. This period is divided into five time periods at 1.0-hour intervals: 2 hours before high tide, 1 hour before high tide, high tide, 1 hour after high tide, and 2 hours after high tide. In each subtable (based on the tidal station reaching the aforementioned graded tidal range), enter the vertical average flow velocity, vertical average flow direction, and vertical average crossflow at each characteristic point along the waterway within the design ship's fully loaded draft, corresponding to these five time periods. A sample table for a graded tidal range of 5.0 m is shown in Table 1.

[0081] Table 1 Example 5.0m graded tidal range tidal forecast table

[0082]

[0083]

[0084] Note: The above table gives the forecast data of some feature points

[0085] Finally, the various sub-tables under the graded tidal ranges of 2.0m, 2.5m, 3.0m, 3.5m, 4.0m, 4.5m, 5.0m and 5.5m are combined to form the full tidal current forecast table for the WY section of the waterway.

[0086] Step 6: Based on the predicted tidal range of a certain tidal process given by the tidal forecast table, query the tidal data given by the tidal forecast table along the channel under adjacent graded tidal ranges, and perform linear interpolation to obtain the hourly navigable water flow conditions at each characteristic point along the channel.

[0087] A 300,000-ton bulk carrier needs to enter the port during the day on the 18th day of the ninth lunar month. The tide forecast table indicates a daily tidal range of 4.9 meters at the long-term tide station. The tidal forecast table along the waterway is used to query tidal data for tidal ranges of 5 and 4.5 meters. Linear interpolation based on the tidal range yields the hourly tidal levels at each characteristic point along the waterway, as well as the vertical average velocity, vertical average flow direction, and vertical average crossflow within the vessel's fully loaded draft.

[0088] The above descriptions and embodiments are provided to facilitate understanding and application of the present invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these contents and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above descriptions and embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should fall within the scope of protection of the present invention.

Claims

1. A method for compiling a full-tide tidal current forecast table along a sea area waterway, characterized by: Based on the measured tidal range data of the tide station in the sea area where the waterway is located, typical tidal range values covering astronomical spring tide, moderate tide and neap tide are selected as the graded tidal range. Based on the three-dimensional tidal numerical model, the hourly tidal current field along the waterway under each graded tidal range is calculated to obtain the navigable water flow condition data, including flow velocity, flow direction and cross flow, and compile the hourly tidal current forecast table along the waterway under different graded tidal ranges. The full tidal type refers to covering astronomical spring tide, astronomical moderate tide and astronomical neap tide, and includes the following steps: S1. Establish a three-dimensional tidal numerical model of the waterway and the sea area in which it is located; S2. Use the measured tide level, current velocity, and flow direction data of the sea area where the channel is located to verify the three-dimensional tidal numerical model and determine the calculation parameters; S3. Using a validated three-dimensional tidal numerical model, simulate and calculate the hourly tide level, vertical flow velocity, and flow direction at each layer along the waterway under different tidal ranges at tide stations in the sea area where the waterway is located; S4. Based on the simulation results of S3, calculate the hourly tide level at each characteristic point along the channel under different tidal ranges and the vertical average flow velocity, vertical average flow direction, and vertical average crossflow within the range of the designed ship's fully loaded draft; S5. Based on the calculation results of S4, prepare a tidal current forecast table along the waterway, including the hourly tide level at each characteristic point along the waterway, the vertical average flow velocity within the full-load draft range of the designed ship type, the vertical average flow direction and the vertical average cross flow.

2. The method for compiling a full-tide tidal current forecast table along a sea area waterway according to claim 1 is characterized in that: Said S1 comprises: S1a. Determine the calculation range and open boundary settings of the three-dimensional tidal numerical model based on the topographic characteristics of the sea area where the waterway is located, as well as the tidal wave propagation characteristics and tidal current movement characteristics; S1b. Perform plane meshing of the 3D tidal numerical model based on the design scale and layout of the waterway and the terrain characteristics along the waterway. S1c. Determine the number of vertical calculation layers of the three-dimensional tidal numerical model based on the fully loaded draft of the designed ship type in the channel and the tidal range in the area.

3. The method for compiling a full-tide tidal current forecast table along a sea area waterway according to claim 1 is characterized in that: The S3 includes: S3a. Based on the measured tidal range at the tidal stations in the sea area where the waterway is located, determine the tidal range levels required for the compilation of tidal forecast tables and the flow field calculations required for the three-dimensional tidal numerical model; S3b. Adjust the open boundary input conditions of the three-dimensional tidal numerical model so that the calculated tidal range values at the tidal stations in the sea area where the waterway is located obtained by the numerical model are the same as the tidal range values at the various levels required for the compilation of the tidal forecast table; S3c. Using a three-dimensional tidal numerical model, based on the open boundary input conditions corresponding to each tidal range, simulate the hourly tide level, flow velocity and direction of each vertical layer along the waterway under each tidal range.

4. The method for compiling a full-tide tidal current forecast table along a sea area waterway according to claim 1 is characterized in that: The S4 includes: S4a. Based on the waterway's plan layout, the placement of buildings or structures along the waterway, and the flow characteristics along the waterway, determine the locations of characteristic points along the waterway that need to be included in the tidal current forecast table. S4b. For each characteristic point along the channel included in the tidal forecast table, the hourly tide level, layered flow velocity and flow direction under different tidal ranges at that point are calculated based on the three-dimensional tidal numerical model, and the calculated value of the tidal level is calculated within the full-load draft depth range H of the designed ship type. m The hourly vertical average flow velocity V m , flow to α m , which is calculated as follows: In formula (1), i is the i-th layer number of the three-dimensional tidal numerical model, i=1 is the surface layer, i=n is the bottom layer, and n is the total number of vertical layers of the three-dimensional tidal numerical model; V i With α i is the flow velocity and direction of a certain layer at a certain feature point; k is the number of layers of the three-dimensional tidal current numerical model within the full-load draft depth range of the designed ship type at that point, and its value is The calculated result is rounded, k≤n; H is the still water depth of the feature point that does not change with the tide level; ζ is the hourly tide level of the point; In formula (2), arctan2() is the four-quadrant inverse tangent function; if the calculated α m If it is less than 0°, add 360°; S4c. Based on the results of S4b and the channel strike angle, calculate the hourly vertical average crosscurrent Vc as follows: V c =|V m sin(α m -α c , official(3) In formula (3), α c is the channel strike angle of the feature point.

5. The method for compiling a full-tide tidal current forecast table along a sea area waterway according to claim 1 is characterized in that: The S5 includes: S5a. Prepare a separate table of tidal current forecasts along the waterway for each tidal range classification, including the hourly tide levels at each characteristic point along the waterway, the vertical average current velocity within the full-load draft range of the designed ship type, the vertical average current direction, and the vertical average crosscurrent; S5b. Gather the separate tables of tidal current forecast along the waterway under different tidal ranges to form a complete table of tidal current forecast along the waterway.

6. A method for using a full-tide tidal current forecast table along a sea area and waterway compiled according to the method for compiling a full-tide tidal current forecast table along a sea area and waterway according to any one of claims 1 to 5, characterized in that: When in use, based on the predicted tidal range of the tide station in the sea area where the waterway is located given by the tidal forecast table, by querying the tidal data given by the hourly tidal forecast table along the waterway under adjacent graded tidal ranges, linear interpolation is performed to quickly determine the hourly navigation flow conditions along the waterway, providing a basis for ship maneuvering and early formulation of pilotage plans.

7. The method according to claim 6, characterized in that The following steps are involved: (1) Based on the predicted tidal range of a certain tidal process given in the tidal forecast table, query the tidal data given in the tidal forecast table along the channel under the adjacent graded tidal range; (2) Linear interpolation is performed based on the tidal range to obtain the hourly navigation flow conditions at each characteristic point along the channel, including the tidal level, the vertical average flow velocity within the range of the designed ship's full-load draft, the vertical average flow direction and the vertical average crossflow.

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