A dredging depth control method and a dredging vessel

Abstract

The application discloses a dredging depth control method and a dredging and desilting ship, relates to the environmental protection dredging field, and confirms the first critical depth and at least one second critical depth of a silt layer according to a silt layer depth confirmation method, determines the final critical depth of the silt layer by averaging the one or more second critical depths, finally calculates the ratio of the critical depth and the first critical depth to obtain the relationship between the critical depth and the first critical depth of the silt layer, and constructs a bottom mud distribution map of a dredging area according to the result, so that the dredging and desilting ship can implement dredging operation according to the bottom mud distribution map of the dredging area, precise control of the dredging operation is realized, different digging depths are implemented according to different conditions of different dredging point positions, the dredging effect is ensured to be good, the growth of bottom organisms is protected, and the damage to the ecological environment is avoided.

Description

Technical Field

[0001] This invention relates to the field of environmental dredging, and in particular to a dredging depth control method and a dredging vessel. Background Technology

[0002] Environmental dredging primarily removes silt containing pollutants such as nutrients, harmful substances, and organic matter. Since the concentration of nutrients and organic matter in the silt typically varies vertically, pollutants decrease with increasing depth, and most pollutants are deposited within a certain range of silt below the surface.

[0003] During dredging operations, under-dredging or missing sections will result in poor dredging results, while over-dredging will affect the growth of organisms at the bottom and damage the ecological environment.

[0004] Therefore, environmentally friendly dredging requires strict control over dredging accuracy. For dredging areas with uneven water characteristics, the dredging depth should not be determined based on the average thickness of the bottom sediment pollution layer. Instead, a differentiated environmentally friendly dredging depth design should be carried out based on site conditions, pollution severity, and other factors.

[0005] Current small, modular dredging vessels cannot meet this requirement, and there is an urgent need to propose a method for achieving precise control of dredging depth and a dredging vessel that uses this method. Summary of the Invention

[0006] The purpose of this invention is to provide a dredging depth control method and a dredging vessel to solve the problems existing in the prior art. When carrying out dredging operations, the dredging can be precisely controlled according to the different conditions of the water source, so as to ensure good dredging effect without damaging the ecological environment.

[0007] To achieve the above objectives, the present invention provides the following solution: This invention provides a method for controlling dredging depth, comprising the following steps: S1: Surveying and Planning; S101: Set sampling points in the work area; S102: Conduct sediment surveys at the sampling points, collect sediment samples, and record the sampling locations; S103: Conduct experimental testing and analysis on the collected samples, and obtain the first critical depth of the silt layer and at least one second critical depth according to the silt layer depth confirmation method. S104: Based on the evaluation results in step S103, if there is one second critical depth, then the second critical depth is the final critical depth of the silt layer; if there are multiple second critical depths, then the average value of the multiple second critical depths is the final critical depth of the silt layer. S105: Within the area to be dredged, calculate the ratio of the final critical depth to the first critical depth to obtain the relationship between the critical depth of the silt layer and the first critical depth. S106: Based on the location and water depth data collected during the survey, and combined with the critical depth of the silt layer determined in step S105, draw a map of the bottom sediment distribution in the area to be dredged. S2: Dredging operation implemented; S201: Determine the coordinates of the dredging point and mark the first critical depth of the current dredging point according to the silt layer depth confirmation method; S202: Based on the results obtained in step S105, the critical depth of the silt layer at the current dredging point is determined by multiplying the relationship between the critical depth of the silt layer and the first critical depth with the first critical depth of the current dredging point. S203: Scan the terrain before dredging to obtain the depth of the mud surface; S204: Determine the target dredging depth by calculating the difference between the critical depth of the silt layer and the depth of the mud surface at the current dredging point, execute the target dredging depth, and establish a dredging model for the area to be dredged based on the target dredging surface and the bottom mud distribution map drawn in step S106. S205: Dredging operations are carried out on the bottom layer of the water source area based on the dredging model of the area to be dredged established in step S204.

[0008] Preferably, in step S103, the method for confirming the depth of the silt layer includes the visual stratification method, the ecological risk index method, the inflection point method, and the stratified release method.

[0009] Preferably, the first critical depth is determined by visual layering.

[0010] Preferably, in step S105, the relationship between the critical depth of the silt layer and the first critical depth at locations not at the sampling position is determined using the center interpolation method.

[0011] Preferably, step S2 further includes the following sub-steps: S206: Real-time feedback of actual operating depth data, comparison and analysis with the dredging design model, adjustment of dredging progress, and ensuring that dredging operations proceed within the critical depth of the silt layer.

[0012] Preferably, it also includes step S3: post-dredging adjustment operation, which includes the following sub-steps: S301: Obtain the mud surface depth, compare the dredging area with the dredging model of the area to be dredged established in step S204, and calculate the elevation difference between the actual terrain after dredging and the designed dredging target surface. Based on the dredging effect judgment threshold, identify and mark all areas whose actual elevation is higher or lower than the target surface, as well as areas that have not been dredged at all, and count the area of ​​under-dredging areas, the average under-dredging depth, and the volume of earthwork. S302: Based on the spatial distribution characteristics of under-dredging areas, supplementary dredging path planning is carried out, with priority given to key areas or contiguous areas. The difference between the mud surface depth after dredging and the mud surface depth before dredging is calculated to obtain the supplementary dredging depth. S303: Supplementary dredging of areas that do not meet the standards.

[0013] Preferably, step S3 further includes the following sub-steps: S304: Iterative acceptance. After completing the supplementary dredging, repeat steps S301-S302. If there are still areas that do not meet the standards, start the second supplementary dredging process until the entire dredged area fully meets the standards.

[0014] The present invention also provides a dredging vessel, which applies the dredging depth control method described above. The dredging vessel is used in steps S2-S3 and includes a hull module for providing overall load-bearing capacity and buoyancy, a control module for operating the dredging vessel, a detection module for detecting the environment at the dredging point during operation, a positioning module for positioning the hull, dredging equipment for cleaning river silt, a discharge pipe for transporting silt to shore for treatment, and a bridge module that carries the discharge pipe and dredging equipment.

[0015] Preferably, the hull module includes a positioning float and an operating float, used to provide overall load-bearing capacity and surface buoyancy.

[0016] Preferably, it also includes a connecting transmission module, wherein the positioning float and the working float are connected by a connecting rotation module, and the connecting rotation module is provided with a swing cylinder inside, which is used to drive the working float to swing relative to the positioning float.

[0017] The present invention achieves the following technical effects compared to the prior art: This invention obtains the first critical depth and at least one second critical depth of the silt layer based on a silt layer depth confirmation method. The final critical depth of the silt layer is determined by averaging one or more second critical depths. Finally, the ratio of the critical depth to the first critical depth is calculated to obtain the relationship between the critical depth and the first critical depth. Based on this result, a bottom sediment distribution map of the dredging area is constructed. The dredging vessel then carries out dredging operations according to this map, achieving precise control of the dredging operation. Different excavation depths are implemented based on the different conditions at different dredging points, ensuring good dredging results while protecting the growth of bottom organisms and avoiding damage to the ecological environment. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram illustrating the steps of the dredging depth control method. Figure 2 Schematic diagram of a dredging and desilting vessel; Among them, 101-positioning float, 102-operation float, 2-connecting transmission module, 3-control module, 401-imaging equipment, 402-bottom mud stratification sampler, 403-three-dimensional terrain scanning equipment, 501-positioning pile, 502-trolley, 601-winch, 602-support frame, 603-bridge frame, 7-mud discharge pipe, and 8-dredging equipment. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The purpose of this invention is to provide a dredging depth control method and a dredging vessel to solve the problems existing in the prior art, so as to enable precise control of dredging operations, which not only ensures good dredging results, but also protects the growth of bottom organisms and avoids damage to the ecological environment.

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] like Figure 1 As shown, the present invention provides a method for controlling dredging depth, comprising the following steps: S1: Survey and planning. Before construction, the area to be dredged is surveyed and planned to define the scope of the work area. S101: Conduct a comprehensive survey of the dredged water area to clarify the scope of the work area. To reduce errors, the work area can be divided into work blocks according to the different comprehensive conditions at different locations in the work area, and a sampling point can be set at the center of each work block. To further reduce errors, the size of the work area can be limited, and work areas with a side length of ≤500m can be divided based on the survey data; S102: Conduct sediment surveys at the sampling points, collect sediment samples, and record the coordinates of the sampling locations on-site. ; S103: Conduct experimental testing and analysis on the collected sediment samples; To avoid increased detection errors due to sample contamination, the samples can be transported to the laboratory after being preserved at low temperatures. The collected sediment samples can then be analyzed in the laboratory using professional instruments. Based on the experimental data, the silt layer depth confirmation method was used to obtain the critical depth of the silt layer, which is the first critical depth. Critical depth refers to the depth at which the concentration of pollutants in the bottom sediment layer reaches a certain threshold during dredging. Determining the critical depth provides an important reference for subsequent dredging operations. Methods for confirming the depth of the silt layer include, but are not limited to, the following: Visual stratification, also known as sedimentological stratification, involves observing the vertical stratification characteristics of sediment profiles manually or with instruments. Based on the sediment's color, odor, particle size, and viscosity, it qualitatively analyzes the characteristics and thickness of the contaminated, transition, and normal layers. The critical depth of the silt layer is determined using contour lines of the contaminated and transition layers. The minimum value is the thickness of the contamination layer, and the maximum value is the thickness of the transition layer. Ecological Risk Index Method: By measuring and analyzing the concentration and toxicity of pollutants in the sediment of the dredged area, and combining this with the potential exposure level to organisms, one or more risk index values ​​are calculated to assess the pollution risk in the sediment, determine the ecological risk level of the sediment, and determine the pollution index and pollution level according to the maximum pollution degree index, thus obtaining the critical depth of the silt layer. ; Inflection Point Method: As the concentration of suspended sediment in water increases, its negative impact on aquatic organisms (such as fish and shellfish) does not increase linearly and uniformly. Instead, there exists a critical concentration below which the impact is acceptable or minor. However, once this concentration is exceeded, the negative impact increases dramatically. Based on the characteristics of the vertical distribution of major pollutants in the sediment, the appropriate dredging depth is determined. The point where the vertical distribution curve of the pollution changes direction upwards or downwards is found, and the corresponding thickness is the critical depth of the sediment layer. ; Stratified release method: The release rate of pollutants in contaminated sediment is not the same at all depths. By collecting sediment samples from different depths, the rate and amount of pollutant release into the water are simulated in the laboratory to identify the critical depth at which the pollutant release rate changes significantly. Physical and chemical properties of the sediment are then analyzed to determine the organic matter content, nitrogen and phosphorus content, heavy metal content, etc., thus determining the decomposition rate and stability of the sediment and obtaining the critical depth of the silt layer. ; In addition to the four methods listed above, other methods can be used to determine the critical depth, such as acoustic detection and resistivity / conductivity imaging. If more layered depth detection methods are available in the construction scenario, other methods besides the four mentioned above can be used for experimental testing and analysis. S104: Based on the evaluation results in step S103, determine the final critical depth of the silt layer. If only one method for confirming the silt layer depth is used, and a second critical depth is obtained, then this second critical depth is the final critical depth. ; If the method for confirming the depth of the silt layer is used, and multiple second critical depths are obtained, then the average value of these multiple second critical depths is taken as the final critical depth. For example, the ecological risk index method, the inflection point method, and the stratified release method were used to obtain... The three second critical depths are used as the average value, which is the final critical depth of the silt layer. ; S105: Within the area to be dredged, calculate the ratio of the final critical depth to the first critical depth. The relationship between the critical depth of the silt layer and the first critical depth was obtained. To facilitate direct measurement during construction, the visual stratification method can be used to analyze the results, obtain the first critical depth, and then calculate the ratio of the final critical depth to the first adjacent depth. This leads to the relationship between the final critical depth of the silt layer and the visual stratification depth, and further establishes the relationship between dredging location, bottom sediment visual stratification, and critical depth. The above visual stratification method can be replaced with other methods for confirming the depth of the silt layer, depending on the different on-site construction conditions. The relationship between the critical depth not located at the sampling position and the visual layering critical depth It can be obtained through central interpolation; depending on the specific on-site construction conditions, central interpolation may not be used, but sampling points may be set up again, and the relationship between the critical depth of the silt layer and the first critical depth can be obtained through further sampling. S106: Based on the location and water depth data collected during the survey, and combined with the relationship between the critical depth of the silt layer and the first critical depth determined in step S105, draw a spatial distribution map of the bottom sediment in the area to be dredged.

[0024] S2: Dredging operation implementation. Based on the three-dimensional spatial distribution map of the bottom sediment in the dredging area drawn in step S106, the critical depth of different dredging points is determined, so as to accurately control the excavation depth of the dredging machinery. S201: Determine the dredging point Coordinates are used to determine the first critical depth of the current dredging point based on the silt layer depth confirmation method. ; The method for confirming the depth of the silt layer can be selected according to the actual conditions of the construction site. To facilitate direct measurement during construction, the visual stratification method can be used to determine the first critical depth of the bottom silt layer. ; S202: Based on the relationship between the critical depth of the silt layer and the first critical depth obtained in step S105, the critical depth of the silt layer at the current dredging point is determined by multiplying the relationship between the critical depth of the silt layer and the first critical depth by the first critical depth of the current dredging point. ; S203: Obtain mud surface depth. The method for obtaining mud surface depth can be selected according to the specific conditions of the construction site. For example, scanning the terrain before dredging to obtain detailed mud surface depth. ; S204: Calculate the difference between the critical depth of the silt layer and the depth of the silt surface at the current dredging point to determine the target dredging depth, i.e. Based on the target dredging surface and the spatial distribution map of bottom sediment drawn in step S106, a dredging design model for the area to be dredged is established. S205: Dredging operations are carried out on the bottom layer of the water source area based on the dredging model of the area to be dredged established in step S204.

[0025] Based on the above, in order to further control the dredging operation more precisely, a new sub-step S206 is added to step S2; S206: Real-time feedback of actual operating depth data, comparison and analysis with dredging design model, timely adjustment of dredging progress based on the feedback operating depth data and data in dredging design model, ensuring that dredging operations proceed within the critical depth of silt layer, and avoiding under-dredging and over-dredging.

[0026] Based on the above, in order to further control dredging operations more precisely and ensure that remedial operations can be carried out in a timely manner even if under-dredging or over-dredging occurs, step S3 is added: post-dredging adjustment operation; S3: Post-dredging adjustment work; S301: Obtain mud depth The method for obtaining the mud surface depth can be selected according to the conditions of the construction site. The dredging area is compared with the dredging design model of the area to be dredged established in step S204, and the elevation difference between the actual terrain after dredging and the designed dredging target surface is calculated. Based on the dredging effect judgment threshold, i.e. the allowable positive and negative elevation deviation value, such as ±0.1 meters, identify and mark all areas where the actual elevation is higher than the design target surface (i.e. under-dredging) or significantly lower than the design target surface (i.e. over-dredging), as well as areas that have not been dredged at all, and count the area of ​​under-dredging areas, the average under-dredging depth, and the volume of earthwork. S302: Based on the spatial distribution characteristics of under-dredged areas, supplementary dredging path planning is performed, prioritizing key or contiguous areas. The supplementary dredging depth is obtained by calculating the difference between the post-dredging mud surface depth and the pre-dredging mud surface depth. ; S303: Conduct precise, small-scale supplementary dredging in areas that do not meet the standards; Based on the above, in order to further avoid missing under-excavation and over-excavation areas, a sub-step S304 is added on the basis of step S3: iterative acceptance; S304: Iterative acceptance. After completing the supplementary dredging, repeat steps S301-S302. If there are still areas that do not meet the standards, start the second supplementary dredging process until the entire dredged area fully meets the standards.

[0027] The present invention also discloses a dredging and silt removal vessel, applied in steps S2-S3, including a hull module, a connecting transmission module 2, a control module 3, a detection module, a positioning module, a bridge module, a sludge discharge pipe 7, and silt removal equipment 8; All of the above modules are standardized functional modules that can be transported to the designated dredging area and then assembled.

[0028] The hull module constitutes the main hull, including the positioning float 101 and the working float 102, which are used to provide overall load-bearing capacity and buoyancy. Other modules are assembled on this basis. The positioning float 101 and the working float 102 are connected together by the connecting transmission module 2. The positioning float 101 and the working float 102 are connected in a hinged manner. The connecting transmission module 2 is equipped with a swing cylinder, which is used to drive the working float 102 to swing relative to the positioning float 101.

[0029] The control module 3 is located on the positioning float 101. The control room is equipped with a central control system that is connected to the motor drive equipment of each business execution mechanism on board. At the same time, the control module 3 has a shore-based remote control function, which can realize the separation of ship and personnel operation.

[0030] The positioning module is a dual-pile trolley system, consisting of two independently liftable positioning piles 501 and two trolleys 502. The bottom of each positioning pile 501 is designed to be inserted into the underwater silt layer, and is mainly used for the positioning and relocation of the vessel during operation.

[0031] The detection module includes an imaging device 401 and a bottom sediment stratification sampler 402, both of which are located at the bow of the working float 102; a three-dimensional terrain scanning device 403 is located at the bow of the working float 102. The sediment layer sampler 402 can operate automatically or semi-automatically. It drills into the sediment through an adjustable drill bit or gripping mechanism, collects samples at a preset depth, and preserves the original structure of each layer. Imaging device 401 is equipped with multiple cameras, which can acquire images of the collected layered sediment. The three-dimensional terrain scanning device 403 is located at the bow of the working float 102. It uses a sonar or multispectral optical system to scan and image the seabed terrain and obstacles in real time and transmit the data to the control module 3 in real time.

[0032] The cable tray module includes a winch 601, a support frame 602, and a cable tray 603; The winch 601 is located on the deck of the working float 102. It receives instructions from the control module 3 to wind up and wind up the wire rope. The wire rope passes around the support frame 602 and is connected to the bridge frame 603. The bridge 603 adopts a truss structure and is arranged in the working float 102. It can rotate around the trunnion and is equipped with an angle sensor. The depth of the dredging tool 8 is determined by the angle change of the angle sensor.

[0033] The dredging equipment 8 is installed at the front end of the cable tray 603. Different types of cutter heads or suction heads can be replaced as needed to adapt to the complex environment of the water source. The equipment is equipped with a protective cover to reduce the spread of pollutants into the water body due to disturbance when excavating the polluted mud layer, thereby reducing secondary pollution.

[0034] The sludge discharge pipe 7 and the cable are arranged inside the cable tray 603. The sludge discharge pipe 7 transports the sludge sucked up by the dredging equipment 8 from the bow to the shore treatment facility. The sludge discharge pipe 7 adopts a double-layer pipe structure to prevent sludge leakage.

[0035] The specific application process of the dredging and desilting vessel disclosed in this invention in steps S2-S3 is as follows: S2: Dredging operations are carried out using dredging and silt removal vessels; S201: Control module 3 receives dredging point The coordinate system drives the positioning pile 501 and the trolley 502 to fix the hull at the target location; the detection module lowers the bottom sediment stratification sampler 402 to collect data at the current dredging point. The sediment columnar sample was collected, and an image of the sediment columnar sample was obtained using imaging device 401. The image was then transmitted to the control module 3 for image recognition, and the first critical depth of the current dredging point was determined using the silt layer depth confirmation method. ; S202: The control module 3 matches the relationship between the critical depth of the silt layer and the first critical depth obtained in step S105 to determine the critical depth of the silt layer at the current dredging point, i.e. ; S203: The detection module activates the 3D terrain scanning device 403 to scan the terrain before dredging and obtain detailed mud surface depth. ; S204: Control module 3 calculates the difference between the critical depth of the silt layer and the depth of the mud surface at the current dredging point, and determines the target dredging depth, i.e. Based on the target dredging surface and the three-dimensional spatial distribution map of bottom sediment drawn in step S106, a dredging design model for the area to be dredged is automatically established. S205: The control module 3 sends a lowering command to the winch 601, adjusts the pitch angle of the bridge 603 to position the dredging tool 8 on the mud surface, and starts the dredging tool 8 and the mud discharge pipe 7 to dredge and suck up the bottom mud of the water source. S206: The sensors installed on the bridge 603 transmit the actual working depth data in real time to the control module 3, which compares and analyzes it with the data in the dredging design model in real time, and adjusts the winch 601 and trolley 502 in a timely and accurate manner to ensure that the dredging operation is always carried out precisely within the critical depth of the silt layer.

[0036] S3: Post-dredging adjustment work; S301: The detection module activates the 3D terrain scanning device 403 to scan the post-dredging terrain and obtain detailed mud surface depth. The control module 3 automatically compares the dredging area with the dredging design model established in step S204, calculates the elevation difference between the actual terrain after dredging and the design dredging target surface, the dredging effect judgment threshold, i.e. the allowable positive and negative elevation deviation value, such as ±0.1 meters, automatically identifies and highlights all areas where the actual elevation is higher than the design target surface (i.e., under-dredging) or significantly lower than the design target surface (i.e., over-dredging), as well as areas that have not been dredged at all, and automatically calculates the area of ​​under-dredging areas, the average under-dredging depth, and the volume of earthwork. S302: Control module 3 plans supplementary dredging paths based on the spatial distribution characteristics of under-dredged areas, prioritizing key or contiguous areas, and calculates the difference between the post-dredging mud surface depth and the pre-dredging mud surface depth to obtain the supplementary dredging depth. ; S303: Precise and small-scale supplementary dredging is carried out in areas that do not meet the standards. The control module 3 drives the dual-pile trolley system to move to the target location, and the dredging equipment 8 performs small-scale operations. S304: Iterative acceptance. After completing the supplementary dredging, repeat steps S301-S302. If there are still areas that do not meet the standards, the secondary supplementary dredging process will be automatically started until the entire dredged area fully meets the standards.

[0037] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A method for controlling dredging depth, characterized in that, Includes the following steps: S1: Surveying and Planning; S101: Set sampling points in the work area; S102: Conduct sediment surveys at the sampling points, collect sediment samples, and record the sampling locations; S103: Conduct experimental testing and analysis on the collected samples, and obtain the first critical depth of the silt layer and at least one second critical depth according to the silt layer depth confirmation method. S104: Based on the evaluation results of step S103, if there is a second critical depth, then the second critical depth is the final critical depth of the silt layer; if there are multiple second critical depths, then the average value of the multiple second critical depths is the final critical depth of the silt layer. S105: Within the area to be dredged, calculate the ratio of the final critical depth to the first critical depth to obtain the relationship between the critical depth of the silt layer and the first critical depth. S106: Based on the location and water depth data collected during the survey, and combined with the critical depth of the silt layer determined in step S105, draw a map of the bottom sediment distribution in the area to be dredged. S2: Dredging operation implemented; S201: Determine the coordinates of the dredging point and mark the first critical depth of the current dredging point according to the silt layer depth confirmation method; S202: Based on the results obtained in step S105, the critical depth of the silt layer at the current dredging point is determined by multiplying the relationship between the critical depth of the silt layer and the first critical depth with the first critical depth of the current dredging point. S203: Obtain mud depth; S204: Determine the target dredging depth by calculating the difference between the critical depth of the silt layer and the depth of the mud surface at the current dredging point, execute the target dredging depth, and establish a dredging model for the area to be dredged based on the target dredging surface and the bottom mud distribution map drawn in step S106. S205: Dredging operations are carried out on the bottom layer of the water source area based on the dredging model of the area to be dredged established in step S204. In step S2, there is also It includes the following steps: S206: Real-time feedback of actual operating depth data, comparison and analysis with the dredging model, adjustment of dredging progress, and ensuring that dredging operations proceed within the critical depth of the silt layer; It also includes step S3: post-dredging adjustment work, which includes the following sub-steps: S301: Obtain the mud surface depth, compare the dredging area with the dredging model of the area to be dredged established in step S204, and calculate the elevation difference between the actual terrain after dredging and the designed dredging target surface. Based on the dredging effect judgment threshold, identify and mark all areas whose actual elevation is higher or lower than the target surface, as well as areas that have not been dredged at all, and count the area of ​​under-dredging areas, the average under-dredging depth, and the volume of earthwork. S302: Based on the spatial distribution characteristics of under-dredging areas, supplementary dredging path planning is carried out, with priority given to key areas or contiguous areas. The difference between the mud surface depth after dredging and the mud surface depth before dredging is calculated to obtain the supplementary dredging depth. S303: Supplementary dredging of areas that do not meet the standards.

2. The dredging depth control method according to claim 1, characterized in that, The first critical depth was determined by visual layering.

3. The dredging depth control method according to claim 1, characterized in that, In step S105, the relationship between the critical depth of the silt layer and the first critical depth at locations not at the sampling position is determined using the center interpolation method.

4. The dredging depth control method according to claim 1, characterized in that, Step S3 further includes the following sub-steps: S304: Iterative acceptance. After completing the supplementary dredging, repeat steps S301-S302. If there are still areas that do not meet the standards, start the second supplementary dredging process until the entire dredged area fully meets the standards.

5. A dredging and desilting vessel, characterized in that, Applying any one of the dredging depth control methods as described in claims 1-4, the dredging vessel is used in steps S2-S3, including a hull module for providing overall load-bearing capacity and buoyancy, a control module (3) for operating the dredging vessel, a detection module for detecting the environment at the dredging point during operation, a positioning module for positioning the hull, a dredging machine (8) for cleaning river silt, a discharge pipe (7) for transporting silt to shore for treatment, and a bridge module that carries the discharge pipe (7) and the dredging machine (8).

6. The dredging and cleaning vessel according to claim 5, characterized in that, The hull module includes a positioning float (101) and an operating float (102) for providing overall load-bearing capacity and surface buoyancy.

7. The dredging and cleaning vessel according to claim 6, characterized in that, It also includes a connecting transmission module (2), the positioning float (101) and the working float (102) are connected through the connecting transmission module (2), the connecting transmission module (2) is equipped with a swing cylinder inside, which is used to drive the working float (102) to swing relative to the positioning float (101).

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