Sediment sampling device and determination method

Abstract

The invention discloses a sediment sampling device and a determination method, and the sediment sampling device comprises a filter screen which is provided with a plurality of filter holes penetrating through the upper surface and the lower surface of the filter screen; the supporting mechanism comprises a fixing assembly connected with the peripheral part of the filter screen and an anchoring rod connected with the fixing assembly, the height of the upper surface of the fixing assembly is not higher than that of the upper surface of the filter screen, and the anchoring rod is located below the fixing assembly. When the sediment sampling device disclosed by the invention is used for sampling sediments in a sampling area, the problem that the sampling device affects the movement of the sediments in the vertical direction and the horizontal direction before the sediments are not deposited can be solved, so that the sediments deposited on the filter screen can better reflect the real deposition condition; and the authenticity and effectiveness of sampled data are ensured.

Description

Technical Field

[0001] The invention relates to the technical field of sediment measurement, and in particular to a sediment sampling device and a measurement method. Background Art

[0002] Coastal wetlands are an important part of the marine ecosystem, and marine surveys such as the determination of sediment deposition rates are crucial for assessing wetland health, predicting evolution trends, and formulating protection strategies. However, existing technologies have the disadvantages of long sampling cycles, high costs, and especially interference with the natural movement of sediment. In intertidal areas where tidal phenomena are obvious, the vertical sedimentation and horizontal diffusion of sediment strongly affect the scouring and silting process. The existing equipment itself is prone to hindering the horizontal and vertical transport of sediment, resulting in the collected samples being unable to reflect the original state of the sediment, which in turn interferes with subsequent sediment property analysis work such as sedimentation rate calculations. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a sediment sampling device and a measurement method, which can make the sample obtained reflect the sedimentation situation more realistically.

[0004] According to an embodiment of the first aspect of the present invention, the sediment sampling device includes: a filter screen having a plurality of filter holes extending through the upper and lower surfaces thereof; a supporting mechanism including a fixing assembly connected to the outer peripheral portion of the filter screen, and an anchor rod connected to the fixing assembly, wherein the height of the upper surface of the fixing assembly is not higher than the height of the upper surface of the filter screen, and the anchor rod is located below the fixing assembly.

[0005] The sediment sampling device according to the embodiment of the present invention has at least the following beneficial effects: When using the sediment sampling device of the present invention to sample sediment in a sampling area, the problem that the sampling device itself affects the movement of sediment in the vertical and horizontal directions before it is deposited can be improved, so that the sediment deposited on the filter screen can better reflect the actual deposition situation, thereby ensuring the authenticity and validity of the sampling data.

[0006] According to some embodiments of the present invention, the peripheral portion of the filter screen is bent downward, and the fixing assembly includes an inner ring abutting against the inner side wall of the peripheral portion of the filter screen, and an outer hoop abutting against the outer side wall of the peripheral portion of the filter screen; Wherein, the height of the upper surface of the outer hoop is not higher than the height of the upper surface of the filter screen.

[0007] According to some embodiments of the present invention, the outer hoop includes an outer hoop body abutting against an outer side wall of an outer peripheral portion of the filter screen, and a fastener locking the outer hoop body.

[0008] According to some embodiments of the present invention, the height of the anchor rod satisfies: ; in, is the height of the anchor rod; is the safety factor; is the drag coefficient; is the density of seawater in the sampling area; is the average velocity of seawater in the sampling area; is the diameter of the filter; is the height of the outer hoop; is the number of anchor rods; The single anchor rod is subjected to the anchoring force of the soil in the sampling area.

[0009] According to some embodiments of the present invention, there are multiple types of filter screens, and different types of filter screens can be selectively connected to the fixing assembly.

[0010] According to some embodiments of the present invention, there are multiple anchor rods, and the multiple anchor rods are spaced apart and arranged in parallel.

[0011] According to some embodiments of the present invention, the sediment sampling device further comprises a handle disposed on the supporting mechanism.

[0012] The sediment measuring method according to the second aspect of the present invention is characterized in that the sediment sampling device of the above embodiment is applied; Wherein, the sediment sampling device satisfies: if sedimentation rate analysis, particle size analysis or porosity analysis of sediment is performed, the diameter D of the filter screen is set within the range of 3 cm to 5 cm; if carbon reserve analysis is performed, the diameter D of the filter screen is set within the range of 5 cm to 10 cm; The sediment determination method comprises: The sediment sampling device is buried in the sampling area, and the filter screen is exposed in the soil; removing the sediment sampling device after the sampling period ends; The thickness of the sediment deposited on the filter screen is measured and the deposition rate of the sediment is calculated.

[0013] The sediment measurement method according to the embodiment of the present invention has at least the following beneficial effects: When using the sediment sampling device of the present invention to sample sediment in a sampling area, the problem that the sampling device itself affects the movement of sediment in the vertical and horizontal directions before it is deposited can be improved, so that the sediment deposited on the filter screen can better reflect the actual deposition situation, thereby ensuring the authenticity and validity of the sampling data.

[0014] According to some embodiments of the present invention, the density of seawater in the sampling area The measurement method is as follows: Take multiple samples of seawater from the sampling area to measure the density and take the average value; Average flow velocity of seawater in the sampling area The measurement method is as follows: The changes of seawater flow velocity over time at high tide and low tide in the sampling area were measured respectively, and the average flow velocity of seawater in the sampling area was calculated according to the following formula: ; in, and They are the functions of the seawater velocity measured at high tide and low tide as a function of time; and are the weight factors of the rising and falling tide velocities, respectively; and They are the time when the measurement starts and ends at high tide, respectively; and They are the start and end times of low tide measurement, respectively.

[0015] According to some embodiments of the present invention, a single anchor rod is subjected to an anchoring force of soil in the sampling area. The measurement method is as follows: The diameter of the production d , length is t The test anchor rod is inserted vertically into the soil at a uniform speed in the sampling area until it just enters the soil as a whole. The pressure on the bottom of the rod during the insertion process is recorded. The experiment is repeated many times, and the average pressure obtained is .

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 A schematic structural diagram of a sediment sampling device according to an embodiment of the present invention; Figure 2 A partial structural schematic diagram of a sediment sampling device according to an embodiment of the present invention; Figure 3 for Figure 2 An exploded view of the figure shown; Figure 4 for Figure 2 a cross-sectional view of the figure shown; Figure 5 for Figure 4 Enlarged view of point A in the middle.

[0018] Figure Number: 10. Sediment sampling device; 100, filter screen; 110, lower turning part; 200, support mechanism; 210, fixing assembly; 211, inner ring; 212, outer hoop; 2121, outer hoop body; 2122, fastener; 220, anchor rod; 300. Handle. DETAILED DESCRIPTION

[0019] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0020] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] like Figure 1 As shown, a sediment sampling device 10 provided in an embodiment of the present invention is used to be arranged in a sampling area to collect sediment (silt). The sampling area may refer to a coastal wetland.

[0023] like Figure 1 As shown, the sediment sampling device 10 includes a filter screen 100 and a support mechanism 200. The support mechanism 200 is used to support the filter screen 100. The support mechanism 200 is used to be inserted into the soil in the sampling area. The filter screen 100 can allow seawater flowing in a vertical direction to pass through and carry sediment.

[0024] The filter screen 100 is arranged horizontally, and the filter holes on the filter screen 100 penetrate the upper and lower surfaces of the filter screen 100. The filter screen 100 can allow seawater flowing in the vertical direction to pass freely. Before the sediment reaches the filter screen 100, the filter screen 100 will not change the basic state of the sediment moving in the vertical direction.

[0025] The support mechanism 200 includes a fixing assembly 210 connected to the peripheral portion of the filter 100 and an anchor rod 220 connected to the fixing assembly 210, wherein the height of the upper surface of the fixing assembly 210 is not higher than the height of the upper surface of the filter 100, and the anchor rod 220 is located below the fixing assembly 210.

[0026] It is understandable that the fixing assembly 210 is connected to the outer peripheral portion of the filter screen 100 to fix the filter screen 100, and the anchor rod 220 is used to be inserted into the soil in the sampling area to fix the entire sampling device. The highest position of the entire support mechanism 200 does not exceed the upper surface of the filter screen 100, so the problem of the support mechanism 200 affecting the horizontal movement of sediment can be improved.

[0027] In summary, when using the sediment sampling device 10 of the present invention to sample sediment in the sampling area, the problem that the sampling device itself affects the vertical and horizontal movement of sediment before deposition can be improved, so that the sediment deposited on the filter 100 can better reflect the actual deposition situation, thereby ensuring the authenticity and validity of the sampling data.

[0028] like Figures 2 to 5 As shown, in some embodiments, the peripheral portion of the filter 100 is bent downward, and the fixing assembly 210 includes an inner ring 211 that abuts against the inner wall of the peripheral portion of the filter 100, and an outer hoop 212 that abuts against the outer wall of the peripheral portion of the filter 100.

[0029] Specifically, the filter screen 100 is circular in shape as a whole, and the outer peripheral portion of the filter screen 100 is turned down to form a downwardly turned portion 110 , and the inner ring 211 and the outer hoop 212 together clamp and fix the downwardly turned portion 110 of the filter screen 100 .

[0030] The height of the upper surface of the outer hoop 212 is not higher than the height of the upper surface of the filter screen 100 . In this way, the outer hoop 212 can be prevented from affecting the sediment deposition on the filter screen 100 .

[0031] Furthermore, the outer hoop 212 includes an outer hoop body 2121 abutting against the outer side wall of the outer peripheral portion of the filter screen 100 , and a fastener 2122 locking the outer hoop body 2121 .

[0032] It is understandable that the outer hoop body 2121 can change its tightness under the action of the fastener 2122 , and after being locked by the fastener 2122 , the outer hoop body 2121 can cooperate with the inner ring 211 to clamp the filter screen 100 .

[0033] Specifically, the outer hoop body 2121 includes two oppositely disposed ends, and the fastener 2122 includes a bolt and a nut. With the cooperation of the bolt and the nut, the distance between the two ends of the outer hoop body 2121 can be tightened, so that the outer hoop body 2121 clamps the filter screen 100.

[0034] like Figure 1 As shown, the anchor rod 220 is connected below the outer hoop 212, and there are multiple anchor rods 220, which are arranged in parallel and spaced apart from each other. In this way, the stability of the sampling device after being inserted into the soil can be improved.

[0035] In some embodiments, the height of the anchor rod 220 satisfies: ;in, is the height of the anchor rod 220, in meters (m); is the safety factor, dimensionless; is the drag coefficient, dimensionless; The density of seawater in the sampling area is expressed in kilograms per cubic meter (Kg*m -3 ); is the average velocity of seawater in the sampling area, in meters per second (m*s -1 ); is the diameter of the filter 100, in meters (m); is the height of the outer hoop 212, in meters (m); is the number of anchor rods 220; It is the anchoring force of the single anchor rod 220 on the soil in the sampling area, and its unit is Newton (N).

[0036] It should be noted that the safety factor The value range is 1.1-5, which can be determined according to the local wave impact strength and weather conditions. The stronger the wave impact strength or the worse the weather, The larger the value of It is advisable to take 1.17, the height of the outer hoop 212 Should be less than or equal to 1cm, anchor rod 220 quantity It is better to take 3. If the wave impact in the sampling area is strong, the number of anchor rods 220 can be appropriately increased. In addition, the diameter of the anchor rod 220d Should not be larger than 10mm.

[0037] The density of seawater in the sampling area is The measurement method is as follows: Take several samples of seawater from the sampling area to measure the density and take the average value.

[0038] Average flow velocity of seawater in the sampling area The measurement method is as follows: The changes of seawater flow velocity over time at high tide and low tide in the sampling area were measured respectively, and the average flow velocity of seawater in the sampling area was calculated according to the following formula: ; in, and They are the functions of the seawater velocity measured at high tide and low tide as a function of time; and are the weight factors of the rising and falling tide velocities, respectively; and They are the time when the measurement starts and ends at high tide, respectively; , They are the start and end times of low tide measurement, respectively.

[0039] In addition, the single anchor rod 220 is subjected to the anchoring force of the soil in the sampling area. The measurement method is as follows: The diameter of the production d , length is t The test anchor rod is inserted vertically into the soil at a uniform speed in the sampling area until it just enters the soil as a whole. The pressure on the bottom of the rod during the insertion process is recorded. The experiment is repeated many times, and the average pressure obtained is .

[0040] It can be understood that by setting the size of the anchor rod 220 under the guidance of the safety factor, push-drag coefficient and the constraints of real parameters such as the seawater density and flow rate in the sampling area, it can be ensured that the device can effectively resist the impact of waves and cope with severe weather during the sampling period, ensure that the device is stably fixed to the sampling point, and ensure the authenticity and validity of the sampling data.

[0041] It should be noted that there are many types of filter screens 100, and different types of filter screens 100 can be selectively connected to the fixing assembly 210. Among them, different types of filter screens 100 have different diameters, filter hole diameters and / or filter hole densities.

[0042] The sampling device of the present application is suitable for sedimentation rate measurement, carbon storage measurement, particle size analysis and porosity measurement of sediment in coastal wetland scenes. The diameter of the filter 100 is set according to the use requirements. If sedimentation rate analysis, particle size analysis or porosity analysis is performed, the diameter of the filter 100 Set within the range of 3cm~5cm; if carbon storage analysis is performed, the diameter of the filter 100 Set it within the range of 5cm~10cm. In addition, if the main component of the sediment is clay (particle size <0.002mm), the pore size of the filter Φ Set it to less than or equal to 0.001mm; if the main component of the sediment is soil particles (particle size between 0.002mm-0.02mm), the pore size of the filter Φ Set to less than or equal to 0.02mm; if the sediment is mainly composed of sand particles (particle size between 0.02mm-2mm), the pore size of the filter Φ Set to less than or equal to 2mm; if the sediment is mainly composed of gravel (particle size> 2mm), the pore size of the filter Φ The size setting should ensure that gravel of all sizes cannot pass through the filter holes.

[0043] It is understandable that the diameter of the filter 100 is designed according to the demand for samples, and is accurately suitable for sedimentation rate determination, carbon storage determination, particle size analysis and porosity determination, to prevent insufficient or excessive sample collection. By setting the filter 100 with different pore sizes and pore densities for sediments of different particle sizes, it can be ensured that seawater can pass freely in the vertical direction, and the target sediment is limited on the filter 100, while also solving the problems of blockage and obstruction.

[0044] In some embodiments, the sediment sampling device 10 further includes a handle 300 disposed on the supporting mechanism 200 . When the sampling device completes sampling, the sampling device can be taken out with the help of the handle 300 .

[0045] It should be noted that the handle 300 is a rod connected to the outer hoop 212 and extending upward. The projection of the handle 300 on the horizontal plane does not overlap with the projection of the filter 100 on the horizontal plane. The handle 300 will not affect the sediment that moves in the vertical direction and is about to be deposited on the filter 100. In addition, when plugging in the sampling device, the handle 300 should not block the front of the filter 100 and affect the sediment that moves in the horizontal direction.

[0046] In addition, the filter screen 100, the outer hoop 212, the inner ring 211, the anchor rod 220 and the handle 300 are made of materials resistant to seawater corrosion and impact, such as stainless steel, titanium alloy or copper alloy, preferably 10CrMoAI material.

[0047] The present application also provides a sediment measurement method, which uses the sediment sampling device 10 of the above embodiment. The sediment measurement method includes: S100, burying the sediment sampling device 10 in the sampling area, and making the filter screen 100 exposed in the soil; S200, taking out the sediment sampling device 10 after the sampling period ends; S300 , measuring the thickness of the sediment deposited on the filter screen 100 and calculating the deposition rate of the sediment.

[0048] Of course, after step S300, the sediment sample can be stored and transported to a laboratory for further carbon storage analysis, particle size analysis, and porosity analysis.

[0049] The above-mentioned sediment determination method is introduced with two specific embodiments as follows: Embodiment 1 Sediment was collected from the first sampling area as follows: (1) Set the diameter of the filter 100 is 4.2 cm; the height of the inner ring 211 and the outer hoop 212 is 1 cm; the diameter of the anchor rod 220 d The length is 1cm and the quantity is 3.

[0050] (2) A test anchor rod 220 is made according to the dimensions specified above, and the anchor rod 220 is inserted vertically into the soil in the sampling area at a uniform speed. The force pushing the anchor rod 220 vertically downward during this process is recorded. The anchoring force T of the soil in the sampling area on a single anchor rod 220 is 1821N.

[0051] (3) Collect three samples of seawater from the sampling area and measure the average density =1023kg / m 3 .

[0052] (4) Function of the change of seawater velocity on the surface of the sampling area during 1 hour of high / low tide / , it has been observed that the disturbance of seawater to the device is slightly stronger when the tide is high than when the tide is low in the sampling area, so the weight factor of the tide is =0.6, ebb weight factor =0.4, according to the formula, the average flow rate of seawater for: 1.52m / s.

[0053] (5) The three sampling devices designed and installed were buried according to the designed sampling points and time, and the sampling period was set to 90 days. The wind and waves in the sampling area were large, and the safety factor was =2.1, push-pull coefficient =1.17, according to the formula, the height of the anchor rod 220 for: .

[0054] (6) The main component of the soil in the sampling area is soil particles, and the pore size of the filter is 100 Φ =0.01mm, the hole density is medium density.

[0055] (7) A sampling device is made according to the obtained value, and the sampling period is set to 90 days. The sampling device is buried in the sampling area when the tide is low. When the tide is low at the end of the sampling period, the sampling device and the sediment on the device are pulled out. The sediment above the filter 100 is the sample for this sampling. The average thickness of the sample is measured with a vernier caliper and is 3.791 mm. The sedimentation rate is calculated to be 1.5164 cm / s based on the sampling period. The sample is then packaged and transported to the laboratory for other analysis.

[0056] Embodiment 2 Sediment was collected from the second sampling area as follows: (1) Set the diameter of the filter 100 =5.0cm; the height of the inner ring 211 and the outer hoop 212 = 1cm; the diameter of the anchor rod 220 d =1cm, quantity is 3.

[0057] (2) Make a test anchor rod 220 according to the dimensions specified above, and insert the anchor rod 220 vertically into the soil in the sampling area at a uniform speed. Record the force that pushes the anchor rod 220 vertically downward during this process. This is the anchoring force T = 2142 N exerted on the single anchor rod 220 by the soil in the sampling area.

[0058] (3) Collect three samples of seawater from the sampling area and measure the average density =1017kg / m 3 .

[0059] (4) Function of the change of seawater velocity on the surface of the sampling area during 1 hour of high / low tide / , it has been observed that the disturbance of seawater to the device is stronger during high tide than during low tide in the sampling area, so the weight factor of high tide is =0.7, low tide weight factor =0.3, according to the formula, the average flow rate of seawater for: 0.92m / s.

[0060] (5) The three sampling devices designed and installed were buried according to the designed sampling points and time, and the sampling period was set to 90 days. The wind and waves in the sampling area were small, and the safety factor was =1.7, push-pull coefficient =1.17, according to the formula, the height of the anchor rod 220 for: .

[0061] (6) The main component of the soil in the sampling area is soil particles, and the pore size of the filter is 100 Φ =0.01mm, the hole density is medium density.

[0062] (7) A sampling device is made according to the obtained value, and the sampling period is set to 90 days. The sampling device is buried in the sampling area when the tide is low. When the tide is low at the end of the sampling period, the sampling device and the soil on the device are pulled out with the recovery handle 300. The soil above the filter 100 is the sample for this sampling. The average thickness of the sample is measured with a vernier caliper and is 4.12 mm. The sedimentation rate is calculated to be 1.64 cm / s based on the sampling period. The sample is then packaged and transported to the laboratory for other analysis.

[0063] After implementation, the average sedimentation rate was measured in two places, and the results were close to the historical record data, with an average relative error of , and a high accuracy. The sediment samples collected by the method and device of the present invention can effectively reflect the original state of the sediment and provide credible evidence for marine surveys.

[0064] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0065] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A sediment sampling device, characterized in that: include: A filter screen having a plurality of filter holes extending through the upper and lower surfaces thereof; A supporting mechanism, the supporting mechanism comprising a fixing assembly connected to the peripheral portion of the filter screen, and an anchor rod connected to the fixing assembly, wherein the height of the upper surface of the fixing assembly is not higher than the height of the upper surface of the filter screen, and the anchor rod is located below the fixing assembly.

2. The sediment sampling device according to claim 1, characterized in that: The peripheral portion of the filter screen is bent downward, and the fixing assembly includes an inner ring abutting against the inner side wall of the peripheral portion of the filter screen, and an outer hoop abutting against the outer side wall of the peripheral portion of the filter screen; Wherein, the height of the upper surface of the outer hoop is not higher than the height of the upper surface of the filter screen.

3. The sediment sampling device according to claim 2, characterized in that: The outer hoop comprises an outer hoop body abutting against an outer side wall of an outer peripheral portion of the filter screen, and a fastener locking the outer hoop body.

4. The sediment sampling device according to claim 2, characterized in that: The height of the anchor rod satisfies: ; in, is the height of the anchor rod; is the safety factor; is the drag coefficient; is the density of seawater in the sampling area; is the average velocity of seawater in the sampling area; is the diameter of the filter; is the height of the outer hoop; is the number of anchor rods; The anchoring force of a single anchor rod is exerted by the soil in the sampling area.

5. The sediment sampling device according to claim 1, characterized in that: There are many types of filter screens, and different types of filter screens can be selectively connected to the fixing assembly.

6. The sediment sampling device according to claim 1, characterized in that: There are multiple anchor rods, and the multiple anchor rods are arranged in parallel and at intervals.

7. The sediment sampling device according to claim 1, characterized in that: Also included is a handle disposed on the support mechanism.

8. A sediment measurement method, characterized in that: The sediment sampling device according to claim 4 is used; Wherein, the sediment sampling device satisfies: if sedimentation rate analysis, particle size analysis or porosity analysis of sediment is performed, the diameter D of the filter screen is set within the range of 3 cm to 5 cm; if carbon reserve analysis is performed, the diameter D of the filter screen is set within the range of 5 cm to 10 cm; The sediment determination method comprises: The sediment sampling device is buried in the sampling area, and the filter screen is exposed in the soil; removing the sediment sampling device after the sampling period ends; The thickness of the sediment deposited on the filter screen is measured and the deposition rate of the sediment is calculated.

9. The sediment measurement method according to claim 8, characterized in that: Density of seawater in the sampling area The measurement method is as follows: Take multiple samples of seawater from the sampling area to measure the density and take the average value; Average flow velocity of seawater in the sampling area The measurement method is as follows: The changes of seawater flow velocity over time at high tide and low tide in the sampling area were measured respectively, and the average flow velocity of seawater in the sampling area was calculated according to the following formula: ； in, and They are the functions of the seawater velocity measured at high tide and low tide as a function of time; and are the weight factors of the rising and falling tide velocities, respectively; and They are the time when the measurement starts and ends at high tide, respectively; and They are the start and end times of low tide measurement, respectively.

10. The sediment measurement method according to claim 8, characterized in that: A single anchor rod is subjected to the anchoring force of the soil in the sampling area The measurement method is as follows: The diameter of the production d , length is t The test anchor rod is inserted vertically into the soil at a uniform speed in the sampling area until it just enters the soil as a whole. The pressure on the bottom of the rod during the insertion process is recorded. The experiment is repeated many times, and the average pressure obtained is .

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