Seabed sedimentary environment dynamic change characteristic inversion method based on three-phase potential

Abstract

The invention provides a submarine sedimentary environment dynamic change characteristic inversion method based on three-phase potential. The method comprises the steps of in-situ data processing, electrical signal calibration, mathematical model establishment and dynamic change analysis. A seabed electrode array is arranged, signals of natural potential, resistivity, oxidation-reduction potential and the like are collected in real time, and seabed sedimentary environment characteristics such as seabed interface position, suspended particle concentration, sediment density, porosity, water content and the like are deduced by adopting an inversion algorithm. The method is combined with multi-frequency signal analysis, and can monitor seabed sedimentary environment changes in real time, identify sediment movement and the like. Compared with the prior art such as CN118153411B and CN110411923B, more abundant inversion contents are covered, the monitoring precision and efficiency are improved through the complementarity of potential signals, and higher adaptability and reliability are achieved. The method has low equipment and maintenance cost, is suitable for large-range and long-term monitoring, and can provide an innovative solution in the fields of deep sea monitoring, environment evaluation, resource exploration and the like.

Description

Technical Field

[0001] The present application relates to the fields of seabed exploration technology and marine engineering geology technology, and more specifically, to a method for inverting the dynamic change characteristics of a seabed sediment environment based on three-phase potential. Background Art

[0002] The development of seabed mineral resources and the discharge of plumes have led to dynamic changes in the seabed sedimentary environment. The seabed sedimentary environment is a transition zone between the water body and the seabed sediments. The processes of marine sediments and seawater flow in this layer have an important impact on the marine ecosystem, resource distribution and engineering structure stability. However, traditional monitoring methods (such as acoustic, optical and seismic detection) are often limited by signal attenuation and low resolution in turbid environments, especially in complex sedimentary layer structures. It is difficult to obtain accurate data. In contrast, electrical detection methods (such as conductivity, resistivity and natural electric field detection) can directly reflect the changes in electrical parameters of seabed sediments, and have strong penetration ability, and can obtain stable measurement results in high turbidity and deep environments.

[0003] At present, with the integration and development of ocean dynamics, sedimentology and electromagnetic detection technology, the improvement of inversion algorithms (such as the introduction of machine learning and Kalman filtering) has also made the application of electrical inversion in boundary layer monitoring more real-time and accurate. Therefore, the inversion technology of dynamic change characteristics of seabed sedimentary environment based on electrical methods is becoming an important direction in the field of seabed environmental monitoring, promoting the in-depth research of seabed sedimentary processes, material transportation and engineering geological conditions. However, the current seabed sedimentary environment inversion method for electrical signals is subject to the uncertainty of multiple media. The single natural potential signal processing cannot meet the needs of the current inversion method, and cannot uniformly analyze the changes in the seabed interface caused by mining disturbance. There is an urgent need for a method that can be used to invert the seabed sedimentary environment, including the concentration of suspended particles, the seabed interface and the properties of sediments. Summary of the invention

[0004] In order to make up for the deficiencies of the prior art, the present application provides a method for inverting the dynamic change characteristics of the seabed sediment environment based on three-phase potential.

[0005] The method for inverting the dynamic change characteristics of the seabed sediment environment based on three-phase potential provided in this application specifically includes:

[0006] Three-phase potential data collection preprocessing, three-phase potential and suspended particle concentration data processing, interface processing, three-phase potential and sediment properties processing;

[0007] Determination of seabed sediment environment data;

[0008] Finally, it is necessary to realize the dynamic description of the seabed sedimentary environment characteristics based on the three-phase potential, and then implement real-time dynamic monitoring.

[0009] Optionally, three-phase potential data acquisition preprocessing mainly includes data acquisition and processing, based on the natural potential potential difference, resistivity, oxidation in-situ potential, sequential inversion of seabed sediments, seabed interface and suspended particle concentrations, and then processing them over time;

[0010] Data preprocessing: different value ranges are used for data features, so the input data needs to be preprocessed, data with a large value range is processed, each feature is marked for further standard processing, data with large errors are distinguished, and data with good quality are retained;

[0011] The data set and measured data are analyzed and fitted, and further preprocessed with the help of neural network learning, mainly processing the three-phase potential to make it consistent with the correspondence with in-situ monitoring.

[0012] Sedimentary environment data set: First, establish an in-situ monitoring database set, including obtaining deep-sea in-situ soil and water bodies, mainly including the concentration of suspended particulate matter in the water body, changes in the position of the seabed interface, and the basic physical properties of seabed sediments, including basic parameters of density, water content, and porosity.

[0013] Three-phase potential data calibration: Natural potential processing: According to the obtained electrode parameters, the natural potential is first analyzed, and the main electrode difference processing is performed from the first electrode ring to the nth electrode ring (n≥30) to obtain the electrode difference SPd belonging to each electrode ring compared to the reference electrode. Each potential difference value represents the potential characteristic value for the reference electrode.

[0014]

[0015] In the formula, SPd is the potential difference, X i is the actual measured value, Xc is the reference electrode value, and N is the n-fold magnification of the electrode data, that is, the original value is reduced by n times to obtain the true potential difference value; the true potential difference value can be obtained, making the monitoring difference in the in-situ process more obvious.

[0016] Seabed resistivity calibration: Obtain resistivity values ​​based on in-situ monitoring, divide the intervals into sections, and obtain the average apparent resistivity value within a certain distance.

[0017]

[0018] In the formula, the current I and voltage V, the electrode constant K, are usually provided by the electrode manufacturer or calibrated with a standard solution to obtain the ρ resistivity, and the ε reference error resistivity. Through this formula, the resistivity value can be corrected, especially relative to the initial resistivity value. Compared with the traditional resistivity value, this formula adds error analysis, making the data more able to invert the real situation.

[0019] Processing of seabed redox potential: Processing is performed according to the temperature at that time. Redox potential usually changes with temperature, so temperature compensation is performed:

[0020] ORP T =ORP T0 +α(TT 0 )

[0021] ORP T is the corrected oxidation-reduction potential; is the corrected oxidation-reduction potential; ORP T0 is the corrected redox potential; α is the temperature coefficient, which is usually a constant and depends on the specific measurement system. The oxidation potential calibration for the measured temperature is added, and the oxidation in situ potential treatment at the stable monitoring temperature on the seabed is determined.

[0022] Salinity has a relatively small effect on the redox potential, but in high-salinity waters, corrections are also required. Salinity corrections can be made by looking up the specific salinity-ORP relationship.

[0023] Optionally, three-phase potential and suspended particle concentration data processing: data calibration, first select the monitoring data of the target area, and perform numerical fitting based on the natural potential interpolation and suspended particle concentration. During deep-sea mining, the concentration of suspended particles in the plume changes significantly.

[0024] Natural potential treatment: Dynamic indoor data changes in the seabed sediment environment. The maximum concentration of suspended sediment in the estuary in still water is 30 mg / L. The maximum concentration of suspended sediment on the seabed during tides can reach 8.69 g / L. The maximum concentration near the bottom during a typhoon can reach 14.2 g / L. During storm surges, the concentration will increase 30 times. The test configuration has a suspended sediment solution concentration range of 0-20 g / L. The test range is 0-20 g / L, with an accuracy of 1 g / L. The correlation is established:

[0025] c=f(SP)S,t,DO,Z-1.82275e-8.75061

[0026] Where c is the suspended sediment concentration in g / L, SP is the natural potential in mV (for saturated calomel electrode), Z is the test water level in cm, S is the salinity, t is the temperature in °C, and DO is the dissolved oxygen in mg / L;

[0027] SPM=0.00315*RR%+0.5146

[0028] SPM represents the mass of suspended sediment on the seafloor, and RR measures the decrease in sediment resistivity, in %. Further analysis can be performed based on the decrease in resistivity, so that the baseline resistivity value can be obtained;

[0029] Then indoor test resistivity correction:

[0030] c=-4.30948ln(ρ-0.28402 / 0.05594)S,t

[0031] Where c is the suspended sediment concentration in g / L, ρ is the resistivity in Ω·m, S is the salinity, and t is the temperature in °C. The resistivity has a certain logarithmic relationship with the identification of suspended particle concentration.

[0032] The relationship between redox potential and suspended particulate matter concentration is analyzed using the suspended sediment mass of the South China Sea. The relationship analysis of sediment redox potential is as follows:

[0033] TOC=8.147TN+0.0192

[0034] ORP=-f(pH)a+b

[0035] pH = f(C TOC ,C TN )

[0036] C SPM =f(C DO , C OM , ORP)

[0037] Among them, C SPM Indicates the concentration of suspended particles and dissolved oxygen concentration C DO , organic matter concentration C OM , ORP stands for oxidation-reduction potential, TOC is the total organic carbon in the sediment, TN is the total organic nitrogen, and then the oxidation-reduction potential is correlated with the total organic carbon and total organic nitrogen in the sediment, a and b are the correlation coefficients, pH is the pH value of the solution, C TOC , C TN Compared with traditional indoor tests, this formula points out that the redox potential is mainly affected by sediments, and there is a negative proportional relationship between the redox potential and the solution pH. This results in a nonlinear relationship between the redox potential and the solution, and it can be analyzed based on specific indoor tests, especially calibrated based on the organic matter concentration.

[0038] Optionally, the three-phase potential and sediment property parameter data are processed to establish a mathematical relationship between sediment density, water content, porosity and natural potential. The density of the sediment is usually determined by the relative proportion of solid particles and pore water.

[0039] The natural potential can be expressed by the following formula:

[0040]

[0041] Among them, ρ s is the density of the solid particle, ρ w is the pore water density, It is the porosity. It is mainly calibrated according to the pore water content in the sediment:

[0042] The water content is

[0043]

[0044] The porosity is

[0045]

[0046] Among them, V w is the density of the solid particles, V p is the density of solid particles, V is the total volume, and compared with the pore water between sediments, it focuses more on the sediment pore density in situ in the seabed sediment environment than traditional calculation methods.

[0047] A mathematical model can be established with sediment density, water content, and porosity:

[0048]

[0049] Resistivity can be used to establish a mathematical model with sediment porosity and water content:

[0050]

[0051] R is the resistivity of the sediment (Ω·m), R W is the resistivity of water (Ω·m), is the porosity of the sediment, is the porosity saturated with water;

[0052]

[0053] R is the resistivity of the sediment (Ω·m), R 0 is the resistivity of dry sediment (Ω·m), ρ min is the density of sediment minerals (2.5-3.0 g / cm 3 ), ρ bulk is the overall density of the sediment (g / cm3 );

[0054] The following model can be used to comprehensively consider the combined effects of porosity, water content and density on resistivity. Compared with the data from previous indoor tests, the sediment properties and resistivity fitting calibration can be performed based on the clay properties of the seabed mining area:

[0055] R=9.651ω -0.5711

[0056]

[0057] ρ=0.31R 2 +1.96R+1.50

[0058]

[0059] The above formula calibrates the laws of resistivity, density, water content and porosity of seabed clay. Compared with existing patents, this formula more clearly points out the influencing factors and is more in line with the in-situ monitoring environment.

[0060] Redox potential, taking into account the combined effects of porosity, water content, and density on resistivity. ρ represents the compactness of the sediment and is usually related to the content of organic matter, minerals, and the degree of compaction of the sediment. Higher density may lead to lower porosity, which in turn affects the diffusion rate of oxygen and other oxidants. Therefore, higher sediment density often corresponds to lower redox potential, especially in anaerobic environments.

[0061] ORP=ab·ρ

[0062] a, b are empirical constants, and their specific values ​​depend on the environment and sediment type.

[0063] Water content, W, directly affects the availability and diffusion rate of oxygen in sediments. Higher water content generally indicates lower oxygen content, especially in anaerobic environments. Therefore, ORP tends to decrease with increasing water content. Common empirical formula:

[0064] ORP=cd·W

[0065] Indicates the ratio of void volume to total volume in the sediment. High porosity usually means faster oxygen diffusion and higher ORP. When the porosity is low, oxygen is difficult to enter, the ORP is low, and a reducing environment is easily formed.

[0066]

[0067] Finally, the comprehensive model:

[0068]

[0069] The redox potential is related to the density, water content and porosity of the sediment, but the specific mathematical relationship is greatly affected by the environment and experimental conditions. Compared with the previous indoor test calibration, this formula is more accurate, more suitable for indoor tests and in-situ monitoring, and covers a more comprehensive range.

[0070] Optionally, the seabed sediment environment data is determined by determining the dynamic change characteristics of the seabed sediment environment based on known monitoring data:

[0071] The first step is to determine the interface position. The three-phase potential (natural potential, resistivity, redox potential) data can be preprocessed. Based on the traditional change point method model, an electrode determination direction is added to determine the interface position. The natural potential data is set as F(t, j). Assuming that at a certain time t, for the data F(t, j), the three-phase potential vertical distribution data F(t, j) is divided into two parts based on the seabed interface position m;

[0072]

[0073] Among them, β i are independent random errors with expected value 0 and common variance σ 2 , 0<σ 2 <∞. Here m, α 1 , α 2 , σ 2 Unknown. Corresponding to the resistivity observation process near the seabed interface, α 1 is the natural potential difference of the sediment, α 2 is the natural potential difference of seawater, n is the total number of natural potential electrodes, m is the position where the natural potential difference value changes suddenly, and the mean change at position j is

[0074]

[0075] Among them, d+1≤j≤n-d+1, obviously, when j is in the seawater layer or sediment layer, due to the similar natural potential difference, G j is relatively small or even tends to 0; when j is in the transition zone, especially at the seabed, the natural potential difference between seawater and sediment will be G j Larger, so

[0076] |G m |=max|G j |=γ

[0077] At this time, m is the mutation point, that is, the position of the seabed interface, and γ is the test level. The critical value E can be taken according to experience. m|>E, the change point exists; if not, it is assumed that all the spontaneous potential electrodes are in seawater or sediment (depending on the expected value of the spontaneous potential difference).

[0078] Secondly, the concentration of suspended particulate matter is determined based on the in-situ monitoring data;

[0079] Natural potential: The three-phase potential interpolation is filtered from top to bottom. After filtering out 1 / 2 of the repeated values, the natural potential inversion model has a strong correlation with the suspended sediment concentration, and both conform to the Gauss Amp function model. Based on this, the empirical formula can be obtained:

[0080]

[0081] Where x represents the potential difference of the reference electrode in mV, y represents the concentration of suspended particles in g / L, and y 0 , A, x c , ω are the variables explained according to the range of potential difference, which can be assigned values ​​in intervals. According to the long-term monitoring data of natural potential, the concentration of suspended particles can be determined and identified respectively, and the entire suspended sediment concentration profile structure can be obtained.

[0082] Resistivity inversion:

[0083] c=-4.30948ln(ρ-0.28402 / 0.05594)S,t

[0084] Redox potential inversion:

[0085] TOC=8.147TN+0.0192

[0086] ORP=-f(pH)a+b

[0087] pH = f(C TOC ,C TN )

[0088] C SPM =f(C DO , C OM , ORP)

[0089] According to the sediment type, the most suitable suspended particulate matter concentration inversion method is selected after the in-situ test data and sediment property calibration;

[0090] Finally, the basic properties of sediments are analyzed, and a multivariate regression model is established based on the previously associated data:

[0091]

[0092] Among them, a is a constant term, b 1 、b2 、b 3 is the coefficient to be determined, and ε is the error term.

[0093] Modeling of natural potential difference:

[0094]

[0095] Inversion equations:

[0096]

[0097] Optimization algorithms (such as the least squares method or other optimization techniques) are used to solve these equations and solve for the unknown sediment density, water content, and porosity. Combining the above equations, the final model can be expressed as

[0098]

[0099] Resistivity inversion sediment relationship: The resistivity relationship between density, water content and porosity is indirect. It can be comprehensively expressed by combining various models and considering the interaction of these factors. Resistivity can be used to establish a mathematical model with sediment porosity and water content:

[0100]

[0101] The relationship between redox potential and sediment, redox potential and sediment density, water content, porosity have a certain correlation, but the specific mathematical relationship is greatly affected by the environment and experimental conditions. Compared with the previous indoor test calibration, this formula is more accurate, more suitable for indoor tests and in-situ monitoring, and covers a more comprehensive range.

[0102] ORP=ab·ρ

[0103] ORP=cd·W

[0104]

[0105] According to the three-phase potential value, we first analyze the advantages of the three-phase potential, determine the interface according to the natural potential and redox potential, determine the concentration of suspended particles according to the natural potential and resistivity, and invert the sediment properties according to the natural potential and resistivity. First, the seabed water-soil interface is determined, then the suspended particle concentration can be obtained, and finally the sediment properties can be obtained, and the main change effect of the dynamic change of the seabed interface from top to bottom can be obtained.

[0106] Optionally, the implementation method comprises:

[0107] (1) Through the electrode array arranged on the seabed, electrical signals such as natural potential, resistivity, and redox potential are collected in real time.

[0108] (2) The electrical signal is processed using the above inversion algorithm to deduce the seabed interface of the sedimentary environment, and the seabed interface is determined based on the combination of the three potentials.

[0109] (3) Based on the position of the seabed interface, the concentration of suspended particulate matter in the sedimentary environment above the seabed interface is calibrated jointly based on natural potential, resistivity, and redox potential.

[0110] (4) Below the seabed interface, the physical parameters of the seabed sedimentary environment, such as sediment density, porosity, water content, etc., are derived based on the three-phase potential.

[0111] (5) Combined with multi-frequency signal analysis methods such as noise reduction filtering of three-phase potential, the resolution and accuracy of inversion can be improved.

[0112] (6) Dynamic monitoring: Based on the changes in electrical signals, the dynamic changes of the seabed sediment environment are monitored in real time to identify environmental changes, sediment movement, etc.

[0113] Due to the adoption of the above technical solution, the present application has the following beneficial effects compared with the prior art:

[0114] 1. The present application can provide higher spatial and temporal resolution. Compared with the previous patent, the inversion method proposed in this patent covers the concentration of suspended particles on the seabed, changes in the seabed interface, and the physical and mechanical properties of seabed sediments. Its connotation is richer and more advanced, and more data information is inverted in one interpretation method. The potential not only adopts the natural potential, but also adds resistivity and redox potential. The three-phase potentials complement and correct each other, with higher monitoring accuracy, richer inversion content, higher efficiency, and monitoring and early warning. The comparative document CN118425241A is a method for electrically testing the concentration of suspended particles in seawater. The method is not only suitable for seawater, but also for sea surface and seabed sediments, which is more advanced than the existing technical methods.

[0115] 2. This application is a method for inverting the dynamic changes in the characteristics of the seabed sediment environment under the influence of deep-sea mining. It can simultaneously invert multiple physical parameters (such as density, porosity, and water content), provide more comprehensive seabed environmental information, and enhance the understanding of the seabed sediment environment. It is suitable for complex marine environments, including different sediment types and hydrological conditions, and has good adaptability and reliability. Compared with traditional monitoring methods (such as sonar, sampling, etc.), this method has lower equipment costs and maintenance costs, and is suitable for large-scale, long-term monitoring. Comparative document CN110411923B-In-situ real-time monitoring device and method for seabed sediment environment based on natural potential measurement, this method is not only designed for in-situ devices, but also can monitor and warn, and contains a more complex, convenient and effective interpretation algorithm, which is more advanced than the prior art methods.

[0116] 3. This application is reasonably designed, and the invention can realize data integration and intelligent analysis: combining machine learning and data mining technology, intelligent analysis of the collected data can automatically identify potential dynamic change patterns and provide decision support for environmental management and scientific research. The electrical-based inversion method for the dynamic change characteristics of the seabed sediment environment has obvious advantages and can provide innovative solutions in the fields of deep-sea monitoring, environmental assessment and resource exploration. Its high precision, real-time, non-invasive and other characteristics can effectively supplement and improve the performance of existing monitoring technologies.

[0117] Additional aspects and advantages of the present application will become apparent in the following description or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0118] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0119] Figure 1 Data processing flow of the method for inversion of dynamic change characteristics of seabed sediment environment based on three-phase potential provided in this application Figure 1 ;

[0120] Figure 2 Data processing flow of the method for inversion of dynamic change characteristics of seabed sediment environment based on three-phase potential provided in this application Figure 2 ;

[0121] Figure 3 A seabed interface recognition effect diagram for implementing the method for inverting the dynamic change characteristics of the seabed sediment environment based on three-phase potential provided in this application;

[0122] Figure 4 A suspended particle inversion effect diagram for implementing the method for inverting the dynamic change characteristics of the seabed sediment environment based on three-phase potential provided in this application;

[0123] Figure 5 A sediment property identification effect diagram for implementing the method for inverting the dynamic change characteristics of the seabed sediment environment based on three-phase potential provided in this application;

[0124] Figure 6 A method flow chart for implementing the method for inverting the dynamic change characteristics of the seabed sediment environment based on three-phase potential provided in this application. DETAILED DESCRIPTION

[0125] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0126] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0127] Combine the following Figures 1 to 5 A method for inverting the dynamic change characteristics of the seabed sediment environment based on three-phase potential of the present application is specifically described.

[0128] Combination Figure 1-2 The dynamic change characteristics of the seabed sediment environment based on three-phase potential provided by this application

[0129] Inversion methods include:

[0130] S1, three-phase potential data collection preprocessing, three-phase potential and suspended particle concentration data processing, interface processing, three-phase potential and sediment properties processing;

[0131] S2, determination of seafloor sediment environment data;

[0132] S3, finally, it is necessary to realize the dynamic description of the seabed sediment environment characteristics based on the three-phase potential, and then implement real-time dynamic monitoring.

[0133] like Figure 1 , Figure 2 As shown in the figure, the three-phase potential data acquisition preprocesses the long-term in-situ monitoring data of the seabed sediment environment, processes the natural potential, resistivity, and redox potential, and then processes the seabed interface, suspended matter concentration, sediment density, water content, and porosity data; further establishes the relationship between the natural potential, resistivity, redox potential and the sediment interface, corresponding to Figure 1 Middle S1 part;

[0134] Establish the relationship between natural potential, resistivity, redox potential and suspended solids concentration; establish the relationship between natural potential, resistivity, redox potential and sediment density, water content and porosity; process natural potential, resistivity and redox potential to invert sediment interface, suspended solids concentration and sediment properties, corresponding Figure 1 Middle S2 part;

[0135] Finally, a model was established based on the three-phase potential and the characteristics of the seabed sedimentary environment changes; the dynamic changes of the seabed sedimentary environment caused by mining disturbance were explained, corresponding to Figure 1 Middle S3 part;

[0136] The three-phase potential data acquisition preprocesses the long-term in-situ monitoring data of the seabed sediment environment, and processes the natural potential, resistivity, redox potential, and then processes the seabed interface, suspended matter concentration, sediment density, water content, and porosity data.

[0137] Data preprocessing: different value ranges are used for data features, so the input data needs to be preprocessed, data with a large value range is processed, each feature is marked for further standard processing, data with large errors are distinguished, and data with good quality are retained;

[0138] The data set and measured data are analyzed and fitted, and further preprocessed with the help of neural network learning, mainly processing the three-phase potential to make it consistent with the correspondence with in-situ monitoring.

[0139] Sedimentary environment data set: First, establish an in-situ monitoring database set, including obtaining deep-sea in-situ soil and water bodies, mainly including the concentration of suspended particulate matter in the water body, changes in the position of the seabed interface, and the basic physical properties of seabed sediments, including basic parameters of density, water content, and porosity.

[0140] Three-phase potential data calibration: Natural potential processing: According to the obtained electrode parameters, the natural potential is first analyzed, and the main electrode difference processing is performed from the first electrode ring to the nth electrode ring (n≥30) to obtain the electrode difference SPd belonging to each electrode ring compared to the reference electrode. Each potential difference value represents the potential characteristic value for the reference electrode.

[0141]

[0142] In the formula, SPd is the potential difference, X i is the actual measured value, Xc is the reference electrode value, and N is the n-fold magnification of the electrode data, that is, the original value is reduced by n times to obtain the true potential difference value; the true potential difference value can be obtained, making the monitoring difference in the in-situ process more obvious.

[0143] Seabed resistivity calibration: Obtain resistivity values ​​based on in-situ monitoring, divide the intervals into sections, and obtain the average apparent resistivity value within a certain distance.

[0144]

[0145] In the formula, the current I and voltage V, the electrode constant K, are usually provided by the electrode manufacturer or calibrated with a standard solution to obtain the ρ resistivity, and the ε reference error resistivity. Through this formula, the resistivity value can be corrected, especially relative to the initial resistivity value. Compared with the traditional resistivity value, this formula adds error analysis, making the data more able to invert the real situation.

[0146] Processing of seabed redox potential: Processing is performed according to the temperature at that time. Redox potential usually changes with temperature, so temperature compensation is performed:

[0147] ORP T =ORP T0 +α(TT 0 )

[0148] ORP T is the corrected oxidation-reduction potential; is the corrected oxidation-reduction potential; ORP T0 is the corrected redox potential; α is the temperature coefficient, which is usually a constant and depends on the specific measurement system. The oxidation potential calibration for the measured temperature is added, and the oxidation in situ potential treatment at the stable monitoring temperature on the seabed is determined.

[0149] Salinity has a relatively small effect on the redox potential, but in high-salinity waters, corrections are also required. Salinity corrections can be made by looking up the specific salinity-ORP relationship.

[0150] The relationship between natural potential, resistivity, redox potential and sediment interface is established:

[0151] Combination Figure 2 As shown, the sediment interface property determination of the present application can pre-process the three-phase potential data, and based on the traditional change point method model, an electrode determination direction is added to determine the interface position. The natural potential data is set as F(t, j). Assuming that at a certain time t, for the data F(t, j), the natural potential vertical distribution data F(t, j) is divided into two parts according to the seabed interface position m;

[0152]

[0153] Among them, β i are independent random errors with expected value 0 and common variance σ 2 , 0<σ 2 <∞. Here m, α1 , α 2 , σ 2 Unknown. Corresponding to the resistivity observation process near the seabed interface, α 1 is the natural potential difference of the sediment, α 2 is the natural potential difference of seawater, n is the total number of natural potential electrodes, m is the position where the natural potential difference value changes suddenly, and the mean change at position j is

[0154]

[0155] Among them, d+1≤j≤n-d+1, obviously, when j is in the seawater layer or sediment layer, due to the similar natural potential difference, G j is relatively small or even tends to 0; when j is in the transition zone, especially at the seabed, the natural potential difference between seawater and sediment will be G j Larger, so

[0156] |G m |=max|G j |=γ

[0157] At this time, m is the mutation point, that is, the position of the seabed interface, and γ is the test level. The critical value E can be taken according to experience. m |>E, the change point exists; if not, it is assumed that all the spontaneous potential electrodes are in seawater or sediment (depending on the expected value of the spontaneous potential difference).

[0158] The relationship between natural potential, resistivity, redox potential and suspended particle concentration is established:

[0159] Three-phase potential and suspended particle concentration data processing: Data calibration, first select the monitoring data of the target area, and perform numerical fitting based on the natural potential interpolation and suspended particle concentration. During deep-sea mining, the concentration of suspended particles in the plume changes significantly.

[0160] Natural potential treatment: Dynamic indoor data changes in the seabed sediment environment. The maximum concentration of suspended sediment in the estuary in still water is 30 mg / L. The maximum concentration of suspended sediment on the seabed during tides can reach 8.69 g / L. The maximum concentration near the bottom during a typhoon can reach 14.2 g / L. During storm surges, the concentration will increase 30 times. The test configuration has a suspended sediment solution concentration range of 0-20 g / L. The test range is 0-20 g / L, with an accuracy of 1 g / L. The correlation is established:

[0161] c=f(SP)S,t,DO,Z-1.82275e-8.75061

[0162] Where c is the suspended sediment concentration in g / L, SP is the natural potential in mV (for saturated calomel electrode), Z is the test water level in cm, S is the salinity, t is the temperature in °C, and DO is the dissolved oxygen in mg / L;

[0163] SPM=0.00315*RR%+0.5146

[0164] SPM represents the mass of suspended sediment on the seafloor, and RR measures the decrease in sediment resistivity in %. Further analysis can be performed based on the decrease in resistivity, so that the baseline resistivity value can be obtained.

[0165] Then indoor test resistivity correction:

[0166] c=-4.30948ln(ρ-0.28402 / 0.05594)S,t

[0167] Where c is the suspended sediment concentration in g / L, ρ is the resistivity in Ω·m, S is the salinity, and t is the temperature in °C. The resistivity has a certain logarithmic relationship with the identification of suspended particle concentration.

[0168] The relationship between redox potential and suspended particulate matter concentration is analyzed using the suspended sediment mass of the South China Sea. The relationship analysis of sediment redox potential is as follows:

[0169] TOC=8.147TN+0.0192

[0170] ORP=-f(pH)a+b

[0171] pH = f(C TOC ,C TN )

[0172] C SPM =f(C DO , C OM , ORP)

[0173] Among them, C SPM Indicates the concentration of suspended particles and dissolved oxygen concentration C DO , organic matter concentration C OM , ORP stands for oxidation-reduction potential, TOC is the total organic carbon in the sediment, TN is the total organic nitrogen, and then the oxidation-reduction potential is correlated with the total organic carbon and total organic nitrogen in the sediment, a and b are the correlation coefficients, pH is the pH value of the solution, C TOC , C TNCompared with the traditional indoor test, this formula points out that the redox potential is mainly affected by the sediment, and there is a negative proportional relationship between the redox potential and the solution pH. In this way, the nonlinear relationship between the redox potential and the solution is obtained, and it can be analyzed according to specific indoor tests, especially the calibration of organic matter concentration.

[0174] The relationship between natural potential, resistivity, redox potential and sediment density, water content and porosity is established:

[0175] The three-phase potential and sediment property parameter data are processed to establish the mathematical relationship between sediment density, water content, porosity and natural potential. The density of sediment is usually determined by the relative proportion of solid particles and pore water.

[0176] The natural potential can be expressed by the following formula:

[0177]

[0178] Among them, ρ s is the density of the solid particle, ρ w is the pore water density, It is the porosity. It is mainly calibrated according to the pore water content in the sediment:

[0179] The water content is

[0180]

[0181] The porosity is

[0182]

[0183] Among them, V w is the density of the solid particles, V p is the density of solid particles, V is the total volume, and compared with the pore water between sediments, it focuses more on the sediment pore density in situ in the seabed sediment environment than traditional calculation methods.

[0184] A mathematical model can be established with sediment density, water content, and porosity:

[0185]

[0186] Resistivity can be used to establish a mathematical model with sediment porosity and water content:

[0187]

[0188] R is the resistivity of the sediment (Ω·m), R W is the resistivity of water (Ω·m), is the porosity of the sediment, is the porosity saturated with water;

[0189]

[0190] R is the resistivity of the sediment (Ω·m), R 0 is the resistivity of dry sediment (Ω·m), ρ min is the density of sediment minerals (2.5-3.0 g / cm 3 ), ρ bulk is the overall density of the sediment (g / cm 3 );

[0191] The following model can be used to comprehensively consider the combined effects of porosity, water content and density on resistivity. Compared with the data from previous indoor tests, the sediment properties and resistivity fitting calibration can be performed based on the clay properties of the seabed mining area:

[0192] R=9.651ω -0.5711

[0193]

[0194] ρ=0.31R 2 +1.96R+1.50

[0195]

[0196] The above formula calibrates the laws of resistivity, density, water content and porosity of seabed clay. Compared with existing patents, this formula more clearly points out the influencing factors and is more in line with the in-situ monitoring environment.

[0197] Redox potential, taking into account the combined effects of porosity, water content, and density on resistivity. ρ represents the compactness of the sediment and is usually related to the content of organic matter, minerals, and the degree of compaction of the sediment. Higher density may lead to lower porosity, which in turn affects the diffusion rate of oxygen and other oxidants. Therefore, higher sediment density often corresponds to lower redox potential, especially in anaerobic environments.

[0198] ORP=ab·ρ

[0199] a, b are empirical constants, and their specific values ​​depend on the environment and sediment type.

[0200] Water content, W, directly affects the availability and diffusion rate of oxygen in sediments. Higher water content generally indicates lower oxygen content, especially in anaerobic environments. Therefore, ORP tends to decrease with increasing water content. Common empirical formula:

[0201] ORP=cd·W

[0202] Indicates the ratio of void volume to total volume in the sediment. High porosity usually means faster oxygen diffusion and higher ORP. When the porosity is low, oxygen is difficult to enter, the ORP is low, and a reducing environment is easily formed.

[0203]

[0204] Finally, the comprehensive model:

[0205]

[0206] The redox potential is related to the density, water content and porosity of the sediment, but the specific mathematical relationship is greatly affected by the environment and experimental conditions. Compared with the previous indoor test calibration, this formula is more accurate, more suitable for indoor tests and in-situ monitoring, and covers a more comprehensive range.

[0207] Finally, by processing the natural potential, resistivity, and redox potential, inverting the sediment interface, suspended matter concentration, and sediment properties, the dynamic changes in the seabed sedimentary environment caused by mining disturbance are further explained, and a characteristic model of three-phase potential and seabed sedimentary environment changes is established.

[0208] Figure 3 The figure in the figure is the effect diagram of using the above formula. The horizontal axis represents the natural potential difference, and the vertical axis represents the observation electrode ring number. It can be clearly seen from the figure that there is a sudden change from +20mv to -60mv in the potential difference at the sediment-water interface. The difference is huge at the sediment-water interface. Above the interface is water, and below it is sediment.

[0209] Combination Figure 4 As shown, the correlation analysis between the concentration of suspended particles in seawater and resistivity was carried out, including sand and clay; the regression analysis between the natural potential and the concentration of suspended particles in seawater was carried out, including sand and clay; the regression analysis between the redox potential and the concentration of suspended particles in seawater was carried out, including sand and clay;

[0210] This application requires filtering of the three-phase potential interpolation from top to bottom. After filtering out 1 / 2 of the repeated values, the natural potential inversion model has a strong correlation with the suspended sediment concentration, and both conform to the Gauss Amp function model. Based on this, the empirical formula can be obtained:

[0211]

[0212] Where x represents the potential difference of the reference electrode in mV, y represents the concentration of suspended particles in g / L, and y 0 , A, x c, ω are the variables explained according to the range of potential difference, which can be assigned values ​​in intervals. According to the long-term monitoring data of natural potential, the concentration of suspended particles can be determined and identified respectively, and the entire suspended sediment concentration profile structure can be obtained.

[0213] Resistivity inversion:

[0214] c=-4.30948ln(ρ-0.28402 / 0.05594)S,t

[0215] Redox potential inversion:

[0216] TOC=8.147TN+0.0192

[0217] ORP=-f(pH)a+b

[0218] pH = f(C TOC ,C TN )

[0219] C SPM =f(C DO , C OM , ORP)

[0220] According to the sediment type, the most suitable suspended particle concentration inversion method is selected after calibration of in-situ test data and sediment properties.

[0221] Figure 4 The above formula is used for analysis. The horizontal axis of the six graphs is the concentration of suspended particles in seawater, and the vertical axis is the value of the three-phase point, from which the correlation analysis is established; a and d represent the correlation analysis between the concentration of suspended particles in seawater and resistivity, including sand and clay; b and e represent the regression analysis of natural potential and the concentration of suspended particles in seawater, including sand and clay; c and f represent the regression analysis of redox potential and the concentration of suspended particles in seawater, including sand and clay;

[0222] Combination Figure 5 , Figure 6 , this application also needs to analyze the basic properties of sediments, Figure 5 The main selected diagram is the correlation diagram between resistivity and sediment density, porosity and water content in three-phase potential.

[0223] Figure 5 Select resistivity, use the horizontal axis as the resistivity value, and the vertical axis as the values ​​of sediment density, porosity, and water content. Then, based on the previously associated data, establish a multiple regression model:

[0224]

[0225] Among them, a is a constant term, b 1, b 2 , b 3 is the coefficient to be determined, and ε is the error term.

[0226] Modeling of natural potential difference:

[0227]

[0228] Inversion equations:

[0229]

[0230] Optimization algorithms (such as the least squares method or other optimization techniques) are used to solve these equations and solve for the unknown sediment density, water content, and porosity. Combining the above equations, the final model can be expressed as

[0231]

[0232] Resistivity inversion sediment relationship: The resistivity relationship between density, water content and porosity is indirect. It can be comprehensively expressed by combining various models and considering the interaction of these factors. Resistivity can be used to establish a mathematical model with sediment porosity and water content:

[0233]

[0234] The relationship between redox potential and sediment, redox potential and sediment density, water content, porosity have a certain correlation, but the specific mathematical relationship is greatly affected by the environment and experimental conditions. Compared with the previous indoor test calibration, this formula is more accurate, more suitable for indoor tests and in-situ monitoring, and covers a more comprehensive range.

[0235] ORP=ab·ρ

[0236] ORP=cd·W

[0237]

[0238] Combination Figure 6 As shown, the application implementation of the method of the present application also includes:

[0239] (1) Deployment of electrode arrays: By deploying electrode arrays on the seabed, the natural potential, resistivity, and redox potential electrical signals are collected in real time.

[0240] (2) Inversion of electrical signals. The electrical signals are processed using the above inversion algorithm to deduce the seabed interface of the sedimentary environment, and the seabed interface is determined based on the combination of the three potentials;

[0241] Based on the seabed interface of the sedimentary environment, the concentration of suspended particulate matter in the sedimentary environment is calibrated jointly by natural potential, resistivity, and redox potential;

[0242] Below the seabed interface, the physical parameters of the seabed sedimentary environment, such as sediment density, porosity, and water content, are derived based on the three-phase potential. Figure 1 S1 in.

[0243] (3) Multi-frequency signal analysis. The noise reduction and filtering multi-frequency signal analysis method combined with the three-phase potential can improve the resolution and accuracy of the inversion. Figure 1 S2 in.

[0244] (4) Dynamic monitoring and identification: Based on the changes in electrical signals, the dynamic changes in the seabed sediment environment are monitored in real time to identify environmental changes and sediment movement. Figure 1 S3 in.

[0245] Figure 5 Select resistivity, use the horizontal axis as the resistivity value, and the vertical axis as the values ​​of sediment density, porosity, and water content, and establish a related model. Figure 6 This is a more detailed rendering of the whole. Figure 6 Data judgment and model building correspondence Figure 1 S1 in the inversion law corresponds to Figure 1 S2 in the application implementation corresponds to Figure 1 S3 in.

[0246] In the description of this application, the term "multiple" refers to two or more than two. Unless otherwise clearly defined, the orientation or position relationship indicated by the terms "upper" and "lower" is based on the orientation or position relationship shown in the drawings. It is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on this application; the terms "connect", "install", "fixed" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0247] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. 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 application. 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 can be combined in any one or more embodiments or examples in a suitable manner.

[0248] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for inverting the dynamic change characteristics of the seabed sediment environment based on three-phase potential, characterized in that: include: Three-phase potential data collection preprocessing, three-phase potential and suspended particle concentration data processing, interface processing, three-phase potential and sediment properties processing; Determination of seabed sediment environment data; Finally, it is necessary to realize the dynamic description of the seabed sedimentary environment characteristics based on the three-phase potential, and then implement real-time dynamic monitoring.

2. The method for inverting the dynamic change characteristics of the seabed sediment environment based on three-phase potential according to claim 1 is characterized in that: Three-phase potential data acquisition preprocessing, including: data acquisition and processing, based on the natural potential potential difference, resistivity, oxidation in-situ potential, the seabed sediment, seabed interface and suspended particle concentration are sequentially inverted, and then processed as time changes; data preprocessing, different value ranges are used for data features, so it is necessary to preprocess the input data, process data with a large value range, mark each feature for further standard processing, distinguish data with large errors, retain data with good quality, analyze and fit the data set and measured data, and further preprocess with the help of neural network learning, mainly processing the three-phase potential to make it correspond to the in-situ monitoring; Sedimentary environment data set: First, establish an in-situ monitoring database set, including obtaining deep-sea in-situ soil and water bodies, mainly including the concentration of suspended particles in the water body, changes in the position of the seabed interface, and basic physical properties of seabed sediments, including basic parameters of density, water content, and porosity; Three-phase potential data calibration: Natural potential processing: According to the obtained electrode parameters, the natural potential is first analyzed, and the electrode difference processing is performed from the first electrode ring to the nth electrode ring (n≥30), and the electrode difference SPd of each electrode ring compared with the reference electrode is obtained. Each potential difference value represents the potential characteristic value for the reference electrode; In the formula, SPd is the potential difference, X i is the actual measured value, Xc is the reference electrode value, and N is the magnification of the electrode acquisition by n times, that is, the original value is reduced by n times to obtain the real potential difference value; the real potential difference value can be obtained, making the monitoring difference in the in-situ process more obvious; Seabed resistivity calibration: Obtain resistivity values ​​based on in-situ monitoring, divide the intervals into sections, and obtain the average apparent resistivity value within a certain distance; In the formula, the current I and voltage V, the electrode constant K, which is usually provided by the electrode manufacturer or obtained by calibration with a standard solution, is the resistivity ρ, and the reference error resistivity ε; This formula can be used to correct the resistivity value, especially relative to the initial resistivity value. Compared with the traditional resistivity value, this formula adds error analysis, making the data more able to invert the real situation. Processing of seabed redox potential: Processing according to the temperature at that time. The redox potential usually changes with temperature, and temperature compensation is performed: ORP T =ORP T0 +α(T-T0) ORP T is the corrected oxidation-reduction potential; is the corrected oxidation-reduction potential; ORP T0 is the corrected redox potential; α is the temperature coefficient, which is usually a constant and depends on the specific measurement system. The oxidation potential calibration for the measured temperature is added, and the oxidation in situ potential treatment at a stable monitoring temperature on the seabed is determined. The effect of salinity on the redox potential is relatively small, but in high-salinity water bodies, correction is also required. The salinity correction can be made by referring to the specific salinity-ORP relationship.

3. The method for inverting the dynamic change characteristics of the seabed sediment environment based on three-phase potential according to claim 1 is characterized in that: The three-phase potential and suspended particle concentration data processing includes: data calibration, firstly selecting the monitoring data of the target area, and performing numerical fitting based on the natural potential interpolation and suspended particle concentration. During deep-sea mining, the concentration of suspended particles in the plume changes significantly; Natural potential processing: Dynamic indoor data changes of seabed sediment environment, based on the maximum suspended sediment concentration of 30mg / L in estuaries in still water, the maximum suspended sediment concentration on the seabed during tides can reach 8.69g / L, the maximum concentration near the bottom during typhoons can reach 14.2g / L, and the concentration will increase 30 times during storm surges. Based on the suspended sediment solution concentration range of 0-20g / L; the test interval is 0-20g / L, and the accuracy is 1g / L, a correlation relationship is established: c=f(SP)S,t,DO,Z-1.82275e-8.75061 Where c is the suspended sediment concentration in g / L, SP is the natural potential in mV (for saturated calomel electrode), Z is the test water level in cm, S is the salinity, t is the temperature in °C, and DO is the dissolved oxygen in mg / L; SPM=0.00315*RR%+0.5146 SPM represents the mass of suspended sediment on the seafloor, and RR measures the decrease in sediment resistivity in %. Further analysis can be performed based on the decrease in resistivity, so that the baseline resistivity value can be obtained. Then indoor test resistivity correction: c=-4.30948ln(ρ-0.28402 / 0.05594)S,t Where c is the suspended sediment concentration in g / L, ρ is the resistivity in Ω·m, S is the salinity, and t is the temperature in °C. The resistivity has a certain logarithmic relationship with the identification of suspended particle concentration. The relationship between redox potential and suspended particulate matter concentration is analyzed using the suspended sediment mass of the South China Sea. The relationship analysis of sediment redox potential is as follows: TOC=8.147TN+0.0192 ORP=-f(pH)a+b pH=f(C TOC ,C TN ) C SPM =f(C DO ,C OM ,ORP) Among them, C SPM Indicates the concentration of suspended particles and dissolved oxygen concentration C DO , organic matter concentration C OM , ORP stands for oxidation-reduction potential, TOC is the total organic carbon in the sediment, TN is the total organic nitrogen, and then the oxidation-reduction potential is correlated with the total organic carbon and total organic nitrogen in the sediment, a and b are the correlation coefficients, pH is the pH value of the solution, C TOC , C TN Compared with the traditional indoor test, this formula points out that the redox potential is mainly affected by the sediment, and there is a negative proportional relationship between the redox potential and the solution pH. In this way, the nonlinear relationship between the redox potential and the solution is obtained, and it can be analyzed according to specific indoor tests, especially the calibration of organic matter concentration.

4. The method for inverting the dynamic change characteristics of the seabed sediment environment based on three-phase potential according to claim 1 is characterized in that: Data processing of three-phase potential and sediment property parameters, including: establishing the mathematical relationship between sediment density, water content, porosity and natural potential. Sediment density is usually determined by the relative proportion of solid particles and pore water; The natural potential can be expressed by the following formula: Among them, ρ s is the density of the solid particles, ρ w is the pore water density, Porosity; mainly calibrated based on the pore water content in the sediment The water content is The porosity is Among them, V w is the density of the solid particles, V p is the density of solid particles, V is the total volume, and compared with the pore water between sediments, it focuses more on the sediment pore density in situ in the seafloor sediment environment than traditional calculation methods; A mathematical model can be established with sediment density, water content, and porosity: Resistivity can be used to establish a mathematical model with sediment porosity and water content: R is the resistivity of the sediment (Ω·m), R W is the resistivity of water (Ω·m), is the porosity of the sediment, is the porosity saturated with water R is the resistivity of the sediment (Ω·m), R0 is the resistivity of the dry sediment (Ω·m), ρ min is the density of sediment minerals (2.5-3.0 g / cm 3 ), ρ bulk is the overall density of the sediment (g / cm 3 ) The following model can be used to comprehensively consider the combined effects of porosity, water content and density on resistivity. Compared with the data from previous indoor tests, the sediment properties and resistivity fitting calibration can be performed based on the clay properties of the seabed mining area: R=9.651ω -0.5711 ρ=0.31R 2 +1.96R+1.50 ORP, taking into account the combined effects of porosity, water content and density on resistivity, ρ indicates the compactness of the sediment, which is usually related to the content of organic matter and minerals and the compaction degree of the sediment. Higher density may lead to lower porosity, which in turn affects the diffusion rate of oxygen and other oxidants. Therefore, higher sediment density often corresponds to lower redox potential, especially in anaerobic environments. ORP = ab·ρ a and b are empirical constants, and their specific values ​​depend on the environment and sediment type; Water content, W, directly affects the availability and diffusion rate of oxygen in sediments; higher water content generally indicates lower oxygen content, especially in anaerobic environments. Therefore, ORP tends to decrease with increasing water content. The common empirical formula is: ORP=cd·W It refers to the ratio of void volume in the sediment to the total volume. High porosity usually means faster oxygen diffusion and higher ORP. When the porosity is low, oxygen is difficult to enter, the ORP is low, and a reducing environment is easily formed. Finally, the comprehensive model There is a certain correlation between the redox potential and the density, water content and porosity of the sediment, but the specific mathematical relationship is greatly affected by the environment and experimental conditions. Compared with the previous indoor test calibration, this formula is more accurate, more suitable for indoor tests and in-situ monitoring, and covers a more comprehensive range.

5. The method for inverting the dynamic change characteristics of the seabed sediment environment based on three-phase potential according to claim 1 is characterized in that: Determination of seabed sediment environment data, including: Determination of the dynamic change characteristics of the seabed sediment environment based on known monitoring data: First, the interface position is determined. The three-phase potential (natural potential, resistivity, redox potential) data can be preprocessed. Based on the traditional change point method model, an electrode determination direction is added to determine the interface position. The natural potential data is set to F(t, j). Assuming that at a certain time t, for the data F(t, j), the three-phase potential vertical distribution data F(t, j) is divided into two parts according to the seabed interface position m. Among them, β i are independent random errors with an expected value of 0 and a common variance σ2, 0<σ2<∞; here m, α1, α2, σ2 are unknown; corresponding to the resistivity observation process near the seabed interface, α1 is the natural potential difference of the sediment, α2 is the natural potential difference of the seawater, n is the total number of natural potential electrodes, m is the mutation position of the natural potential difference, and the mean change at position j is Among them, d+1≤j≤n-d+1, obviously, when j is in the seawater layer or sediment layer, due to the similar natural potential difference, G j is relatively small or even tends to 0; when j is in the transition zone, especially at the seabed, the natural potential difference between seawater and sediment will be G j Larger, so |G m |=max|G j |=c At this time, m is the mutation point, that is, the position of the seabed interface, and γ is the test level. The critical value E can be taken according to experience. m |>E, the change point exists; if not, it is assumed that all the spontaneous potential electrodes are in seawater or sediment (depending on the expected value of the spontaneous potential difference). Secondly, the concentration of suspended particulate matter is determined based on the in-situ monitoring data. Natural potential: The three-phase potential interpolation is filtered from top to bottom. After filtering out 1 / 2 of the repeated values, the natural potential inversion model has a strong correlation with the suspended sediment concentration, and both conform to the Gauss Amp function model. Based on this, the empirical formula can be obtained: Among them, x represents the potential difference of the reference electrode, the unit is mV, y represents the concentration of suspended particles, the unit is g / L, y0, A, x c , ω are the changes that are explained according to the range of the potential difference, and can be assigned values ​​in intervals. Based on the long-term monitoring data of the natural potential, the concentration of suspended particles can be determined and identified, and the entire suspended sediment concentration profile structure can be obtained. Resistivity inversion: c=-4.30948ln(ρ-0.28402 / 0.05594)S,t Redox potential inversion: TOC=8.147TN+0.0192 ORP=-f(pH)a+b pH=f(C TOC ,C TN ) C SPM =f(C DO ,C OM ,ORP) According to the sediment type, the most suitable suspended particulate matter concentration inversion method is selected after the in-situ test data and sediment properties are calibrated. Finally, the basic properties of sediments are analyzed, and a multivariate regression model is established based on the previously associated data: Among them, a is a constant term, b1, b2, b3 are coefficients to be determined, and ε is an error term; Modeling of natural potential difference: Inversion equations: Optimization algorithms (such as least squares method or other optimization techniques) are used to solve these equations and solve the unknown sediment density, water content and porosity; Combining the above equations, the final model can be expressed as Resistivity inversion sediment relationship: The resistivity relationship between density, water content and porosity is indirect. It can be comprehensively expressed by combining various models and considering the interaction of these factors. Resistivity can be used to establish a mathematical model with sediment porosity and water content: The relationship between redox potential and sediment. There is a certain correlation between redox potential and sediment density, water content, and porosity, but the specific mathematical relationship is greatly affected by the environment and experimental conditions. Compared with the previous indoor test calibration, this formula is more accurate, more suitable for indoor tests and in-situ monitoring, and covers a more comprehensive range. ORP=ab·ρ ORP=cd·W 6. The method for inverting the dynamic change characteristics of the seabed sediment environment based on three-phase potential according to claim 1 is characterized in that: Implementation methods include: (1) Deploy electrode arrays to collect electrical signals of natural potential, resistivity, and redox potential in real time through electrode arrays arranged on the seabed; (2) Inverting the electrical signal, using the above-mentioned inversion algorithm to process the electrical signal, deriving the seabed interface of the sedimentary environment, and determining the seabed interface based on the combination of the three potentials; Based on the seabed interface of the sedimentary environment, the concentration of suspended particulate matter in the sedimentary environment is calibrated jointly by natural potential, resistivity, and redox potential; (Below the seabed interface, the physical parameters of the seabed sedimentary environment, such as sediment density, porosity, and water content, are derived based on the three-phase potential; (3) Multi-frequency signal analysis, combining the noise reduction and filtering multi-frequency signal analysis method of the three-phase potential to improve the resolution and accuracy of the inversion; (4) Dynamic monitoring and identification: Based on the changes in electrical signals, the dynamic changes of the seabed sediment environment are monitored in real time to identify environmental changes and sediment movement.

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