Soil unsaturated zone vertical migration simulation method based on adsorption coefficient layering

Abstract

The invention provides a soil unsaturated zone vertical migration simulation method based on adsorption coefficient stratification, and relates to the technical field of soil pollution investigation and remediation.The method comprises the steps that a soil profile sample in a research area is collected, the soil property distribution depth is determined, and soil organic matter and inorganic ion distribution depth is combined; dividing the soil profile into multiple layers based on cross values; carrying out an equilibrium adsorption experiment in each layer of soil, and calculating an adsorption coefficient value of each layer according to an experiment result; inputting the soil property and the adsorption coefficient value of each layer of soil into pollutant migration simulation software, simulating the vertical migration characteristics of pollutants in each layer of soil layer by layer by using the pollutant migration simulation software, and calculating the bottom water yield and the pollutant concentration of each layer; and superposing simulation results of each layer of soil to obtain a pollutant vertical distribution result of the whole soil unsaturated zone. The limitation of using a surface layer to fix a unique adsorption coefficient value can be broken through.

Description

Technical Field

[0001] The present application relates to the technical field of soil pollution investigation and remediation, and in particular to a method for simulating vertical migration of unsaturated zones of soil based on adsorption coefficient stratification. Background Art

[0002] Hydrus-1D is an important tool currently widely used to simulate the vertical migration of pollutants in unsaturated soil media. The model requires the use of three basic parameters: upper and lower boundary conditions (input and output of soil moisture, etc.), soil hydrodynamic parameters (soil porosity, etc.), and solute transport parameters (such as adsorption coefficient, etc.). The adsorption coefficient value plays an important role in the model, characterizing the adsorption capacity of pollutants in the soil and affecting its vertical migration. Usually, the adsorption coefficient value is obtained through adsorption experiments on surface soil, or the value in the reference literature. However, the differences in adsorption coefficient values ​​at different depths of the soil profile have not been taken into account in existing studies.

[0003] Current simulations typically assume a fixed adsorption coefficient value throughout the entire unsaturated soil layer. Although the adsorption coefficient can vary by 8% to 260% at different locations within the soil profile, simulations often use a uniform value, leading to significant errors. When the adsorption coefficient varies significantly, simulation results may overestimate or underestimate the vertical migration risk of contaminants, and errors accumulate with increasing soil depth, making it difficult to provide an accurate basis for soil remediation efforts. Consequently, existing methods cannot accurately reflect the impact of different layers within the soil profile on contaminant migration. Summary of the Invention

[0004] The present application aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, the first purpose of this application is to propose a method for simulating the vertical migration of the unsaturated zone of soil based on adsorption coefficient stratification.

[0006] The second purpose of this application is to propose a soil unsaturated zone vertical migration simulation device based on adsorption coefficient stratification.

[0007] The third objective of this application is to provide an electronic device.

[0008] The fourth object of this application is to provide a computer-readable storage medium.

[0009] A fifth object of this application is to provide a computer program product.

[0010] To achieve the above objectives, the first embodiment of the present application proposes a method for simulating vertical migration of unsaturated soil zones based on adsorption coefficient stratification, comprising:

[0011] Soil profile samples were collected in the study area to determine the distribution depth of soil properties, and the soil profile was divided into multiple layers based on the cross-values, combined with the distribution depth of soil organic matter and inorganic ions;

[0012] Conduct equilibrium adsorption experiments in each layer of soil and calculate the adsorption coefficient value of each layer based on the experimental results;

[0013] Inputting the soil properties and adsorption coefficient values ​​of each soil layer into the pollutant migration simulation software, using the pollutant migration simulation software to simulate the vertical migration characteristics of pollutants in each soil layer layer by layer, and calculating the water output and pollutant concentration at the bottom of each layer;

[0014] The simulation results of each layer of soil are superimposed to obtain the vertical distribution results of pollutants in the entire unsaturated zone of the soil.

[0015] Optionally, performing equilibrium adsorption experiments in each layer of soil and calculating the adsorption coefficient value of each layer based on the experimental results include:

[0016] In each layer of soil, a preset mass of soil sample is taken and mixed with the pollutant solution. After sufficient reaction, the concentration change of the pollutant in the solution is measured to obtain the equilibrium concentration C e ;

[0017] By measuring the initial concentration C0 of the pollutant in the solution and the concentration C after the reaction equilibrium e , calculate the adsorption amount Q of pollutants in soil, the formula is:

[0018]

[0019] The adsorption coefficient K of each layer of soil is calculated using the following formula: d The value is:

[0020]

[0021] Among them, Q is the amount of pollutants adsorbed by the soil, C e is the concentration of the pollutant in the solution after the reaction equilibrium, C0 is the initial concentration of the pollutant in the solution, V is the volume of the solution, and M is the mass of the soil.

[0022] Optionally, the soil properties and adsorption coefficient values ​​of each soil layer are input into the pollutant migration simulation software, and the pollutant migration simulation software is used to simulate the vertical migration characteristics of pollutants in each soil layer layer by layer, and calculate the water output and pollutant concentration at the bottom of each layer, including:

[0023] In n layers of soil, the topsoil is set as the first layer, and so on, the bottom soil is set as the nth layer;

[0024] Inputting the soil properties and adsorption coefficient values ​​of the first layer of soil into the pollutant migration simulation software, and simultaneously inputting the pollutants into the pollutant migration simulation software through a constant flux or constant head input method, simulating the vertical distribution characteristics of the pollutants in the first layer of soil, and calculating the water output at the bottom of the first layer of soil, and calculating the pollutant concentration of the effluent water of the first layer of soil based on the water output at the bottom of the first layer of soil;

[0025] Inputting the soil properties and adsorption coefficient values ​​of the second layer of soil into the pollutant migration simulation software, and inputting the pollutant concentration of the first layer of soil into the pollutant migration simulation software in a constant flux manner, simulating the vertical distribution characteristics of the pollutants in the second layer of soil, and calculating the water output at the bottom of the second layer of soil, and calculating the pollutant concentration of the effluent water of the second layer of soil based on the water output at the bottom of the second layer of soil;

[0026] Similarly, the soil properties and adsorption coefficient values ​​of the nth layer of soil are input into the pollutant migration simulation software, and the pollutant concentration of the n-1th layer of effluent is input into the software in a constant flux manner to simulate the vertical distribution characteristics of pollutants in the nth layer of soil.

[0027] To achieve the above-mentioned purpose, the second embodiment of the present application proposes a soil unsaturated zone vertical migration simulation device based on adsorption coefficient stratification, comprising:

[0028] The collection and stratification module is used to collect soil profile samples in the study area, determine the distribution depth of soil properties, and divide the soil profile into multiple layers based on cross-values ​​in combination with the distribution depth of soil organic matter and inorganic ions;

[0029] Adsorption coefficient calculation module, used to carry out equilibrium adsorption experiments in each layer of soil and calculate the adsorption coefficient value of each layer based on the experimental results;

[0030] A layer-by-layer simulation module is used to input the soil properties and adsorption coefficient values ​​of each soil layer into the pollutant migration simulation software, use the pollutant migration simulation software to simulate the vertical migration characteristics of pollutants in each soil layer layer by layer, and calculate the water output and pollutant concentration at the bottom of each layer;

[0031] The superposition module is used to superimpose the simulation results of each layer of soil to obtain the vertical distribution results of pollutants in the entire unsaturated zone of the soil.

[0032] To achieve the above-mentioned purpose, a third embodiment of the present application provides an electronic device, comprising: a processor, and a memory communicatively connected to the processor;

[0033] The memory stores computer-executable instructions;

[0034] The processor executes the computer-executable instructions stored in the memory to implement the method as described in any one of the first aspects.

[0035] To achieve the above-mentioned purpose, the fourth embodiment of the present application proposes a computer-readable storage medium, which stores computer-executable instructions. When the computer-executable instructions are executed by a processor, they are used to implement the method as described in any one of the first aspects.

[0036] To achieve the above-mentioned objectives, the fifth embodiment of the present application proposes a computer program product, which implements any one of the methods in the first aspect when executed by a processor.

[0037] The technical solutions provided by the embodiments of this application bring at least the following beneficial effects:

[0038] This application can improve the accuracy of existing simulations of the vertical migration of soil pollutants, especially under long-term irrigation conditions. By combining the changes in adsorption coefficient values ​​at different layers in the soil profile, a vertical migration simulation method based on layered changes in adsorption coefficient values ​​is established, thereby overcoming the limitations of the existing technology of using a single fixed adsorption coefficient value and providing more accurate simulation results for more effective soil pollution remediation and risk assessment.

[0039] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0041] Figure 1 A schematic flow chart of a method for simulating vertical migration of unsaturated soil zones based on adsorption coefficient stratification provided in an embodiment of the present application;

[0042] Figure 2 A schematic diagram of a technical route for simulating vertical migration of unsaturated soil zones based on adsorption coefficient stratification provided in an embodiment of the present application;

[0043] Figure 3 The embodiment of the present application provides a fixed K d Value and use of stratified K d Schematic diagram of the vertical distribution of pollutants simulated by the value. DETAILED DESCRIPTION

[0044] The following describes in detail embodiments of the present application, 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 intended to be used to explain the present application, and should not be construed as limiting the present application.

[0045] Hydrus-1D is currently an important tool for simulating the vertical migration of pollutants in unsaturated soil media. The model involves three types of parameters: upper and lower boundary conditions (rainfall, etc.), soil hydrodynamics (soil porosity, etc.), and solute transport (adsorption coefficient Kd, etc.). d The value is an important parameter in the model, K d The larger the value, the stronger the pollutant adsorption capacity and the weaker the migration capacity. d The value is usually obtained based on adsorption experiments of soil samples taken from the surface, or K in the reference literature. d That is, the entire unsaturated layer of soil uses a single fixed K d value. But K d The value is affected by soil organic matter, inorganic ions and soil properties (texture, bulk density, etc.). Organic matter is generally enriched in the soil surface layer (0-40cm), and ionic strength is generally enriched in the surface layer (0-10cm) and the bottom layer (100-120cm). The soil texture (such as Beijing) is plain fill soil at around 0-40cm, sandy silt soil at 40cm-180cm, and fine sand soil at 180cm-230cm. The K value of pollutants (such as antibiotics) is affected by organic matter, inorganic ions and soil texture at different locations in the soil profile. d The value can vary from 8% to 260% in the entire unsaturated layer profile. d The value gradually decreases, then based on the initial state K d The predicted results of the K value will underestimate the vertical migration risk of pollutants, and vice versa, it will overestimate the migration risk, which is contrary to the purpose of precise environmental prevention and control. d value as input parameter, that is, assuming that the K d The same value will cause the deep simulation results to be 13% or even 10% 2 -10 5 % error. This shows that it is necessary to conduct a more detailed stratified investigation of the Kd values ​​at different locations on the soil profile.

[0046] The current technology has the following shortcomings: d The values ​​vary at different locations in the soil profile, such as the K d The value of K in the soil profile can vary by 8%-260%. d When the values ​​differ by only 8%, if the simulation uses only fixed Kd The prediction error increases gradually with the deepening of the profile (up to 87%), and there are differences in different simulation cycles. Therefore, even with a smaller K d Any change in the value will cause a large change in the simulation error, making it difficult to provide a basis for soil and groundwater pollution prevention and control.

[0047] To address this issue, an embodiment of the present application provides a method for simulating the vertical migration of the unsaturated zone of soil based on adsorption coefficient stratification, thereby breaking through the limitation of using a fixed unique adsorption coefficient value for the surface layer.

[0048] Figure 1 and Figure 2 They are respectively a flow chart and a technical route chart of a method for simulating vertical migration of unsaturated soil zone based on adsorption coefficient stratification provided in an embodiment of the present application. Figure 1 and Figure 2 As shown, the method includes the following steps:

[0049] Step 101: collect soil profile samples in the study area, determine the distribution depth of soil properties, and divide the soil profile into multiple layers based on cross-values ​​in combination with the distribution depth of soil organic matter and inorganic ions.

[0050] In this embodiment of the present application, it is first necessary to sample the soil profile within the study area. The purpose of this step is to determine the basic properties of the soil so that subsequent simulation and analysis work can obtain accurate results. The specific steps are as follows:

[0051] (1) Select typical soil profile locations within the study area. Typically, areas with diverse soil types, topographical features, vegetation cover, and potential pollution sources should be selected. The sampling points should be selected to fully reflect the variations in soil properties at different locations to ensure representativeness of the results.

[0052] (2) According to the research needs, soil profile samples of a certain depth are collected. The sampling depth usually needs to cover the entire unsaturated zone of the soil, including the surface soil and the deeper soil layers. The depth of each layer needs to be reasonably divided according to the changes in soil properties. The common soil stratification method is to stratify the soil profile according to the changes in soil properties to ensure that the physical and chemical properties of each layer of soil are consistent within the layer.

[0053] (3) Determine the soil properties of the collected soil samples, including but not limited to texture (such as sand, clay, loam, etc.), bulk density, porosity, wetting characteristics, permeability, etc. These parameters have an important impact on the transport characteristics of soil water and the migration behavior of pollutants.

[0054] (4) In each soil layer, determine the content of soil organic matter and the concentration distribution of inorganic ions. Soil organic matter is usually concentrated in the soil surface layer (0-40 cm), while inorganic ions generally have higher concentrations between the surface and bottom layers (e.g., 100-120 cm). Based on this, combined with the changes in soil properties, determine the distribution depth of organic matter and inorganic ions in the profile.

[0055] (5) Based on the collected soil samples and the test results, the soil profile was divided using the cross-sampling method, combined with the soil properties and the distribution depth of organic matter and inorganic ions. The cross-sampling method can comprehensively consider the influence of different soil properties and material distribution, and reasonably divide multiple soil layers to reflect the diversity of soil at different spatial scales.

[0056] In this embodiment, by implementing the above steps, the multi-layer structure of the soil profile can be accurately divided, providing detailed parameter input for subsequent soil pollutant migration simulation.

[0057] Step 102: Perform equilibrium adsorption experiments in each layer of soil, and calculate the adsorption coefficient value of each layer based on the experimental results.

[0058] In the embodiment of the present application, step 102 is to conduct an equilibrium adsorption experiment in each layer of soil and calculate the adsorption coefficient value of each layer based on the experimental results. The specific steps are as follows:

[0059] First, a soil sample of a predetermined mass is taken from each layer of soil in the n-layer system and thoroughly mixed with a pollutant solution of a certain concentration. During the mixing process, the soil sample and the pollutant solution are in full contact to ensure that the reaction reaches equilibrium. After the reaction is complete, the concentration change of the pollutant in the solution is measured to obtain the concentration C after the reaction is balanced. e .

[0060] Then, by measuring the initial concentration C0 of the pollutant in the solution and the concentration C after the reaction equilibrium e , calculate the adsorption amount Q of pollutants in soil. The specific calculation formula is:

[0061]

[0062] Finally, the adsorption amount Q calculated above is combined with the concentration C of the pollutant in the solution after the reaction equilibrium. e , use the following formula to calculate the adsorption coefficient K of each layer of soil d The value is:

[0063]

[0064] Among them, K dis the adsorption coefficient, which indicates the adsorption capacity of soil to pollutants, Q is the adsorption amount of soil to pollutants (unit: mg / kg), C e is the concentration of the pollutant in the solution after the reaction equilibrium (unit: mg / L), C0 is the initial concentration of the pollutant in the solution (unit: mg / L), V is the volume of the solution (unit: L), and M is the mass of the soil (unit: kg).

[0065] Through this series of steps, the adsorption coefficient K of each layer of soil can be accurately calculated. d values, thereby providing necessary parameter support for subsequent pollutant migration simulation.

[0066] In step 103, the soil properties and adsorption coefficient values ​​of each soil layer are input into the pollutant migration simulation software. The pollutant migration simulation software is used to simulate the vertical migration characteristics of pollutants in each soil layer layer by layer, and the water output and pollutant concentration at the bottom of each layer are calculated.

[0067] In this embodiment, step 103 involves inputting the soil properties and adsorption coefficient values ​​of each soil layer into the pollutant migration simulation software. The software is then used to simulate the vertical migration characteristics of pollutants in each soil layer layer by layer, and the water output and pollutant concentration at the bottom of each layer are calculated. The specific implementation steps are as follows:

[0068] First, in the n-layer soil, the surface soil is set as the first layer, and so on, the bottom soil is set as the nth layer. The soil properties of each layer (such as soil texture, bulk density, porosity, etc.) and the adsorption coefficient K of each layer of soil are d The value needs to be input into the pollutant migration simulation software according to the result calculated in step 102.

[0069] First, the soil properties and adsorption coefficient K of the first layer of soil d The values ​​are input into the pollutant migration simulation software, and the constant flux or constant head input method is selected according to the actual situation. The simulation content includes: simulating the vertical distribution characteristics of pollutants in the first layer of soil; calculating the water output at the bottom of the first layer of soil, and calculating the pollutant concentration at the bottom of the first layer of soil based on the water output.

[0070] Then, the soil properties and adsorption coefficient K of the second layer of soil d The values ​​are input into the pollutant migration simulation software, and the pollutant concentration in the first soil layer is input into the simulation software as the constant flux. This step includes: simulating the vertical distribution characteristics of pollutants in the second soil layer; calculating the water flow rate at the bottom of the second soil layer, and calculating the pollutant concentration in the outflow water of the second soil layer based on this water flow rate.

[0071] Similarly, the soil properties and adsorption coefficient values ​​of the nth layer of soil are input into the pollutant migration simulation software, and the pollutant concentration of the n-1th layer of effluent is input into the software in a constant flux manner to simulate the vertical distribution characteristics of pollutants in the nth layer of soil.

[0072] As a possible implementation, the present embodiment uses Hydrus-1D software to perform the above-mentioned pollutant migration simulation. This software can perform layer-by-layer simulation and can accurately simulate the migration process of pollutants in the soil profile by combining parameters such as the physical and chemical properties and adsorption coefficient of the soil.

[0073] In step 104 , the simulation results of each soil layer are superimposed to obtain the vertical distribution results of pollutants in the entire unsaturated zone of the soil.

[0074] In the embodiment of the present application, step 104 is to superimpose the simulation results of each layer of soil to obtain the vertical distribution results of pollutants in the entire unsaturated zone of the soil.

[0075] First, the vertical distribution of pollutants in each soil layer, calculated layer by layer using the pollutant migration simulation software, was summarized. During the simulation of each soil layer, information such as the concentration distribution of pollutants in that layer and the amount of water discharged from the bottom was obtained.

[0076] These layer-by-layer vertical distribution results are then superimposed to create a composite vertical distribution map of pollutants across the entire unsaturated soil profile. Specifically, the simulation results for each soil layer include the concentration distribution of pollutants in that layer and the effluent pollutant concentration at the base. During the superposition process, the simulation results for each layer must be aligned to ensure a consistent and accurate representation of pollutant migration characteristics across the entire soil profile.

[0077] Finally, through this series of superposition calculations, the vertical distribution results of pollutants in the entire soil unsaturated zone profile were obtained, providing data support for subsequent pollutant risk assessment and remediation scope delineation.

[0078] In addition, the embodiment of the present application also provides a method for using a fixed K d Value and use of stratified K d Schematic diagram of the vertical distribution of pollutants simulated by the value, as shown in Figure 3 As shown. Figure 3 It can be seen that using a fixed K d In the simulation results, the K value of the upper soil is used. d Therefore, the simulation accuracy of the upper soil layer is higher, while the simulation accuracy of the bottom layer is lower. d Value simulation improves the simulation accuracy of the bottom.

[0079] In addition, in the embodiment of this application, in order to achieve more efficient simulation and analysis of the vertical migration of soil pollutants, the above analysis steps can be embedded in the Hydrus software based on the Python language to implement the application process. The specific steps are as follows:

[0080] (1) To enable users to easily input the hierarchical structure of the soil profile, the Hydrus software will provide an interface that allows users to enter the number of soil layers (n) and set the specific layer thickness for each layer. This setting interface will allow users to flexibly adjust the hierarchical division of the soil profile according to the actual situation of the study area to ensure the accuracy and rationality of the simulation results.

[0081] (2) The Hydrus software will provide a dedicated interface for inputting the physical properties of each layer of soil (such as texture, bulk density, porosity, etc.) and the adsorption coefficient K d The user can input the adsorption coefficient K of each layer of soil according to the experimental value or the data in the reference literature. d The accuracy of soil property data is ensured. These input parameters will become the basic data for subsequent pollutant migration simulation.

[0082] (3) After completing soil profile stratification and soil properties, adsorption coefficient K d After entering the values, Hydrus automatically calculates the vertical distribution characteristics of pollutants in each soil layer, as well as the bottom water flow and pollutant concentrations. By setting a constant flux input method and transferring the water flow pollutant concentration layer by layer, Hydrus completes the simulation for each soil layer. Ultimately, the simulation results for all layers are automatically superimposed to obtain the vertical distribution of pollutants across the entire unsaturated soil profile.

[0083] This automated approach eliminates the need for manual calculations and input of intermediate results throughout the simulation process, significantly improving computational efficiency and reliability. The resulting vertical distribution of pollutants can provide a scientific basis for soil remediation and risk assessment.

[0084] To implement the above embodiment, the present application also proposes a device for simulating vertical migration of unsaturated soil zones based on adsorption coefficient stratification. The device comprises:

[0085] The collection and stratification module is used to collect soil profile samples in the study area, determine the distribution depth of soil properties, and divide the soil profile into multiple layers based on cross-values ​​in combination with the distribution depth of soil organic matter and inorganic ions;

[0086] Adsorption coefficient calculation module, used to carry out equilibrium adsorption experiments in each layer of soil and calculate the adsorption coefficient value of each layer based on the experimental results;

[0087] The layer-by-layer simulation module is used to input the soil properties and adsorption coefficient values ​​of each soil layer into the pollutant migration simulation software, use the pollutant migration simulation software to simulate the vertical migration characteristics of pollutants in each soil layer layer by layer, and calculate the water output and pollutant concentration at the bottom of each layer;

[0088] The superposition module is used to superimpose the simulation results of each layer of soil to obtain the vertical distribution results of pollutants in the entire unsaturated zone of the soil.

[0089] Regarding the apparatus in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0090] In order to implement the above embodiments, the present application also proposes an electronic device, comprising: a processor, and a memory communicatively connected to the processor; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory to implement the method provided by the above embodiments.

[0091] In order to implement the above embodiments, the present application also proposes a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the methods provided by the above embodiments.

[0092] In order to implement the above embodiments, the present application also proposes a computer program product, including a computer program, which implements the methods provided by the above embodiments when executed by a processor.

[0093] The collection, storage, use, processing, transmission, provision and disclosure of user personal information involved in this application are in compliance with relevant laws and regulations and do not violate public order and good morals.

[0094] It is important to note that personal information collected from users should be used for legitimate and reasonable purposes and should not be shared or sold beyond these legitimate uses. Furthermore, such collection / sharing should be conducted only after receiving the user's informed consent, including but not limited to notifying the user to read the user agreement / user notice and sign an agreement / authorization that includes the relevant user information before using the feature. Furthermore, any necessary steps must be taken to safeguard and secure access to such personal information and ensure that others with access to personal information comply with its privacy policy and procedures.

[0095] This application contemplates providing implementations that allow users to selectively block the use or access of personal information data. Specifically, this disclosure contemplates providing hardware and / or software to prevent or block access to such personal information data. Risks can be minimized by limiting data collection and deleting data once it is no longer needed. Furthermore, where applicable, such personal information can be de-identified to protect user privacy.

[0096] In the descriptions of the foregoing embodiments, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean 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 expressions of the above terms do 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. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are mutually inconsistent.

[0097] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0098] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0099] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic devices), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and a portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0100] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0101] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

[0102] In addition, the functional units in the various embodiments of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into a module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0103] The storage medium mentioned above may be a read-only memory, a magnetic disk, or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application. Persons skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

[0104] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this application can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of this application can be achieved. This is not limited herein.

[0105] The above specific embodiments do not constitute a limitation on the scope of protection of this application. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application shall be included within the scope of protection of this application.

Claims

1. A method for simulating vertical migration of unsaturated soil zone based on adsorption coefficient stratification, characterized in that: The following steps are involved: Soil profile samples were collected in the study area to determine the distribution depth of soil properties, and the soil profile was divided into multiple layers based on the cross-values, combined with the distribution depth of soil organic matter and inorganic ions; Conduct equilibrium adsorption experiments in each layer of soil and calculate the adsorption coefficient value of each layer based on the experimental results; Inputting the soil properties and adsorption coefficient values ​​of each soil layer into the pollutant migration simulation software, using the pollutant migration simulation software to simulate the vertical migration characteristics of pollutants in each soil layer layer by layer, and calculating the water output and pollutant concentration at the bottom of each layer; The simulation results of each layer of soil are superimposed to obtain the vertical distribution results of pollutants in the entire unsaturated zone of the soil.

2. The method according to claim 1, characterized in that The equilibrium adsorption experiment is carried out in each layer of soil, and the adsorption coefficient value of each layer is calculated based on the experimental results, including: In each layer of soil, a preset mass of soil sample is taken and mixed with the pollutant solution. After sufficient reaction, the concentration change of the pollutant in the solution is measured to obtain the equilibrium concentration C e ; By measuring the initial concentration C0 of the pollutant in the solution and the concentration C after the reaction equilibrium e , calculate the adsorption amount Q of pollutants in soil, the formula is: The adsorption coefficient K of each layer of soil is calculated using the following formula: d The value is: Among them, Q is the amount of pollutants adsorbed by the soil, C e is the concentration of the pollutant in the solution after the reaction equilibrium, C0 is the initial concentration of the pollutant in the solution, V is the volume of the solution, and M is the mass of the soil.

3. The method according to claim 2, characterized in that The soil properties and adsorption coefficient values ​​of each soil layer are input into the pollutant migration simulation software, and the pollutant migration simulation software is used to simulate the vertical migration characteristics of pollutants in each soil layer layer by layer, and calculate the water output and pollutant concentration at the bottom of each layer, including: In n layers of soil, the topsoil is set as the first layer, and so on, the bottom soil is set as the nth layer; Inputting the soil properties and adsorption coefficient values ​​of the first layer of soil into the pollutant migration simulation software, and simultaneously inputting the pollutants into the pollutant migration simulation software through a constant flux or constant head input method, simulating the vertical distribution characteristics of the pollutants in the first layer of soil, and calculating the water output at the bottom of the first layer of soil, and calculating the pollutant concentration of the effluent water of the first layer of soil based on the water output at the bottom of the first layer of soil; Inputting the soil properties and adsorption coefficient values ​​of the second layer of soil into the pollutant migration simulation software, and inputting the pollutant concentration of the first layer of soil into the pollutant migration simulation software in a constant flux manner, simulating the vertical distribution characteristics of the pollutants in the second layer of soil, and calculating the water output at the bottom of the second layer of soil, and calculating the pollutant concentration of the effluent water of the second layer of soil based on the water output at the bottom of the second layer of soil; Similarly, the soil properties and adsorption coefficient values ​​of the nth layer of soil are input into the pollutant migration simulation software, and the pollutant concentration of the n-1th layer of effluent is input into the software in a constant flux manner to simulate the vertical distribution characteristics of pollutants in the nth layer of soil.

4. A device for simulating vertical migration of unsaturated soil zone based on adsorption coefficient stratification, characterized in that: include: The collection and stratification module is used to collect soil profile samples in the study area, determine the distribution depth of soil properties, and divide the soil profile into multiple layers based on cross-values ​​in combination with the distribution depth of soil organic matter and inorganic ions; Adsorption coefficient calculation module, used to carry out equilibrium adsorption experiments in each layer of soil and calculate the adsorption coefficient value of each layer based on the experimental results; A layer-by-layer simulation module is used to input the soil properties and adsorption coefficient values ​​of each soil layer into the pollutant migration simulation software, use the pollutant migration simulation software to simulate the vertical migration characteristics of pollutants in each soil layer layer by layer, and calculate the water output and pollutant concentration at the bottom of each layer; The superposition module is used to superimpose the simulation results of each layer of soil to obtain the vertical distribution results of pollutants in the entire unsaturated zone of the soil.

5. An electronic device, characterized in that: include: a processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 1 to 3.

6. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 3 when executed by a processor.

7. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 1 to 3 when executed by a processor.

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