A method and system for identifying and assessing damage from groundwater contamination risk

Abstract

The application discloses a method and system for identifying and evaluating groundwater diffusion risk damage, and belongs to the technical field of risk assessment. The technical problem to be solved is that the prediction of future pollution risk trend is not considered, the pollution diffusion process cannot be dynamically responded, the groundwater diffusion risk damage cannot be quantified, and the quantification precision is low. The technical points are that the method comprises the following steps: S1, obtaining a pollution source and hydrological parameters; S2, constructing a pollution diffusion model; S3, calculating the concentration of a coordinate position at a t time in real time, and forming an over-standard area according to the over-standard groups; S4, calculating a risk index; S5, calculating a diffusion risk damage quantification value according to the risk index; S6, constructing a fusion network according to the risk index, performing risk space-time prediction, and obtaining a future risk index.

Description

Technical Field

[0001] This invention relates to the field of risk assessment technology, and in particular to a method and system for identifying and assessing groundwater diffusion risk damage. Background Technology

[0002] Groundwater is a vital source of drinking water and agricultural irrigation. Once chemically contaminated, its remediation is costly, time-consuming, and highly uncertain. Current groundwater pollution assessments often rely on on-site monitoring or empirical curve extrapolation, lacking a unified and reproducible mathematical calculation system, leading to significant discrepancies between assessment results and actual damage quantification. Furthermore, existing methods rarely consider water flow directionality, pollutant self-degradation effects, and regional economic and ecological sensitivity simultaneously, resulting in a lack of precision in risk level classification.

[0003] Chinese patent CN120258518A, published on July 4, 2025, discloses a method and related apparatus for assessing the pollution risk of groundwater environment. This method, through the construction of a groundwater pollutant migration model, can accurately simulate the migration and diffusion of pollutants in groundwater. It calculates exposure levels by combining the distribution of sensitive receptors, and calculates the risk index and probability based on toxicological parameters, ultimately determining the risk level.

[0004] The prior art represented by the aforementioned patents has at least the following technical problems or defects that need to be addressed: it does not take into account the prediction of future pollution risk trends, and it cannot dynamically reflect the pollution diffusion process, making it impossible to quantify the risk of groundwater diffusion damage, and the quantification accuracy is low. Summary of the Invention

[0005] The purpose of this invention is to provide:

[0006] A method and system for identifying and assessing groundwater diffusion risk damage, and related technologies, to solve technical problems such as the inability to quantify groundwater diffusion risk damage and low quantification accuracy, or a combination thereof.

[0007] Terminology Explanation: Unless otherwise defined, all technical terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this subject matter pertains. Unless otherwise stated, all patents, patent inventions, and disclosures cited throughout this document are incorporated herein by reference in their entirety. Where multiple definitions exist for terms herein, the definitions provided in this chapter shall prevail.

[0008] It should be understood that the above brief description and the following detailed description are exemplary and for illustrative purposes only, and do not limit the subject matter of the invention in any way. In this invention, the singular is used in conjunction with the plural unless otherwise specifically stated. It should also be noted that, unless otherwise stated, the use of “or” or “or” means “and / or”. Furthermore, the use of the term “comprising” and other forms such as “including,” “containing,” and “contains” are not limiting.

[0009] The definition of the standard terminology can be found in the reference "Theory and Practice of Groundwater Environmental Investigation, Assessment and Pollution Prevention Zoning".

[0010] Unless otherwise stated, conventional methods within the scope of the art, such as grey clustering or fuzzy data methods, shall be used.

[0011] Unless otherwise defined, the use of various commercially available products as described herein employs standard techniques. These techniques and methods can generally be implemented according to conventional methods well-known in the art, based on the descriptions in the numerous general and more specific documents cited and discussed in this specification.

[0012] In a first aspect, the present invention provides: a method for identifying and assessing the risk of groundwater diffusion damage.

[0013] This includes the following steps: S1. Obtain pollution source and hydrological parameters, and perform standardized processing; S2. Construct a pollution diffusion model; S3. Calculate the real-time value at time t based on the pollution diffusion model. Concentration at coordinate location Set three levels of indicators for groundwater environmental quality. ,when When it is judged to be exceeding the standard, the excess is... Forming areas exceeding standards ; S4, based on real-time calculations and areas exceeding standards Calculate the risk index; S5. Calculate the quantitative value of the spread risk damage based on the risk index; S6. Based on the risk index, construct a fusion network to perform spatiotemporal risk prediction and obtain the future risk index.

[0014] The pollution diffusion model constructed in step S2 is calculated using the following formula: ; In the above formula, Indicates the pollutant at time t. Concentration at coordinate location, Indicates total emissions. The x-coordinate represents the location of the pollutant. The vertical coordinate represents the location of the pollutant; Indicates the diffusion coefficient. , These represent the components of the groundwater flow velocity in the x and y directions, respectively. This indicates factors that take into account adsorption, degradation, or dilution.

[0015] in, This can be expressed by the following formula: ; ; In the above formula, The first-order coefficient representing chemical / biodegradation, Indicates the pollution dilution and attenuation factor. This represents the retardation coefficient describing the adsorption lag effect; This indicates the concentration of pollutants released from the source.

[0016] R is calculated using the following formula: ; ; In the above formula, Expressed as the volume density of the underground medium, This represents the linear distribution coefficient, where n represents the effective porosity. This is expressed as the organic carbon partition coefficient. This indicates the organic carbon content of the medium.

[0017] in, The following formula can be used to calculate: ; In the above formula, This indicates the environmental half-life of a pollutant.

[0018] The risk index in step S4 is calculated using the following formula: ; In the above formula, Indicates the risk index. express The weight of the location sampling point.

[0019] In step S5, the quantified value of diffusion risk damage is calculated using the following formula: ; ; In the above formula, This represents the quantified value of the diffusion risk damage at time t. Indicates the economic damage coefficient. Indicates the ecological damage coefficient. Represents the quantified value of the ecosystem service function at time t; Indicates the volume of the contaminated aquifer; This indicates the total volume of the aquifer in the region. This indicates the average pollution concentration of the groundwater pollution plume. This indicates the background concentration of groundwater.

[0020] S6 includes the following steps: S61. The risk index is analyzed and predicted using a time-stepping method, expressed by the following formula: ; ; ; In the above formula, Indicates after time t Quantitative value of the risk of spread over time. Indicates the risk growth rate. Indicates the risk decay factor. t represents the time step. Indicates the actual flow velocity of groundwater. Indicates the characteristic length of the pollution plume. Indicates the environmental half-life of a pollutant; S62. Introduce a two-layer LSTM time series prediction model, using historical risk indices and relevant hydrological and environmental characteristics as inputs to construct a time series network model and output the network prediction values. ; S63, the result obtained in step S61 The result obtained from step S62 By using a weighted fusion method, we obtain the following formula: ; In the above formula, Indicates the weighting coefficient. This represents a future risk index used to estimate future damage. ; Future damage will be achieved through Substitute into the formula for calculating the quantification value of diffusion risk damage in step S5 and replace This is obtained, thus forming a trend curve.

[0021] The pollution source and hydrological parameters obtained in step S1 include initial concentration, total discharge, discharge duration, diffusion coefficient, effective permeability, attenuation coefficient, safe concentration standard, and regional weighting coefficient.

[0022] Secondly, the present invention provides a groundwater diffusion risk assessment system.

[0023] It includes the first module, the second module, the third module, the fourth module, the fifth module, and the sixth module.

[0024] The first module is used to execute the contents of step S1.

[0025] The second module is used to execute the contents of step S2.

[0026] The third module is used to execute the contents of step S3.

[0027] The fourth module is used to execute the contents of step S4.

[0028] The fifth module is used to execute the contents of step S5.

[0029] The sixth module is used to execute the contents of step S6.

[0030] The present invention has at least the following beneficial effects: This invention proposes a formulaic risk quantification index, illustrating the integral relationship between the risk index and concentration distribution, dynamically reflecting the pollution diffusion process; it establishes a damage correlation model, for the first time linearly coupling the risk index with economic / ecological losses, enabling the calculation of compensation amounts; it enhances spatiotemporal prediction capabilities, predicting future pollution risk trends and generating data curves; finally, it introduces weighting factors, considering population density and ecological sensitivity in different regions, to achieve differentiated assessments. Attached Figure Description

[0031] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0032] The technical solution of the present invention will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0033] Example 1 like Figure 1 As shown in the figure, this embodiment provides a method for identifying and assessing groundwater diffusion risk damage, including the following steps: S1. Obtain pollution source and hydrological parameters, and standardize the parameters.

[0034] Pollution sources and hydrological parameters include initial concentration, total discharge, discharge duration, diffusion coefficient, effective permeability, attenuation coefficient, safe concentration standard, and regional weighting coefficient.

[0035] The following formula is used for standardization: ; In the above formula, This represents the i-th pollution source and its hydrological parameters, where i ranges from 1 to 8. This represents the minimum value of the hydrological parameter for the i-th pollution source. This represents the maximum value of the i-th pollution source and the hydrological parameter. This represents the standardized value of the i-th pollution source and hydrological parameters.

[0036] S2. Construct a pollution diffusion model, specifically a two-dimensional transient pollution diffusion equation or a three-dimensional transient pollution diffusion equation. The two-dimensional transient pollution diffusion equation is expressed as: ; In the above formula, Indicates the pollutant at time t. Concentration at coordinate location, mg / L; Indicates total emissions. The x-coordinate represents the location of the pollutant. The vertical coordinate represents the location of the pollutant; Indicates the diffusion coefficient. ; , Let x and y represent the components of the groundwater flow velocity in the x and y directions, respectively, in m / d; This indicates factors that take into account adsorption, degradation, or dilution.

[0037] To more accurately characterize the adsorption, degradation, and dilution processes of pollutants in groundwater systems, To further refine this, it can be expressed as follows: ; In the above formula, The first-order coefficient representing chemical / biodegradation, Indicates the pollution dilution and attenuation factor. This represents the retardation coefficient describing the adsorption lag effect; all three factors together influence the concentration decay behavior over time.

[0038] , , Specifically, it is calculated using the following formula; (1) The lag coefficient R is a dimensionless coefficient used to quantify the degree of "lag" of pollutant migration velocity in groundwater relative to groundwater flow velocity. This coefficient is used to correct the transport velocity of pollutants; it is specifically derived based on the one-dimensional convection-dispersion equation and combined with the linear adsorption isotherm; the specific derivation process is as follows: 1) The transport of pollutants in porous media follows the mass conservation equation, expressed as: ; In the above formula, This indicates the concentration of the solute in the liquid phase, in kg / m³. 3 , The hydrodynamic dispersion coefficient, m 2 / s, where t represents time (s), x represents distance (m), and v represents pore velocity (m / s). The solid concentration at adsorption equilibrium is expressed in kg / kg, and n represents the effective porosity, which is dimensionless. Adsorption terms represent the transfer of solute from the liquid phase to the solid phase due to adsorption.

[0039] 2) Assume the adsorption process is instantaneously reversible and conforms to a linear isotherm, i.e., S is expressed by the following formula: ; Differentiating with respect to time yields the following equation: ; In the above formula, This represents the linear distribution coefficient, in L / kg.

[0040] 3) Substituting the formula in 2) into 1) yields the following formula: ; By arranging and combining like terms, we obtain the following formula: ; In the above formula, As the hysteresis coefficient R, it is expressed as: ; In the above formula, Expressed as the bulk density of underground media, kg / m³ 3 ; represents the linear distribution coefficient, L / kg; n represents the effective porosity, dimensionless.

[0041] The larger the value of R, the stronger the interaction between the pollutant and the solid phase, and the slower its effective transport rate in groundwater. For organic pollutants, It can be determined based on the relationship between the organic carbon partition coefficient and the organic carbon content of the medium, specifically expressed as follows: ; In the above formula, It is expressed as the organic carbon partition coefficient, which is related to the properties of pollutants and can be obtained by querying chemical databases; This indicates the organic carbon content of the medium. For topsoil, Take a value of 0.01-0.1; for shallow aquifers, Take a value of 0.0002-0.002; for deep aquifers, Negligible.

[0042] n is obtained from the soil / medium type reference table in Table 1.

[0043] Table 1. Soil / Media Type Reference Table

[0044] (2) ; In the above formula, Indicates the environmental half-life of a pollutant. For easily degradable organic compounds (such as benzene compounds), or under aerobic conditions, The value range is 0.005~0.071. For recalcitrant organic compounds (such as chlorinated hydrocarbons) or in anaerobic environments, The value range is 0.0002~0.005. For non-degradable pollutants (such as heavy metals), The value of approaches 0.

[0045] (3) ; In the above formula, The concentration released from the pollution source is indicated by the pollution dilution and attenuation factor, which represents the ratio of the pollution source concentration to the concentration in the assessment area after the pollutant enters the groundwater. This factor is used to comprehensively describe the equivalent "volume increase" effect in the groundwater system caused by processes such as lateral clean water recharge, vertical seepage recharge, pumping induction, and artificial recharge, without altering the spatial morphology of the Gaussian distribution, but rather through an exponential term. The non-reactive decay of the overall concentration over time can be reflected by inversion based on empirical formulas or by fitting a curve of the concentration change over time.

[0046] S3. Real-time calculation based on pollution diffusion model And determine whether the concentration of pollutants at that time and location exceeds the standard. At that time, among them, This indicates that the groundwater environmental quality level 3 index value is considered to be exceeding the standard. constituting an area exceeding the standard .

[0047] S4, based on real-time calculations and areas exceeding standards The risk index is calculated using the following formula: ; In the above formula, Indicates the risk index. express The weight of the location sampling point.

[0048] S5. Based on the risk index, calculate the quantitative value of the diffusion risk damage, thereby quantifying the economic and ecological damage. Specifically, this is calculated using the following formula: ; ; In the above formula, This represents the quantified value of the diffusion risk damage at time t. Indicates the economic damage coefficient. Indicates the ecological damage coefficient. This represents the quantified value of the ecosystem service function at time t. The volume of the contaminated aquifer is expressed in meters (m). 3 ; The total volume of the aquifer in the region is expressed in m. 3 ; This indicates the average pollution concentration of the groundwater pollution plume, expressed in kg / m³. 3 ; This indicates the background concentration of groundwater, in kg / m³. 3 ;

[0049] Economic damage coefficient Ecological damage coefficient The values ​​are determined according to different groundwater functional zones, as shown in Table 2 below.

[0050] Table 2. Values ​​based on groundwater functional zone division

[0051] S6. Based on the risk index, construct a fusion network to perform spatiotemporal risk prediction, specifically including the following steps: S61. The risk index is analyzed and predicted using a time-stepping method, specifically expressed by the following formula: ; In the above formula, Indicates after time t Quantitative value of the risk of spread over time. Indicates the risk growth rate. Indicates the risk decay factor. t represents the time step.

[0052] The risk growth rate g represents the rate of contamination expansion caused by groundwater convection and diffusion, and is specifically calculated using the following formula: ; In the above formula, This indicates the actual flow velocity of groundwater, in m / s; The characteristic length of the pollution plume is expressed in meters (m).

[0053] Risk decay factor The risk decay factor characterizes the natural decay rate of pollutant concentration per unit time, mainly determined by biodegradation, based on first-order reaction kinetics. Specifically, it is calculated using the following formula: .

[0054] S62. Introduce the time-series prediction function of the large-scale network model, using historical risk indices, hydrological and environmental characteristics as inputs, construct a time-series network model, and output network prediction values. .

[0055] A two-layer LSTM (Long Short-Term Memory) temporal prediction model is constructed, consisting of an input layer, an encoding layer, and an output layer. The input layer uses a tensor with a receiving time step of 30 and a feature dimension of 5. The encoding layer contains two stacked LSTM units: the first layer has 64 hidden units and uses the tanh activation function to extract high-order temporal features, while the second layer has 32 hidden units for feature compression. Dropout = 0.2 is added between the first and second layers to prevent overfitting. The output layer is a fully connected layer with an output dimension of 1, directly outputting the data. The predicted risk value at time step. The Adam optimizer (learning rate 0.001) is used to minimize the mean squared error (MSE) loss function. The historical risk index is divided into training and test sets (ratio 8:2). The network weights are updated through backpropagation until the loss converges.

[0056] S63, the result obtained in step S61 The result obtained from step S62 By using a weighted fusion method, we obtain the following formula: ; In the above formula, This represents the weighting coefficient, which is determined based on historical prediction errors or model reliability. This represents a future risk index used to estimate future damage. The amount of future damage will be achieved through Substitute into the formula for calculating the quantification value of diffusion risk damage in step S5 and replace This yields a trend curve.

[0057] Example 2 This embodiment provides a groundwater diffusion risk assessment system, including a first module, a second module, a third module, a fourth module, a fifth module, and a sixth module. The first module is used to execute the contents of step S1, the second module is used to execute the contents of step S2, the third module is used to execute the contents of step S3, the fourth module is used to execute the contents of step S4, the fifth module is used to execute the contents of step S5, and the sixth module is used to execute the contents of step S6.

[0058] This invention utilizes monitoring data, introduces flow direction parameters and regional weights to improve the spatial resolution of risk; it possesses trend prediction capabilities to support early warning; and it meets the requirements of forensic identification for scientific rigor, traceability, and repeatability. It proposes a formulaic risk quantification index, illustrating the integral relationship between the risk index and concentration distribution, dynamically reflecting the pollution diffusion process; it establishes a damage correlation model, linearly coupling the risk index with economic / ecological losses for the first time, enabling the calculation of compensation amounts; it enhances spatiotemporal prediction capabilities, predicting future pollution risk trends and generating data curves; finally, it introduces weighting factors, considering population density and ecological sensitivity in different regions, to achieve differentiated assessments.

[0059] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A method for identifying and assessing groundwater diffusion risk damage, characterized in that, Includes the following steps: S1. Obtain pollution source and hydrological parameters, and perform standardized processing; S2. Construct a pollution diffusion model; S3. Calculate the real-time value at time t based on the pollution diffusion model. Concentration at coordinate location Set three levels of indicators for groundwater environmental quality. ,when When it is judged to be exceeding the standard, the excess is... Forming areas exceeding standards ; S4, based on real-time calculations and areas exceeding standards Calculate the risk index; S5. Calculate the quantitative value of the spread risk damage based on the risk index; S6. Based on the risk index, construct a fusion network to perform spatiotemporal risk prediction and obtain the future risk index.

2. The method for identifying and assessing groundwater diffusion risk damage according to claim 1, characterized in that, The pollution diffusion model constructed in step S2 is calculated using the following formula: ； In the above formula, Indicates the pollutant at time t. Concentration at coordinate location, Indicates total emissions. The x-coordinate represents the location of the pollutant. The vertical coordinate represents the location of the pollutant; Indicates the diffusion coefficient. , These represent the components of the groundwater flow velocity in the x and y directions, respectively. This indicates factors that take into account adsorption, degradation, or dilution.

3. The method for identifying and assessing groundwater diffusion risk damage according to claim 2, characterized in that, This can be expressed by the following formula: ； ； In the above formula, The first-order coefficient representing chemical / biodegradation, Indicates the pollution dilution and attenuation factor. This represents the retardation coefficient describing the adsorption lag effect; This indicates the concentration of pollutants released from the source.

4. The method for identifying and assessing groundwater diffusion risk damage according to claim 3, characterized in that, R is calculated using the following formula: ； ； In the above formula, Expressed as the volume density of the underground medium, This represents the linear distribution coefficient, where n represents the effective porosity. This is expressed as the organic carbon partition coefficient. This indicates the organic carbon content of the medium.

5. The method for identifying and assessing groundwater diffusion risk damage according to claim 3, characterized in that, The following formula can be used to calculate: ； In the above formula, This indicates the environmental half-life of a pollutant.

6. The method for identifying and assessing groundwater diffusion risk damage according to claim 1, characterized in that, The risk index in step S4 is calculated using the following formula: ； In the above formula, Indicates the risk index. express The weight of the location sampling point.

7. The method for identifying and assessing groundwater diffusion risk damage according to claim 6, characterized in that, In step S5, the quantified value of diffusion risk damage is calculated using the following formula: ； ； In the above formula, This represents the quantified value of the diffusion risk damage at time t. Indicates the economic damage coefficient. Indicates the ecological damage coefficient. Represents the quantified value of the ecosystem service function at time t; Indicates the volume of the contaminated aquifer; This indicates the total volume of the aquifer in the region. This indicates the average pollution concentration of the groundwater pollution plume. This indicates the background concentration of groundwater.

8. The method for identifying and assessing groundwater diffusion risk damage according to claim 6, characterized in that, S6 includes the following steps: S61. The risk index is analyzed and predicted using a time-stepping method, expressed by the following formula: ； ； ； In the above formula, Indicates after time t Quantitative value of the risk of spread over time. Indicates the risk growth rate. Indicates the risk decay factor. t represents the time step. Indicates the actual flow velocity of groundwater. Indicates the characteristic length of the pollution plume. Indicates the environmental half-life of a pollutant; S62. Introduce a two-layer LSTM time series prediction model, using historical risk indices and relevant hydrological and environmental characteristics as inputs to construct a time series network model and output the network prediction values. ; S63, the result obtained in step S61 The result obtained from step S62 By using a weighted fusion method, we obtain the following formula: ； In the above formula, Indicates the weighting coefficient. This represents a future risk index used to estimate future damage. ; Future damage will be achieved through Substitute into the formula for calculating the quantification value of diffusion risk damage in step S5 and replace This is obtained, thus forming a trend curve.

9. The method for identifying and assessing groundwater diffusion risk damage according to claim 1, characterized in that, The pollution source and hydrological parameters obtained in step S1 include initial concentration, total discharge, discharge duration, diffusion coefficient, effective permeability, attenuation coefficient, safe concentration standard, and regional weighting coefficient.

10. A groundwater diffusion risk assessment system, characterized in that, The method for identifying and assessing groundwater diffusion risk damage according to any one of claims 1-9 includes a first module, a second module, a third module, a fourth module, a fifth module, and a sixth module. The first module is used to perform the content of step S1, the second module is used to perform the content of step S2, the third module is used to perform the content of step S3, the fourth module is used to perform the content of step S4, the fifth module is used to perform the content of step S5, and the sixth module is used to perform the content of step S6.

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