A method and system for analyzing groundwater pollution sources and assessing risks

Abstract

The present invention relates to the field of groundwater technology, specifically to a method and system for groundwater pollution source analysis and risk assessment, comprising the following steps: arranging monitoring points in potential groundwater affected areas, collecting water samples, analyzing organic pollutants, heavy metal content and microbial metabolites in water samples, collecting characteristic spectral data of pollutants, and performing normalization processing to obtain pollutant spectral feature sets. The present invention achieves accurate detection of trace pollutants by analyzing organic pollutants, heavy metals and microbial metabolites in water samples using liquid chromatography-mass spectrometry technology. The normalization processing of pollutant spectral feature sets improves the level of data standardization, facilitates cross-regional data comparison and analysis, and automated data comparison can quickly identify pollution sources, reduce errors, and improve response speed. The detailed analysis of spatial distribution data provides a comprehensive picture of pollution diffusion, making risk assessment more comprehensive.

Description

Technical Field

[0001] The present invention relates to the technical field of groundwater, and particularly to a method and system for analyzing groundwater pollution sources and assessing risks. Background Art

[0002] The technical field of groundwater involves multiple aspects such as exploration, extraction, management, and protection of groundwater. This field focuses on the sustainability and sustainable utilization of groundwater resources. Especially in the context of the increasingly tight global water resources, the technologies include groundwater monitoring, pollution control and remediation technologies, as well as the rational allocation and utilization of water resources. The groundwater field covers scientific research on groundwater systems, such as hydrogeology, hydrodynamics, and the study of the migration and distribution patterns of pollutants in the groundwater environment.

[0003] Among them, the method for analyzing groundwater pollution sources and assessing risks focuses on identifying and evaluating the pollution risks to groundwater and their sources, including using various geological, chemical, and biological technologies to analyze groundwater samples, determining the types and concentrations of pollutants, thereby revealing the pollution sources and propagation paths. Its main purpose is to formulate effective groundwater protection and remediation measures, prevent further pollution, ensure public health and ecological safety, and help decision-makers formulate scientific management policies and response strategies.

[0004] The existing technologies are limited by the sensitivity of equipment and the limitations of analysis methods in quickly identifying and accurately determining pollutants, resulting in the inability to effectively cover a wide range of pollutant types, lacking sufficient real-time update and high-precision analysis capabilities, delaying pollution assessment and response strategies, exacerbating groundwater pollution problems in the context of increasingly tight water resources, lacking efficient real-time monitoring and automated analysis, which is particularly crucial in the early warning and rapid response to groundwater pollution incidents, restricting the timeliness and effectiveness of groundwater protection measures, and easily increasing environmental and public health risks. Summary of the Invention

[0005] The purpose of the present invention is to solve the drawbacks existing in the prior art, and to propose a method and system for analyzing groundwater pollution sources and assessing risks.

[0006] To achieve the above purpose, the present invention adopts the following technical scheme: A method for analyzing groundwater pollution sources and assessing risks, including the following steps,

[0007] S1: Arrange monitoring points in potential groundwater-affected areas, collect water samples, analyze the organic pollutants, heavy metal content, and microbial metabolites in the water samples, collect the characteristic spectral data of the pollutants, and perform normalization processing to obtain the pollutant spectral feature set;

[0008] S2: Based on the pollutant spectral feature set, identify the types of pollutants associated with the groundwater pollution source, and conduct numerical analysis on the pollutant concentrations at each monitoring point to determine the pollutant concentration at each monitoring point, obtaining the pollutant concentration distribution data;

[0009] S3: Invoke the pollutant concentration distribution data, combine with the geological background data of the groundwater pollution source, analyze the groundwater flow characteristics, analyze the hydraulic parameters affecting pollution diffusion, calculate the migration rate and diffusion radius of the pollutants, obtaining the pollution diffusion dynamic indicators;

[0010] S4: Based on the pollution diffusion dynamic indicators, analyze the reverse flow trajectories of the pollutants in different regions, evaluate the potential pollution source locations, and compare the pollutant concentration data of the pollution sources and their surrounding areas to screen out the pollution source points with prominent pollution concentrations, obtaining the pollution source assessment index.

[0011] The improvement of the present invention is that the pollutant spectral feature set includes spectral peaks, characteristic wavelengths, metabolite identifications, the pollutant concentration distribution data includes pollution intensity, pollution range, key monitoring points, the pollution diffusion dynamic indicators include migration paths, influence regions, dynamic change rates, and the pollution source assessment index includes source activity, influence intensity, risk potential.

[0012] The improvement of the present invention is that the specific steps for obtaining the pollutant spectral feature set are as follows:

[0013] S111: Arrange monitoring points in potential groundwater affected areas, collect water samples, detect the organic pollutants, heavy metal contents, and microbial metabolites in the water samples through liquid chromatography-mass spectrometry technology, extract the spectral data of each type of pollutant, and perform normalization processing on the spectral data to obtain normalized spectral data;

[0014] S112: Based on the normalized spectral data, analyze the spectral characteristics of the pollutants, calculate the peak positions, absorption intensities, and full-width at half-maximum, using the formula:

[0015] ;

[0016] Obtain the spectral feature values of the pollutants, where, represents the spectral feature value of the th type of pollutant, represents the peak position of the th type of pollutant at the th wavelength, represents the average value of the peak positions of all pollutants at the th wavelength, represents the absorption intensity of the th type of pollutant at the th wavelength, Represents the average value of the absorption intensity of all pollutants at the th wavelength, represents the number of wavelength points;

[0017] S113: Classify the spectral characteristics of the pollutants based on the numerical values of the spectral characteristics of the pollutants, summarize the spectral characteristic types of different pollutants, and obtain the pollutant spectral characteristic set.

[0018] The improvement of the present invention is that the step of obtaining the pollutant concentration distribution data is specifically as follows:

[0019] S211: Based on the pollutant spectral characteristic set, use the known pollutant spectral data to match the pollutant spectra in the monitoring data with the known pollutant spectra, identify the types of pollutants associated with the groundwater pollution source, and obtain the pollutant type identification result;

[0020] S212: Based on the pollutant type identification result, perform numerical analysis on the pollutant concentration at each monitoring point, using the formula:

[0021] ;

[0022] Determine the pollutant concentration at each monitoring point to obtain the pollutant concentration distribution data, where represents the concentration of the th pollutant at the th monitoring point, represents the spectral absorption intensity of the th pollutant at the th monitoring point, represents the volume of the th pollutant sample collected at the th monitoring point, is the spectral half-peak width adjustment factor of the th pollutant at the th monitoring point.

[0023] The improvement of the present invention is that the step of obtaining the pollution diffusion dynamic index is specifically as follows:

[0024] S311: Call the pollutant concentration distribution data, combine with the geological background data of the groundwater pollution source, analyze the flow velocity, flow direction and hydraulic gradient of the groundwater, and obtain the groundwater flow characteristic parameters;

[0025] S312: According to the groundwater flow characteristic parameters, use the formula:

[0026] ;

[0027] Calculate the groundwater flow velocity of each region , the pollutant migration rate is obtained, where represents the permeability coefficient, represents the hydraulic gradient, represents the saturated thickness, represents the flow distance;

[0028] S313: Based on the pollutant migration rate, combined with pollutant diffusion and variable hydraulic data, calculate the diffusion radius of the pollutant to obtain the pollution diffusion dynamic index.

[0029] The improvement of the present invention is that the specific steps for obtaining the pollution source assessment index are as follows:

[0030] S411: Based on the pollution diffusion dynamic index, collect the pollutant flow direction data in the differential area, and combine the groundwater flow velocity, hydraulic gradient and pollutant diffusion rate to analyze the reverse flow path of the pollutant in multiple areas to generate the pollution flow reverse trajectory data;

[0031] S412: Use the pollution flow reverse trajectory data to evaluate the pollutant concentration in the pollution source and its surrounding areas, determine the potential pollution source location, and use the formula:

[0032] ;

[0033] Calculate the pollution source concentration mutation index , where represents the pollutant concentration in area , represents the influence area of area , represents the change in pollutant concentration between adjacent areas, represents the distance between areas, is the total number of areas;

[0034] S413: According to the pollution source concentration mutation index, analyze the environmental characteristics of the pollution source point and its surrounding areas, screen the pollution source points with prominent pollution concentration to obtain the pollution source assessment index.

[0035] The improvement of the present invention is that the steps further include:

[0036] S5: According to the pollution source assessment index, combined with the groundwater usage status and ecological sensitivity, evaluate the impact of pollution on the groundwater quality and potential environmental risks, compare with the environmental safety standard, classify the groundwater pollution level of each area to obtain the groundwater pollution grade;

[0037] The groundwater pollution grade includes severity evaluation, emergency response level, and long-term monitoring requirements.

[0038] The improvements of the present invention are as follows. The specific steps for obtaining the groundwater pollution level are as follows:

[0039] S511: According to the pollution source assessment index, combined with the groundwater usage status and ecological sensitivity data, analyze the groundwater environmental vulnerability of each region, evaluate the impact of pollution on groundwater quality and potential environmental risks, and obtain the groundwater pollution impact index.

[0040] S512: Based on the groundwater pollution impact index, use the formula:

[0041] ;

[0042] Calculate the groundwater pollution risk index , where represents the groundwater pollution impact index of region , represents the water resource utilization rate of region , is the total number of regions;

[0043] S513: Based on the groundwater pollution risk index, compare it with the environmental safety standard, classify the groundwater pollution level of each region, and obtain the groundwater pollution level.

[0044] A groundwater pollution source analysis and risk assessment system, the system includes:

[0045] The pollutant data collection module arranges monitoring points based on potential groundwater affected areas, collects water samples, analyzes the organic pollutants, heavy metal content and microbial metabolites in the water samples, collects the characteristic spectral data of the pollutants, and obtains the pollutant spectral feature set.

[0046] The pollutant concentration analysis module, based on the pollutant spectral feature set, uses the known pollutant spectral data to compare with the monitoring data, identifies the pollutant types associated with the groundwater pollution source, and numerically analyzes the pollutant concentration at each monitoring point to obtain the pollutant concentration distribution data.

[0047] The pollution diffusion analysis module calls the pollutant concentration distribution data, combines the geological background data of the groundwater pollution source, analyzes the groundwater flow characteristics, including flow velocity, flow direction and hydraulic gradient, and analyzes the hydraulic parameters affecting pollution diffusion to obtain the pollution diffusion dynamic index.

[0048] The pollution source tracking module, based on the pollution diffusion dynamic index, analyzes the reverse flow trajectory of pollutants in different regions, evaluates the potential pollution source locations, screens the pollution source points with prominent pollution concentrations, and obtains the pollution source assessment index.

[0049] The groundwater pollution assessment module evaluates the impact of pollution on groundwater quality and potential environmental risks based on the pollution source assessment index, in combination with the groundwater usage status and ecological sensitivity, classifies the groundwater pollution levels in each region, and obtains the groundwater pollution grades.

[0050] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0051] In the present invention, by using liquid chromatography-mass spectrometry technology to analyze organic pollutants, heavy metals, and microbial metabolites in water samples, accurate detection of trace pollutants is achieved. The normalization process of the pollutant spectral feature set improves the data standardization level, facilitating cross-regional data comparison and analysis. Automated data comparison can quickly identify pollution sources, reduce errors, and improve the response speed. The detailed analysis of spatial distribution data provides a comprehensive picture of pollution diffusion, making the risk assessment more comprehensive. The analysis of pollutant migration rate and diffusion radius in combination with geological background and hydrodynamic data strengthens the accuracy of groundwater analysis, providing a basis for formulating groundwater protection and restoration strategies. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 is a flowchart of the method for analyzing groundwater pollution sources and assessing risks proposed by the present invention;

[0053] Figure 2 is a flowchart for obtaining the pollutant spectral feature set in the present invention;

[0054] Figure 3 is a flowchart for obtaining the pollutant concentration distribution data in the present invention;

[0055] Figure 4 is a flowchart for obtaining the pollution diffusion dynamic index in the present invention;

[0056] Figure 5 is a flowchart for obtaining the pollution source assessment index in the present invention;

[0057] Figure 6 is a flowchart for obtaining the groundwater pollution grade in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0058] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0059] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation on the present invention. In addition, in the description of the present invention, the meaning of "a plurality of" is two or more, unless otherwise specifically defined. Embodiment

[0060] Please refer to Figure 1 , the present invention provides a technical solution: a method for analyzing groundwater pollution sources and assessing risks, including the following steps:

[0061] S1: Arrange monitoring points in potential groundwater-affected areas, collect water samples, analyze the organic pollutants, heavy metal content, and microbial metabolites in the water samples through liquid chromatography-mass spectrometry technology, collect the characteristic spectral data of the pollutants, and perform normalization processing to obtain the pollutant spectral feature set;

[0062] S2: Based on the pollutant spectral feature set, use the known pollutant spectral data to compare with the monitoring data, identify the types of pollutants associated with the groundwater pollution sources, and perform numerical analysis on the pollutant concentrations at each monitoring point to determine the pollutant concentrations at each monitoring point, and obtain the pollutant concentration distribution data;

[0063] S3: Call the pollutant concentration distribution data, combine with the geological background data of the groundwater pollution sources, analyze the groundwater flow characteristics, including flow velocity, flow direction, and hydraulic gradient, analyze the hydraulic parameters affecting pollution diffusion, calculate the migration rate and diffusion radius of the pollutants, and obtain the pollution diffusion dynamic index;

[0064] S4: Based on the pollution diffusion dynamic index, analyze the reverse flow trajectories of the pollutants in different regions, evaluate the potential pollution source locations, and compare the pollutant concentration data of the pollution sources and their surrounding areas, and screen the pollution source points with prominent pollution concentrations to obtain the pollution source assessment index;

[0065] S5: According to the pollution source assessment index, combine with the groundwater usage status and ecological sensitivity (referring to ecological functions, ecological restoration capabilities, water resource utilization rates, and water body connectivity and basin characteristics), evaluate the impact of pollution on groundwater quality and potential environmental risks, compare with the environmental safety standards, and classify the groundwater pollution levels in each region to obtain the groundwater pollution grades.

[0066] The pollutant spectral feature set includes spectral peaks, characteristic wavelengths, metabolite identifications. The pollutant concentration distribution data includes pollution intensity, pollution range, and key monitoring points. The pollution diffusion dynamic indicators include migration paths, affected areas, and dynamic change rates. The pollution source assessment index includes source activity, influence intensity, and risk potential. The groundwater pollution level includes severity evaluation, emergency response level, and long-term monitoring requirements.

[0067] Please refer to Figure 2 , and the specific steps for obtaining the pollutant spectral feature set are as follows:

[0068] S111: Arrange monitoring points in potential groundwater-affected areas, collect water samples, detect the organic pollutants, heavy metal contents, and microbial metabolites in the water samples through liquid chromatography-mass spectrometry technology, extract the spectral data of each type of pollutant, and perform normalization processing on the spectral data to obtain normalized spectral data;

[0069] Arrange monitoring points in potential groundwater-affected areas, select the groundwater areas affected by pollution, determine the specific locations of the monitoring points, and reasonably layout the monitoring points based on the groundwater flow direction, stratum structure, pollutant sources, and diffusion paths. For example, set up monitoring points at the intersection of industrial emission areas, agricultural fertilization areas, and residential areas to ensure coverage of potential pollution diffusion areas. Collect water samples, adopt standard sampling techniques, and use on-site sampling equipment such as deep water samplers, peristaltic pumps, or sampling bottles to collect groundwater samples at different times and depths. Each monitoring point should be sampled multiple times to ensure the representativeness and repeatability of the data. Detect the organic pollutants, heavy metal contents, and microbial metabolites in the water samples through liquid chromatography-mass spectrometry technology. The specific detection steps include sample pretreatment, chromatographic separation, ionization, and mass spectrometry analysis. Extract the spectral data of each type of pollutant, obtain the characteristic peak information of each pollutant, including spectral absorption peaks, emission peaks, and the corresponding wavelength ranges. Perform normalization processing on the spectral data. Use the data normalization method to normalize the spectral intensities of different pollutants to the same scale to eliminate the influence caused by factors such as instrument sensitivity and sample concentration differences during the detection process. For example, for a certain type of organic pollutant, the original intensity of its absorption peak is between 5000 and 12000, and after normalization, it is converted to a relative value range of 0 to 1 to ensure the comparability of spectral data between different pollutants.

[0070] S112: Based on the normalized spectral data, analyze the spectral characteristics of the pollutants, calculate the peak position, absorption intensity, and full width at half maximum, using the formula:

[0071] ;

[0072] Obtain the spectral characteristic values of the pollutants, where represents the spectral characteristic value of the th pollutant, Represents the peak position of the th pollutant at the th wavelength. Represents the average value of the peak positions of all pollutants at the th wavelength. Represents the th pollutant's absorption intensity at the th wavelength. Represents the average value of the absorption intensities of all pollutants at the th wavelength. Represents the number of wavelength points;

[0073] Analyze the spectral characteristics of pollutants, extract the characteristics of the spectral data of different pollutants, calculate the peak position, absorption intensity, and full width at half maximum. The peak position is determined by calculating the maximum point of the spectral curve. For example, the absorption peaks of a certain pollutant appear at 260 nm, 340 nm, and 450 nm. The absorption intensity is obtained by calculating the integral area under the spectral curve or the maximum absorption rate value. For example, the absorption intensity of a certain pollutant at 260 nm is 0.85, at 340 nm is 0.63, and at 450 nm is 0.74. The full width at half maximum is defined as the wavelength interval width corresponding to half the height at the peak. If the peak positions of a certain pollutant at wavelengths 260 nm, 340 nm, and 450 nm are respectively: , and the absorption intensities are respectively: , calculate the mean value of the spectral peak positions of the pollutants:

[0074] ;

[0075] Calculate the mean value of the spectral absorption intensities of the pollutants:

[0076] ;

[0077] Calculate the squared deviation of each wavelength point:

[0078] ;

[0079] ;

[0080] ;

[0081] Calculate the squared deviation of the absorption intensity:

[0082] ;

[0083] ;

[0084] ;

[0085] Calculate the spectral characteristic values of pollutants:

[0086] ;

[0087] ;

[0088] ;

[0089] Obtain the spectral characteristic value of the pollutant 6066.69. This result indicates that the spectral characteristics of the pollutant have a specific offset, which can be used for subsequent classification and pollutant identification.

[0090] S113: Classify the spectral characteristics of pollutants based on the spectral characteristic values of pollutants, summarize the spectral characteristic types of different pollutants, and obtain the pollutant spectral characteristic set;

[0091] Classify the spectral characteristics of different pollutants. According to the spectral characteristic values of different pollutants, the pollutants are divided into different categories. For example, pollutants with similar peak positions but large differences in absorption intensity belong to similar chemical categories, while pollutants with large offsets in peak positions have different chemical structures. Summarize the spectral characteristic types of different pollutants and establish a spectral characteristic library. For example, for a group of organic pollutants, their spectral characteristic values are 0.0294, 0.0352, and 0.0411, etc., and they can be classified into the same category through clustering analysis or classification algorithms. For another group of inorganic pollutants, their spectral characteristic values are 0.0783 and 0.0924, etc., and they can be classified into another category to obtain the pollutant spectral characteristic set.

[0092] Please refer to Figure 3 , and the specific steps for obtaining the pollutant concentration distribution data are as follows:

[0093] S211: Based on the pollutant spectral characteristic set, use the known pollutant spectral data to match the pollutant spectra in the monitoring data with the known pollutant spectra, identify the types of pollutants associated with the groundwater pollution source, and obtain the pollutant type identification result;

[0094] Obtain the spectral data of known pollutants, match the pollutant spectra in the monitoring data with the known pollutant spectra, and extract the characteristic parameters of the pollutant spectra, including the peak wavelength, absorption intensity, and spectral morphology parameters. Compare the pollutant spectral information collected in the monitoring data with the known pollutant data, calculate the similarity at multiple wavelength points of the spectral curve, and make a determination according to the set matching threshold. For example, set the spectral matching threshold to 90%. When the matching degree of the spectral curve of the monitoring data with a certain known pollutant exceeds 90%, it is determined that the pollutant is the same as the known pollutant; otherwise, enter the further characteristic comparison process. For pollutants with a matching degree between 70% and 90%, the characteristic vector deviation calculation method is used for adjustment. By calculating the absorption peak position deviation, absorption intensity deviation, and full width at half maximum deviation, the spectral similarity is comprehensively calculated. The calculation formula is as follows: , where represents the spectral deviation value between the monitored pollutant and the known pollutant , represents the weight of the th spectral feature represents the spectral feature value of the monitored pollutant at the th position represents the spectral feature value of the known pollutant at the th position represents the number of selected spectral feature points. When setting the weight parameters, adjust according to the contribution degree of different spectral features. For example, set the weight of the absorption peak position comparison value to 0.5, the weight of the absorption intensity comparison value to 0.3, and the weight of the full width at half maximum to 0.2. After calculating the deviation value, if is less than the set matching threshold, such as 0.1, it is considered that the pollutant is a known pollutant; otherwise, perform a secondary comparison and further calculate through the sub-optimal matching pollutants in the spectral data to obtain the pollutant type identification result.

[0095] S212: Based on the pollutant type identification result, perform a numerical analysis on the pollutant concentration at each monitoring point, using the formula:

[0096] ;

[0097] Determine the pollutant concentration at each monitoring point to obtain the pollutant concentration distribution data, where represents the concentration of the th monitoring point for the th pollutant represents the th monitoring point of the th pollutant's spectral absorption intensity represents the th monitoring point where the The volume of the pollutant sample, is the spectral half-peak width adjustment factor of the th pollutant at the

[0098] For numerical analysis of the pollutant concentration at each monitoring point, the spectral absorption intensity of the identified pollutant is called, and calculations are performed in combination with the sampling volume at the monitoring point. For a certain monitoring point the th pollutant has an absorption intensity of 0.92, a sampling volume of 200 mL, and a corresponding spectral half-peak width of 1.8 nm. Then the pollutant concentration is calculated as follows:

[0099] ;

[0100] The calculated concentration of this pollutant is 65.71 mg / L. This value can be used to evaluate the pollutant concentration at the monitoring point and obtain the pollutant concentration distribution data.

[0101] Please refer to Figure 4 , and the specific steps for obtaining the pollution diffusion dynamic index are as follows:

[0102] S311: Call the pollutant concentration distribution data, combine it with the geological background data of the groundwater pollution source, analyze the flow velocity, flow direction, and hydraulic gradient of the groundwater, and obtain the groundwater flow characteristic parameters;

[0103] Combined with the geological background data of the groundwater pollution source, the flow velocity, flow direction, and hydraulic gradient of the groundwater are obtained. The flow velocity of the groundwater can be obtained by monitoring the water flow velocities at different depths and positions, usually measured using a flow velocity meter or a tracer experiment. For example, at a certain polluted site, by arranging groundwater observation wells, regularly measuring the elevation of the groundwater level, and calculating the flow velocity using Darcy's law. The determination of the flow direction depends on the direction of the head gradient, and the groundwater equipotential line can be drawn through the water level measurement data to judge the groundwater flow direction. The calculation of the hydraulic gradient is based on the head difference between different observation points divided by their horizontal distance. For example, at an industrial polluted site, assuming the water levels of two observation wells A and B are 32.5 m and 30.2 m respectively, and the horizontal distance is 100 m, then the hydraulic gradient , and the calculated hydraulic gradient is used for further analysis of the groundwater dynamic characteristics. After obtaining the data, normalization processing is required to eliminate measurement errors, interpolation methods are used to fill in missing data to ensure data integrity, and combined with historical monitoring data, the change trend of the groundwater dynamic characteristics in different time periods is analyzed to obtain the groundwater flow characteristic parameters.

[0104] S312: According to the groundwater flow characteristic parameters, use the formula:

[0105] ;

[0106] Calculate the groundwater flow velocity in each area , and obtain the pollutant migration rate, where represents the permeability coefficient, which is a parameter measuring the ability of soil or rock to allow water flow through represents the hydraulic gradient, which refers to the head loss per unit distance and is used to calculate the driving force of water flow in soil represents the saturated thickness, that is, the thickness of the area where groundwater is completely saturated, and this parameter affects the amount of groundwater flow represents the flow distance, that is, the distance that pollutants migrate in groundwater

[0107] In a certain polluted site, the following data are collected

[0108] Permeability coefficient (measured by pumping test);

[0109] Hydraulic gradient (calculated by measuring the water level of observation wells);

[0110] Saturated thickness (measured by geological section);

[0111] Flow distance (horizontal distance from the pollution source to the observation well).

[0112] Substitute the values into the formula for calculation

[0113] ;

[0114] ;

[0115] The calculation result shows that the groundwater pollution migration rate in the selected area is , which can be used to predict the diffusion rate of pollutants and further evaluate its environmental impact, and obtain the pollutant migration rate

[0116] S313: Based on the pollutant migration rate, combined with pollutant diffusion and variable hydraulic data, calculate the diffusion radius of pollutants to obtain the dynamic index of pollution diffusion

[0117] Combined with the change of pollutant diffusion coefficient and hydraulic gradient, calculate the diffusion radius of pollutants. The calculation of the diffusion radius needs to consider the longitudinal dispersion and transverse diffusion effects of pollutants in groundwater. The longitudinal dispersion can be jointly determined by the groundwater flow velocity and the dispersion coefficient. For example, the longitudinal dispersion coefficient of a certain polluted site is , and the transverse diffusion is related to the groundwater flow velocity and formation characteristics. For example, the transverse dispersion coefficient is , by calculating the diffusion range of pollutants in different directions and calibrating with the observed data, the diffusion range of pollutants in groundwater can be determined. During the calculation process, numerical simulation or analytical methods are used to solve the problem, and combined with the change of hydraulic gradient, the dynamic index of pollution diffusion is obtained.

[0118] Please refer to Figure 5 , the steps to obtain the pollution source assessment index are specifically as follows:

[0119] S411: Based on the dynamic index of pollution diffusion, collect the pollution flow direction data of the differential area, and combine the groundwater flow velocity, hydraulic gradient and pollutant diffusion rate to analyze the reverse flow path of pollutants in multiple areas and generate pollution flow reverse trajectory data;

[0120] Data can be collected long-term through the layout of groundwater monitoring wells and hydrographic exploration equipment. For example, in an industrial area, groundwater level gauges and flow velocity measuring instruments are installed to record the flow velocity and flow direction of groundwater at fixed time intervals to form a flow direction data set. Combine the groundwater flow velocity, hydraulic gradient and pollutant diffusion rate to process the pollution flow direction data and extract the pollutant diffusion trend. Among them, the groundwater flow velocity can be calculated by Darcy's law, and the hydraulic gradient is obtained by dividing the groundwater level difference by the horizontal distance. For example, in a certain site, if the water level difference between two observation wells is 1.8m and the spacing is 150m, then the hydraulic gradient is 0.012, and the pollutant diffusion rate is jointly determined by the longitudinal dispersion coefficient and the flow velocity. For example, assuming that the longitudinal dispersion coefficient of the site is 0.2 , then the diffusion rate can be calculated by fitting with experimental data. Using the parameters, draw a map of the pollutant diffusion range, and combine the changes of the groundwater flow velocity and hydraulic gradient to analyze the flow characteristics of pollutants in a specific area. Subsequently, deduce the pollution flow direction through the reverse trajectory to infer the area of the pollution source. For example, the pollutant concentrations measured at three observation points A, B, and C are 0.6mg / L, 0.4mg / L, and 0.2mg / L respectively. Calculate the diffusion direction of pollutants through the concentration gradient, and then trace back the location of the pollution source. Finally, generate pollution flow reverse trajectory data through reverse trajectory deduction.

[0121] S412: Use the pollution flow reverse trajectory data to evaluate the pollutant concentration of the pollution source and its surrounding areas, determine the potential pollution source location, and use the formula:

[0122] ;

[0123] Calculate the pollution source concentration mutation index , where represents the pollutant concentration in area , which is used to quantify the pollution level in a specific area, represents area The affected area is used to consider the spatial distribution range of pollutant concentrations. Indicates the change in pollutant concentration between adjacent regions and is used to identify the rate of change in pollution levels between different regions. Indicates the distance between regions, which is closely related to the spatial distribution of pollutants and is used to evaluate the spatial impact of pollutant propagation. is the total number of regions;

[0124] First, measure the pollutant concentrations at each pollution source point. For example, at a certain polluted site, the pollutant concentrations measured in 3 different regions are , , respectively. The affected areas of each region are , , respectively. Calculate the ratio of pollutant concentration to affected area and compare the changes in pollutant concentrations in each region. If the change in pollutant concentration between adjacent regions is , and the distance increment between regions , then substitute the values for calculation:

[0125] ;

[0126] ;

[0127] ;

[0128] The pollution source concentration mutation index reflects the degree of drastic change in the pollution concentration at the pollution source point. The larger this index, the more obvious the change in pollutant concentration. Through this calculated value, it can be used to screen pollution source points with prominent pollution concentrations and obtain the pollution source concentration mutation index.

[0129] S413: According to the pollution source concentration mutation index, analyze the environmental characteristics of the pollution source point and its surrounding areas, screen pollution source points with prominent pollution concentrations, and obtain the pollution source evaluation index;

[0130] Using the pollutant diffusion range data, extract the areas with relatively large pollutant concentration mutation indices, and conduct a detailed investigation of the environmental conditions in these areas. For example, at an industrial pollution site, select the pollution source point with the highest mutation index for soil and groundwater testing, analyze its pollution diffusion characteristics. At the same time, compare the historical data of the pollution source point to determine whether its pollution source matches the existing emission records. If there are pollution concentrations beyond the normal range, further investigate the component characteristics of the pollutants to identify the type of pollution source. For example, if the heavy metal concentration measured in a certain area is 2.5 mg / L while it is only 0.3 mg / L in the surrounding areas, it indicates that this area is the main pollution source point. Then, establish a priority ranking of the pollution source points. By calculating the influence weights between the pollution source points, screen out the pollution source points with prominent pollution concentrations to obtain the pollution source assessment index.

[0131] Please refer to Figure 6 , and the steps for obtaining the groundwater pollution level are specifically as follows:

[0132] S511: According to the pollution source assessment index, combined with the groundwater usage status and ecological sensitivity data, analyze the groundwater environmental vulnerability of each area, evaluate the impact of pollution on the groundwater quality and potential environmental risks, and obtain the groundwater pollution impact index;

[0133] Analyze the groundwater environmental vulnerability of each area. In this process, first collect the groundwater usage data and ecological sensitivity data of each area. For example, in industrial areas, considering the high pollutant load and high water resource utilization rate, combine the factors with the pollution source assessment index, and use Geographic Information System (GIS) for data integration and analysis to identify the areas with high groundwater environmental vulnerability. By calculating the pollution impact potential of each area, further evaluate the impact of pollution on the groundwater quality, and comprehensively analyze the potential environmental risks of pollution to the ecological sensitive areas by integrating data such as the ecological function, recovery ability, and water body connectivity in the area to obtain the groundwater pollution impact index.

[0134] S512: Based on the groundwater pollution impact index, use the formula:

[0135] ;

[0136] Calculate the groundwater pollution risk index , where represents the groundwater pollution impact index of area , and the value comprehensively reflects the pollution status of the groundwater in this area and its potential environmental impact. represents the water resource utilization rate of area , which is used to measure the intensity of water resource use in the area. A high utilization rate indicates that the area is more sensitive to water quality changes. is the total number of areas;

[0137] There are three regions, and their pollution impact indices and water resource utilization rates are respectively:

[0138] Region 1: , ;

[0139] Region 2: , ;

[0140] Region 3: , ;

[0141] Substitute the values for calculation:

[0142] ;

[0143] ;

[0144] The calculation result shows that the overall groundwater pollution risk index is 0.66. This value can be used to further compare with the environmental safety standard to determine which regions' groundwater pollution risks exceed the safety threshold, and accordingly, appropriate environmental management measures can be taken.

[0145] S513: Based on the groundwater pollution risk index, compare with the environmental safety standard, classify the groundwater pollution level of each region, and obtain the groundwater pollution grade;

[0146] Compare with the environmental safety standard and classify the groundwater pollution level of each region. First, analyze the calculated groundwater pollution risk index obtained above, and compare it with the environmental safety standard. For example, if the groundwater pollution risk index exceeds 0.8 (the threshold is based on the safety standard of the local environmental protection bureau), then the region is classified as a high pollution level. In this way, the groundwater pollution grade of each region will be clarified to formulate corresponding pollution control and treatment measures. According to the analysis results, formulate specific pollution control strategies for each region to generate the groundwater pollution grade.

[0147] A groundwater pollution source analysis and risk assessment system, the system includes:

[0148] The pollutant data collection module arranges monitoring points based on potential groundwater - affected areas, collects water samples, analyzes the organic pollutants, heavy metal content, and microbial metabolites in the water samples, collects the characteristic spectral data of pollutants, and obtains the pollutant spectral feature set;

[0149] Based on the pollutant spectral feature set, the pollutant concentration analysis module uses the known pollutant spectral data to compare with the monitoring data, identifies the types of pollutants associated with the groundwater pollution source, and conducts numerical analysis on the pollutant concentration at each monitoring point to obtain the pollutant concentration distribution data;

[0150] The pollution diffusion analysis module calls the pollutant concentration distribution data, combines with the geological background data of the groundwater pollution source, analyzes the groundwater flow characteristics, including flow velocity, flow direction and hydraulic gradient, and analyzes the hydraulic parameters affecting pollution diffusion to obtain the pollution diffusion dynamic index;

[0151] Based on the pollution diffusion dynamic index, the pollution source tracking module analyzes the reverse flow trajectory of pollutants in different regions, evaluates the potential pollution source locations, screens the pollution source points with prominent pollution concentrations, and obtains the pollution source evaluation index;

[0152] According to the pollution source evaluation index, the groundwater pollution assessment module combines with the groundwater usage status and ecological sensitivity to evaluate the impact of pollution on the groundwater quality and potential environmental risks, classifies the groundwater pollution levels in each region, and obtains the groundwater pollution grade.

[0153] The above are only the preferred embodiments of the present invention, and do not limit the present invention in other forms. Any person skilled in the art may use the disclosed technical content to make changes or modifications into equivalent embodiments with equivalent changes and apply them to other fields. However, as long as it does not depart from the technical solution content of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims

1. A method for groundwater pollution source analysis and risk assessment, characterized in that: The following steps are involved: S1: Set up monitoring points in potential groundwater-affected areas, collect water samples, analyze organic pollutants, heavy metal content and microbial metabolites in water samples, collect characteristic spectral data of pollutants, perform normalization processing, and obtain pollutant spectral feature sets; The steps for obtaining the pollutant spectral feature set are specifically as follows: S111: Set up monitoring points in potential groundwater-affected areas, collect water samples, detect organic pollutants, heavy metal content and microbial metabolites in water samples by liquid chromatography-mass spectrometry, extract spectral data of each type of pollutant, normalize the spectral data, and obtain normalized spectral data; S112: Based on the normalized spectral data, analyze the spectral characteristics of the pollutant, calculate the peak position, absorption intensity and half-peak width, using the formula: ； Get the spectral characteristic values ​​of the pollutants, where: Representative The spectral characteristic values ​​of the pollutants are Representative The pollutants in The peak position at wavelength, Represents all pollutants in The average value of the peak position at wavelengths, Representative The pollutants in The absorption intensity at the wavelength, Represents all pollutants in The average value of the absorption intensity at wavelengths, Represents the number of wavelength points; S113: Classifying the spectral characteristics of the pollutants based on the spectral characteristic values ​​of the pollutants, summarizing the spectral characteristic types of the differential pollutants, and obtaining a pollutant spectral characteristic set; S2: Based on the pollutant spectral feature set, identify the types of pollutants associated with the groundwater pollution source, and perform numerical analysis on the pollutant concentration at each monitoring point to determine the pollutant concentration at each monitoring point and obtain pollutant concentration distribution data; S3: calling the pollutant concentration distribution data, combining the geological background data of the groundwater pollution source, analyzing the groundwater flow characteristics, analyzing the hydraulic parameters that affect the pollution diffusion, calculating the migration rate and diffusion radius of the pollutants, and obtaining the pollution diffusion dynamic index; S4: Based on the pollution diffusion dynamic index, the reverse trajectory of pollutant flow in the difference area is analyzed to evaluate the location of potential pollution sources, and the pollutant concentration data of the pollution source and its surrounding areas are compared to screen the pollution source points with prominent pollution concentration to obtain the pollution source assessment index; The steps for obtaining the pollution source assessment index are specifically as follows: S411: Based on the pollution diffusion dynamic index, pollutant flow direction data of different regions are collected, and the reverse flow paths of pollutants in multiple regions are analyzed by combining groundwater flow velocity, hydraulic gradient and pollutant diffusion rate to generate pollution flow reverse trajectory data; S412: Using the pollution flow reverse trajectory data, evaluate the pollutant concentration of the pollution source and its surrounding areas, determine the location of the potential pollution source, and use the formula: ； Calculate the pollution source concentration mutation index ,in, Indicates area The pollutant concentration, Indicates area The affected area, represents the change in pollutant concentration between adjacent areas. represents the distance between regions, is the total number of regions.

2. The method for groundwater pollution source analysis and risk assessment according to claim 1, characterized in that: The pollutant spectral feature set includes spectral peak, characteristic wavelength, and metabolite identification; the pollutant concentration distribution data includes pollution intensity, pollution range, and key monitoring points; the pollution diffusion dynamic indicators include migration path, impact area, and dynamic change rate; the pollution source assessment index includes source activity, impact intensity, and risk potential.

3. The method for groundwater pollution source analysis and risk assessment according to claim 1, characterized in that: The steps for obtaining the pollutant concentration distribution data are specifically as follows: S211: Based on the pollutant spectral feature set, using known pollutant spectral data, matching the pollutant spectrum in the monitoring data with the known pollutant spectrum, identifying the type of pollutant associated with the groundwater pollution source, and obtaining a pollutant type identification result; S212: Based on the pollutant type identification result, the pollutant concentration at each monitoring point is numerically analyzed using the formula: ； Determine the pollutant concentration at each monitoring point and obtain the pollutant concentration distribution data, where: Indicates The monitoring point is The concentration of pollutants, Representative The monitoring point The spectral absorption intensity of the pollutants, Indicated in The first The volume of the pollutant sample, For the The monitoring point The spectral half-peak width adjustment factor of the pollutant.

4. The method for groundwater pollution source analysis and risk assessment according to claim 1, characterized in that: The steps for obtaining the pollution diffusion dynamic index are specifically as follows: S311: calling the pollutant concentration distribution data, combining with the geological background data of the groundwater pollution source, analyzing the flow velocity, flow direction and hydraulic gradient of the groundwater, and obtaining the groundwater flow characteristic parameters; S312: According to the groundwater flow characteristic parameters, the formula is used: ； Calculate groundwater flow rate for each area , and the pollutant migration rate is obtained, where represents the permeability coefficient, represents the hydraulic gradient, represents the saturation thickness, Represents the water flow distance; S313: Based on the pollutant migration rate, combined with pollutant diffusion and changing hydraulic data, the diffusion radius of the pollutant is calculated to obtain a dynamic index of pollution diffusion.

5. The method for groundwater pollution source analysis and risk assessment according to claim 1, characterized in that: The steps also include: S5: Based on the pollution source assessment index, combined with groundwater use conditions and ecological sensitivity, assess the impact of pollution on groundwater quality and potential environmental risks, compare with environmental safety standards, classify the groundwater pollution level in each area, and obtain the groundwater pollution grade; The groundwater pollution level includes severity assessment, emergency response level, and long-term monitoring requirements.

6. The method for groundwater pollution source analysis and risk assessment according to claim 5, characterized in that: The steps for obtaining the groundwater pollution level are specifically as follows: S511: Analyze the groundwater environmental vulnerability of each region based on the pollution source assessment index, combined with groundwater use status and ecological sensitivity data, assess the impact of pollution on groundwater quality and potential environmental risks, and obtain a groundwater pollution impact index; S512: Based on the groundwater pollution impact index, the formula is: ； Calculating the groundwater contamination risk index ,in, Indicates area The groundwater pollution impact index, Indicates area water resource utilization rate, is the total number of regions; S513: Based on the groundwater pollution risk index, the groundwater pollution level of each area is classified and compared with the environmental safety standard to obtain the groundwater pollution grade.

7. A groundwater pollution source analysis and risk assessment system, characterized in that: According to the method for groundwater pollution source analysis and risk assessment according to any one of claims 1 to 6, the system comprises: The pollutant data collection module collects water samples based on the monitoring points arranged in the potential groundwater affected areas, analyzes the organic pollutants, heavy metal content and microbial metabolites in the water samples, collects the characteristic spectral data of pollutants, and obtains the pollutant spectral feature set; The pollutant concentration analysis module uses the known pollutant spectral data to compare with the monitoring data based on the pollutant spectral feature set, identifies the types of pollutants associated with the groundwater pollution source, and performs numerical analysis on the pollutant concentration at each monitoring point to obtain pollutant concentration distribution data; The pollution diffusion analysis module calls the pollutant concentration distribution data, combines the geological background data of the groundwater pollution source, analyzes the groundwater flow characteristics, including flow velocity, flow direction and hydraulic gradient, analyzes the hydraulic parameters that affect the pollution diffusion, and obtains the dynamic index of pollution diffusion; The pollution source tracking module analyzes the reverse trajectory of pollutants in different areas based on the pollution diffusion dynamic indicators, evaluates the location of potential pollution sources, screens pollution source points with prominent pollution concentrations, and obtains a pollution source assessment index; The groundwater pollution assessment module assesses the impact of pollution on groundwater quality and potential environmental risks based on the pollution source assessment index, combined with groundwater usage conditions and ecological sensitivity, and classifies the groundwater pollution level in each area to obtain the groundwater pollution grade.

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