A method for locating and tracing the source of heavy metal waste in concealed areas

Abstract

This invention relates to the field of pollutant tracing technology, and in particular to a method for locating and tracing the source of heavy metal waste in concealed areas; it includes the following steps: S1, dividing the target area into sub-basin distributions and small watershed distributions; S2, during the dry season, setting up multiple sampling points in the small watershed distributions, obtaining the first tracer concentration value, heavy metal load index, and flow value at each sampling point, thereby obtaining the pollution source input area; S3, setting up multiple first sampling points, obtaining the river flow and heavy metal load at each first sampling point as data samples; S4, setting up multiple second sampling points, obtaining the river flow and heavy metal load at each second sampling point as data samples; S5, classifying all data samples to obtain multiple categories of data, each category of data corresponding to a mining area as a pollution source; S6, obtaining the polluting heavy metals in the pollution source; improving the accuracy of locating and tracing the source of heavily concealed heavy metal waste.

Description

Technical Field

[0001] This invention relates to the field of pollutant tracing technology, and in particular to a method for locating and tracing the source of heavy metal waste residue in concealed areas. Background Technology

[0002] Throughout the history of mineral resource development, illegal mining has frequently occurred, resulting in large quantities of heavy metal-containing waste being dumped directly in mountainous areas without treatment or disposal. In mining areas located deep in the mountains, after years of abandonment and natural vegetation regeneration, the surface vegetation cover is high, making it difficult to discern the harmfulness of the waste from its appearance. However, under the influence of water erosion such as rainfall, the heavy metals in these historically left wastes gradually migrate and spread to the surrounding soil and water bodies, causing serious pollution of the regional ecological environment, which in turn affects soil quality and endangers agricultural production and human health.

[0003] Traditional heavy metal waste identification technologies primarily rely on remote sensing monitoring and manual ground-based investigation. However, remote sensing monitoring suffers from low image resolution and significant vegetation interference in dense forests and high-coverage areas, making it difficult to identify concealed heavy metal waste. Manual ground-based investigation is hampered by time constraints and high labor costs, and the rugged terrain of mountainous areas can lead to omissions or misjudgments. Therefore, traditional heavy metal waste identification technologies struggle to clearly define the spatial distribution of waste and its specific impact on hydrological processes, limiting their ability to accurately identify waste and its migration and diffusion processes.

[0004] Existing technology CN119438003A discloses a method and electronic device for analyzing groundwater pollution sources based on multiple tracers. The method includes: setting monitoring points; acquiring concentration information of multiple tracers in groundwater; drawing spatial distribution maps of multiple tracers; determining initial key pollution areas and initial migration and diffusion areas; simulating the historical pollution state of groundwater based on a groundwater fluid model; simulating historical key pollution areas and historical migration and diffusion areas of groundwater by combining the initial key pollution areas and initial migration and diffusion areas; and determining the pollution source and migration and diffusion direction based on changes in the historical key pollution areas and historical migration and diffusion areas. However, the accuracy of the above-mentioned pollution source determination method in locating and tracing the source of highly concealed heavy metal waste needs improvement.

[0005] Therefore, there is an urgent need to provide a method for locating and tracing heavy metal waste in concealed areas, which can improve the accuracy of locating and tracing heavy metal waste with strong concealment compared with existing technologies. Summary of the Invention

[0006] This invention addresses the technical problems existing in the prior art and provides a method for locating and tracing the source of heavy metal waste residue in concealed areas.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for locating and tracing the source of heavy metal waste in concealed areas includes the following steps:

[0009] S1. Divide the target area into watersheds to obtain the sub-watershed distribution and small watershed distribution of the target area;

[0010] S2. During the dry season in the target area, the first tracer is released into the target area. Multiple sampling points are set up in the small watershed distribution to obtain the first tracer concentration value, heavy metal load index and flow value at each sampling point, thereby obtaining the pollution source input area.

[0011] S3. In the pollution source input area, release the first tracer, set up multiple first sampling points, and obtain the river flow and heavy metal load at each first sampling point;

[0012] S4. In the pollution source input area, a second tracer is released, and multiple second sampling points are set up to obtain the river flow and heavy metal load at each second sampling point;

[0013] S5. Take the river flow and heavy metal load of each first sampling point as a data sample, and the river flow and heavy metal load of each second sampling point as a data sample to obtain multiple data samples. Use hierarchical cluster analysis to classify all data samples to obtain multiple data categories. Each data category corresponds to a mining area as a pollution source.

[0014] S6. Based on the data sample corresponding to each pollution source, obtain the heavy metals in that pollution source.

[0015] Further, in step S2, a curve is constructed using the first tracer concentration and flow rate values ​​of all sampling points, with the flow rate value on the horizontal axis and the first tracer concentration value on the vertical axis. The change value of the first tracer concentration at each sampling point is obtained based on the change curve. For the sampling points on the change curve except for the two ends, the difference between the first tracer concentration value of each sampling point and the first tracer concentration values ​​of the sampling points on both sides is taken, and then the average value is taken as the change value of the first tracer concentration at that sampling point. For the sampling points at both ends of the change curve, the difference between the first tracer concentration values ​​of the sampling points at both ends and the first tracer concentration values ​​of the sampling points on one side is taken as the change value of the first tracer concentration at the sampling points at both ends.

[0016] Set a first tracer concentration change threshold, and use the sampling points corresponding to the first tracer concentration change values ​​that are greater than or equal to the first tracer concentration change threshold as pollution source sampling points.

[0017] Set a heavy metal load threshold, and also use the sampling points corresponding to the heavy metal load index that is greater than or equal to the heavy metal load threshold as pollution source sampling points.

[0018] The smallest area enclosed by all the sampling points of the pollution sources is taken as the pollution source input area.

[0019] Furthermore, the threshold for the change in the concentration of the first tracer is calculated using the following formula:

[0020] ;

[0021] In the above formula, This indicates the threshold for the change in the concentration of the first tracer. This represents the i-th change in the concentration of the first tracer, where i ranges from 1 to I, and I represents the total number of changes in the concentration of the first tracer. This represents the largest change in the concentration of the first tracer. Indicates taking , Large algebraic values ​​in the middle.

[0022] Furthermore, the heavy metal load threshold is calculated using the following formula:

[0023] ;

[0024] In the above formula, Indicates the heavy metal load threshold. This indicates the total number of all heavy metals involved in the target area. This indicates the amount of heavy metals at the sampling point with the highest concentration.

[0025] Furthermore, in step S3, the river flow at each first sampling point is calculated using the following formula:

[0026] ;

[0027] In the above formula, This represents the river flow at the e-th sampling point. This indicates the input flow rate of the first tracer. This indicates the concentration at the time of the first tracer injection. This indicates the background concentration of the first tracer. This represents the sampling concentration value of the first tracer at the e-th first sampling point, where e ranges from 1 to E, and E represents the total number of first sampling points.

[0028] Furthermore, in step S3, the heavy metal load at each first sampling point is calculated based on the river flow at that first sampling point, specifically as follows:

[0029] ;

[0030] In the above formula, This represents the heavy metal load at the e-th first sampling point. This represents the weight value of the f-th heavy metal in the e-th first sampling point. Let f represent the concentration value of the f-th heavy metal in the e-th first sampling point, where f ranges from 1 to F, and F represents the total number of heavy metals in the e-th first sampling point.

[0031] Further, in step S4, for each second sampling point, a monitoring point is set up upstream, and multiple sampling times are set. At each sampling time, the conductivity value is acquired for each second sampling point and its monitoring point, thereby constructing a curve showing the change in conductivity value versus sampling time for each second sampling point, and a curve showing the change in conductivity value versus sampling time for the corresponding monitoring point. The river flow at each second sampling point is calculated using the following formula:

[0032] ;

[0033] In the above formula, This represents the river flow at the d-th second sampling point. This represents the river flow at the monitoring point corresponding to the d-th second sampling point. The area enclosed by the curves showing the change in conductivity value versus time at the d-th second sampling point is represented by the d-th sampling point. This represents the area enclosed by the curves showing the change in conductivity value versus time at the d-th second sampling point.

[0034] Furthermore, in step S4, the heavy metal load at the second sampling point is calculated based on the river flow at that second sampling point, specifically as follows:

[0035] ;

[0036] In the above formula, This represents the heavy metal load at the d-th second sampling point. This represents the weight value of the h-th heavy metal in the d-th second sampling point. This represents the concentration value of the h-th heavy metal in the d-th second sampling point, where h ranges from 1 to H, and H represents the total number of heavy metals corresponding to the d-th second sampling point.

[0037] Furthermore, in step S5, hierarchical clustering analysis is used to calculate the similarity between the data sample and the other data samples, and a similarity threshold is set. For each data sample, other data samples with similarity greater than or equal to the similarity threshold are classified into the same category of data, thereby obtaining multiple categories of data.

[0038] The first and second sampling points corresponding to data samples of the same data type belong to the same pollution source. The distance between the locations of the first and second sampling points belonging to the same pollution source and the location of each mining area in the target area is calculated. The distances between each first and second sampling point in each data type and the same mining area are summed to obtain the total distance value of each data type to each mining area. The mining area corresponding to the minimum total distance value of each data type is set as the pollution source of that data type.

[0039] Further, in step S6, for each pollution source, the contribution rate of each heavy metal in that pollution source is calculated, and the heavy metal with the largest contribution rate is set as the polluting heavy metal of that pollution source; the contribution rate of each metal in each pollution source is calculated by the following formula:

[0040] ;

[0041] In the above formula, This represents the contribution rate of the b-th heavy metal in the pollution source. This represents the concentration of the b-th heavy metal in the pollution source at the a-th sampling point. Let represent the river flow at the 'a'th sampling point. The sampling point can be either the first or the second sampling point. 'a' ranges from 1 to A, where A represents the total number of sampling points in the pollution source. 'b' ranges from 1 to B, where B represents the total number of heavy metals in the pollution source.

[0042] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0043] (1) During the dry season, the present invention injects a first tracer to screen the pollution source input area and select the large-scale pollution of the target area. Then, combined with the analysis of the concentration peak of the first rain in spring, multiple first sampling points and multiple second sampling points are set in the selected pollution source input area. All the first sampling points and second sampling points are classified. The first sampling points and second sampling points of the same category are pollution points from a mining area, so as to obtain the distribution of pollution points corresponding to each mining area. Based on all the pollution points corresponding to each mining area, the contribution rate of each heavy metal in the mining area is calculated, so as to obtain the pollution heavy metals in each mining area. The pollution source identification and pollution heavy metal identification performed by the present invention are more accurate. Even in mountainous areas with complex terrain and strong concealment, the pollution source can be effectively locked, which improves the accuracy of pollution source tracing and breaks through the limitation of remote sensing monitoring affected by high-density vegetation cover.

[0044] (2) This invention can accurately quantify the pollution contribution rate of each small watershed and narrow the screening scope by combining pollutant flow path analysis, thus reducing the pollution investigation from the overall screening of the area where the mineral vein is located to the specific catchment area. Therefore, it reduces the workload of manual surveying, lowers the screening cost, and improves the efficiency of pollution source tracing. This invention reveals the long-term impact of heavy metal waste on the water environment, making pollution monitoring more scientific and accurate, improving the pertinence of pollution control, and providing data support for watershed water environment management and policy decision-making. Attached Figure Description

[0045] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0046] 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.

[0047] like Figure 1 As shown, this invention provides a method for locating and tracing the source of heavy metal waste in concealed areas, comprising the following steps:

[0048] S1. Divide the target area into watersheds, resulting in the distribution of sub-watersheds and smaller watersheds within the target area, specifically:

[0049] S11. Obtain geographic and hydrological data for the target area, including topographic elevation data, river network distribution data, river flow data, and regional mineral vein distribution data.

[0050] S12. Using ArcGIS hydrological analysis technology, based on the topographic elevation data, use the depression filling tool to preprocess the topographic elevation data, use the flow direction tool to determine the flow direction of each river in the river network distribution data, and use the flow rate tool to calculate the flow rate of each river in the river network distribution data.

[0051] S13. Set flow thresholds. Rivers with flow rates greater than or equal to the river threshold are designated as sub-basins, and rivers with flow rates less than the river threshold are designated as small-basins, thus obtaining the sub-basin distribution and small-basin distribution.

[0052] S2. During the dry season in the target area, the first tracer is released into the target area. Multiple sampling points are set up in the small watershed to obtain water samples from each sampling point. The concentration of the first tracer and the heavy metal load are detected on the water samples from each sampling point. At the same time, the flow rate at each sampling point is also obtained. The concentration value of the first tracer, the heavy metal load index, and the flow rate value of each sampling point are obtained. The concentration value of the first tracer, the heavy metal load index, and the flow rate value are processed to obtain the pollution source input area.

[0053] Construct a curve showing the change in flow rate and first tracer concentration at all sampling points. In the curve, the flow rate is on the x-axis and the first tracer concentration is on the y-axis. The first tracer concentration value at each sampling point on the curve is subtracted from the first tracer concentration values ​​at its two adjacent sampling points, and the average value is taken as the change in first tracer concentration at that sampling point. For sampling points at both ends of the curve, the first tracer concentration values ​​at both ends are subtracted from the first tracer concentration values ​​at their adjacent sampling points on one side, and the average value is taken as the change in first tracer concentration at both ends of the curve.

[0054] Set a first tracer concentration change threshold, and use the sampling points corresponding to the first tracer concentration change values ​​that are greater than or equal to the first tracer concentration change threshold as pollution source sampling points.

[0055] The threshold for the first tracer concentration change is calculated using the following formula:

[0056] ;

[0057] In the above formula, This indicates the threshold for the change in the concentration of the first tracer. This represents the i-th change in the concentration of the first tracer, where i ranges from 1 to I, and I represents the total number of changes in the concentration of the first tracer. This represents the largest change in the concentration of the first tracer. Indicates taking , Large algebraic values ​​in the middle.

[0058] Set a heavy metal load threshold, and also use the sampling points corresponding to heavy metal load indices that are greater than or equal to the heavy metal load threshold as pollution source sampling points.

[0059] The heavy metal load threshold is calculated using the following formula:

[0060] ;

[0061] In the above formula, Indicates the heavy metal load threshold. This indicates the total number of all heavy metals involved in the target area. This indicates the amount of heavy metals at the sampling point with the highest concentration.

[0062] The smallest area enclosed by all the sampling points of the pollution sources is taken as the pollution source input area; the dry season is the time from winter to before the first rain in spring in the target area.

[0063] S3. After the first spring rain in the target area and before the next dry season, set up multiple first sampling points in the pollution source input area. The first sampling points are distributed at the outlet of the sub-basin and the confluence of various rivers. Sampling equipment is set up at the first sampling points. The sampling equipment is a bromide sensor. The bromide sensor is used to detect the sampling concentration value of the first tracer in real time. Based on the sampling concentration value of the first tracer corresponding to each first sampling point, the river flow at that first sampling point is calculated. The heavy metal load of the first sampling point is calculated based on the river flow at each first sampling point.

[0064] Specifically, the river flow at each first sampling point is calculated using the following formula:

[0065] ;

[0066] In the above formula, This represents the river flow at the e-th sampling point. This indicates the input flow rate of the first tracer. This indicates the concentration at the time of the first tracer injection. This indicates the background concentration of the first tracer. This represents the sampling concentration value of the first tracer at the e-th first sampling point, where e ranges from 1 to E, and E represents the total number of first sampling points.

[0067] Based on the river flow at the first sampling point, the heavy metal load at that point is calculated using the following formula:

[0068] ;

[0069] In the above formula, This represents the heavy metal load at the e-th first sampling point. This represents the weight value of the f-th heavy metal in the e-th first sampling point. Let f represent the concentration value of the f-th heavy metal in the e-th first sampling point, where f ranges from 1 to F, and F represents the total number of heavy metals in the e-th first sampling point.

[0070] S4. After the first spring rainfall in the target area and before the next dry season, inject a second tracer in the pollution source input area and set up multiple second sampling points. The second sampling points are set at river sections with abnormal flow, including springs, river bifurcation points, and mine entrances. A monitoring point is set up upstream of each second sampling point. Multiple sampling times are set up. At each sampling time, conductivity values ​​are obtained for each second sampling point and its upstream monitoring point. The conductivity values ​​are measured using a conductivity meter. Construct a conductivity value versus time curve for each second sampling point and a conductivity value versus time curve for the corresponding monitoring point for each second sampling point. At the same time, water samples are obtained from the second sampling points and heavy metal load analysis is performed on the water samples.

[0071] Based on the conductivity value versus time curves corresponding to each second sampling point, and the conductivity value versus time curves of each monitoring point corresponding to each second sampling point, the river flow at each second sampling point is obtained, specifically calculated using the following formula:

[0072] ;

[0073] In the above formula, This represents the river flow at the d-th second sampling point. This represents the river flow at the monitoring point corresponding to the d-th second sampling point. The area enclosed by the curves showing the change in conductivity value versus time at the d-th second sampling point is represented by the d-th sampling point. This represents the area enclosed by the curves showing the change in conductivity value versus time at the d-th second sampling point.

[0074] The heavy metal load at each second sampling point is calculated based on the river flow rate at each second sampling point, specifically using the following formula:

[0075] ;

[0076] In the above formula, This represents the heavy metal load at the d-th second sampling point. This represents the weight value of the h-th heavy metal in the d-th second sampling point. This represents the concentration value of the h-th heavy metal in the d-th second sampling point, where h ranges from 1 to H, and H represents the total number of heavy metals corresponding to the d-th second sampling point.

[0077] S5. Take the river flow and heavy metal load of each first sampling point obtained in step S3 as a data sample, and take the river flow and heavy metal load of each second sampling point obtained in step S4 as a data sample, thus obtaining multiple data samples. Treat each data sample as a whole, and perform hierarchical cluster analysis on all data samples. Calculate the similarity between each data sample and the other data samples, set a similarity threshold, and for each data sample, classify other data samples with similarity greater than or equal to the similarity threshold into the same category as the data sample, thus obtaining multiple categories of data. The first and second sampling points corresponding to data samples in the same category belong to the same pollution source. Calculate the distance between the locations of the first and second sampling points belonging to the same pollution source and the locations of each mining area in the regional vein ore data. Sum the distances between each first and second sampling point in each category of data and the same mining area to obtain the total distance value of each category of data to that mining area. Set the mining area corresponding to the minimum total distance value of each category of data as the pollution source of that category of data.

[0078] The similarity threshold is set between 0.6 and 0.8.

[0079] S6. For each pollution source, calculate the contribution rate of each heavy metal in that source, and define the heavy metal with the largest contribution rate as the polluting heavy metal of that source. The contribution rate of each metal in each pollution source is calculated using the following formula:

[0080] ;

[0081] In the above formula, This represents the contribution rate of the b-th heavy metal in the pollution source. This represents the concentration of the b-th heavy metal in the pollution source at the a-th sampling point. Let represent the river flow at the 'a'th sampling point. The sampling point can be either the first or the second sampling point. 'a' ranges from 1 to A, where A represents the total number of sampling points in the pollution source. 'b' ranges from 1 to B, where B represents the total number of heavy metals in the pollution source.

[0082] The first tracer is Br⁻, and the second tracer is Mg. 2+ wait.

[0083] This invention involves injecting a first tracer during the dry season to screen pollution source input areas and identify large-scale pollution areas in the target region. Then, combined with the analysis of peak concentrations from the first spring rainfall, multiple first and second sampling points are set up in the selected pollution source input areas. All first and second sampling points are classified, with those in one category representing pollution points from a single mining area. This yields the pollution point distribution for each mining area. Based on all pollution points in each mining area, the contribution rate of each heavy metal in that mining area is calculated, thus determining the polluted heavy metals in each mining area. This invention provides more accurate pollution source and heavy metal identification, effectively locating pollution sources even in complex, concealed mountainous terrain, improving the accuracy of pollution tracing, and overcoming the limitations of remote sensing monitoring affected by high-density vegetation cover.

[0084] This invention can accurately quantify the pollution contribution rate of each small watershed and, combined with pollutant flow path analysis, narrow down the screening scope, reducing pollution investigation from the overall area where the mineral vein is located to specific catchment areas. Therefore, it reduces the workload of manual surveying, lowers screening costs, and improves the efficiency of pollution source tracing. This invention reveals the long-term impact of heavy metal waste on the water environment, making pollution monitoring more scientific and precise, improving the targeting of pollution control, and providing data support for watershed water environment management and policy decision-making.

[0085] 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 locating and tracing heavy metal waste residues in concealed areas, characterized in that, The method comprises the following steps: S1, performing watershed division on the target region to obtain sub-basin distribution and small-basin distribution of the target region; specifically comprising the following steps: S11, obtaining geographic hydrological data of the target region, the geographic hydrological data comprising terrain elevation data, water system river network distribution data, water system flow data and regional vein distribution data; S12, using an Arc GIS hydrological analysis technology, pre-processing the terrain elevation data using a fill-in tool according to the terrain elevation data, determining the flow direction of each river in the water system river network distribution data using a flow direction tool, and calculating the flow of each river in the water system river network distribution data using a flow tool; S13, setting a flow threshold, rivers with flow greater than or equal to the river threshold being set as sub-basins, and rivers with flow less than the river threshold being set as small-basins, thereby obtaining the sub-basin distribution and the small-basin distribution; S2, in the dry season of the target region, putting a first tracer into the target region, setting multiple sampling points in the small-basin distribution, obtaining the first tracer concentration value, heavy metal load index and flow value of each sampling point, thereby obtaining a pollution source input region; constructing a change curve with flow value as the horizontal coordinate and first tracer concentration value as the vertical coordinate through the first tracer concentration value and flow value of all sampling points, obtaining the first tracer concentration change value of each sampling point according to the change curve, for the remaining sampling points on the change curve except the two ends, taking the average of the difference between the first tracer concentration value of each sampling point and the first tracer concentration values of the adjacent sampling points on both sides as the first tracer concentration change value of the sampling point; for the sampling points at both ends of the change curve, taking the difference between the first tracer concentration value of the sampling points at both ends and the first tracer concentration value of the adjacent sampling point on one side as the first tracer concentration change value of the sampling points at both ends; setting a first tracer concentration change threshold, taking the sampling points corresponding to the first tracer concentration change value greater than or equal to the first tracer concentration change threshold as pollution source sampling points; setting a heavy metal load threshold, also taking the sampling points corresponding to the heavy metal load index greater than or equal to the heavy metal load threshold as pollution source sampling points; taking the smallest region surrounded by all pollution source sampling points as the pollution source input region; S3, in the pollution source input region, putting a first tracer, setting multiple first sampling points, and obtaining the river flow and heavy metal load of each first sampling point; S4, in the pollution source input region, putting a second tracer, setting multiple second sampling points, and obtaining the river flow and heavy metal load of each second sampling point; S5, taking the river flow and heavy metal load of each first sampling point as a data sample, also taking the river flow and heavy metal load of each second sampling point as a data sample, obtaining multiple data samples, using hierarchical cluster analysis to classify all data samples, obtaining multiple categories of data, and each category of data corresponding to a mining area as a pollution source; S6, obtaining the pollution heavy metal in the pollution source according to the data sample corresponding to each pollution source; for each pollution source, calculating the contribution rate of each heavy metal in the pollution source, setting the heavy metal with the largest contribution rate as the pollution heavy metal of the pollution source; the contribution rate of each metal in each pollution source is calculated by the following formula: ； In the above formula, represents the contribution rate of the bth heavy metal in the pollution source, represents the concentration value of the bth heavy metal in the pollution source at the ath sampling point, represents the river flow at the ath sampling point, the sampling point being the first sampling point or the second sampling point, a being 1 to A, A representing the total number of sampling points in the pollution source, b being 1 to B, B representing the total number of heavy metals in the pollution source.

2. The method for locating and tracing the heavy metal waste residue in the hidden area according to claim 1, characterized in that, The first tracer concentration change threshold is calculated by the following formula: ； In the above formulae, denotes a first tracer concentration change threshold value, denotes the i-th first tracer concentration change value, i takes values from 1 to I, I denotes the total number of first tracer concentration change values, denotes the maximum first tracer concentration change value, denotes the maximum first tracer concentration change value, , the larger algebraic value in 3. The method for locating and tracing the heavy metal waste residue in the hidden area according to claim 1, characterized in that, The heavy metal load threshold is calculated by the following formula: ； In the above formula, represents a heavy metal load threshold value, represents the total number of all heavy metals involved in the target area, represents the number of heavy metals corresponding to the sampling point with the largest number of heavy metals.

4. The method for locating and tracing the heavy metal waste residue in the hidden area according to claim 1, characterized in that, In step S3, the river flow of each first sampling point is calculated by the following formula: ； In the above formula, Qe represents the river flow at the e-th first sampling point, Qin represents the input flow of the first tracer, Cin represents the concentration at the time of input of the first tracer, Cback represents the background concentration of the first tracer, Ces represents the sampling concentration value of the first tracer at the e-th first sampling point, e is 1 to E, and E represents the total number of first sampling points.

5. The method for locating and tracing the heavy metal waste residues in the hidden area according to claim 4, characterized in that, In step S3, the heavy metal load of each first sampling point is calculated according to the river flow of the first sampling point, specifically: ； In the above formula, represents the heavy metal load of the e-th first sampling point, represents the weight value of the f-th heavy metal in the e-th first sampling point, represents the concentration value of the f-th heavy metal in the e-th first sampling point, f is 1 to F, and F represents the total number of heavy metals in the e-th first sampling point.

6. The method for locating and tracing the heavy metal waste residue in the hidden area according to claim 1, characterized in that, In step S4, for each second sampling point, a monitoring point is set upstream of it, a plurality of sampling times are set, and at each sampling time, the conductivity value of each second sampling point and its monitoring point is obtained once, so as to construct the change curve of the conductivity value of each second sampling point and the sampling time, the change curve of the conductivity value of the corresponding monitoring point and the sampling time; the river flow of each second sampling point is calculated by the following formula: ； In the above formula, represents the river flow of the dth second sampling point, represents the river flow of the monitoring point corresponding to the dth second sampling point, represents the area surrounded by the change curve of the conductivity value corresponding to the monitoring point of the dth second sampling point and time, represents the area surrounded by the change curve of the conductivity value corresponding to the dth second sampling point and time.

7. The method for locating and tracing the heavy metal waste residue in the hidden area according to claim 6, characterized in that, In step S4, the heavy metal load of the second sampling point is calculated according to the river flow of the second sampling point, specifically: ； In the above formula, represents the heavy metal load of the dth second sampling point, represents the weight value of the hth heavy metal in the dth second sampling point, represents the concentration value of the hth heavy metal in the dth second sampling point, h is 1 to H, and H represents the total number of heavy metals corresponding to the dth second sampling point.

8. The method of claim 1, wherein the method further comprises: In step S5, hierarchical cluster analysis is used to calculate the similarity between the data sample and the remaining data samples, set a similarity threshold, for each data sample, other data samples with similarity greater than or equal to the similarity threshold are divided into the same class of data, so as to obtain multiple classes of data; The first sampling point and the second sampling point corresponding to the data sample in the same class of data belong to the same pollution source; the distance between the positions of the first sampling point and the second sampling point belonging to the same pollution source and the position of each mining area in the target area is calculated, the distance between each first sampling point and second sampling point in each class of data and the same mining area is added, to obtain the total distance value of each mining area for each class of data, setting the mining area corresponding to the smallest total distance value of each class of data as the pollution source of the class of data.

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