A GIS-assisted monitoring method for heavy metal pollution range in mine downstream

Abstract

The application relates to the technical field of spectral analysis, in particular to a GIS-assisted mine downstream heavy metal pollution range monitoring method. First, the method considers that shielding will cause errors in part of the spectral data, so the initial concentration is corrected by means of the heavy metal substance concentration in the neighborhood range of each monitoring point, then the decay factor corresponding to each monitoring point is determined by combining the reference concentration decay area of each heavy metal substance in the neighborhood direction according to the corrected reference concentration distribution; further, the final concentration of each heavy metal substance from each pollution outlet in each monitoring point is more accurately determined by comprehensively analyzing the decay factor of each monitoring point and the heavy metal substance reference concentration of each position, so that the pollution influence range of each pollution outlet defined according to the final concentration is more accurate, and the effect of corresponding heavy metal pollution range monitoring is better.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of spectral analysis, and particularly relates to a GIS-assisted mine downstream heavy metal pollution range monitoring method. BACKGROUND

[0002] The impact of mining activities on the environment is a global problem, especially heavy metal pollution. Heavy metal pollution not only affects the ecological environment, but also threatens human health. In order to effectively manage and restore contaminated areas, it is necessary to accurately monitor and assess the range of heavy metal pollution. Geographic Information System (GIS) technology, as a powerful spatial analysis tool, can provide detailed geographic location information to more accurately determine the specific pollution range of pollution, thereby indirectly improving the accuracy of heavy metal pollution monitoring.

[0003] Considering that the spectral information corresponding to heavy metals can be monitored through spectral data, the prior art usually combines hyperspectral remote sensing technology that can reflect heavy metal content on the basis of GIS technology to monitor the range of heavy metal pollution downstream of mines, that is, the range corresponding to the area where the heavy metal content monitored by the hyperspectral remote sensing technology is greater than the pollution threshold or contains heavy metals is taken as the pollution range.

[0004] However, there are usually multiple pollution outlets in mining activities. The heavy metal pollution range monitoring method in the prior art can only determine the observed comprehensive pollution area, and cannot clearly determine the independent pollution range of each pollution outlet, which makes it difficult to develop targeted pollution control measures and affects the effect and efficiency of pollution prevention and control. That is, the method of monitoring the range of heavy metal pollution downstream of mines by combining GIS technology with hyperspectral remote sensing technology in the prior art cannot effectively determine the independent pollution range of each pollution outlet, resulting in poor heavy metal pollution range monitoring effect. SUMMARY

[0005] The application provides a GIS-assisted mine downstream heavy metal pollution range monitoring method, which first considers that shielding will cause errors in part of the spectral data, and therefore corrects the initial concentration by means of the heavy metal substance concentration in the neighborhood range of each monitoring point, and then determines the attenuation factor corresponding to each monitoring point by combining the reference concentration distribution of each heavy metal substance in the neighborhood direction and the reference concentration attenuation area of each heavy metal substance in the neighborhood direction; further, the final concentration of each heavy metal substance from each pollution outlet in each monitoring point is determined more accurately by comprehensively analyzing the attenuation factor of each monitoring point and the reference concentration of each heavy metal substance at each position, so that the problem that the prior art cannot effectively determine the independent pollution range of each pollution outlet when the GIS technology is combined with the hyperspectral remote sensing technology to monitor the heavy metal pollution range downstream of the mine is solved, and the pollution influence range of each pollution outlet defined according to the final concentration is more accurate, and the heavy metal pollution range monitoring effect is better.

[0006] The first aspect of the application provides a GIS-assisted mine downstream heavy metal pollution range monitoring method, comprising:

[0007] According to the hyperspectral remote sensing data in the monitoring area centered on the mine pollution outlet, the initial concentration of each heavy metal substance corresponding to each monitoring point in the monitoring area is determined.

[0008] According to the relative deviation of the initial concentration of each heavy metal substance in the neighborhood range of each monitoring point, the initial concentration is corrected to determine the reference concentration of each heavy metal substance corresponding to each monitoring point.

[0009] According to the distribution of the reference concentration, the attenuation factor of each monitoring point in each neighborhood direction, which represents the attenuation trend of the reference concentration of each heavy metal substance, is determined.

[0010] According to the attenuation factor on the pollution transmission path from each pollution outlet to each monitoring point and the reference concentration, the final concentration of each heavy metal substance from each pollution outlet in each monitoring point is determined.

[0011] According to the final concentration, the pollution influence range of each pollution outlet is determined.

[0012] In an embodiment of the first aspect of the application, the reference concentration acquisition method comprises:

[0013] The other monitoring points in the preset neighborhood range of each monitoring point are taken as neighborhood points of each monitoring point; initial concentration differences between each monitoring point and each corresponding neighborhood point under each heavy metal substance are calculated; a normalized value of an accumulated value of the initial concentration differences between each monitoring point and all neighborhood points under all heavy metal substances is taken as a shielding probability of each monitoring point; and monitoring points with a corresponding shielding probability greater than a preset shielding threshold are taken as shielding points.

[0014] The reference concentration of each heavy metal substance of each shielding point is obtained by interpolating the initial concentration of each neighborhood point corresponding to each shielding point according to the initial concentration of each neighborhood point corresponding to each shielding point by using the Kriging interpolation method; and the initial concentration of each heavy metal substance of the other monitoring points except the shielding points is taken as the corresponding reference concentration.

[0015] In an embodiment of the first aspect of the present application, the method for obtaining the attenuation factor comprises:

[0016] Each neighborhood direction is sequentially taken as a target direction, and each monitoring point is sequentially taken as a target point; a next monitoring point of the target point in the target direction is taken as a corresponding first direction point; and a previous monitoring point of the target point in the target direction is taken as a corresponding second direction point.

[0017] Under each heavy metal substance, when the reference concentration of the target point is greater than the reference concentration of the corresponding first direction point, an attenuation factor of each heavy metal substance of the target point in the target direction is obtained according to a reference concentration change of the target point relative to the first direction point and the second direction point.

[0018] Under each heavy metal substance, when the reference concentration of the target point is less than or equal to the reference concentration of the corresponding first direction point, a preset attenuation coefficient is taken as the attenuation factor of each heavy metal substance of the target point in the target direction.

[0019] In an embodiment of the first aspect of the present application, the method for obtaining the attenuation factor of each heavy metal substance of the target point in the target direction according to the reference concentration change of the target point relative to the first direction point and the second direction point comprises:

[0020] Under each heavy metal substance, a ratio between the reference concentration of the target point and the reference concentration of the corresponding first direction point is taken as a first concentration ratio; a ratio between the reference concentration of the corresponding second direction point and the reference concentration of the target point is taken as a second concentration ratio; and a positive correlation mapping value of a mean value between the first concentration ratio and the second concentration ratio is taken as the corresponding attenuation factor.

[0021] In an embodiment of the first aspect of the present application, the method for obtaining the pollution transmission path comprises:

[0022] The pollution transmission path from each pollution outlet to each monitoring point is planned by using the Floyd algorithm.

[0023] In an embodiment of the first aspect of the application, the method for obtaining the final concentration comprises:

[0024] Under each heavy metal substance, the cumulative attenuation coefficient of each pollution outlet to each monitoring point under each heavy metal substance is determined by multiplying and fusing the negative correlation mapping values of the attenuation factors of all monitoring points in the path extension direction according to the pollution transmission path.

[0025] The target concentration of each heavy metal substance discharged by each pollution outlet is weighted by using the cumulative attenuation coefficient, and the final concentration of each heavy metal substance from each pollution outlet in each monitoring point is determined.

[0026] In an embodiment of the first aspect of the application, the method for obtaining the target concentration comprises:

[0027] Under each heavy metal substance, the monitoring point with a normalized value of the reference concentration greater than a preset exceeding threshold is taken as a concentration-exceeding point corresponding to each heavy metal substance.

[0028] Under each heavy metal substance, a target function model under each heavy metal substance is constructed based on the least square method according to the cumulative attenuation coefficient of all pollution outlets to each concentration-exceeding point and the reference concentration of the corresponding concentration-exceeding point.

[0029] The target function is solved by using the gradient descent method, and the target concentration of each heavy metal substance discharged by each pollution outlet under the optimal solution is determined.

[0030] In an embodiment of the first aspect of the application, the target function model comprises:

[0031]

[0032] Wherein, L k represents the target function value under the kth heavy metal substance; N is the number of concentration-exceeding points; C k，i is the reference concentration of the ith concentration-exceeding point under the kth heavy metal substance; n is the number of pollution outlets; ρ′ k，y，i is the cumulative attenuation coefficient of the yth pollution outlet to the ith concentration-exceeding point under the kth heavy metal substance; P k，y is the target concentration of the kth heavy metal substance discharged by the yth pollution outlet.

[0033] In an embodiment of the first aspect of the application, the method for obtaining the pollution influence range comprises:

[0034] Under each heavy metal substance, the monitoring point with a final concentration greater than the preset pollution threshold from each pollution outlet is taken as a pollution monitoring point of each pollution outlet; and a region formed by all the pollution monitoring points corresponding to each pollution outlet is taken as a pollution influence range of each heavy metal substance discharged by each pollution outlet.

[0035] In an embodiment of the first aspect of the application, the preset attenuation coefficient is set to 0.

[0036] In a second aspect, the application provides a GIS-assisted heavy metal pollution range monitoring system for a mine downstream, which comprises:

[0037] A data acquisition module is configured to determine, according to hyperspectral remote sensing data in a monitoring region centered on a pollution outlet of a mine, an initial concentration of each heavy metal substance corresponding to each monitoring point in the monitoring region;

[0038] A concentration correction module is configured to correct the initial concentration according to a relative deviation of the initial concentration of each heavy metal substance in a neighborhood range of each monitoring point, and determine a reference concentration of each heavy metal substance corresponding to each monitoring point;

[0039] A first determination module is configured to determine, according to a distribution of the reference concentration, an attenuation factor representing an attenuation trend of the reference concentration of each heavy metal substance in each neighborhood direction of each monitoring point;

[0040] A second determination module is configured to determine, according to the attenuation factor on a pollution transmission path from each pollution outlet to each monitoring point and the reference concentration, a final concentration of each heavy metal substance from each pollution outlet in each monitoring point;

[0041] A pollution influence range monitoring module is configured to determine, according to the final concentration, a pollution influence range of each heavy metal substance discharged by each pollution outlet.

[0042] In a third aspect, the application provides a computer device comprising a memory and a processor. The memory is configured to store computer program code, and the processor is configured to call and run the computer program code from the memory to execute the method of the first aspect or any embodiment of the first aspect of the application.

[0043] In a fourth aspect, the application provides a computer program product comprising computer program code, which, when executed, performs the method of the first aspect or any embodiment of the first aspect of the application.

[0044] In a fifth aspect, the application provides a computer-readable storage medium storing computer program code, which, when executed, performs the method of the first aspect or any embodiment of the first aspect of the application.

[0045] The present application has the following beneficial effects:

[0046] The present application takes into account the problem that the accuracy of the corresponding hyperspectral remote sensing data will be affected after the ground is covered by vegetation, buildings and other ground coverings, and according to the relative deviation of the heavy metal concentration in the neighborhood range of each monitoring point, the initial concentration corresponding to the monitoring point is corrected to obtain a more accurate reference concentration and improve the accuracy of subsequent analysis. Further, according to the characteristics of the heavy metal material showing attenuation continuity during pollution diffusion, the reference concentration change of each monitoring point in each neighborhood direction is determined to determine the corresponding attenuation factor, so that the more accurate final concentration of each heavy metal material from each pollution outlet in each monitoring point is determined by comprehensive analysis according to the attenuation factor of each monitoring point combined with the reference concentration of heavy metal material at each position, so that the pollution influence range of each pollution outlet defined according to the final concentration is more accurate, and the effect of monitoring the corresponding heavy metal pollution range is better. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art and the advantages thereof, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained from these drawings without creative labor.

[0048] Figure 1 A GIS-assisted mine downstream heavy metal pollution range monitoring method flowchart provided by an embodiment of the present application;

[0049] Figure 2 A GIS-assisted mine downstream heavy metal pollution range monitoring system structure diagram provided by an embodiment of the present application;

[0050] Figure 3 A computer device structure schematic diagram provided by an embodiment of the present application. DETAILED DESCRIPTION

[0051] In order to further illustrate the technical means and effects taken by the present application to achieve the predetermined inventive purpose, the following describes in detail the specific implementation, structure, features and effects of a GIS-assisted mine downstream heavy metal pollution range monitoring method according to the present application, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment, and the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form. In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Therefore, the features with "first" and "second" can be explicitly or implicitly included one or more features.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0053] The specific scheme of the GIS-assisted mine downstream heavy metal pollution range monitoring method provided by the present application is described in detail below in combination with the accompanying drawings.

[0054] The present application provides a GIS-assisted mine downstream heavy metal pollution range monitoring method, please refer to Figure 1 which shows a GIS-assisted mine downstream heavy metal pollution range monitoring method flowchart provided by one embodiment of the present application, the method comprises:

[0055] Step S101: According to the hyperspectral remote sensing data in the monitoring area centered on the mine pollution outlet, the initial concentration of each heavy metal substance corresponding to each monitoring point in the monitoring area is determined.

[0056] The scene of the embodiment of the present application is the monitoring of the heavy metal pollution range discharged by the mine through the pollution outlet, and the main purpose is to determine the pollution influence range of each heavy metal substance discharged by each pollution outlet, so as to perform better heavy metal pollution range monitoring. Considering that the hyperspectral remote sensing data can directly observe the concentration of each heavy metal substance at each position, the initial concentration of each heavy metal substance corresponding to each monitoring point in the monitoring area centered on the mine pollution outlet is determined by means of the hyperspectral remote sensing data. In one specific implementation manner of the embodiment of the present application, a circular range with a radius of 20 kilometers corresponding to the mine pollution outlet is taken as the corresponding monitoring area, and the implementer can adjust the radius size according to the specific implementation environment; and in the monitoring area, the airborne remote sensing mode is used to traverse the monitoring area to obtain the corresponding hyperspectral remote sensing data, and the obtained hyperspectral remote sensing data of the monitoring area is input into the GIS system for subsequent analysis; wherein the spatial resolution of the hyperspectral remote sensing data is set to 30 meters, which can be adjusted according to the specific implementation environment.

[0057] After obtaining the hyperspectral remote sensing data, the hyperspectral remote sensing data is input into the trained heavy metal concentration estimation model, and the concentration of each heavy metal substance corresponding to each monitoring point in the monitoring area is output as the initial concentration.

[0058] In one specific implementation of the embodiment of the present application, the soil corresponding to the sample points in the monitoring area is collected, and the corresponding heavy metal concentration is measured; the partial least squares regression model is selected to establish the heavy metal concentration estimation model, and the spectral data corresponding to each sample point in the hyperspectral remote sensing data is taken as the input, and the measured heavy metal concentration is taken as the output, so as to obtain the trained heavy metal concentration estimation model, and the unit of heavy metal concentration is set to mg / kg, that is, the number of milligrams of pollutants contained in each kilogram of soil. In other specific implementations of the embodiment of the present application, water samples of each sample point can also be collected to establish the heavy metal concentration estimation model.

[0059] In one specific implementation of the embodiment of the present application, the monitoring area is rastered to obtain the raster data corresponding to the monitoring area, the center point of each grid in the raster data is taken as the corresponding monitoring point, and each grid is set to a square of 30 meters in size, which can be adjusted in size, and will not be further described here.

[0060] In one specific implementation of the embodiment of the present application, the types of heavy metal substances are selected as lead, mercury, copper and zinc, and the implementer can select the types of heavy metals in the wastewater discharged by the mine according to the specific implementation environment, and will not be further described here.

[0061] Step S102: correcting the initial concentration according to the relative deviation of the initial concentration of each heavy metal substance in the neighborhood range of each monitoring point, to determine the reference concentration of each heavy metal substance corresponding to each monitoring point.

[0062] After obtaining the contents of heavy metal substances at different geographical locations, the contents of heavy metals in some areas may be blocked by the ground coverings such as vegetation and buildings, affecting the acquisition and accuracy of the hyperspectral data, or when the heavy metal pollution is transmitted through groundwater, the hyperspectral data cannot directly reflect the concentration of heavy metals in the groundwater, which will make the obtained concentration change not accurate enough. Therefore, according to the continuity of concentration diffusion, the concentration is corrected according to the relative deviation of the initial concentration in the neighborhood of each monitoring point, so as to obtain more accurate reference concentration and improve the accuracy of subsequent analysis.

[0063] Preferably, in some possible implementations of the embodiment of the present application, the method for obtaining the reference concentration comprises:

[0064] The other monitoring points in the preset neighborhood range of each monitoring point are taken as the neighborhood points of each monitoring point; the initial concentration difference between each monitoring point and each corresponding neighborhood point under each heavy metal substance is calculated; the normalized value of the cumulative value of the initial concentration difference between each monitoring point and all neighborhood points under all heavy metal substances is taken as the shielding probability of each monitoring point; the monitoring points with the corresponding shielding probability greater than a preset shielding threshold are taken as the shielding points; the concentration of each heavy metal substance corresponding to the shielding points is interpolated according to the initial concentration of each neighborhood point corresponding to each shielding point by the Kriging interpolation method, to obtain the reference concentration of each heavy metal substance of each shielding point; and the initial concentration of each heavy metal substance of the other monitoring points except the shielding points is taken as the corresponding reference concentration. In one specific implementation manner of the embodiment of the present application, the preset neighborhood range is set to a 24-neighborhood range, and the preset shielding threshold is set to 0.9, which can be adjusted according to the specific implementation environment.

[0065] The heavy metal pollutants have a certain continuity in the diffusion direction in the diffusion process, but the heavy metal content measured by the monitoring points will appear partially discontinuous due to shielding and other factors, so the greater the initial concentration difference between each monitoring point and each neighborhood point, the more likely the monitoring point is shielded, the more likely the corresponding initial concentration is not true, and the more the concentration needs to be corrected. Therefore, the corresponding shielding probability is obtained according to the initial concentration difference between the monitoring point and each neighborhood point, and the shielding points with a large shielding probability that need to be corrected are screened out by a preset shielding threshold. And because the heavy metal pollutants have a certain continuity in the diffusion process, the reference concentration more consistent with the true heavy metal substance concentration is obtained by interpolating according to the initial concentration of each neighborhood point by the Kriging interpolation method. It should be noted that when all the neighborhood points in the preset neighborhood range of the shielding point are shielding points, the reference concentration of the neighborhood points is calculated first, and the reference concentration of the neighborhood points is taken as the initial concentration in the interpolation process, so that the reference concentration of the corresponding shielding point is calculated, which will not be described further.

[0066] In one specific implementation manner of the embodiment of the present application, the shielding probability is obtained by the formula

[0067]

[0068] wherein, is the shielding probability of the rth monitoring point; z is the number of heavy metal substance types; ω r is the number of neighborhood points corresponding to the rth monitoring point; S u，r is the initial concentration of the rth monitoring point under the uth heavy metal substance; S u，r，lis the initial concentration of the lth neighborhood point corresponding to the rth monitoring point of the uth heavy metal substance; || is an absolute value symbol; Norm() is a linear normalization function.

[0069] Step S103: According to the distribution of the reference concentration, determine the attenuation factor of each monitoring point in each neighborhood direction, which represents the attenuation trend of the reference concentration of each heavy metal substance.

[0070] The heavy metal substance gradually flows downstream along the river after being discharged through the pollution outlet, and then causes certain pollution to the land along the way and its adjacent land due to heavy metal deposition and other reasons, so the concentration of each heavy metal substance changes continuously and gradually decreases in the diffusion direction or transmission direction. In the application of hyperspectral remote sensing data, the concerned area corresponding to a single spectrum is relatively small, and the environmental conditions in these small ranges, such as water flow rate, water depth, pollutant concentration, etc., are relatively uniform, so the change of pollutant concentration in a small range can be simplified as an exponential decay model. Because the water flow rate is different at different positions, and the pH value and dissolved oxygen of the water area at different positions are different, higher water flow rate will accelerate the diffusion and dilution of heavy metal substances, resulting in a higher attenuation factor; and certain heavy metals may form precipitates under different pH conditions, which will also affect the corresponding attenuation factor. Therefore, due to the difference in environmental conditions, the corresponding attenuation factors of different monitoring points are also different; therefore, the attenuation factor of each monitoring point is calculated to facilitate subsequent analysis.

[0071] Considering that the heavy metal substance may appear diffusion in each direction, that is, the attenuation of each monitoring point in each direction is different; the reference concentration of the corresponding heavy metal substance attenuates more severely in each neighborhood direction of each monitoring point, and the corresponding attenuation factor is larger, so according to the distribution of the reference concentration, the attenuation factor of each monitoring point in each neighborhood direction is determined.

[0072] Preferably, in some possible implementation manners of the embodiments of the present application, the method for obtaining the attenuation factor comprises:

[0073] sequentially taking each neighborhood direction as a target direction and each monitoring point as a target point; taking the next monitoring point of the target point in the target direction as a corresponding first direction point and the previous monitoring point of the target point in the target direction as a corresponding second direction point; obtaining, under each heavy metal substance, an attenuation factor of each heavy metal substance of the target point in the target direction according to a reference concentration variation of the target point relative to the first direction point and the second direction point when the reference concentration of the target point is greater than the reference concentration of the corresponding first direction point; and taking a preset attenuation coefficient as the attenuation factor of each heavy metal substance of the target point in the target direction when the reference concentration of the target point is less than or equal to the reference concentration of the corresponding first direction point. In one specific implementation manner of the embodiment of the present application, the preset attenuation coefficient is set to 0 and can be adjusted automatically.

[0074] Since the reference concentration of the heavy metal substance attenuates more severely in each neighborhood direction, the attenuation factor in the corresponding neighborhood direction is greater. However, if the reference concentration increases or remains unchanged in the corresponding neighborhood direction instead of attenuating, it is indicated that attenuation does not exist in the corresponding direction, and therefore the corresponding attenuation factor is set to 0 when the reference concentration of the target point is less than or equal to the reference concentration of the corresponding first direction point. Moreover, the more severe or more obvious the reference concentration variation in the corresponding neighborhood direction is, the greater the corresponding attenuation factor is, and therefore the attenuation factor is determined according to the reference concentration variation of the target point relative to the first direction point and the second direction point.

[0075] Preferably, in some possible implementation manners of the embodiment of the present application, the process of obtaining the attenuation factor of each heavy metal substance of the target point in the target direction according to the reference concentration variation of the target point relative to the first direction point and the second direction point includes:

[0076] under each heavy metal substance, taking a ratio between the reference concentration of the target point and the reference concentration of the corresponding first direction point as a first concentration ratio and a ratio between the reference concentration of the corresponding second direction point and the reference concentration of the target point as a second concentration ratio; and taking a positive correlation mapping value of a mean value between the first concentration ratio and the second concentration ratio as the corresponding attenuation factor. That is, when the reference concentration of the target point is greater than the reference concentration of the first direction point, the attenuation factor is measured according to the reference concentration variation ratio of the second direction point to the target point and the target point to the first direction point in the corresponding neighborhood direction, and the greater the mean value between the corresponding first concentration ratio and the second concentration ratio is, the faster the attenuation in the corresponding neighborhood direction is and the greater the corresponding attenuation factor is.

[0077] In one specific implementation manner of the embodiment of the present application, the method for obtaining the attenuation factor includes:

[0078]

[0079] wherein φ v，u，r is the attenuation factor of the u-th heavy metal substance corresponding to the r-th monitoring point in the v-th neighborhood direction; C u，r is the reference concentration of the u-th heavy metal substance corresponding to the r-th monitoring point; C" v，u，r is the reference concentration of the u-th heavy metal substance of the corresponding second direction point of the r-th monitoring point in the v-th neighborhood direction; C' v，u，r is the reference concentration of the u-th heavy metal substance of the corresponding first direction point of the r-th monitoring point in the v-th neighborhood direction; lb() is the logarithmic function with the natural constant as the base. It should be noted that, in order to be more consistent with the objective facts, when the reference concentration of any one of the monitoring points in the target point, the corresponding first direction point and the second direction point under the corresponding heavy metal substance is 0, the attenuation factor corresponding to the target point is set to 0 to prevent the denominator from being 0, which will not be described further herein.

[0080] Step S104: determining the final concentration of each heavy metal substance from each pollution outlet in each monitoring point according to the attenuation factor on the pollution transmission path from each pollution outlet to each monitoring point and the reference concentration.

[0081] For each pollution outlet, the concentration of the corresponding heavy metal substance is only obtained from the spectral data, and in its corresponding local range, the reference concentration of the heavy metal substance not only includes its own emission amount, but also includes the heavy metal substance concentration from other pollution outlets upstream of the pollution outlet, so the reference concentration of the monitoring point corresponding to each pollution outlet cannot represent the true concentration of each heavy metal substance discharged by the pollution outlet. However, considering that the reference concentration of the heavy metal substance of each monitoring point is obtained by the influence of multiple pollution outlets, and the attenuation factor and the reference concentration of each monitoring point are known on the corresponding pollution transmission path, a target function can be constructed according to these data to obtain the true concentration of each heavy metal substance discharged by each pollution outlet, so as to determine a more accurate final concentration of each heavy metal substance from each pollution outlet in each monitoring point according to the true concentration and the attenuation factor on the pollution transmission path.

[0082] Preferably, in some possible implementation manners of the embodiment of the present application, the method for obtaining the pollution transmission path comprises: planning the pollution transmission path from each pollution outlet to each monitoring point by the Floyd algorithm. That is, the corresponding shortest attenuation path from each pollution outlet to each monitoring point is obtained by the Floyd algorithm as the corresponding pollution transmission path, so that the total attenuation degree of the true concentration of each heavy metal substance discharged by the pollution outlet to reach each monitoring point is obtained according to the attenuation factor of each monitoring point on the path in the path direction, so that the target function constructed according to this feature is more intuitive.

[0083] Preferably, in some possible implementation manners of the embodiments of the present application, the method for obtaining the final concentration comprises:

[0084] Under each heavy metal substance, the cumulative attenuation coefficients of each pollution outlet to each monitoring point under each heavy metal substance are determined by multiplying and fusing the negative correlation mapping values of the attenuation factors of all monitoring points in the path extension direction according to the pollution transmission path; the target concentration of each heavy metal substance discharged by each pollution outlet is weighted by the cumulative attenuation coefficients, to determine the final concentration of each heavy metal substance from each pollution outlet in each monitoring point. And in the method for obtaining the final concentration, the method for obtaining the target concentration comprises: under each heavy metal substance, the monitoring points with the normalized values of the reference concentration greater than the preset exceeding threshold are taken as the concentration exceeding points corresponding to each heavy metal substance; under each heavy metal substance, a target function model under each heavy metal substance is constructed based on the least square method according to the cumulative attenuation coefficients of all pollution outlets to each concentration exceeding point in combination with the reference concentration of the corresponding concentration exceeding point; the target function is solved by the gradient descent method to determine the target concentration of each heavy metal substance discharged by each pollution outlet under the optimal solution. In one specific implementation manner of the embodiments of the present application, the linear normalization is adopted for the normalization method of the reference concentration, and the preset exceeding threshold is set to 0.8. The implementer can also take the monitoring points with the reference concentration greater than the concentration exceeding threshold as the concentration exceeding points according to the prior concentration exceeding threshold according to the specific implementation environment, which will not be further described here.

[0085] Firstly, since the reference concentration of the heavy metal substance is regarded as exponential attenuation in the diffusion and propagation process, and the attenuation factor is considered as the coefficient of inhibition, the negative correlation mapping needs to be performed in advance when integrating the cumulative attenuation coefficient, so that the final concentration obtained by weighting the target concentration by the cumulative attenuation coefficient is smaller when the overall attenuation factor is larger; therefore, the cumulative attenuation coefficient of each pollution outlet pointing to each monitoring point is determined by multiplying the negative correlation mapping values of all attenuation factors in the path extension direction. And the corresponding path extension direction is the neighborhood direction along the path extension direction, so that the attenuation factor of each monitoring point can be obtained. Secondly, the true concentration of each heavy metal substance discharged by each pollution outlet is unknown, that is, the target concentration is unknown, but the cumulative attenuation coefficient of each pollution outlet pointing to each monitoring point and the reference concentration of each concentration exceeding point are truly known, so the target function model can be constructed based on the least square method according to the cumulative attenuation coefficient of all pollution outlets to each concentration exceeding point in combination with the reference concentration of the corresponding concentration exceeding point, so that the target function is analyzed by the gradient descent method to determine the target concentration of each heavy metal substance discharged by each pollution outlet under the optimal solution.

[0086] Because the cumulative attenuation coefficient is known, all the different target concentrations corresponding to the pollution outlets, after being propagated to each monitoring point in combination with the cumulative attenuation coefficient, the greater the deviation between the corresponding attenuated heavy metal substance concentration and the reference concentration, the greater the residual corresponding to the target function, and the less likely it is to be the optimal solution; therefore, after the target function is constructed, the gradient descent method is used for iteration to obtain the target concentration under the optimal solution that is most consistent with the actual situation and has the minimum residual. In one specific implementation manner of the embodiment of the present application, the initialization variable of the gradient descent method is set as the mean value of the reference concentrations of all the monitoring points adjacent to each pollution outlet, and the upper limit of the iteration number is set as 200 to prevent the iteration from being unable to stop. It should be noted that the least square method and the gradient descent method are prior art known to those skilled in the art, and are not further limited and described here.

[0087] In one specific implementation manner of the embodiment of the present application, the acquisition process of the cumulative attenuation coefficient is represented by a formula as follows:

[0088]

[0089] wherein ρ′ k，h，t is the cumulative attenuation coefficient from the hth pollution outlet to the tth monitoring point under the tth heavy metal substance, D h，t is the number of monitoring points on the pollution transmission path from the hth pollution outlet to the tth monitoring point; φ′ k，h，t，d is the attenuation factor of the dth monitoring point on the pollution transmission path from the hth pollution outlet to the tth monitoring point under the kth heavy metal substance in the path extension direction; exp( ) is an exponential function with a natural constant as the base; and Π is a multiplication symbol.

[0090] Preferably, in some possible implementation manners of the embodiment of the present application, the target function model comprises:

[0091]

[0092] wherein L k represents the target function value under the kth heavy metal substance; N is the number of concentration-exceeding points; C k，i is the reference concentration of the ith concentration-exceeding point under the kth heavy metal substance; n is the number of pollution outlets; ρ′ k，y，i is the cumulative attenuation coefficient from the yth pollution outlet to the ith concentration-exceeding point under the kth heavy metal substance; P k，y is the target concentration of the kth heavy metal substance discharged by the yth pollution outlet.

[0093] Based on the construction principle of the target function of the least square method, C k，i is the true value,

[0094] The objective function is constructed for the estimated value. Since the reference concentration of each heavy metal substance of each concentration exceeding the standard point is obtained by the comprehensive influence of each pollution outlet, the corresponding estimated value is obtained by accumulation. It should be noted that the least square method is a prior art known to those skilled in the art, and therefore the meaning of the objective function construction is not further described. Further, according to the constructed objective function, the target concentration of each heavy metal substance discharged by each pollution outlet in the optimal solution is obtained by the gradient descent method. Further, the final concentration of each heavy metal substance discharged by each pollution outlet is weighted by the cumulative attenuation coefficient to determine the final concentration of each heavy metal substance from each pollution outlet in each monitoring point.

[0095] In a specific implementation of the embodiment of the present application, the process of obtaining the final concentration is represented in formula as:

[0096] Q k,h，t = ρ' k，h，t × P' k，h

[0097] Wherein, Q k，h，t is the final concentration of the kth heavy metal substance from the hth pollution outlet in the tth monitoring point; ρ' k，h，t is the cumulative attenuation coefficient of the hth pollution outlet to the tth monitoring point under the kth heavy metal substance; P' k，h is the target concentration of the kth heavy metal substance discharged by the hth pollution outlet.

[0098] Step S105: determining the pollution influence range of each heavy metal substance discharged by each pollution outlet according to the final concentration.

[0099] After obtaining the final concentration of each heavy metal substance from each pollution outlet in each monitoring point, the pollution influence range of each heavy metal substance discharged by each pollution outlet can be determined according to the size of all the final concentrations corresponding to each pollution outlet, so that pollution prevention and control can be targeted, and the effect and efficiency of pollution prevention and control are higher, that is, the effect of heavy metal pollution range monitoring is improved.

[0100] Preferably, in some possible implementation manners of the embodiment of the present application, the method for obtaining the pollution influence range comprises:

[0101] Under each heavy metal substance, the monitoring point with the final concentration greater than the preset pollution threshold from each sewage outlet is taken as a pollution monitoring point of each sewage outlet, and the area formed by all the pollution monitoring points corresponding to each sewage outlet is taken as the pollution influence range of each heavy metal substance discharged by each sewage outlet. In a specific implementation manner of the embodiment of the present application, the preset pollution threshold is set to 0.15 mg / kg. After the pollution influence range is obtained, the sewage discharge of each sewage outlet is treated in a targeted manner according to the size of the pollution influence range of each heavy metal substance and the concentration distribution of the heavy metal substance in the pollution influence range, so that better pollution prevention and control can be performed.

[0102] In summary, the GIS-assisted mine downstream heavy metal pollution range monitoring method first considers that shielding will cause errors in part of the spectral data, so the initial concentration is corrected by means of the heavy metal substance concentration in the neighborhood range of each monitoring point, and then the decay factor corresponding to each monitoring point is determined by means of the corrected reference concentration distribution and the reference concentration decay area of each heavy metal substance in the neighborhood direction; further, the final concentration of each heavy metal substance from each sewage outlet in each monitoring point is more accurately determined by means of comprehensive analysis of the decay factor of each monitoring point and the reference concentration of the heavy metal substance at each position, so that the pollution influence range of each sewage outlet defined according to the final concentration is more accurate, and the effect of the corresponding heavy metal pollution range monitoring is better.

[0103] The present application also provides a GIS-assisted mine downstream heavy metal pollution range monitoring system, please refer to Figure 2 which shows the structure diagram of the GIS-assisted mine downstream heavy metal pollution range monitoring system provided by an embodiment of the present application, and the system comprises a data acquisition module 201, a concentration correction module 202, a first determination module 203, a second determination module 204 and a pollution influence range monitoring module 205.

[0104] The data acquisition module 201 is used to determine the initial concentration of each heavy metal substance corresponding to each monitoring point in the monitoring area according to the hyperspectral remote sensing data in the monitoring area centered on the mine sewage outlet.

[0105] The concentration correction module 202 is used to correct the initial concentration according to the relative deviation of the initial concentration of each heavy metal substance in the neighborhood range of each monitoring point, and determine the reference concentration of each heavy metal substance corresponding to each monitoring point.

[0106] The first determination module 203 is used to determine the decay factor representing the decay trend of the reference concentration of each heavy metal substance in each neighborhood direction of each monitoring point according to the distribution of the reference concentration.

[0107] The second determining module 204 is configured to determine the final concentration of each heavy metal substance from each pollution outlet in each monitoring point according to the attenuation factor on the pollution transmission path from each pollution outlet to each monitoring point and the reference concentration.

[0108] The pollution influence range monitoring module 205 is configured to determine the pollution influence range of each heavy metal substance discharged by each pollution outlet according to the final concentration.

[0109] It should be noted that the system provided in the above embodiment is only exemplified by the division of the above functional modules, and in actual application, the above functions can be completed by different functional modules according to needs, that is, the internal structure of the computer device is divided into different functional modules to complete all or part of the functions described above. In addition, the GIS-assisted mine downstream heavy metal pollution range monitoring system and the GIS-assisted mine downstream heavy metal pollution range monitoring method provided in the above embodiment belong to the same concept, and the specific implementation process is described in the method embodiment, which will not be repeated here.

[0110] The computer device provided in the embodiment of the present application also provides a computer device, please refer to Figure 3 which shows a computer device structure schematic diagram provided by an embodiment of the present application, the computer device includes memory 301, processor 302 and computer program 303 stored in the memory 301 and running on the processor 302, wherein the processor 302 executes the computer program 303, so that the computer device can execute any one of the above-mentioned GIS-assisted mine downstream heavy metal pollution range monitoring method.

[0111] The computer device provided in the embodiment of the present application also provides a computer device, please refer to Figure 3 which shows a computer device structure schematic diagram provided by an embodiment of the present application, the computer device includes memory 301, processor 302 and computer program 303 stored in the memory 301 and running on the processor 302, wherein the processor 302 executes the computer program 303, so that the computer device can execute any one of the above-mentioned GIS-assisted mine downstream heavy metal pollution range monitoring method.

[0112] The computer device provided in the embodiment of the present application also provides a computer device, please refer to Figure 3 which shows a computer device structure schematic diagram provided by an embodiment of the present application, the computer device includes memory 301, processor 302 and computer program 303 stored in the memory 301 and running on the processor 302, wherein the processor 302 executes the computer program 303, so that the computer device can execute any one of the above-mentioned GIS-assisted mine downstream heavy metal pollution range monitoring method.

[0113] In the embodiments provided in the present application, it should be understood that the computer device, computer program product and computer readable storage medium provided are all used to execute the corresponding method provided above, so the beneficial effects that can be achieved are referred to the beneficial effects of the method provided above, which will not be repeated here.

[0114] It is to be noted that the sequential order of the above-described embodiments of the present application only for the purpose of description, but not the advantages and disadvantages of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are also possible or can be advantageous.

[0115] Each of the embodiments in the specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the difference from other embodiments.

Claims

1. A GIS-assisted-based method for monitoring the scope of heavy metal pollution downstream of a mine, characterized in that, The method comprises: According to the hyperspectral remote sensing data in the monitoring area centered on the mine pollution outlet, the initial concentration of each heavy metal substance corresponding to each monitoring point in the monitoring area is determined; According to the relative deviation of the initial concentration of each heavy metal substance in the neighborhood range of each monitoring point, the initial concentration is corrected to determine the reference concentration of each heavy metal substance corresponding to each monitoring point; According to the distribution of the reference concentration, the attenuation factor of each monitoring point in each neighborhood direction representing the attenuation trend of the reference concentration of each heavy metal substance is determined; According to the attenuation factor on the pollution transmission path from each pollution outlet to each monitoring point and the reference concentration, the final concentration of each heavy metal substance from each pollution outlet in each monitoring point is determined; According to the final concentration, the pollution influence range of each heavy metal substance discharged by each pollution outlet is determined; The method for obtaining the reference concentration comprises: Other monitoring points in the preset neighborhood range of each monitoring point are taken as the neighborhood points of each monitoring point; the initial concentration difference between each monitoring point and each corresponding neighborhood point under each heavy metal substance is calculated; the normalized value of the cumulative value of the initial concentration difference between each monitoring point and all neighborhood points under all heavy metal substances is taken as the shielding probability of each monitoring point; the monitoring points with the corresponding shielding probability greater than the preset shielding threshold are taken as the shielding points; The concentration of each heavy metal substance corresponding to the shielding point is interpolated by the Kriging interpolation method according to the initial concentration of each neighborhood point corresponding to each shielding point, to obtain the reference concentration of each heavy metal substance of each shielding point; the initial concentration of each heavy metal substance of other monitoring points except the shielding points is taken as the corresponding reference concentration; The method for obtaining the attenuation factor comprises: Each neighborhood direction is sequentially taken as the target direction, and each monitoring point is sequentially taken as the target point; the next monitoring point of the target point in the target direction is taken as the corresponding first direction point; the previous monitoring point of the target point in the target direction is taken as the corresponding second direction point; Under each heavy metal substance, when the reference concentration of the target point is greater than the reference concentration of the corresponding first direction point, the attenuation factor of each heavy metal substance of the target point in the target direction is obtained according to the reference concentration change of the target point relative to the first direction point and the second direction point; Under each heavy metal substance, when the reference concentration of the target point is less than or equal to the reference concentration of the corresponding first direction point, a preset attenuation coefficient is taken as the attenuation factor of each heavy metal substance of the target point in the target direction; The method for obtaining the final concentration comprises: Under each heavy metal substance, the cumulative attenuation coefficient of each pollution outlet to each monitoring point under each heavy metal substance is determined by multiplying the negative correlation mapping values of the attenuation factors of all monitoring points in the path extension direction of the pollution transmission path; The final concentration of each heavy metal substance from each pollution outlet in each monitoring point is determined by weighting the target concentration of each heavy metal substance discharged by each pollution outlet through the cumulative attenuation coefficient; The method for obtaining the target concentration comprises: The monitoring point with a normalized value of the reference concentration greater than the preset exceeding threshold is taken as a concentration-exceeding point corresponding to each heavy metal substance under each heavy metal substance; Under each heavy metal substance, a target function model under each heavy metal substance is constructed based on the least square method according to the cumulative attenuation coefficients of all the pollution outlets to each concentration-exceeding point and the reference concentration of the corresponding concentration-exceeding point; The target function is solved by the gradient descent method to determine the target concentration of each heavy metal substance discharged by each pollution outlet under the optimal solution; The target function model comprises: in, Indicates the first Objective function values ​​for various heavy metal substances; This refers to the number of points where the concentration exceeded the standard. For the first The concentration exceeded the standard at the first... Reference concentrations for various heavy metal substances; Number of sewage outlets; For the first The first heavy metal substance From the first sewage outlet to the first The cumulative attenuation coefficient for each concentration exceeding the standard point; For the first The first sewage outlet discharged the first The target concentration of a certain heavy metal substance.

2. The GIS-assisted mine downstream heavy metal pollution range monitoring method according to claim 1, characterized in that, The method for obtaining the attenuation factor of each heavy metal substance of the target point in the target direction according to the reference concentration change of the target point relative to the first direction point and the second direction point comprises: Under each heavy metal substance, a ratio between the reference concentration of the target point and the reference concentration of the corresponding first direction point is taken as a first concentration ratio; a ratio between the reference concentration of the corresponding second direction point and the reference concentration of the target point is taken as a second concentration ratio; and a positive correlation mapping value of the mean value between the first concentration ratio and the second concentration ratio is taken as the corresponding attenuation factor.

3. The GIS-assisted mine downstream heavy metal pollution range monitoring method according to claim 1, characterized in that, The method for obtaining the pollution transmission path comprises: The pollution transmission path from each pollution outlet to each monitoring point is planned by the Floyd algorithm.

4. The GIS-assisted mine downstream heavy metal pollution range monitoring method according to claim 1, characterized in that, The method for obtaining the pollution influence range comprises: Under each heavy metal substance, the monitoring point with the final concentration greater than the preset pollution threshold from each pollution outlet is taken as a pollution monitoring point of each pollution outlet; and an area formed by all the pollution monitoring points corresponding to each pollution outlet is taken as a pollution influence range of each heavy metal substance discharged by each pollution outlet.

5. The GIS-assisted mine downstream heavy metal pollution range monitoring method according to claim 1, characterized in that, The preset attenuation coefficient is set to 0.

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