Regional soil heavy metal content evaluation method and system

Abstract

The invention relates to the technical field of environmental science and engineering, and particularly discloses a regional soil heavy metal content evaluation method and system. Comprising the steps of obtaining a current time interval corresponding to a to-be-evaluated heavy metal content and region parameters of a region; calculating the heavy metal content of a second region in the current time interval according to a second value of the current time interval and the change trend of the heavy metal content in the region, and calculating the heavy metal content of a second sub-region in the current time interval according to the second value and the change trend of the heavy metal content of the sub-region; and determining the sum of the heavy metal content in the first region, the heavy metal content in the second region, the heavy metal content in the first sub-region, the heavy metal content in the second sub-region and the random error as the heavy metal content in a third region from the reference time interval to the current time interval, and evaluating the dynamic change trend of the heavy metal content in the third region. According to the invention, the evaluation accuracy can be improved.

Description

Technical Field

[0001] The present disclosure relates to the field of environmental science and engineering technology, and particularly to a method and system for evaluating the heavy metal content in regional soil. Background Art

[0002] Due to the rapid development of industry and agriculture, the problem of heavy metal pollution in soil has become particularly prominent and has attracted great attention.

[0003] Soil is an important part of the ecological environment. With the rapid development of industry and agriculture, the unreasonable exploitation of mineral resources, and the sewage irrigation, unreasonable use of chemical fertilizers, and livestock and poultry breeding in agricultural production, the pollution of heavy metals in soil has gradually intensified.

[0004] Based on this, it is necessary to determine the change trend of heavy metal content in soil to evaluate its ecological risk and health risk, and provide a scientific basis for formulating regional pollution prevention and control policies. For example, the patent application document (CN118243904A) proposes to determine the heavy metal content of the entire detection area by determining the heavy metal content of the detection points, and use it as the basis for evaluating its ecological risk and health risk. However, in this related technology, the heavy metal content of the entire detection area is determined based on the heavy metal content of multiple detection points, and the evaluation of the change trend of heavy metal content in regional soil is inaccurate. Summary of the Invention

[0005] To solve the above technical problems, the present disclosure provides a method for evaluating the heavy metal content in regional soil, including the following steps: Obtain the current time interval corresponding to the heavy metal content to be evaluated and the regional parameters of the area where it is located. Each area includes multiple sub-areas, and each sub-area includes multiple monitoring points; the regional parameters include the heavy metal content in the first area within the reference time interval and the change trend of the heavy metal content within the area, the heavy metal content in the first sub-area within the reference time interval and the change trend of the heavy metal content in the sub-area, the heavy metal content of the first monitoring point within the reference time interval, and the random error; determine the first value within the reference time interval, and determine the second value within the current time interval based on the first value; calculate the heavy metal content in the second area within the current time interval according to the second value and the change trend of the heavy metal content within the area, and calculate the heavy metal content in the second sub-area within the current time interval according to the second value and the change trend of the heavy metal content in the sub-area; determine the sum of the heavy metal content in the first area, the heavy metal content in the second area, the heavy metal content in the first sub-area, the heavy metal content in the second sub-area, and the random error as the heavy metal content in the third area from the reference time interval to the current time interval, and evaluate the dynamic change trend of the heavy metal content in the third area.

[0006] Further, determining a first value of the reference time interval and determining a second value of the current time interval based on the first value includes: Determining that the value of the reference time interval is 0 and determining that the value of the current time interval is 1.

[0007] Further, calculating the heavy metal content in the second region within the current time interval according to the second value and the change trend of the heavy metal content in the region includes: Calculating the cumulative heavy metal content in the region within the current time interval based on the change trend of the heavy metal content in the region; and determining the cumulative heavy metal content in the region as the heavy metal content in the second region.

[0008] Further, calculating the heavy metal content in the second sub-region within the current time interval according to the second value and the change trend of the heavy metal content in the sub-region includes: Calculating the cumulative heavy metal content in the sub-region within the current time interval based on the change trend of the heavy metal content in the sub-region; and determining the cumulative heavy metal content in the sub-region as the heavy metal content in the second sub-region.

[0009] Further, evaluating the dynamic change trend of the heavy metal content in the third region includes: Obtaining the heavy metal content in the fourth region at different time points from the heavy metal content in the third region based on the same region; counting the regional change trend of the heavy metal content in the fourth region; and in response to the fixed slope of the regional change trend not being equal to zero, evaluating that the regional heavy metal content changes linearly with time.

[0010] Further, evaluating the dynamic change trend of the heavy metal content in the third region includes: Obtaining the sub-region change trend of the heavy metal content in multiple sub-regions within the same region from the heavy metal content in the third region; determining the random slope variance of the sub-region change trend; and in response to the random slope variance being greater than zero, evaluating that there are differences in the heavy metal content in each sub-region.

[0011] Further, evaluating the dynamic change trend of the heavy metal content in the third region includes: Determining the overall slope of each sub-region change trend; in response to each overall slope not being equal to zero, sorting the sub-region change trends in descending order; and based on the largest sub-region change trend, evaluating the change trend of the heavy metal content in the sub-region corresponding to the largest sub-region change trend.

[0012] Furthermore, the step of obtaining the current time interval and the regional parameters of the region corresponding to the heavy metal content to be evaluated further includes: Abnormal data of the regional parameters are determined and the abnormal data are eliminated.

[0013] The present disclosure also provides a regional soil heavy metal content assessment system, comprising: An acquisition module is used to obtain the current time interval corresponding to the heavy metal content to be evaluated and the regional parameters of the area where the area is located, each of which includes multiple sub-areas, and each of which includes multiple monitoring points; the regional parameters include the heavy metal content in the first area of ​​the reference time interval and the heavy metal content change trend in the area, the heavy metal content in the first sub-area of ​​the reference time interval and the heavy metal content change trend in the sub-area, the heavy metal content at the first monitoring point of the reference time interval, and the random error; a determination module is used to determine the first value of the reference time interval, and determine the second value of the current time interval based on the first value; according to the second value and the heavy metal content change trend in the area, calculate the heavy metal content of the second area in the current time interval, and calculate the heavy metal content of the second sub-area in the current time interval according to the second value and the heavy metal content change trend in the sub-area; an evaluation module is used to determine the sum of the heavy metal content in the first area, the heavy metal content in the second area, the heavy metal content in the first sub-area, the heavy metal content in the second sub-area, and the random error as the heavy metal content of the third area from the reference time interval to the current time interval, and evaluate the dynamic change trend of the heavy metal content in the third area.

[0014] The embodiments of the present disclosure have the following technical effects: The method for evaluating the heavy metal content in regional soil provided by the present disclosure, first, obtains the time interval corresponding to the heavy metal content to be evaluated and the regional parameters of the region; wherein each of the regions includes multiple sub-regions, and each of the sub-regions includes multiple monitoring points; the regional parameters include the heavy metal content in the first region of the reference time interval and the heavy metal content change trend in the region, the heavy metal content in the first sub-region of the reference time interval and the heavy metal content change trend in the sub-region, the heavy metal content in the first monitoring point of the reference time interval, and the random error. Through multi-level parameters, the influencing factors of different levels can be considered to provide more accurate and reliable data for evaluating the dynamic change trend of heavy metal content. The time interval and regional parameters are calculated to determine the regional heavy metal content, that is, the heavy metal content of the third region from the reference time interval to the current time interval is accurately calculated. Based on the heavy metal content of the third region, the dynamic change trend of regional heavy metal content is evaluated, which can more comprehensively capture the changes in soil heavy metal content over time at different spatial scales, and provide an effective reference basis, so that the best strategy for managing soil heavy metals can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] Figure 1 is a flowchart of a method for evaluating the heavy metal content in regional soil provided by an embodiment of the present disclosure; Figure 2 is a flowchart of a method for determining the temporal variation trend of the heavy metal content in a region provided by an embodiment of the present disclosure; Figure 3 is a flowchart of a method for determining the differences in the heavy metal content in sub-regions provided by an embodiment of the present disclosure; Figure 4 is a flowchart of a method for ranking the heavy metal content in sub-regions provided by an embodiment of the present disclosure; Figure 5 is a schematic diagram of the variation trend of the heavy metal content in each sub-region in a region provided by an embodiment of the present disclosure; Figure 6 is a schematic diagram of a system for evaluating the heavy metal content in a region provided by an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] To make the objectives, technical solutions, and advantages of the present disclosure clearer, the following will clearly and completely describe the technical solutions of the present disclosure. Obviously, the described embodiments are only some embodiments of the present disclosure, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present disclosure without creative efforts belong to the scope of the present disclosure.

[0018] The present application proposes a method and system for evaluating the heavy metal content in regional soil, constructs a heavy metal content calculation model with multi-dimensional and multi-level random effects, and determines the heavy metal content based on the time interval, region, and regional parameters, so as to more accurately and reliably evaluate the dynamic changes of the heavy metal content in the soil.

[0019] Among heavy metals, cadmium is one of the most toxic elements in the environment. At the same time, due to the low mobility of cadmium in the soil, the pollution of cadmium to the soil is basically an irreversible process. Once the soil is polluted by cadmium, it is very difficult to recover. The research on cadmium-polluted soil and its remediation is currently a hot topic in soil environment research. Therefore, the present disclosure takes cadmium metal element as an example to illustrate the present disclosure, but the embodiments of the present disclosure are not limited to cadmium metal element.

[0020] Figure 1 This is the flowchart of the method for evaluating the heavy metal content in regional soil provided by the embodiments of the present disclosure. Refer to Figure 1 , which specifically includes the following steps: In step S11, obtain the time interval corresponding to the heavy metal content to be evaluated and the regional parameters of the region where it is located.

[0021] Among them, each region includes multiple sub-regions, and each sub-region includes multiple monitoring points.

[0022] The regional parameters include the heavy metal content in the first region within the reference time interval and the changing trend of the heavy metal content within the region, the heavy metal content in the first sub-region within the reference time interval and the changing trend of the heavy metal content in the sub-region, the heavy metal content at the first monitoring point within the reference time interval, and the random error.

[0023] In the embodiments of the present disclosure, data for the dynamic change of heavy metal content can be obtained from multiple dimensions. The present disclosure evaluates the spatio-temporal variation law of heavy metal content from the variation factors in the time dimension and the space dimension, so as to make the calculated heavy metal content more accurate.

[0024] In the present disclosure, the target region can be determined, and further multiple sub-regions of the target region, as well as multiple monitoring points in each sub-region, can be determined, so as to select the data of the monitoring points within the target time interval. Among them, the time interval can be one day, one month, or one year, etc. The present disclosure is not limited to a specific time range.

[0025] It should be noted that the heavy metal content in the first region within the reference time interval is the regional global intercept within the reference time interval; the regional global intercept is a fixed effect, which can be the heavy metal content baseline based on the specified time, indicating the average level of the regional soil heavy metal content in this reference state within the specified time. Among them, the period of the specified time can be set to 0. Taking cadmium metal as an example, the global intercept can be the soil cadmium content baseline at the specified time. It should be noted that the global intercept is the theoretical global mean estimated by the heavy metal content calculation model, and is not equal to the mean of each monitoring point within the time interval to be evaluated.

[0026] Both the reference time interval and the current time interval are time variables. The time variable can be understood as an explanatory variable, indicating the observation time of the monitoring point. For example, the period of the reference time interval can take the value of 0, and the value of the current time interval to be evaluated can be 1.

[0027] The changing trend of the heavy metal content within the region is the period effect. The period effect can be understood as the changing trend of the heavy metal content within the region over time, and it is a fixed effect.

[0028] The heavy metal content in the first sub-region of the reference time interval is the sub-region random intercept, which can be understood as representing the difference in the heavy metal content baseline of the sub-region within the time interval compared to the regional heavy metal content baseline.

[0029] The changing trend of the heavy metal content in the sub-region is the sub-region random slope, which can be understood as the independent changing trend of the heavy metal content in the sub-region.

[0030] The heavy metal content at the first monitoring point in the reference time interval is the monitoring point random intercept, which can be understood as the random effect of the monitoring point, representing the difference in the heavy metal content baseline of the monitoring point within the time interval compared to the sub-region heavy metal content baseline.

[0031] The random error is the residual term.

[0032] In the present disclosure, for the time interval of the heavy metal content to be evaluated and the regional parameters of the region where it is located, etc., the number of point samples should preferably be 30 or more in principle. The specific number of samples can be determined according to the actual situation and its relevant regulations. If the sample size requirement is not met, no statistical analysis of the changing trend of soil heavy metal content will be carried out.

[0033] Exemplarily, determine the region where the cadmium metal element content to be evaluated in the soil is located, further determine the time interval for analyzing the change of the cadmium metal element content in the soil within the region over time, and the regional parameters of the cadmium metal element.

[0034] In step S12, determine the first value of the reference time interval, and determine the second value of the current time interval based on the first value.

[0035] In the present disclosure, the reference time interval can be the previous time interval of the current time interval, and no specific limitation is made here.

[0036] In step S13, calculate the second regional heavy metal content within the current time interval according to the second value and the changing trend of the heavy metal content within the region, and calculate the second sub-region heavy metal content within the current time interval according to the second value and the changing trend of the heavy metal content in the sub-region.

[0037] In the embodiment of the present disclosure, the value of the reference time interval can be determined to be 0, so as to determine the value of the current time interval to be 1.

[0038] Among them, the unit of the change trend of heavy metal content in the region and the change trend of heavy metal content in the sub-region is mg / (kg * time interval). Based on this, the present disclosure can calculate the cumulative heavy metal content in the region during the current time interval based on the change trend of heavy metal content in the region, and determine the heavy metal content in the second region as the cumulative heavy metal content in the region. Further, based on the change trend of heavy metal content in the sub-region, calculate the cumulative heavy metal content in the sub-region during the current time interval; determine the cumulative heavy metal content in the sub-region as the heavy metal content in the second sub-region.

[0039] In step S14, the sum of the heavy metal content in the first region, the heavy metal content in the second region, the heavy metal content in the first sub-region, the heavy metal content in the second sub-region, and the random error is determined as the heavy metal content in the third region from the reference time interval to the current time interval, and the dynamic change trend of the heavy metal content in the third region is evaluated.

[0040] In the embodiment of the present disclosure, the dynamic change trend of the heavy metal content in the region and the dynamic change trend of the heavy metal content in each sub-interval can be determined respectively according to the change trend of the heavy metal content in the third region from the reference time interval to the current time interval over time.

[0041] The regional soil heavy metal content evaluation method provided by the present disclosure considers the variation factors of heavy metal content in the soil at different levels through the regional parameters of heavy metals obtained at different times and in different regions. Further, the sum of the heavy metal content in the first region, the heavy metal content in the second region, the heavy metal content in the first sub-region, the heavy metal content in the second sub-region, and the random error is determined as the heavy metal content in the third region from the reference time interval to the current time interval, so as to more comprehensively capture the changes of soil heavy metal content over time at different spatial scales, improve the accuracy and reliability of the evaluation, and better serve soil environmental protection and management.

[0042] In the present disclosure, a heavy metal content calculation model can also be constructed according to the sum operation relationship of the heavy metal content in the first region, the heavy metal content in the second region, the heavy metal content in the first sub-region, the heavy metal content in the second sub-region, and the random error, so as to determine the heavy metal content in the third region from the reference time interval to the current time interval based on the heavy metal content calculation model.

[0043] Furthermore, the implementation manner of training the relationship for calculating heavy metal content is as follows: Obtain the historical data of heavy metals and eliminate the abnormal historical data in the historical data. Construct a neural network model including the sum operation relationship of the heavy metal content in the first region, the heavy metal content in the second region, the heavy metal content in the first sub-region, the heavy metal content in the second sub-region, and the random error; train the neural network model based on the historical data to obtain a heavy metal content calculation model.

[0044] Among them, the historical data includes the region, the historical time interval, and the historical heavy metal content of the region; there is a corresponding relationship among the region, the historical time, and the historical heavy metal content.

[0045] For example, obtain the cadmium metal content within a certain time interval in a region and the relevant parameters used to calculate the cadmium metal content.

[0046] In the present disclosure, before using the historical data to train the heavy metal content calculation model, it is necessary to remove the abnormal data in the historical data to ensure the accuracy of the trained heavy metal content calculation model.

[0047] Furthermore, for statistical units with a sample size greater than 100, an outlier detection method based on the mean and standard deviation is adopted. If the data is normally distributed, remove the outliers outside ; if it is not normally distributed, remove the outliers outside M / D 3 -MD 3 until there are no outliers. For statistical units with a sample size less than or equal to 100, the Grubbs test is used to remove outliers.

[0048] During the outlier removal process, relevant statistical analysis indicators need to be calculated, and the calculation formulas are as follows.

[0049]

[0050] In the formula: n is the sample size, in units; represents the i-th sample value; ; represents the arithmetic mean; S represents the arithmetic standard deviation; M represents the geometric mean; D represents the geometric standard deviation.

[0051] As in the above embodiment, each region in the present disclosure includes a plurality of sub-regions, and each sub-region includes a plurality of monitoring points.

[0052] Among them, in the present disclosure, the sum operation relationship of the heavy metal content in the first region, the heavy metal content in the second region, the heavy metal content in the first sub-region, the heavy metal content in the second sub-region, and the random error is as follows:

[0053] Among them, represents the j-th observation of the k-th monitoring point in the i-th sub-region; represents the heavy metal content in the first region; represents the change trend of the heavy metal content in the region; represents the current time interval; represents the heavy metal content in the first sub-region; Indicates the change trend of heavy metal content in the sub-region; Indicates the random intercept of the monitoring point; Indicates the random error.

[0054] In the embodiments of the present disclosure, before training the heavy metal content calculation model using historical data, it is necessary to remove abnormal data from the historical data to ensure the accuracy of the trained heavy metal content calculation model. And during the process of evaluating the change trend of heavy metal content, it is also necessary to remove abnormal data to ensure the reliability of the change trend of heavy metal content, so as to provide a more accurate basis for subsequent soil environmental protection and management.

[0055] In the present disclosure, the change trend of the heavy metal content in the third region from the reference time interval to the current time interval can be the change trend of the heavy metal content in the region, the change trend of the heavy metal content in the sub-region, or the difference trend of the heavy metal content changes in multiple sub-regions.

[0056] Figure 2 Is the flowchart of the method for determining the time change trend of the heavy metal content in the region provided by the embodiments of the present disclosure. See Figure 2 , the implementation manner of the change trend of the heavy metal content in the region over time is as follows: In step S21, based on the same region, obtain the heavy metal content in the fourth region at different time points within the time interval from the heavy metal content in the third region.

[0057] In step S22, statistically analyze the regional change trend of the heavy metal content in the fourth region.

[0058] In step S23, in response to the fixed slope of the regional change trend not being equal to zero, evaluate that the change of the heavy metal content in the region over time is linearly correlated.

[0059] It should be noted that in the present disclosure, for the sake of distinction, terms such as "first" and "second" are used to describe the heavy metal content in the region.

[0060] In the present disclosure, based on the heavy metal content in the fourth region at different time points within the obtained time interval, a change trend graph can be drawn to more intuitively display the change trend of the heavy metal content in the region. Thus, based on the regional change trend of the heavy metal content in the region, determine the fixed slope of the change trend of this region.

[0061] Assume that the regional change trend of the heavy metal content is not related to the time interval, then the fixed slope of this regional change trend is 0; when the fixed slope of this regional change trend is not equal to 0, determine that the regional change trend of the heavy metal content in the region is related to the time interval.

[0062] Further, when the probability that the regional change trend of the heavy metal content in the region is not related to the time interval is less than 0.05, it is determined that the fixed slope of the regional change trend is not equal to zero, and it is evaluated that the heavy metal content in the region changes significantly linearly with time within the specified time interval.

[0063] In the present disclosure, Figure 3 is a flowchart of a method for determining the difference in heavy metal content in sub-regions provided by an embodiment of the present disclosure. Refer to Figure 3 , and the evaluation method for the change trend of the heavy metal content in the sub-region is as follows: In step S31, the sub-region change trend of the heavy metal content in multiple sub-regions within the same region is obtained from the heavy metal content in the third region.

[0064] In step S32, the variance of the random slope of the sub-region change trend is determined.

[0065] In step S33, in response to the variance of the random slope being greater than zero, it is evaluated that there are differences in the heavy metal content in each sub-region.

[0066] In an embodiment of the present disclosure, the sub-region change trend of the heavy metal content in each sub-region can be obtained from the regional change trend of the statistically heavy metal content in the region. The variance of the random slope of each sub-region change trend is determined according to the obtained sub-region change trend.

[0067] Assuming that the variance of the random slope of each sub-region is 0, it indicates that there are no differences between the change trends of each sub-region; if the variance of the random slope of each sub-region is greater than 0, it is determined that there are differences between the change trends of each sub-region.

[0068] Further, if the variance of the random slope of each sub-region is significantly greater than 0, it is evaluated that there are significant differences in the change trends of the heavy metal content between the sub-regions of the region.

[0069] In the present disclosure, Figure 4 is a flowchart of a method for ranking the heavy metal content in sub-regions provided by an embodiment of the present disclosure. Refer to Figure 4 , and the evaluation method for ranking the change trend of the heavy metal content in the sub-region is as follows: In step S41, the overall slope of the change trend of each sub-region is determined.

[0070] In step S42, in response to each overall slope not being equal to zero, the change trends of the sub-regions are ranked in descending order.

[0071] In step S43, based on the largest sub-region change trend, the change trend of the heavy metal content in the sub-region corresponding to the largest sub-region change trend is evaluated.

[0072] In the present disclosure, the change trend of the heavy metal content in a sub-region with a non-zero overall slope is determined to have a significant change in the change trend of the heavy metal content in the sub-region. The sub-regions with a non-zero overall slope of the change trend in the sub-region are sorted from largest to smallest. Thus, based on the change trend in the sub-region, a sorting from largest to smallest is performed to determine the sorting order of the corresponding sub-regions. Further, according to the sorting order of the sub-regions, the sub-region with the most significant change trend in the heavy metal content of the sub-region is determined.

[0073] Exemplarily, taking the change trend of cadmium content in soil as an example for illustration. Among them, P represents the probability that the region is not related to the change trend of cadmium content in the soil. The region includes fourteen sub-regions. The probability that each sub-region is not related to the change trend of cadmium content in the soil, and the change trend of the heavy metal content in each sub-region can be seen in Table 1.

[0074]

[0075] It should be noted that the elements in the table are independent of each other.

[0076] A line graph of the change trend is drawn according to the data in Table 1, as Figure 5 shown. Figure 5 It is a schematic diagram of the change trend of the heavy metal content in each sub-region of the region provided by the embodiment of the present disclosure.

[0077] In the present disclosure, in combination with Table 1 and Figure 5 it can be seen that the change trend of the heavy metal content in the first sub-region is the most obvious, with a significant change and a significant upward trend.

[0078] Based on the same / similar concept, the present disclosure also provides a regional soil heavy metal content evaluation system, Figure 6 which is a schematic diagram of the regional soil heavy metal content evaluation system provided by the embodiment of the present disclosure. Refer to Figure 6 , the regional soil heavy metal content evaluation system 600 may include: An acquisition module 601, configured to acquire a current time interval corresponding to the heavy metal content to be evaluated and regional parameters of the region where it is located. Each of the regions includes a plurality of sub-regions, and each of the sub-regions includes a plurality of monitoring points; the regional parameters include the heavy metal content in the first region of the reference time interval and the change trend of the heavy metal content in the region, the heavy metal content in the first sub-region of the reference time interval and the change trend of the heavy metal content in the sub-region, the heavy metal content at the first monitoring point in the reference time interval, and a random error; A determination module 602, configured to determine a first value of the reference time interval, and determine a second value of the current time interval based on the first value; calculate the heavy metal content in the second region in the current time interval according to the second value and the change trend of the heavy metal content in the region, and calculate the heavy metal content in the second sub-region in the current time interval according to the second value and the change trend of the heavy metal content in the sub-region; An evaluation module 603, configured to determine the sum of the heavy metal content in the first region, the heavy metal content in the second region, the heavy metal content in the first sub-region, the heavy metal content in the second sub-region, and the random error as the heavy metal content in the third region from the reference time interval to the current time interval, and evaluate the dynamic change trend of the heavy metal content in the third region.

[0079] In the present disclosure, the determination module 602 is configured to determine that the value of the reference time interval is 0 and determine that the value of the current time interval is 1.

[0080] In the present disclosure, the determination module 602 is configured to calculate the cumulative heavy metal content in the region in the current time interval based on the change trend of the heavy metal content in the region; and determine the cumulative heavy metal content in the region as the heavy metal content in the second region.

[0081] In the present disclosure, the determination module 602 is configured to calculate the cumulative heavy metal content in the sub-region in the current time interval based on the change trend of the heavy metal content in the sub-region; and determine the cumulative heavy metal content in the sub-region as the heavy metal content in the second sub-region.

[0082] In the present disclosure, the evaluation module 603 is configured to obtain the heavy metal content in the fourth region at different time points in the heavy metal content in the third region based on the same region; count the regional change trend of the heavy metal content in the fourth region; in response to the fixed slope of the regional change trend not being equal to zero, evaluate that the regional heavy metal content changes linearly with time.

[0083] In the present disclosure, the evaluation module 603 is configured to obtain the sub-region change trend of the heavy metal content in multiple sub-regions within the same region from the heavy metal content in the third region; determine the random slope variance of the sub-region change trend; and in response to the random slope variance being greater than zero, evaluate that there are differences in the heavy metal content of each sub-region.

[0084] In the present disclosure, the evaluation module 603 is configured to determine the overall slope of the change trend of each sub-region; in response to each overall slope not being equal to zero, sort the change trends of the sub-regions in descending order; and based on the largest change trend of the sub-region, evaluate the change trend of the heavy metal content of the sub-region corresponding to the largest change trend of the sub-region.

[0085] In the present disclosure, the determination module 602 is further configured to determine the abnormal data of the regional parameters and eliminate the abnormal data.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure and are not intended to limit them; although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present disclosure.

Claims

1. A method for evaluating the heavy metal content in regional soil, characterized in that, The steps are as follows: Obtain the current time interval corresponding to the heavy metal content to be evaluated and the regional parameters of the area where it is located. Each of the said areas includes multiple sub-areas, and each sub-area includes multiple monitoring points; the regional parameters include the heavy metal content in the first area within the reference time interval and the change trend of the heavy metal content within the area, the heavy metal content in the first sub-area within the reference time interval and the change trend of the heavy metal content in the sub-area, the heavy metal content at the first monitoring point within the reference time interval, and the random error; Determine the first value within the reference time interval, and determine the second value within the current time interval based on the first value; According to the second value and the change trend of the heavy metal content within the area, calculate the heavy metal content in the second area within the current time interval, and calculate the heavy metal content in the second sub-area within the current time interval according to the second value and the change trend of the heavy metal content in the sub-area; Determine the sum of the heavy metal content in the first area, the heavy metal content in the second area, the heavy metal content in the first sub-area, the heavy metal content in the second sub-area, and the random error as the heavy metal content in the third area from the reference time interval to the current time interval, and evaluate the dynamic change trend of the heavy metal content in the third area.

2. The regional soil heavy metal content assessment method according to claim 1, characterized in that The determining the first value within the reference time interval and determining the second value within the current time interval based on the first value includes: Determine that the value within the reference time interval is 0, and determine that the value within the current time interval is 1.

3. The regional soil heavy metal content assessment method according to claim 1, wherein The calculating the heavy metal content in the second area within the current time interval according to the second value and the change trend of the heavy metal content within the area includes: Based on the change trend of the heavy metal content within the area, calculate the cumulative heavy metal content within the area in the current time interval; Determine the cumulative heavy metal content within the area as the heavy metal content in the second area.

4. The regional soil heavy metal content assessment method according to claim 1, characterized in that The calculating the heavy metal content in the second sub-area within the current time interval according to the second value and the change trend of the heavy metal content in the sub-area includes: Based on the change trend of the heavy metal content in the sub-area, calculate the cumulative heavy metal content in the sub-area in the current time interval; Determine the cumulative heavy metal content within the sub-area as the heavy metal content in the second sub-area.

5. The regional soil heavy metal content assessment method according to claim 1, characterized in that The evaluating the dynamic change trend of the heavy metal content in the third area includes: Based on the same area, obtain the heavy metal content in the fourth area at different time points in the heavy metal content in the third area; Statistically analyze the regional change trend of the heavy metal content in the fourth area; In response to the fixed slope of the regional change trend not being equal to zero, evaluate that the regional heavy metal content changes linearly with time.

6. The regional soil heavy metal content assessment method according to claim 1, characterized in that The evaluating the dynamic change trend of the heavy metal content in the third area includes: Obtain the sub-area change trend of the heavy metal content in multiple sub-areas within the same area in the heavy metal content in the third area; Determine the random slope variance of the sub-area change trend; In response to the random slope variance being greater than zero, evaluate that there are differences in the heavy metal content in each sub-area.

7. The regional soil heavy metal content assessment method according to claim 6, wherein, The evaluating the dynamic change trend of the heavy metal content in the third area includes: determining the overall slope of the trend of change in each of the sub-regions; In response to each of the overall slopes not being equal to zero, sorting the sub-region change trends in descending order; Based on the largest sub-region change trend, the heavy metal content change trend of the sub-region corresponding to the largest sub-region change trend is evaluated.

8. The regional soil heavy metal content assessment method according to claim 2, wherein The step of obtaining the current time interval corresponding to the heavy metal content to be evaluated and the regional parameters of the region where the heavy metal content is located also includes: Abnormal data of the regional parameters are determined and the abnormal data are eliminated.

9. A regional soil heavy metal content assessment system, characterized in that, include: An acquisition module is used to obtain the current time interval corresponding to the heavy metal content to be evaluated and the regional parameters of the region where the region is located, each of the regions including multiple sub-regions, and each of the sub-regions including multiple monitoring points; the regional parameters include the heavy metal content in the first region of the reference time interval and the heavy metal content change trend in the region, the heavy metal content in the first sub-region of the reference time interval and the heavy metal content change trend in the sub-region, the heavy metal content at the first monitoring point of the reference time interval, and the random error; a determination module, configured to determine a first value of a reference time interval, and determine a second value of the current time interval based on the first value; Calculate the heavy metal content of the second area within the current time interval according to the second value and the heavy metal content change trend in the area, and calculate the heavy metal content of the second sub-area within the current time interval according to the second value and the heavy metal content change trend in the sub-area; An evaluation module is used to determine the heavy metal content in the first area, the heavy metal content in the second area, the heavy metal content in the first sub-area, the heavy metal content in the second sub-area and the sum of the random errors as the heavy metal content in the third area from the benchmark time interval to the current time interval, and to evaluate the dynamic change trend of the heavy metal content in the third area.

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