A soil pollution investigation zoning sampling method based on complex historical land use types

Abstract

The application discloses a soil pollution investigation zoning sampling method based on complex historical land use types, and relates to the technical field of soil pollution investigation, and comprises the following steps: obtaining the historical land use types of a target land plot, the area corresponding to each historical land use type, and characteristic pollutant data; the characteristic pollutant data comprises the total number of pollutant types and the maximum concentration of each pollutant; according to S1, the pollution risk weight corresponding to each historical land use type is calculated; and according to the pollution risk weight corresponding to each historical land use type, the target land plot is divided into multiple zones; the risk coefficient corresponding to each zone is calculated, and the sampling number of each zone is calculated according to the risk coefficient; and according to the sampling number of each zone, point sampling is carried out. The application can realize dynamic zoning of historical land use types, and can also optimize the sampling number, thereby improving the scientificity and economy of soil environment status investigation.

Description

Technical Field

[0001] This invention relates to the field of soil pollution status investigation technology, and specifically to a method for zoning sampling of soil pollution based on complex historical land use types. Background Technology

[0002] In soil pollution surveys, rationally dividing sampling areas and determining the number of samples are crucial for improving survey efficiency and accuracy. Most related technologies employ uniform grid methods or random sampling, but they do not fully consider the complexity of historical land use. This complexity mainly includes the following three aspects: First, differences in historical land use types: Land parcels may have undergone multiple use changes (e.g., agricultural land → industrial land → mixed-use land), resulting in significant differences in pollutant types and cumulative risks at different historical stages, making uniform sampling unable to accurately reflect pollution distribution. Second, sampling redundancy or insufficiency: Related technologies typically use fixed sampling densities, failing to increase sampling points in high-risk areas, easily leading to sampling redundancy in low-risk areas or insufficient sampling in high-risk areas, affecting the reliability of the survey results. Third, overlapping of complex pollution: Agricultural-industrial-mixed-use land may contain combined pesticide residues and heavy metal pollution, requiring targeted sampling strategies.

[0003] Therefore, there is an urgent need for a method that dynamically zons based on historical land use types and optimizes the number of samples to improve the scientific rigor and cost-effectiveness of pollution investigations. Summary of the Invention

[0004] In view of this, the present invention provides a zonal sampling method for soil pollution investigation based on complex historical land use types. By dividing the pollution risk level areas and dynamically calculating the sampling quantity of each zone, the method solves the problem of mismatch between sampling quantity and pollution risk in related technologies, thereby improving the efficiency and accuracy of the investigation.

[0005] This invention provides a zonal sampling method for soil pollution investigation based on complex historical land use types, comprising:

[0006] S1. Obtain the historical land use type of the target plot, the area corresponding to each type of historical land use, and characteristic pollutant data; the characteristic pollutant data includes: the total number of pollutant types and the maximum concentration of each pollutant.

[0007] S2. Based on S1, calculate the pollution risk weight corresponding to each type of historical land use; and divide the target plot into multiple zones based on the pollution risk weight corresponding to each type of historical land use.

[0008] S3. Calculate the risk coefficient for each partition and the number of samples for each partition based on the risk coefficient;

[0009] S4. Based on the number of samples in each partition, perform sampling at designated points.

[0010] In one optional implementation, the historical land use types include: single-use land and mixed-use land; the single-use land includes: cultivated land, orchard land, forest land, grassland, residential land, public management and public service land, commercial service land, industrial and mining land, warehousing land, green space and open space land, and land not yet developed; the mixed-use land includes at least two types of single-use land.

[0011] The zones include: extremely high-risk zone, high-risk zone, medium-risk zone, and low-risk zone.

[0012] In one optional implementation, in step S2, the formula for calculating the pollution risk weight corresponding to a single land use is:

[0013]

[0014] Among them, W i S represents the pollution risk weight for the i-th type of single-use land; j T is the single-factor risk index for the j-th pollutant. j C is the toxicity parameter of the j-th pollutant; j C represents the concentration of the j-th pollutant; std is the standard limit value for the j-th pollutant; n is the total number of pollutant types within the i-th type of single land use;

[0015] The formula for calculating the pollution risk weight corresponding to mixed land use is as follows:

[0016]

[0017] Among them, W k γ represents the pollution risk weight for the k-th type of mixed land use; γ is the exchange coefficient for historical land use types; W i A represents the pollution risk weight of the i-th single-use land within the k-th type of mixed-use land; i Let A be the area of ​​the i-th type of single-use land; total This refers to the total area of ​​the mixed-use land.

[0018] In one optional implementation, the step of dividing the target land parcel into multiple zones based on the pollution risk weight corresponding to each type of historical land use includes:

[0019] S21. Determine the threshold range for each partition;

[0020] S22. Based on the pollution risk weight corresponding to each type of historical land use, the target plots are divided into extremely high risk areas, high risk areas, medium risk areas or low risk areas according to the threshold range corresponding to each zone.

[0021] For single-use land:

[0022] The threshold range for the extremely high risk zone is [2.5, ∞], the threshold range for the high risk zone is [2.0, 2.5], the threshold range for the medium risk zone is [1.5, 2.0], and the threshold range for the low risk zone is [-∞, 1.5].

[0023] For mixed-use land:

[0024] The threshold range for the extremely high risk zone is [3.0, ∞], the threshold range for the high risk zone is [2.5, 3.0], the threshold range for the medium risk zone is [2.0, 2.5], and the threshold range for the low risk zone is [-∞, 2.0].

[0025] In one optional implementation, S3 includes:

[0026] S31. Calculate the risk coefficient for each partition:

[0027] RC l =W l ×A i ×C avg,i

[0028] Among them, RC l W represents the risk coefficient for the l-th partition. l A is the average pollution risk weight of all historical land use types within zone l; i The area of ​​the l-th partition; C avg,i This is the weighted average concentration of all pollutants within zone l;

[0029] S32. Calculate the number of samples for each partition based on the risk coefficient:

[0030]

[0031] Where, N l N is the number of samples in the l-th partition. total The preset total number of sampling points; RC l The risk coefficient for the l-th partition.

[0032] In one alternative implementation, S4 includes:

[0033] S41. The grid size of each partition is determined by a grid-based densification method; the grid density of the extremely high-risk area is not less than 20m×20m, the grid density of the high-risk area is not less than 40m×40m, the grid density of the medium-risk area is not less than 80m×80m, and the grid density of the low-risk area is not less than 200m×200m.

[0034] S42. Take the grid center of each partition as the surface sampling point, and arrange the surface sampling points of each partition horizontally according to the sampling quantity of each partition.

[0035] In an optional implementation, S4 further includes:

[0036] The sampling depth is set based on the migration characteristics of pollutants within each zone;

[0037] Based on the sampling depth, a deeper sampling point is added vertically below the surface sampling point in each partition.

[0038] In one optional implementation, the number of deep sampling points is 30%-50% of the number of surface sampling points;

[0039] Add 5-15 surface sampling points at the boundary between extremely high-risk areas and high-risk areas.

[0040] In one optional implementation, the number of surface sampling points in the extremely high-risk area is greater than or equal to 40% of the preset total number of sampling points; the number of surface sampling points in the low-risk area is less than or equal to 10% of the preset total number of sampling points.

[0041] The present invention has the following beneficial effects:

[0042] This invention combines historical land use type and activity intensity to delineate risk zones, and achieves precise zoning by calculating the pollution risk weight corresponding to each type of historical land use, thereby improving the ability to identify pollution hotspots. This invention improves sampling efficiency, increasing the number of samples in high-risk areas by 20%-50% and reducing the number in low-risk areas by 30%, resulting in a total sample size saving of over 15%. This invention enhances data reliability, avoiding missed detections caused by uniform sampling, and is particularly suitable for brownfield redevelopment projects with complex histories. Attached Figure Description

[0043] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0044] Figure 1 This is a schematic flowchart of a soil pollution investigation zoning sampling method based on complex historical land use types according to an embodiment of the present invention. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Figure 1 This is a method for zoning sampling of soil pollution based on complex historical land use types according to an embodiment of the present invention. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Also, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0047] like Figure 1 As shown, the process includes the following steps:

[0048] S1. Obtain the historical land use type of the target plot, the area corresponding to each type of historical land use, and characteristic pollutant data; the characteristic pollutant data includes: the total number of pollutant types and the maximum concentration of each pollutant.

[0049] Specifically, historical land use types include single-use land and mixed-use land. Single-use land refers to land used for only one specific purpose in various historical periods, including: arable land, orchards, forest land, grassland, residential land, public administration and public service land, commercial service land, industrial and mining land, warehousing land, green space and open space land, and land not yet developed. Mixed-use land refers to land with at least two specific uses in various historical periods, including at least two types of single-use land. For example, a plot of land with an area of ​​50,000 m²... 2 Historically, the land was used for farmland (20 years) → chemical plant (15 years) → abandoned land (5 years).

[0050] It should be noted that the historical land use type of the plot and the area corresponding to each type of historical land use can be obtained from land use archives, remote sensing images, or on-site survey records. The pollutant data corresponding to each type of historical land use can be obtained from industrial archives (such as enterprise production logs, sewage discharge declaration records, waste liquid treatment ledgers, environmental impact assessment reports (forms)), agricultural archives (such as fertilizer application registration forms, pesticide use records), environmental monitoring archives (soil survey data over the years, groundwater monitoring reports), or relevant soil pollution status investigation reports. The pollutant data for each historical period can be obtained through soil field measurements and model inversion.

[0051] For example, land use types, land use change records, and start and end years for each historical stage of the plot are obtained from land use archives from 1996 to 2025. Historical land use type boundaries are extracted using remote sensing imagery, and area calculations are performed using GIS software. Then, relevant historical raw data on pollutants are obtained from industrial, agricultural, or environmental monitoring archives. Pollutant data for the current year is obtained through soil surveys. Finally, pollution data for each historical stage is predicted using model inversion. This data is then integrated into a historical land use type data table as shown in Table 1 and a pollutant data table as shown in Table 2.

[0052] Table 1

[0053]

[0054]

[0055] Table 2

[0056]

[0057] S2. Based on step S1, calculate the pollution risk weight corresponding to each type of historical land use; and divide the target plot into multiple zones based on the pollution risk weight corresponding to each type of historical land use.

[0058] The zones are divided into: extremely high-risk zones, high-risk zones, medium-risk zones, and low-risk zones.

[0059] In one optional implementation, in step S2, the formula for calculating the pollution risk weight corresponding to a single land use is:

[0060]

[0061] Among them, W i S represents the pollution risk weight for the i-th type of single-use land; j T is the single-factor risk index for the j-th pollutant. j C is the toxicity parameter of the j-th pollutant; j C represents the concentration of the j-th pollutant; std is the standard limit value for the j-th pollutant; n is the total number of pollutant types within the i-th type of single land use;

[0062] The formula for calculating the pollution risk weight corresponding to mixed land use is as follows:

[0063]

[0064] Among them, W k γ represents the pollution risk weight for the k-th type of mixed land use; γ is the exchange coefficient for historical land use types; W iThe pollution risk weight of the i-th single-use land within the k-th type of mixed-use land means the weighting of multiple single-use lands; A i Let A be the area of ​​the i-th type of single-use land; total This refers to the total area of ​​the mixed-use land.

[0065] In one optional implementation, the target land parcel is divided into multiple zones based on the pollution risk weight corresponding to each type of historical land use, including:

[0066] S21. Determine the threshold range for each partition.

[0067] S22. Based on the pollution risk weight corresponding to each type of historical land use, the target plots are divided into extremely high-risk areas, high-risk areas, medium-risk areas, or low-risk areas according to the threshold range corresponding to each zone.

[0068] For single-use land:

[0069] The threshold range for the extremely high risk zone is [2.5, ∞], the threshold range for the high risk zone is [2.0, 2.5], the threshold range for the medium risk zone is [1.5, 2.0], and the threshold range for the low risk zone is [-∞, 1.5].

[0070] For mixed-use land:

[0071] The threshold range for the extremely high risk zone is [3.0, ∞], the threshold range for the high risk zone is [2.5, 3.0], the threshold range for the medium risk zone is [2.0, 2.5], and the threshold range for the low risk zone is [-∞, 2.0].

[0072] S3. Calculate the risk coefficient for each partition and the number of samples for each partition based on the risk coefficient.

[0073] In one optional implementation, step S3 includes:

[0074] S31. Calculate the risk coefficient for each partition:

[0075] RC l =W l ×A i ×C avg,i

[0076] Among them, RC l W represents the risk coefficient for the l-th partition. l A is the average pollution risk weight of all historical land use types within zone l; i The area of ​​the l-th partition; C avg,i This is the weighted average concentration of all pollutants within zone l.

[0077] S32. Calculate the number of samples for each partition based on the risk coefficient:

[0078]

[0079] Where, N l N is the number of samples in the l-th partition. total The preset total number of sampling points; RC l The risk coefficient for the l-th partition.

[0080] S4. Based on the number of samples in each partition, perform sampling at designated points.

[0081] In one alternative implementation, step S4 includes:

[0082] S41. The grid size of each partition is determined by a grid-based densification method; the grid density of the extremely high-risk area is not less than 20m×20m, the grid density of the high-risk area is not less than 40m×40m, the grid density of the medium-risk area is not less than 80m×80m, and the grid density of the low-risk area is not less than 200m×200m.

[0083] S42. Take the center of each grid in each partition as the surface sampling point, and arrange the surface sampling points horizontally according to the grid density of each partition.

[0084] In an optional implementation, step S4 further includes:

[0085] The sampling depth is set based on the migration characteristics of pollutants within each zone;

[0086] Based on the sampling depth, a deeper sampling point is added vertically below the surface sampling point in each partition.

[0087] Examples are shown in Table 3.

[0088] Types of pollutants Layer depth (m) Sampling equipment Heavy metals / inorganic substances 0-0.5,0.5-2 Wooden shovel / plastic shovel organic matter 0-0.5 Stainless steel shovel Deep pollutants 2-5,5-10 Impact drilling rig

[0089] In one optional implementation, the number of deep sampling points is 30%-50% of the number of surface sampling points; 5-15 additional surface sampling points are added at the boundary between the extremely high-risk area and the high-risk area.

[0090] In one optional implementation, the number of surface sampling points in the extremely high-risk area is greater than or equal to 40% of the preset total number of sampling points; the number of surface sampling points in the extremely high-risk area is less than or equal to 10% of the preset total number of sampling points.

[0091] In summary, this invention combines historical land use type and activity intensity to delineate risk areas, and achieves precise zoning by calculating the pollution risk weight corresponding to each type of historical land use, thereby improving the ability to identify pollution hotspots. This invention improves sampling efficiency, increasing the number of samples in high-risk areas by 20%-50% and reducing the number in low-risk areas by 30%, resulting in a total sample size reduction of over 15%. This invention enhances data reliability, avoiding missed detections caused by uniform sampling, and is particularly suitable for brownfield redevelopment projects with complex histories.

[0092] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A zonal sampling method for soil pollution investigation based on complex historical land use types, characterized in that, include: S1. Obtain the historical land use type of the target plot, the area and characteristic pollutant data corresponding to each type of historical land use; The characteristic pollutant data includes: the total number of pollutant types and the maximum concentration of each pollutant; S2. Based on S1, calculate the pollution risk weight corresponding to each type of historical land use; and divide the target plot into multiple zones based on the pollution risk weight corresponding to each type of historical land use. In S2, the formula for calculating the pollution risk weight corresponding to a single land use is: in, For the first i Pollution risk weights for single-use land categories; For the first j Single-factor risk index for each pollutant For the first j Toxicity parameters of the pollutants; For the first j The concentration of the pollutants; For the first j Standard limits for various pollutants; n For the first i The total number of pollutant types within a single type of land use; The formula for calculating the pollution risk weight corresponding to mixed land use is as follows: in, For the first k Pollution risk weights for mixed-use land; The exchange coefficient for historical land use types; For the first k The first type of mixed-use land i Pollution risk weights for single-use land categories; For the first i Area of ​​single-use land; The total area of ​​the mixed-use land; S3. Calculate the risk coefficient for each partition and the number of samples for each partition based on the risk coefficient; S3 includes: S31. Calculate the risk coefficient for each partition: in, For the first l Risk factor of partitioning; For the first l Average pollution risk weights for all historical land use types within the zone; For the first l The area of ​​the partition; For the first l The weighted average concentration of all pollutants within the zone; S32. Calculate the number of samples for each partition based on the risk coefficient: in, For the first l Number of samples per partition This is the preset total number of sampling points; For the first l Risk factor of partitioning; S4. Based on the number of samples in each partition, perform sampling at designated points; The historical land use types include: single-use land and mixed-use land; single-use land includes: cultivated land, orchard land, forest land, grassland, residential land, public management and public service land, commercial service land, industrial and mining land, warehousing land, green space and open space land, and land not yet developed; mixed-use land includes at least two types of single-use land. The zones include: extremely high-risk zone, high-risk zone, medium-risk zone, and low-risk zone.

2. The method according to claim 1, characterized in that, The target land parcel is divided into multiple zones based on the pollution risk weight corresponding to each type of historical land use, including: S21. Determine the threshold range for each partition; S22. Based on the pollution risk weight corresponding to each type of historical land use, the target plots are divided into extremely high risk areas, high risk areas, medium risk areas or low risk areas according to the threshold range corresponding to each zone. For single-use land: The threshold range corresponding to the extremely high risk zone is: The threshold range corresponding to high-risk areas is The threshold range corresponding to the medium-risk area is The threshold range corresponding to the low-risk zone is ; For mixed-use land: The threshold range corresponding to the extremely high risk zone is: The threshold range corresponding to high-risk areas is The threshold range corresponding to the medium-risk area is The threshold range corresponding to the low-risk zone is .

3. The method according to claim 1, characterized in that, S4 includes: S41. The grid size of each partition is determined by a grid-based densification method; the grid density of the extremely high-risk area is not less than 20m×20m, the grid density of the high-risk area is not less than 40m×40m, the grid density of the medium-risk area is not less than 80m×80m, and the grid density of the low-risk area is not less than 200m×200m. S42. Take the center of each grid in each partition as the surface sampling point, and arrange the surface sampling points horizontally according to the grid density of each partition.

4. The method according to claim 3, characterized in that, S4 further includes: The sampling depth is set based on the migration characteristics of pollutants within each zone; Based on the sampling depth, a deeper sampling point is added vertically below the surface sampling point in each partition.

5. The method according to claim 4, characterized in that, The number of deep sampling points shall be at least 30%-50% of the number of surface sampling points; Add 5-15 surface sampling points at the boundary between extremely high-risk areas and high-risk areas.

6. The method according to claim 3, characterized in that, The number of surface sampling points in the extremely high-risk area is greater than or equal to 40% of the preset total number of sampling points; the number of surface sampling points in the low-risk area is less than or equal to 10% of the preset total number of sampling points.

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