Cultivated land heavy metal pollution control zoning method, system, equipment and medium

Abstract

The invention discloses a farmland heavy metal pollution control zoning method, system, equipment and medium, and relates to the technical field of soil treatment and environmental protection. Comprising the following steps: determining soil heavy metal content standard exceeding conditions of cultivated land to be detected, crop heavy metal content standard exceeding conditions, potential ecological risk conditions, human health risk conditions and cultivated land grading results; comprehensively evaluating the soil heavy metal content standard exceeding condition, the crop heavy metal content standard exceeding condition, the potential ecological risk condition, the human health risk condition and the cultivated land grading result, and determining the heavy metal pollution control partition type of the cultivated land to be detected according to the evaluation result. The cultivated land is partitioned through multi-aspect evaluation and constraint of the cultivated land, factors are comprehensively considered, and the accuracy of heavy metal pollution management and control partitioning is improved.

Description

Technical Field

[0001] The present invention relates to the field of soil treatment and environmental protection technology, and in particular to a method, system, equipment and medium for controlling zoning of heavy metal pollution in cultivated land. Background Art

[0002] The evaluation and zoning of heavy metal pollution in cultivated land provides basic information and decision-making basis for formulating zoning and classification control measures for polluted cultivated land and ensuring food security. It can be seen from the theory of environmental functional zoning that the various elements of cultivated land environment and the overall system they constitute are closely related. The resource environment and functional zoning of cultivated land will affect the safety of food production environment and sustainable supply capacity in many aspects. Therefore, after heavy metals cause pollution to the cultivated land system, it not only brings risks to the cultivated land environment, but also leads to a decline in the quality of cultivated land. The former includes potential ecological risks brought by affecting soil microbial activities and human health risks brought by respiratory inhalation, skin contact and food intake. The latter includes reducing the productivity of cultivated land by reducing soil fertility, crop quality and yield, and reducing the health of cultivated land by compound pollution of soil, crops and water environment.

[0003] In the prior art, cultivated land zoning is carried out based on the evaluation results of heavy metal pollution in cultivated land. The specific steps are: collecting and organizing data related to heavy metal pollution in cultivated land, evaluating the degree of heavy metal pollution in cultivated land using evaluation methods such as statistical methods, index methods or ecological risk assessment methods, and determining the pollution index classification standard based on the heavy metal pollution evaluation results; and carrying out cultivated land pollution zoning based on the pollution index classification standard and the actual situation of cultivated land.

[0004] The defects of the above-mentioned existing technology are: the results of the heavy metal pollution control zoning of cultivated land are only based on the level of heavy metal pollution, without considering the negative impact of heavy metal pollution on soil and crops, and the zoning basis lacks comprehensiveness, which leads to inaccurate zoning results. Summary of the invention

[0005] Based on this, it is necessary to provide a method, system, equipment and medium for zoning control of heavy metal pollution in cultivated land to address the above-mentioned technical problems.

[0006] The embodiment of the present invention provides a method for controlling and zoning heavy metal pollution in cultivated land, comprising: Obtain the soil-crop safety index of the cultivated land to be tested IICQ , through the Soil-Crop Safety Index IICQ Determine whether the heavy metal content in the soil of the cultivated land to be tested exceeds the standard and whether the heavy metal content in the crops exceeds the standard; Obtain a single potential ecological risk index for the cultivated land to be tested EARLY and composite potential ecological risk index CERAMIC , through a single potential ecological risk index EARLYand composite potential ecological risk index CERAMIC Determine the potential ecological risk of the cultivated land to be tested; Obtain the non-carcinogenic risk index of the cultivated land to be tested THI and carcinogenic risk index TCR , through the non-carcinogenic risk index THI and carcinogenic risk index TCR Determine the heavy metal carcinogenic risk of the cultivated land to be tested; Obtain the composite human health risk index of the cultivated land to be tested CHRIS , through the composite human health risk index CHRIS Determine the human health impact of the cultivated land to be tested; Combine the carcinogenic risk of heavy metals with the impact on human health to determine the human health risk of the cultivated land to be tested; Obtain the health productivity evaluation result of the cultivated land to be tested, and determine the cultivated land classification result of the cultivated land to be tested according to the health productivity evaluation result; A comprehensive evaluation is conducted on the excessive heavy metal content in the soil, the excessive heavy metal content in crops, the potential ecological risks, the human health risks and the cultivated land classification results, and the heavy metal pollution control zoning type of the cultivated land to be tested is determined based on the evaluation results.

[0007] Optionally, obtain the soil-crop safety index of the cultivated land to be tested IICQ , Soil-Crop Safety Index IICQ Including soil safety index IICQ S and Crop Safety Index IICQ C , specifically including: Get the number of heavy metals whose measured concentration exceeds their screening value X , the number of heavy metals whose measured concentrations exceed their background values Y and the number of heavy metals whose concentrations exceeded their limit values Z ; Based on the number of heavy metals with measured concentrations exceeding their screening values X and the number of heavy metals whose measured concentrations exceed their background values Y Calculating the Soil Safety Index IICQ S , the formula is: ; ; ; ; in, N is the number of heavy metals measured, , and Corresponding to the classification of soil heavy metal pollution , and , n For heavy metals i The oxidation number of is the ratio of the measured concentration of a certain soil heavy metal to its background value. For heavy metals i The background value of RIE is the soil relative impact equivalent, DDDB The concentration of soil elements deviates from the background value. DDSB is the degree to which the overall soil standard deviates from the background value; Based on the number of heavy metals whose measured concentrations exceed their limit values Z Calculating the Crop Safety Index IICQ C , the formula is: ; ; in, , and Corresponding to the classification of heavy metal pollution in crops , and , k is the background correction factor, QIC is the crop quality index; Soil-Crop Safety Index IICQ Determine whether the heavy metal content in the soil of the cultivated land to be tested exceeds the standard and whether the heavy metal content in the crops exceeds the standard, including: when , , , When the soil quality of the tested cultivated land is in a good, healthy and clean state, the heavy metal content in the soil and crops is within the standard; when , , or When , it indicates that the soil environment quality of the tested cultivated land is in a sub-healthy state that cannot be used to produce the current crops. The heavy metal content of the soil has not exceeded the standard, but the heavy metal content of the crops has exceeded the standard. when or , , When , it indicates that the soil environment quality of the tested cultivated land is in a serious sub-healthy state, and the heavy metal content in the soil exceeds the standard, but the heavy metal content in the crops meets the limit standard; when , When , it indicates that the soil environment quality of the tested cultivated land is in an unhealthy state, and the heavy metal content in the soil and crops exceeds the standard; in, X is the number of heavy metals whose measured concentration exceeds their screening value, Z It is the number of heavy metals whose measured concentration exceeds their limit value.

[0008] Optionally, obtain a single potential ecological risk index for the cultivated land to be tested EARLY and composite potential ecological risk index CERAMIC , which specifically include: ; ; in, For heavy metals i A single potential ecological risk index, For heavy metals i The measured concentration of For heavy metals i Soil environmental quality standards, For heavy metals i Toxicity response coefficient; Single Potential Ecological Risk Index EARLY and composite potential ecological risk index CERAMIC Determine the potential ecological risks of the cultivated land to be tested, including: when or When , the risk level of the cultivated land to be tested is slightly polluted; when or When , the risk level of the cultivated land to be tested is slightly polluted; when or When , the risk level of the cultivated land to be tested is moderately polluted; when or When , the risk level of the cultivated land to be tested is severely polluted; when When , the risk level of the cultivated land to be tested is severely polluted.

[0009] Optionally, obtain the non-carcinogenic risk index of the cultivated land to be tested THI and carcinogenic risk index TCR , which specifically include: ; ; ; ; ; ; ; in, For heavy metals i Average daily intake through breathing For heavy metals i Average daily intake through the skin For heavy metals i Average daily intake through intake; For heavy metals i The measured concentration of is the average daily air intake; is the particulate matter emission factor; The surface area of ​​the soil in contact with the skin; is the soil adhesion factor; It is the skin absorption efficiency factor; is the average daily intake from soil; is the exposure frequency; is the duration of exposure; is body weight; is the average contact time; is the conversion factor; j As a route of exposure to heavy metals; , For heavy metals i exist j Non-carcinogenic and carcinogenic risk indexes under exposure routes; , For heavy metals i Non-carcinogenic risk index and carcinogenic risk index; is the non-carcinogenic reference dose. is the carcinogenic intensity coefficient; Non-carcinogenic risk index THI and carcinogenic risk index TCR Determine the heavy metal carcinogenic risk of the cultivated land to be tested, including: When the non-carcinogenic risk index THI When >1, there is a non-heavy metal carcinogenic risk; When the non-carcinogenic risk index THI When it is less than 1, it has little impact on human health; When the cancer risk index TCR >10 -4There is a greater risk of heavy metal carcinogenesis; When 10 -6 <Carcinogenic risk index TCR <10 -4 When the carcinogenic risk of heavy metals is at an acceptable level; When the cancer risk index TCR <10 -6 There is no risk of heavy metal cancer.

[0010] Optionally, obtain the composite human health risk index of the cultivated land to be tested CHRIS , which specifically include: Obtain a single human health risk index for different heavy metals in crops tested in cultivated land HRI , Single human health risk index of heavy metals in all crops HRI The sum of the composite human health risk index CHRIS , and its calculation formula is as follows: ; ; in, For heavy metals i The human health risk index, Heavy metals in crops i The measured concentration of is the average daily intake of crops, is the average daily exposure to heavy metals, is the measured value of heavy metal concentration in crops, is the average daily intake of crops, is the reference dose; Composite Human Health Risk Index CHRIS Determine the human health impact of the cultivated land to be tested: When the composite human health risk index CHRIS When it is >1, it means that the heavy metals accumulated in crops pose a risk to human health; When the composite human health risk index CHRIS When it is less than 1, it means that the heavy metals accumulated in crops have little impact on human health.

[0011] Optionally, obtaining the health productivity evaluation result of the cultivated land to be tested, which specifically includes: Based on the cultivated land productivity index value, the cultivated land to be tested is divided into first-class cultivated land, second-class cultivated land and third-class cultivated land. The calculation formula of the cultivated land productivity index value is: ; ; in, l is the number of evaluation indicators; For the p The evaluation unit r The score of each evaluation indicator; For the r The weight of each evaluation indicator; is the light-temperature production potential index; is the crop yield ratio coefficient; u , v For the corresponding evaluation unit; The cultivated land to be tested is divided into healthy cultivated land, sub-healthy cultivated land and unhealthy cultivated land based on the cultivated land health index value. The calculation formula of the cultivated land health index value is: ; in, H is the farmland health index value, R is the system resilience index, E is the production environment index; The division results of the cultivated land productivity index value and the cultivated land health index value are superimposed to obtain the health productivity evaluation result of the cultivated land to be tested; The method of determining the cultivated land classification result of the cultivated land to be tested by using the healthy productivity evaluation result specifically includes: First-class arable land and healthy arable land are grade 1, second-class arable land and healthy arable land are grade 2, and third-class arable land and healthy arable land are grade 4; First-class farmland and sub-healthy farmland are grade 3, second-class farmland and sub-healthy farmland are grade 5, and third-class farmland and sub-healthy farmland are grade 7; First-class arable land and unhealthy arable land are level 6, second-class arable land and unhealthy arable land are level 8, and third-class arable land and unhealthy arable land are level 9.

[0012] Optionally, the heavy metal pollution control zoning type of the cultivated land to be tested is determined according to the evaluation results, including: The types of heavy metal pollution control zones include priority protection zones, strict control zones, and safe utilization zones; The areas of the cultivated land to be tested where the soil and crops do not exceed the standards are designated as priority protection areas; The areas where the soil in the tested cultivated land exceeds the standard, the crops do not exceed the standard, there is no potential ecological risk, and the cultivated land health productivity is in levels 1-5 are classified as priority protection areas; The areas where the soil in the tested cultivated land exceeds the standard, the crops do not exceed the standard, there is no potential ecological risk, and the cultivated land health production capacity is in the 6-9 level are classified as safe utilization areas; The areas where the soil in the tested cultivated land exceeds the standard but the crops do not exceed the standard, have potential ecological risks and the healthy productivity of cultivated land is in the 1-8 level are classified as safe utilization areas; The areas where the soil of the tested cultivated land exceeds the standard but the crops do not exceed the standard, have potential ecological risks and the healthy production capacity of cultivated land is at level 9 are classified as strict control areas; The areas of the cultivated land to be tested where the soil and crops do not exceed the standards and there is no risk to human health are classified as safe utilization areas; The areas where the soil in the tested cultivated land does not exceed the standard, the crops exceed the standard, and there are risks to human health are divided into strict control areas; Areas where soil and crops exceed the standard in the tested arable land will be designated as strictly controlled areas.

[0013] The embodiment of the present invention also provides a farmland heavy metal pollution control zoning system, including: Soil-crop pollution assessment module, used to obtain the soil-crop safety index of the cultivated land to be tested IICQ , through the Soil-Crop Safety Index IICQ Determine whether the heavy metal content in the soil of the cultivated land to be tested exceeds the standard and whether the heavy metal content in the crops exceeds the standard; Potential ecological risk module, used to obtain a single potential ecological risk index for the cultivated land to be tested EARLY and composite potential ecological risk index CERAMIC , through a single potential ecological risk index EARLY and composite potential ecological risk index CERAMIC Determine the potential ecological risk of the cultivated land to be tested; Heavy metal carcinogenic risk module, used to obtain the non-carcinogenic risk index of the cultivated land to be tested THI and carcinogenic risk index TCR , through the non-carcinogenic risk index THI and carcinogenic risk index TCR Determine the heavy metal carcinogenic risk of the cultivated land to be tested; Human health impact module, used to obtain the composite human health risk index of the cultivated land to be tested CHRIS , through the composite human health risk index CHRIS Determine the human health impact of the cultivated land to be tested; The human health module is used to combine the carcinogenic risk of heavy metals with the impact on human health to determine the human health risk of the cultivated land to be tested; The cultivated land classification module is used to obtain the health and productivity evaluation results of the cultivated land to be tested, and determine the cultivated land classification results of the cultivated land to be tested based on the health and productivity evaluation results; The zoning module is used to comprehensively evaluate the excessive heavy metal content in the soil, the excessive heavy metal content in crops, the potential ecological risks, the human health risks and the arable land classification results, and to determine the heavy metal pollution control zoning type of the tested arable land based on the evaluation results.

[0014] An embodiment of the present invention also provides a computer device, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the steps of the method for controlling and zoning heavy metal pollution in cultivated land are implemented.

[0015] An embodiment of the present invention also provides a storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for controlling and zoning heavy metal pollution in cultivated land are implemented.

[0016] Compared with the prior art, the above-mentioned cultivated land heavy metal pollution control zoning method, system, device and medium provided by the embodiment of the present invention have the following beneficial effects: The present invention conducts a comprehensive evaluation based on the heavy metal pollution status of the cultivated land to be tested, potential heavy metal ecological risks, soil human health risks, crop human health risks and healthy productivity; it not only takes into account the heavy metal pollution degree of the cultivated land to be tested, but also takes into account the potential heavy metal ecological risks, the risks to human health caused by heavy metal pollution of the soil, and the risks to human health caused by heavy metal pollution of crops, and divides the cultivated land into zones based on multi-faceted evaluation and constraints of the cultivated land, taking comprehensive factors into consideration; and determines the heavy metal pollution control zone type of the cultivated land to be tested based on the evaluation results, thereby improving the accuracy of the heavy metal pollution control zone. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the process of constructing a zoning model for a method for zoning farmland heavy metal pollution control provided in an embodiment. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] In one embodiment, a method for controlling heavy metal pollution in cultivated land is provided, such as Figure 1 As shown, the method includes: 1. Cultivated soil-crop pollution assessment indicators Obtain the soil-crop safety index of the cultivated land to be tested IICQ , through the Soil-Crop Safety Index IICQ Determine whether the heavy metal content in the soil of the cultivated land to be tested exceeds the standard and whether the heavy metal content in the crops exceeds the standard.

[0020] Soil-crop safety index IICQ It is used to evaluate cultivated land soil-crop pollution. It can take into account the problems of soil heavy metal pollution and crop heavy metal pollution, effectively combine the heavy metal content in soil and crops, and realize the quantitative evaluation of soil-crop system complex pollution. The index includes soil ( IICQ S ) and crops ( IICQ C ) two parts.

[0021] For soil and crop heavy metal samples at a certain point, the specific process is divided into three steps.

[0022] The first step is to calculate the soil safety index ( IICQ S ).

[0023] First calculate the soil relative impact equivalent ( RIE ), the degree of deviation of soil element concentration from background value ( DDDB ) and the overall soil standard deviation from the background value ( DDSB ). RIE Value and DDDB The larger the value, the more significant the impact of exogenous substances on the soil; DDSB The larger the value, the greater the environmental carrying capacity of the soil and the stronger its buffering capacity against exogenous substances. The specific expression is as follows: ; ; ; Where: N is the number of heavy metals measured; , and Corresponding to the classification of soil heavy metal pollution , and ; n For heavy metals i The oxidation number of heavy metals in soil is generally based on their stable state, which are Cr (3), Pb (2), Cd (2), Hg (2), As (5), Cu (2), Zn (2), and Ni (2); It is the ratio of the measured concentration of a certain soil heavy metal to its background value; For heavy metals i The background values ​​of soil were used, which were Cr (52.9), Pb (23.7), Cd (0.07), Hg (0.086), As (9.2), Cu (17.6), Zn (70.6), and Ni (24.6); RIE is the soil relative impact equivalent, DDDB The concentration of soil elements deviates from the background value. DDSB It is the degree of deviation of the overall soil standard from the background value.

[0024] Then calculate the soil safety index ( IICQ S ): ; Where: Xis the number of soils where the measured concentration of heavy metals exceeds the screening value; Y It is the number of heavy metal concentrations in the soil that exceed their background values.

[0025] The second step is to calculate the crop safety index ( IICQ C ).

[0026] First calculate the crop quality index ( QIC ), when the concentration of heavy metals in crops exceeds the limit standard, QIC The larger the value, the worse the quality of the crop. The specific expression is as follows: ; ; Where: , and Corresponding to the classification of heavy metal pollution in crops , and ; Z The number of crops where the measured concentration of heavy metals exceeds the limit value; k It is the background correction factor, which is related to the ratio of the crop heavy metal limit value to the background value and is generally set to 5.

[0027] The third step is to calculate the soil-crop safety index ( IICQ ).

[0028] ; In general, there are four different types of pollution in the soil-crop system. The evaluation levels and corresponding environmental quality descriptions are shown in Table 1: when , , , When the soil quality of the tested cultivated land is in a good, healthy and clean state, the heavy metal content in the soil and crops is within the standard; when , , or When , it indicates that the soil environment quality of the tested cultivated land is in a sub-healthy state that cannot be used to produce the current crops. The heavy metal content of the soil has not exceeded the standard, but the heavy metal content of the crops has exceeded the standard. when or , , When , it indicates that the soil environment quality of the tested cultivated land is in a serious sub-healthy state, and the heavy metal content in the soil exceeds the standard, but the heavy metal content in the crops meets the limit standard; when , When , it indicates that the soil environmental quality of the tested cultivated land is in an unhealthy state, and the heavy metal content in the soil and crops exceeds the standard. X is the number of heavy metals whose measured concentration exceeds their screening value, Z It is the number of heavy metals whose measured concentration exceeds their limit value.

[0029] Table 1 Classification standards of soil and crop heavy metal pollution index and description of environmental quality

[0030] 2. Cultivated land environmental risk assessment indicators (1) Assessment of potential ecological risks of soil Obtain a single potential ecological risk index for the cultivated land to be tested EARLY and composite potential ecological risk index CERAMIC , through a single potential ecological risk index EARLY and composite potential ecological risk index CERAMIC Determine the potential ecological risk of the cultivated land to be tested. Single potential ecological risk index ( EARLY ) Considering the toxicity and environmental sensitivity of different heavy metals, the potential ecological risks of soil heavy metals are evaluated. Composite Potential Ecological Risk Index ( CERAMIC ) are all soil heavy metals EARLY For a certain soil heavy metal sample, EARLY and CERAMIC The calculation formula is as follows: ; ; Where: For heavy metals i A single potential ecological risk index; For heavy metals i Measured concentration (mg / kg); For heavy metals i soil environmental quality standards; For heavy metals i The toxicity response coefficients are: Cr (2), Pb (5), Cd (30), Hg (40), As (10), Cu (5), Zn (1), Ni (5). The evaluation levels corresponding to different single ecological risk index values ​​and composite ecological risk index values ​​are shown in Table 2.

[0031] when or When , the risk level of the cultivated land to be tested is slightly polluted.

[0032] when or When , the risk level of the cultivated land to be tested is slightly polluted.

[0033] when or When , the risk level of the cultivated land to be tested is moderately polluted.

[0034] when or , the risk level of the cultivated land to be tested is severely polluted.

[0035] when When , the risk level of the cultivated land to be tested is severely polluted.

[0036] Table 2 Classification criteria for soil heavy metal potential ecological risk index

[0037] (2) Soil health risk assessment Obtain the non-carcinogenic risk index of the cultivated land to be tested THI and carcinogenic risk index TCR , through the non-carcinogenic risk index THI and carcinogenic risk index TCR Determine the carcinogenic risk of heavy metals in the cultivated land to be tested.

[0038] Heavy metals in soil enter the human body through breathing, skin and ingestion, causing non-carcinogenic or carcinogenic health risks. USEPA evaluates the health risks of heavy metals in soil to the human body based on the average daily intake of heavy metals. Due to the differences in heavy metal exposure and tolerance among people of different age groups, the research population was divided into two categories: children and adults. For a certain soil heavy metal sample, the average daily intake of the three routes ( ADI ) is calculated as follows: ; ; ; Where: , , Heavy metals i Average daily intake via inhalation, skin, and ingestion (mg / kg / day); For heavy metals i Measured concentration (mg / kg); is the average daily air intake (m³ / day); is the particle emission factor (m³ / kg); is the soil contact skin surface area (cm² / day); is the soil adhesion factor (mg / cm²); It is the skin absorption efficiency factor; is the average daily intake from soil (mg / day); is the exposure frequency (day / year); is the duration of exposure (year); is body weight (kg); is the average contact time (day); is the conversion coefficient, and the specific values ​​of the parameters are shown in Table 3 below.

[0039] Table 3 Related parameters for human health assessment of soil heavy metals

[0040] For a certain soil heavy metal sample, the non-carcinogenic risk index ( THI ) and carcinogenic risk index ( TCR ) is calculated as follows: ; ; ; ; Where: j As a route of exposure to heavy metals; , For heavy metals i exist j Non-carcinogenic and carcinogenic risk indexes under exposure routes; , For heavy metals i Non-carcinogenic and carcinogenic risk index; is the non-carcinogenic reference dose (mg / kg / day), is the carcinogenic intensity coefficient (kg / day / mg), different heavy metals RFD , CSF The specific values ​​of are shown in Table 4 below.

[0041] The total non-carcinogenic and carcinogenic risk indexes of a certain soil heavy metal sample are the sum of the non-carcinogenic and carcinogenic risk indexes of all soil heavy metals under all exposure pathways.

[0042] When the non-carcinogenic risk index THI When >1, there is a non-heavy metal carcinogenic risk; When the non-carcinogenic risk index THI When it is less than 1, it has little impact on human health; When the cancer risk index TCR >10 -4 There is a greater risk of heavy metal carcinogenesis; When 10 -6 <Carcinogenic risk index TCR <10 -4 When the carcinogenic risk of heavy metals is at an acceptable level; When the cancer risk index TCR <10 -6 There is no risk of heavy metal cancer.

[0043] Table 4 Non-carcinogenic reference doses and carcinogenic intensity coefficients of heavy metals in soil

[0044] (3) Crop human health risk assessment Obtain the composite human health risk index of the cultivated land to be tested CHRIS , through the composite human health risk index CHRIS Determine the human health impacts of the cultivated land to be tested.

[0045] Heavy metals in crops enter the human body directly through ingestion. The target hazard coefficient method is used to assess the health risks of heavy metals in crops to the human body. A single human health risk index ( HRI ) indicates. Composite human health risk index ( CHRIS ) is the sum of HRI of all crops heavy metals. For a certain crop heavy metal sample, HRI and CHRIS The calculation formula is as follows: ;

[0046] Where: For heavy metals i Human health risk index; Heavy metals in crops i The measured concentration of is the average daily intake of crops (kg / day), and the specific values ​​are shown in Table 5 below; is the average daily exposure to heavy metals, that is, the daily intake of heavy metals; is the measured value of heavy metal concentration in crops, is the average daily intake of crops (kg / day), see Table 5; is the reference dose (mg / kg / day), which is consistent with the soil heavy metal intake pathways in Table 4. RFD The values ​​are the same; the meanings of other parameters are the same as above.

[0047] When the composite human health risk index CHRIS When it is >1, it means that the heavy metals accumulated in crops pose a risk to human health; When the composite human health risk index CHRISWhen it is less than 1, it means that the heavy metals accumulated in crops have little impact on human health.

[0048] Table 5 Average daily intake of three types of crops by different populations (kg / day)

[0049] Combine the carcinogenic risk of heavy metals and the impact on human health to determine the human health risk of the cultivated land to be tested, that is, whether the cultivated land to be tested has any human health risk.

[0050] (4) Risk space characteristics evaluation Geographic detectors focus on detecting spatial heterogeneity, including four detectors: differentiation and factor detection, interaction detection, risk zone detection, and ecological detection. They are suitable for geospatial analysis of different fields, scales, and data types. Based on environmental risk assessment, differentiation and factor detectors are used to analyze the spatial heterogeneity of the potential ecological risks and human health risks of different heavy metals. q To characterize. q The value range is 0~1. The larger the value, the higher the degree of spatial differentiation of environmental risk, and vice versa. The mathematical expression is as follows: ; Where: It is the product of the environmental risk variance of each sub-study area and the number of sample points; It is the product of the total variance of environmental risk in the whole study area and the total number of sample points; , Sub-study areas k , the number of sampling points in the whole study area; , Sub-study areas k , the environmental risk variance of the entire study area. If the mean value of the environmental risk index in the region is high and q If the value is large, it indicates that the spatial difference of environmental risk of heavy metals in the region is large, and risk control measures need to be formulated according to local conditions; if the mean value of the environmental risk index in the region is high but q The value is small, indicating that the spatial heterogeneity of environmental risks of heavy metals in this area is low, and unified risk control measures can be taken.

[0051] Based on the rank-scale theory, combined with the results of environmental risk assessment and geographic detector analysis, the heavy metal environmental risk level of each sub-study area was calculated and the environmental risk rank was used to rank the heavy metals in the sub-study area. R The specific expression is as follows: ; Where: For research unit The environmental risk ranking; For sub-study area k Internal sample point h Environmental risk index value; is the mean value of the environmental risk index of the entire study area; For sub-study area k According to the requirements of the “Ten Soil Rules” for the environmental quality of cultivated land soil, the heavy metal environmental risks of each sub-study area can be divided into three levels, namely, low risk level ( R <0.8), medium risk level (0.8≤R≤1) and high risk level ( R ≥1).

[0052] 3. Evaluation indicators of healthy productivity of cultivated land Obtain the health productivity evaluation results of the cultivated land to be tested, and determine the cultivated land classification results of the cultivated land to be tested based on the health productivity evaluation results.

[0053] (1) Evaluation of cultivated land productivity The productivity of cultivated land is affected by both natural conditions and human activities. P Climate conditions include solar radiation, temperature, precipitation, etc. in the cultivated area, which determine the production potential of cultivated land and the potential maximum yield of crops, while soil properties ( S )、Field conditions( F ) and technical level ( T ) will affect the actual yield of crops, and the production potential of cultivated land can be corrected accordingly to obtain the cultivated land productivity index P The specific calculation formula is as follows: ; ; Where: l is the number of evaluation indicators; For the p The evaluation unit r The scores of the evaluation indicators are based on the actual situation of each evaluation indicator, and the scores corresponding to the actual situation of each evaluation indicator refer to the "Grades of Cultivated Land Quality" (GB / T33469-2016) and related literature; For the r The weights of the evaluation indicators are determined using the structural equation model; is the light-temperature production potential index; is the crop yield ratio coefficient; u , v The corresponding evaluation unit is the maturity system (e.g., two years and three years, u =2, v=3). According to the availability of relevant literature and data: the evaluation indicators of climate conditions include light-temperature production potential index and yield ratio coefficient; the evaluation indicators of soil properties include surface texture, arable layer thickness, organic matter content, bulk density, nutrient content, pH, cation exchange capacity, gravel content and erosion degree; the evaluation indicators of field conditions include field slope, fragmentation, shape index, field road accessibility and farmland forest network rate; the evaluation indicators of technical level include irrigation guarantee rate, drainage conditions, disaster prevention and control, agronomic management and agricultural mechanization.

[0054] (2) Cultivated land health diagnosis The health of cultivated land is also affected by natural and human factors. H System resilience is the basis of farmland health, which determines the farmland's resistance to external interference and its resilience to external damage. Production environment conditions such as soil and irrigation water will affect the actual health of farmland. The health status of farmland can be corrected accordingly to obtain the farmland health index. First calculate the system resilience index ( R ): ; Where: m is the number of evaluation indicators; It is p Evaluation unit s The score of the indicator, It is s The weights of the indicators are derived and determined in the same way as above. According to the availability of relevant literature and data: the evaluation indicators of system elasticity are organic carbon storage, clay content, pH, cation exchange capacity and coefficient of variation of annual grain output; the evaluation indicators of production environment are irrigation water environment quality and soil heavy metal content.

[0055] Then calculate the production environment index ( E ). The soil heavy metal and irrigation water quality grades were calculated with reference to the soil environmental quality standard GB15618 and the irrigation water quality standard GB5084, and the worst grade of the evaluation unit was used as its comprehensive grade using the minimum limiting factor method, and the points were assigned according to "0 points for the first grade, -0.1 points for the second grade, -0.2 points for the third grade, -0.3 points for the fourth grade, and -0.4 points for the fifth grade". The "1+X" cumulative model was used to calculate the E , where 1 means the farmland is not polluted, X The score of the evaluation unit.

[0056] Finally, the farmland health index was calculated ( H ): ; (3) Classification of healthy productivity of cultivated land Using the natural breakpoint method, the first-class, second-class and third-class cultivated lands were divided based on the cultivated land productivity index value, and the cultivated land health index value was divided into healthy cultivated land, sub-healthy cultivated land and unhealthy cultivated land. The cultivated land health productivity evaluation results of the study area were obtained by superimposing the cultivated land productivity and health evaluation results, which can be divided into 9 levels, and the cultivated land health productivity level gradually decreases from level 1 to level 9, as shown in Table 6.

[0057] Among them, first-class arable land and healthy arable land are level 1, second-class arable land and healthy arable land are level 2, and third-class arable land and healthy arable land are level 4.

[0058] First-class arable land and sub-healthy arable land are level 3, second-class arable land and sub-healthy arable land are level 5, and third-class arable land and sub-healthy arable land are level 7.

[0059] First-class arable land and unhealthy arable land are level 6, second-class arable land and unhealthy arable land are level 8, and third-class arable land and unhealthy arable land are level 9.

[0060] Table 6 Classification of healthy productivity of cultivated land

[0061] 4. Control zoning model for heavy metal pollution in cultivated land A comprehensive evaluation is conducted on the excessive heavy metal content in the soil, the excessive heavy metal content in crops, the potential ecological risks, the human health risks and the cultivated land classification results, and the heavy metal pollution control zoning type of the cultivated land to be tested is determined based on the evaluation results.

[0062] The types of heavy metal pollution control zones include priority protection zones, strict control zones, and safe utilization zones; The areas of the cultivated land to be tested where the soil and crops do not exceed the standards are designated as priority protection areas; The areas where the soil in the tested cultivated land exceeds the standard, the crops do not exceed the standard, there is no potential ecological risk, and the cultivated land health productivity is in levels 1-5 are classified as priority protection areas; The areas where the soil in the tested cultivated land exceeds the standard, the crops do not exceed the standard, there is no potential ecological risk, and the cultivated land health production capacity is in the 6-9 level are classified as safe utilization areas; The areas where the soil in the tested cultivated land exceeds the standard but the crops do not exceed the standard, have potential ecological risks and the healthy productivity of cultivated land is in the 1-8 level are classified as safe utilization areas; The areas where the soil of the tested cultivated land exceeds the standard but the crops do not exceed the standard, have potential ecological risks and the healthy production capacity of cultivated land is at level 9 are classified as strict control areas; The areas of the cultivated land to be tested where the soil and crops do not exceed the standards and there is no risk to human health are classified as safe utilization areas; The areas where the soil in the tested cultivated land does not exceed the standard, the crops exceed the standard, and there are risks to human health are divided into strict control areas; Areas where soil and crops exceed the standard in the tested arable land will be designated as strictly controlled areas.

[0063] Based on the same inventive concept, an embodiment of the present invention also provides a farmland heavy metal pollution control zoning system, including: Soil-crop pollution assessment module, used to obtain the soil-crop safety index of the cultivated land to be tested IICQ , through the Soil-Crop Safety Index IICQ Determine whether the heavy metal content in the soil of the cultivated land to be tested exceeds the standard and whether the heavy metal content in the crops exceeds the standard.

[0064] Potential ecological risk module, used to obtain a single potential ecological risk index for the cultivated land to be tested EARLY and composite potential ecological risk index CERAMIC , through a single potential ecological risk index EARLY and composite potential ecological risk index CERAMIC Determine the potential ecological risk of the cultivated land to be tested.

[0065] Heavy metal carcinogenic risk module, used to obtain the non-carcinogenic risk index of the cultivated land to be tested THI and carcinogenic risk index TCR , through the non-carcinogenic risk index THI and carcinogenic risk index TCR Determine the carcinogenic risk of heavy metals in the cultivated land to be tested.

[0066] Human health impact module, used to obtain the composite human health risk index of the cultivated land to be tested CHRIS , through the composite human health risk index CHRIS Determine the human health impacts of the cultivated land to be tested.

[0067] The human health module is used to combine the carcinogenic risk of heavy metals with the impact on human health to determine the human health risk of the cultivated land to be tested.

[0068] The cultivated land classification module is used to obtain the health and productivity evaluation results of the cultivated land to be tested, and determine the cultivated land classification results of the cultivated land to be tested based on the health and productivity evaluation results.

[0069] The zoning module is used to comprehensively evaluate the excessive heavy metal content in the soil, the excessive heavy metal content in crops, the potential ecological risks, the human health risks and the arable land classification results, and to determine the heavy metal pollution control zoning type of the tested arable land based on the evaluation results.

[0070] Based on the same inventive concept, the present invention also provides a computer device, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the steps in the embodiment of the method for controlling and zoning heavy metal pollution in cultivated land are implemented.

[0071] Based on the same inventive concept, the present invention also provides a computer-readable storage medium containing instructions, wherein a computer program is stored on the storage medium, such as a memory containing instructions, wherein the instructions can be executed by a processor of a computer device to complete the above method.

[0072] For example, the non-temporary computer-readable storage medium may be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, and an optical data storage device. When the computer program is executed by the processor, the steps in the method embodiment for controlling the heavy metal pollution of cultivated land can be implemented. The specific implementation method can be found in the method embodiment, which will not be repeated here.

[0073] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for controlling heavy metal pollution in cultivated land, characterized in that: include: Obtain the soil-crop safety index of the cultivated land to be tested IICQ , through the Soil-Crop Safety Index IICQ Determine whether the heavy metal content in the soil of the cultivated land to be tested exceeds the standard and whether the heavy metal content in the crops exceeds the standard; Obtain a single potential ecological risk index for the cultivated land to be tested ERI and composite potential ecological risk index CERI , through a single potential ecological risk index ERI and composite potential ecological risk index CERI Determine the potential ecological risk of the cultivated land to be tested; Obtain the non-carcinogenic risk index of the cultivated land to be tested THI and carcinogenic risk index TCR , through the non-carcinogenic risk index THI and carcinogenic risk index TCR Determine the heavy metal carcinogenic risk of the cultivated land to be tested; Obtain the composite human health risk index of the cultivated land to be tested CHRI , through the composite human health risk index CHRI Determine the human health impact of the cultivated land to be tested; Combine the carcinogenic risk of heavy metals with the impact on human health to determine the human health risk of the cultivated land to be tested; Obtain the health productivity evaluation result of the cultivated land to be tested, and determine the cultivated land classification result of the cultivated land to be tested according to the health productivity evaluation result; A comprehensive evaluation is conducted on the excessive heavy metal content in the soil, the excessive heavy metal content in crops, the potential ecological risks, the human health risks and the cultivated land classification results, and the heavy metal pollution control zoning type of the cultivated land to be tested is determined based on the evaluation results.

2. A method for controlling heavy metal pollution in cultivated land according to claim 1, characterized in that: The soil-crop safety index of the cultivated land to be tested is obtained IICQ , Soil-Crop Safety Index IICQ Including soil safety index IICQ S and Crop Safety Index IICQ C , specifically including: Get the number of heavy metals whose measured concentration exceeds their screening value X , the number of heavy metals whose measured concentrations exceed their background values Y and the number of heavy metals whose concentrations exceeded their limit values Z ; Based on the number of heavy metals with measured concentrations exceeding their screening values X and the number of heavy metals whose measured concentrations exceed their background values Y Calculating the Soil Safety Index IICQ S , the formula is: ； ； ； ； in, N is the number of heavy metals measured, , and Corresponding to the classification of soil heavy metal pollution , and , n For heavy metals i The oxidation number of is the ratio of the measured concentration of a certain soil heavy metal to its background value. For heavy metals i The background value of RIE is the soil relative impact equivalent, DDDB The concentration of soil elements deviates from the background value. DDSB is the degree to which the overall soil standard deviates from the background value; Based on the number of heavy metals whose measured concentrations exceed their limit values Z Calculating the Crop Safety Index IICQ C , the formula is: ； ； in, , and Corresponding to the classification of heavy metal pollution in crops , and , k is the background correction factor, QIC is the crop quality index; Soil-Crop Safety Index IICQ Determine whether the heavy metal content in the soil of the cultivated land to be tested exceeds the standard and whether the heavy metal content in the crops exceeds the standard, including: when , , , When the soil quality of the tested cultivated land is in a good, healthy and clean state, the heavy metal content in the soil and crops is within the standard; when , , or When , it indicates that the soil environment quality of the tested cultivated land is in a sub-healthy state that cannot be used to produce the current crops. The heavy metal content of the soil has not exceeded the standard, but the heavy metal content of the crops has exceeded the standard. when or , , When , it indicates that the soil environment quality of the tested cultivated land is in a serious sub-healthy state, and the heavy metal content in the soil exceeds the standard, but the heavy metal content in the crops meets the limit standard; when , When , it indicates that the soil environment quality of the tested cultivated land is in an unhealthy state, and the heavy metal content in the soil and crops exceeds the standard; in, X is the number of heavy metals whose measured concentration exceeds their screening value, Z It is the number of heavy metals whose measured concentration exceeds their limit value.

3. A method for controlling heavy metal pollution in cultivated land according to claim 1, characterized in that: The single potential ecological risk index of the cultivated land to be tested is obtained ERI and composite potential ecological risk index CERI , specifically including: ； ； in, For heavy metals i A single potential ecological risk index, For heavy metals i The measured concentration of For heavy metals i Soil environmental quality standards, For heavy metals i Toxicity response coefficient; Single Potential Ecological Risk Index ERI and composite potential ecological risk index CERI Determine the potential ecological risks of the cultivated land to be tested, including: when or When , the risk level of the cultivated land to be tested is slightly polluted; when or When , the risk level of the cultivated land to be tested is slightly polluted; when or When , the risk level of the cultivated land to be tested is moderately polluted; when or When , the risk level of the cultivated land to be tested is severely polluted; when When , the risk level of the cultivated land to be tested is severely polluted.

4. A method for controlling heavy metal pollution in cultivated land according to claim 1, characterized in that: The method of obtaining the non-carcinogenic risk index of the cultivated land to be tested THI and carcinogenic risk index TCR , specifically including: ； ； ； ； ； ； ； in, For heavy metals i Average daily intake through breathing For heavy metals i Average daily intake through the skin For heavy metals i Average daily intake through intake; For heavy metals i The measured concentration of is the average daily air intake; is the particulate matter emission factor; The surface area of ​​the soil in contact with the skin; is the soil adhesion factor; It is the skin absorption efficiency factor; is the average daily intake from soil; is the exposure frequency; is the duration of exposure; is body weight; is the average contact time; is the conversion factor; j As a route of exposure to heavy metals; , For heavy metals i exist j Non-carcinogenic and carcinogenic risk indexes under exposure routes; , For heavy metals i Non-carcinogenic risk index and carcinogenic risk index; is the non-carcinogenic reference dose. is the carcinogenic intensity coefficient; Non-carcinogenic risk index THI and carcinogenic risk index TCR Determine the heavy metal carcinogenic risk of the cultivated land to be tested, including: When the non-carcinogenic risk index THI When >1, there is a non-heavy metal carcinogenic risk; When the non-carcinogenic risk index THI When it is less than 1, it has little impact on human health; When the cancer risk index TCR >10 -4 There is a greater risk of heavy metal carcinogenesis; When 10 -6 <Carcinogenic risk index TCR <10 -4 When the carcinogenic risk of heavy metals is at an acceptable level; When the cancer risk index TCR <10 -6 There is no risk of heavy metal cancer.

5. A method for controlling heavy metal pollution in cultivated land according to claim 1, characterized in that: The composite human health risk index of the cultivated land to be tested is obtained CHRI , specifically including: Obtain a single human health risk index for different heavy metals in crops tested in cultivated land HRI , Single human health risk index of heavy metals in all crops HRI The sum of the composite human health risk index CHRI , and its calculation formula is as follows: ； ； in, For heavy metals i The human health risk index, Heavy metals in crops i The measured concentration of is the average daily intake of crops, is the average daily exposure to heavy metals, is the measured value of heavy metal concentration in crops, is the average daily intake of crops, is the reference dose; Composite Human Health Risk Index CHRI Determine the human health impact of the cultivated land to be tested: When the composite human health risk index CHRI When it is >1, it means that the heavy metals accumulated in crops pose a risk to human health; When the composite human health risk index CHRI When it is less than 1, it means that the heavy metals accumulated in crops have little impact on human health.

6. A method for controlling heavy metal pollution in cultivated land according to claim 1, characterized in that: The obtaining of the health productivity evaluation result of the tested cultivated land specifically includes: Based on the cultivated land productivity index value, the cultivated land to be tested is divided into first-class cultivated land, second-class cultivated land and third-class cultivated land. The calculation formula of the cultivated land productivity index value is: ； ； in, l is the number of evaluation indicators; For the p The evaluation unit r The score of each evaluation indicator; For the r The weight of each evaluation indicator; is the light-temperature production potential index; is the crop yield ratio coefficient; u , v For the corresponding evaluation unit; The cultivated land to be tested is divided into healthy cultivated land, sub-healthy cultivated land and unhealthy cultivated land based on the cultivated land health index value. The calculation formula of the cultivated land health index value is: ； in, H is the farmland health index value, R is the system resilience index, E is the production environment index; The division results of the cultivated land productivity index value and the cultivated land health index value are superimposed to obtain the health productivity evaluation result of the cultivated land to be tested; The method of determining the cultivated land classification result of the cultivated land to be tested by using the healthy productivity evaluation result specifically includes: First-class arable land and healthy arable land are grade 1, second-class arable land and healthy arable land are grade 2, and third-class arable land and healthy arable land are grade 4; First-class farmland and sub-healthy farmland are grade 3, second-class farmland and sub-healthy farmland are grade 5, and third-class farmland and sub-healthy farmland are grade 7; First-class arable land and unhealthy arable land are level 6, second-class arable land and unhealthy arable land are level 8, and third-class arable land and unhealthy arable land are level 9.

7. A method for controlling heavy metal pollution in cultivated land according to claim 1, characterized in that: Determining the heavy metal pollution control zone type of the cultivated land to be tested based on the evaluation results specifically includes: The types of heavy metal pollution control zones include priority protection zones, strict control zones, and safe utilization zones; The areas of the cultivated land to be tested where the soil and crops do not exceed the standards are designated as priority protection areas; The areas where the soil in the tested cultivated land exceeds the standard, the crops do not exceed the standard, there is no potential ecological risk, and the cultivated land health productivity is in levels 1-5 are classified as priority protection areas; The areas where the soil in the tested cultivated land exceeds the standard, the crops do not exceed the standard, there is no potential ecological risk, and the cultivated land health production capacity is in the 6-9 level are classified as safe utilization areas; The areas where the soil in the tested cultivated land exceeds the standard but the crops do not exceed the standard, have potential ecological risks and the healthy productivity of cultivated land is in the 1-8 level are classified as safe utilization areas; The areas where the soil of the tested cultivated land exceeds the standard but the crops do not exceed the standard, have potential ecological risks and the healthy production capacity of cultivated land is at level 9 are classified as strict control areas; The areas of the cultivated land to be tested where the soil and crops do not exceed the standards and there is no risk to human health are classified as safe utilization areas; The areas where the soil in the tested cultivated land does not exceed the standard, the crops exceed the standard, and there are risks to human health are classified as strictly controlled areas; Areas where soil and crops exceed the standards in the tested arable land will be designated as strictly controlled areas.

8. A farmland heavy metal pollution control zoning system, characterized in that: include: Soil-crop pollution assessment module, used to obtain the soil-crop safety index of the cultivated land to be tested IICQ , through the Soil-Crop Safety Index IICQ Determine whether the heavy metal content in the soil of the cultivated land to be tested exceeds the standard and whether the heavy metal content in the crops exceeds the standard; Potential ecological risk module, used to obtain a single potential ecological risk index for the cultivated land to be tested ERI and composite potential ecological risk index CERI , through a single potential ecological risk index ERI and composite potential ecological risk index CERI Determine the potential ecological risk of the cultivated land to be tested; Heavy metal carcinogenic risk module, used to obtain the non-carcinogenic risk index of the cultivated land to be tested THI and carcinogenic risk index TCR , through the non-carcinogenic risk index THI and carcinogenic risk index TCR Determine the heavy metal carcinogenic risk of the cultivated land to be tested; Human health impact module, used to obtain the composite human health risk index of the cultivated land to be tested CHRI , through the composite human health risk index CHRI Determine the human health impact of the cultivated land to be tested; The human health module is used to combine the carcinogenic risk of heavy metals with the impact on human health to determine the human health risk of the cultivated land to be tested; The cultivated land classification module is used to obtain the health and productivity evaluation results of the cultivated land to be tested, and determine the cultivated land classification results of the cultivated land to be tested based on the health and productivity evaluation results; The zoning module is used to comprehensively evaluate the excessive heavy metal content in the soil, the excessive heavy metal content in crops, the potential ecological risks, the human health risks and the arable land classification results, and to determine the heavy metal pollution control zoning type of the tested arable land based on the evaluation results.

9. A computer device comprising a memory and a processor, wherein a computer program is stored in the memory, wherein: When the processor executes the computer program, the steps of the cultivated land heavy metal pollution control zoning method described in any one of claims 1-7 are implemented.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the cultivated land heavy metal pollution control zoning method described in any one of claims 1-7 are implemented.

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