Method for determining condition of soil pollution caused by pollution discharge of livestock and poultry breeding

Abstract

The embodiment of the invention provides a method for determining the condition of soil pollution caused by livestock and poultry breeding pollution discharge. The method comprises the steps that a livestock and poultry breeding area and a pollution monitoring area in a target monitoring area are determined; dividing the pollution monitoring area into a key monitoring area and a non-key monitoring area based on the position of the livestock and poultry breeding area in the pollution monitoring area and the geographic features of the pollution monitoring area; determining a sampling point position in the key monitoring area according to a first point distribution mode, determining a sampling point position in the non-key monitoring area according to a second point distribution mode, and performing point distribution sampling according to the sampling point position to obtain a soil sample; and carrying out pollutant detection on the soil sample to obtain pollutant data of each sampling point, and inferring the soil pollution condition of the pollution monitoring area caused by pollution discharge of the livestock and poultry breeding area based on the pollutant data. According to the disclosed embodiment scheme, a point distribution sampling scheme with an instructive value is provided for livestock and poultry breeding, and the determined soil pollution condition can reflect the influence of distribution characteristics generated by geographic characteristics.

Description

Technical Field

[0001] The present disclosure relates to the technical field of pollution monitoring, and particularly relates to a method for determining the soil pollution status caused by livestock and poultry breeding sewage discharge. Background Art

[0002] Currently, the output value of the livestock and poultry breeding industry in China accounts for more than one-fourth of the output value of agriculture (agriculture, forestry, animal husbandry, and fishery).

[0003] Livestock and poultry breeding areas are generally located in rural areas far from cities. Various pollution emissions generated may leak into surrounding agricultural and forestry lands and spread under the action of agricultural irrigation, surface runoff of farmland, and groundwater seepage, causing pollution to surrounding agricultural lands and groundwater. In order to understand the current situation of pollution brought by livestock and poultry breeding to agricultural and forestry lands from a global perspective, relevant competent departments have put forward the requirement of conducting soil environmental monitoring around livestock and poultry breeding areas.

[0004] The prerequisite for realizing soil environmental monitoring in livestock and poultry breeding areas is to obtain reasonable soil samples. The current soil sampling method is for the entire earth environmental soil circle, and only principle requirements for site layout and sampling are put forward, which cannot directly guide the soil pollution monitoring of agricultural and forestry lands caused by livestock and poultry breeding problems. Summary of the Invention

[0005] The embodiments of the present disclosure provide a method for determining the soil pollution status caused by livestock and poultry breeding sewage discharge, including:

[0006] Determine the livestock and poultry breeding areas and pollution monitoring areas associated with the livestock and poultry breeding areas in the target monitoring area;

[0007] Based on the location of the livestock and poultry breeding areas in the pollution monitoring area and the geographical features of the pollution monitoring area, divide the pollution monitoring area into key monitoring areas and non-key monitoring areas, where the key monitoring areas are areas significantly affected by livestock and poultry breeding pollution emissions;

[0008] Determine sampling points in the key monitoring areas according to the first site layout method, determine sampling points in the non-key monitoring areas according to the second site layout method, and conduct site layout and sampling according to the sampling points to obtain soil samples; the site layout density in the first site layout method is greater than the site layout density in the second site layout method;

[0009] Detect pollutants in the soil samples to obtain pollutant data for each sampling point, and infer the soil pollution status of the pollution monitoring area caused by sewage discharge from the livestock and poultry breeding areas based on the pollutant data.

[0010] Optionally, dividing the pollution monitoring area into key monitoring areas and non-key monitoring areas based on the location of the livestock and poultry breeding areas in the pollution monitoring area and the geographical features of the pollution monitoring area includes:

[0011] Based on the location of the livestock and poultry breeding area in the pollution monitoring area and the geographical characteristics of the pollution monitoring area, determine the downstream area of the livestock and poultry breeding area;

[0012] Demarcate the key monitoring area in the downstream area, and use the area of the pollution monitoring area other than the key monitoring area as the non-key monitoring area.

[0013] Optionally, determining the livestock and poultry breeding areas in the target monitoring area and the pollution monitoring areas associated with the livestock and poultry breeding areas includes:

[0014] In the case where the livestock and poultry breeding area is a large-scale industrial breeding area, determine the area range of the livestock and poultry breeding area based on the boundary of the large-scale industrial breeding area;

[0015] In the case where the livestock and poultry breeding area is a scattered and intensive breeding area, determine the area of the scattered and intensive breeding area based on the breeding quantity of various livestock and poultry in the scattered and intensive breeding area and the unit breeding density of sewage discharge of various livestock and poultry, determine the central position of the scattered and intensive breeding area based on the distribution characteristics of the scattered and intensive breeding area, and determine the area range of the livestock and poultry breeding area based on the central position and the area of the scattered and intensive breeding area;

[0016] And use the remaining area of the target monitoring area or the area affected by the livestock and poultry breeding area as the pollution monitoring area.

[0017] Optionally, it further includes: in the case where the livestock and poultry breeding area is a scattered and intensive breeding area, the method further includes:

[0018] Calculate the maximum possible impact area based on the breeding quantity of various livestock and poultry in the scattered and intensive breeding area and the unit sewage discharge impact area of various livestock and poultry;

[0019] Determine the area range of the target monitoring area based on the maximum possible impact area and the geographical characteristics of the region where the scattered and intensive breeding area is located.

[0020] Optionally, determining sampling points in the key monitoring area according to the first sampling point layout method includes:

[0021] In the key monitoring area, determine sampling points in the way that the sampling point spacing gradually increases from near the livestock and poultry breeding area to far from the livestock and poultry breeding area according to the surface runoff direction.

[0022] Optionally, sampling and obtaining soil samples according to the sampling points includes:

[0023] Determine the root depth of typical crops in the pollution monitoring area, and determine the surface depth, middle depth, and bottom depth according to the root depth of typical crops; the surface depth is the depth above the main roots of typical crops; the middle depth is the depth where the main roots of typical crops are located, and the bottom depth is the depth that cannot be reached by the roots of typical crops;

[0024] At the sampling points, sample the soil at the corresponding depth positions according to the surface depth, middle depth, and bottom depth respectively to obtain soil samples at the corresponding depths;

[0025] Based on the pollutant data, infer the soil pollution status in the pollution monitoring area caused by the sewage discharge from the livestock and poultry breeding area, including: determining the migration of pollutants in the soil depth direction based on the pollutant data corresponding to the soil samples at different depths of each sampling point.

[0026] Optionally, sampling the soil at the corresponding depth positions according to the surface depth, middle depth, and bottom depth at the sampling points to obtain soil samples at the corresponding depths, including:

[0027] Before rainfall, after rainfall, when the rainwater has receded and there is no water accumulation at the sampling points, sample the soil at the corresponding depths according to the surface depth, middle depth, and bottom depth at each sampling point to obtain soil samples at the corresponding depths before and after rainfall;

[0028] The determining the migration of pollutants in the soil depth direction based on the pollutant data corresponding to the soil samples at different depths of each sampling point includes: determining the migration of pollutants formed by rainwater seepage based on the pollutant data corresponding to the soil samples before and after rainfall at each sampling point.

[0029] Optionally, it further includes: determining characteristic pollutants according to the types of livestock and poultry raised in the livestock and poultry breeding area, the feed additives for livestock and poultry feeding, and the agricultural land type in the pollution monitoring area; the characteristic pollutants are pollutants that are difficult to be absorbed by crops or naturally degraded;

[0030] Perform pollutant detection on the soil samples to obtain pollutant data for each sampling point, including: detecting the characteristic pollutants in the soil samples to obtain concentration data of the characteristic pollutants;

[0031] The inferring the soil pollution status in the pollution monitoring area caused by the sewage discharge from the livestock and poultry breeding area based on the pollutant data includes: inferring the soil pollution status in the pollution monitoring area caused by the sewage discharge from the livestock and poultry breeding area based on the concentration data of the characteristic pollutants.

[0032] Optionally, it further includes: determining the upstream monitoring area of the target monitoring area according to the geographical features, and determining sampling control points in the upstream monitoring area;

[0033] Sampling points are set at the sampling control points to obtain control soil samples, and the control soil samples are subjected to pollutant detection to obtain control data;

[0034] Inferring the soil pollution status caused by the sewage discharge from the livestock and poultry breeding area in the pollution monitoring area based on the pollutant data includes: taking the control data as a reference, and inferring the soil pollution status caused by the sewage discharge from the livestock and poultry breeding area in the pollution monitoring area according to the pollutant data of each sampling point.

[0035] Optionally, determining sampling points in the non-key monitoring area according to the second sampling point setting method includes: according to the possible pollution degree estimated by the topographic features of the key area, using one of the diagonal method, the plum blossom point method, the checkerboard method or the serpentine method and the corresponding sampling point density to determine the sampling points.

[0036] In the solution of the embodiment of the present disclosure, after determining the livestock and poultry breeding area and the corresponding pollution monitoring area, the pollution monitoring area is divided into a key monitoring area and a non-key monitoring area based on the geographical features of the livestock and poultry breeding area and the pollution area. Sampling points are determined for the key monitoring area and the non-key monitoring area respectively, soil samples are obtained by setting sampling points according to the sampling points, and then the soil pollution situation in the pollution monitoring area is inferred according to the pollutant data obtained by detecting the soil samples. The solution of the embodiment of the present disclosure proposes a guiding sampling scheme for livestock and poultry breeding, and can make the determined soil pollution status reflect the influence of the distribution characteristics generated by the geographical features. Description of the Drawings

[0037] The drawings here are incorporated into the description and form a part of this description, showing embodiments consistent with the present disclosure, and are used together with the description to explain the principles of the present disclosure.

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings, where:

[0039] Figure 1 is the flowchart of the method for determining the soil pollution status caused by the sewage discharge from the livestock and poultry breeding provided by the embodiment of the present disclosure;

[0040] Figure 2 is the flowchart of the method for determining the key monitoring area in a specific application. Detailed Embodiments

[0041] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although some embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Instead, these embodiments are provided to more thoroughly and completely understand the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not used to limit the protection scope of the present disclosure.

[0042] As used herein, the term "including" and its variants are open-ended, i.e., "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". The relevant definitions of other terms will be given in the following description. In this document, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0043] Embodiments of the present disclosure provide a method for determining the soil pollution status caused by livestock and poultry breeding sewage discharge, which can be directly applied to the investigation of pollutant status in agricultural and forestry land. Figure 1 It is a flowchart of the method for determining the soil pollution status caused by livestock and poultry breeding sewage discharge provided by the embodiments of the present disclosure. As Figure 1 shown, the method for determining the soil pollution status provided by the embodiments of the present disclosure includes S110 - S140.

[0044] S110: Determine the livestock and poultry breeding areas and pollution monitoring areas associated with the livestock and poultry breeding areas within the target monitoring area.

[0045] The target monitoring area is agricultural and forestry land within whose scope there are livestock and poultry breeding areas, and various wastes discharged from the livestock and poultry breeding areas may cause pollution to it. In specific implementation, the target monitoring area can be determined according to the agricultural industry status of each region. For example, if there is a large-scale livestock and poultry breeding output value or output within the concentrated agricultural land area in a certain county-level administrative region, the aforementioned concentrated agricultural land area can be used as the target monitoring area.

[0046] After determining the target monitoring area, the livestock and poultry breeding areas and pollution monitoring areas associated with the livestock and poultry breeding areas therein can be determined according to specific circumstances. The premise for determining the pollution monitoring area is to determine the livestock and poultry breeding areas. In actual application, the methods for determining the livestock and poultry breeding areas may vary. In specific cases, the livestock and poultry breeding areas may be large-scale industrial breeding areas (such as large-scale pig farms, chicken farms), or may be intensive free-range areas (such as free-range areas formed by many individual livestock and poultry farmers of cattle, sheep, chickens, and ducks in villages).

[0047] In the case where the livestock and poultry breeding area is a large-scale industrial breeding area, since the aforementioned industrial breeding area generally requires industrial land planning and the scope of the industrial breeding area is strictly limited by the scope of the industrial land planning, the area determined based on the boundary of the industrial breeding area can be used as the area scope of the corresponding livestock and poultry breeding area. That is to say, in the case where the livestock and poultry breeding area is a large-scale industrial breeding area, the factory area of the large-scale industrial breeding area can be directly used as the area scope of the corresponding livestock and poultry breeding area.

[0048] In the case where the livestock and poultry breeding area is a free-range intensive area, there is no directly determinable boundary for determining the scope of the breeding area. To solve this problem, the embodiments of the present disclosure consider using the following method to determine the area scope of the livestock and poultry breeding area: determining the area of the free-range intensive area based on the breeding quantity of various livestock and poultry in the free-range intensive area and the unit breeding density of various livestock and poultry, determining the central position of the free-range intensive area based on the distribution characteristics of the free-range intensive area, and then determining the area scope of the livestock and poultry breeding area based on the central position of the free-range intensive area and the area of the free-range intensive area. For example, a certain free-range intensive area raises about 10,000 chickens, and it is generally determined that the breeding density range of free-range chickens is 100m 2 / chicken, then it is highly probable that the area of this free-range intensive area is 10,000 * 100 = 1,000,000m 2 (that is, 1km 2 ). In specific implementation, it can be generally determined based on the distribution range of each free-range farmer on what geographical landmark each free-range farmer is distributed, and correspondingly, the central position of the free-range intensive area can be generally determined. After determining the central position and area of the free-range intensive area, based on the central position and area, according to a specific shape type (such as a radiation fan shape, a rectangle, etc., specifically according to the distribution type of the farmers), the area scope of livestock and poultry breeding in the free-range intensive manner can be determined.

[0049] After determining the scope of the livestock and poultry breeding area, the area other than the livestock and poultry breeding area in the target monitoring area can be used as the pollution monitoring area, or according to experience, the area in the target monitoring area affected by the livestock and poultry breeding area can be used as the pollution monitoring area.

[0050] S120: Divide the pollution monitoring area into a key monitoring area and a non-key monitoring area based on the location of the livestock and poultry breeding area in the pollution monitoring area and the geographical characteristics of the pollution monitoring area.

[0051] The key monitoring area is the area significantly affected by the pollution emissions from livestock and poultry breeding. Correspondingly, the non-key monitoring area is the area in the pollution monitoring area other than the key monitoring area.

[0052] In the embodiments of the present disclosure, based on the location of the livestock and poultry breeding area in the pollution monitoring area, the geographical features of the pollution monitoring area divide the pollution monitoring area into a key monitoring area and a non-key monitoring area. The area downstream of the livestock and poultry breeding area can be determined as the key monitoring area by combining the location of the livestock and poultry breeding area in the pollution monitoring area, the surface water flow direction or the surface elevation model of the pollution monitoring area (these data reflect the geographical features of the target detection area).

[0053] In addition, considering that groundwater may also be an important pollution diffusion path for the collection and diffusion of pollutants, the groundwater flow direction is also considered in some applications to determine the key monitoring area.

[0054] Figure 2 It is a flowchart of a method for determining the key monitoring area in a specific application. As Figure 2 shown, in this specific application, the livestock and poultry breeding area is a large-scale industrial breeding area, and its scope is the area determined by the boundary of the breeding farm. According to the surface runoff and groundwater flow direction in the pollution monitoring area, a fan-shaped area or a rectangular area located in the left and lower areas of the livestock and poultry breeding area is determined as the key monitoring area, and the corresponding other areas are determined as non-key monitoring areas.

[0055] Summarizing the above content, in specific implementation, the following S121-S122 can be adopted to determine the key monitoring area and the non-key monitoring area.

[0056] S121: Based on the location of the livestock and poultry breeding area in the pollution monitoring area and the geographical features of the pollution monitoring area, determine the area in the downstream direction of the livestock and poultry breeding area.

[0057] S122: Encircle the key monitoring area in the downstream direction area, and use the area of the pollution monitoring area other than the key monitoring area as the non-key monitoring area.

[0058] The downstream direction mentioned here refers to the downstream direction of the river flow or the surface runoff in the case of having a river or rainfall forming surface runoff. The corresponding downstream direction area is the area in the pollution monitoring area corresponding to the downstream direction.

[0059] S130: Determine the sampling points in the key monitoring area according to the first sampling point layout method, determine the sampling points in the non-key monitoring area according to the second sampling point layout method, and perform sampling according to the sampling points to obtain soil samples.

[0060] The first sampling point layout method is the layout method corresponding to the sampling points in the key monitoring area, and the second sampling point layout method is the layout method corresponding to the sampling points in the non-key monitoring area. The sampling point density in the first sampling point layout method is greater than that in the second sampling point layout method. That is to say, compared with the non-key monitoring area, a higher sampling density will be used for sampling in the key monitoring area to obtain more typical data reflecting the pollutant distribution state.

[0061] As analyzed above, since the key monitoring area is the downstream area located in the livestock and poultry breeding area determined according to geographical features (specifically according to topography and surface runoff), and considering that the spread of pollutants may slow down as the distribution concentration of pollutants decreases, in the embodiments of the present disclosure, for the key monitoring area, sampling points can be determined in such a way that the spacing between the points gradually increases in the direction of the surface runoff, from near the livestock and poultry breeding area to far from the livestock and poultry breeding area.

[0062] As Figure 2 shown, in one embodiment, in the direction from near the livestock and poultry breeding area to far from the livestock and poultry breeding area, the distances from the sampling points to the boundary of the livestock and poultry breeding area are 40m, 100m, 200m, 500m, and 1000m in sequence, reflecting the characteristic of gradually increasing spacing between the points. In addition, in specific implementation, in the direction perpendicular to the runoff in the key monitoring area, sampling points can be arranged in a fan-shaped distribution to reflect the possible fan-shaped diffusion of pollutants.

[0063] For non-key monitoring areas, the diagonal method, the plum blossom point method, the checkerboard method, or the snake method can be used to determine the sampling points, which can be specifically determined according to the topographical features of the non-key area and the possible degree of soil pollution. Among them, the diagonal method is applicable to areas with flat terrain and relatively uniform pollution degree, and is specifically divided into the single diagonal method and the double diagonal method; the plum blossom point method is applicable to areas with relatively large area, flat terrain, and relatively uniform soil pollution degree; the checkerboard method is applicable to areas with medium area, flat terrain, and different degrees of soil pollution; the snake method is applicable to areas with narrow, uneven terrain, large area, and possible different degrees of soil pollution.

[0064] In specific implementation, the sampling points can be determined in the way of longitude and latitude information, or in the way of distance and angle with a specific position point as a reference.

[0065] After determining each sampling point, sampling can then be carried out according to the sampling points to obtain soil samples. It should be noted here that according to the specific situation, the actual sampling points may have a certain positional deviation from the pre-determined sampling points, but the aforementioned positional deviation will not be too large. In addition, in order to adapt to the detection of different types of pollutants in the future, multiple soil samples with basically corresponding properties may be collected at one sampling point.

[0066] S140: Detect pollutants in the soil samples to obtain pollutant data for each sampling point, and infer the soil pollution status in the pollution monitoring area caused by the sewage discharge from the livestock and poultry breeding area based on the pollutant data.

[0067] After obtaining the soil samples of each sampling point, corresponding detection methods can be used to monitor pollutants in the soil samples to obtain pollutant data for each sampling point.

[0068] In specific implementation, the items for monitoring pollutants in soil samples according to some regulations at least include: total nitrogen, total phosphorus, available phosphorus, ammonia nitrogen, nitrite nitrogen, nitrate nitrogen. Additionally, it may also include heavy metals, antibiotics, estrogens (such as in chicken farms targeting egg production), phthalates, alkylphenols, microplastics, and other items. In specific implementation, pollutants can be determined based on the soil type, crop variety, planting rotation, irrigation frequency in the pollution monitoring area, as well as the livestock and poultry species, feed type, feeding frequency in the livestock and poultry breeding area, and then corresponding detection methods are used to monitor pollutants in soil samples to obtain pollutant data.

[0069] After obtaining the pollutant data of each sampling point, a mathematical simulation method can be used to perform simulation based on the pollutant data related to the corresponding category of each sampling point, infer the soil pollution status of the entire pollution monitoring area, and determine the soil pollution status caused by the sewage discharge in the livestock and poultry breeding area in combination with the agricultural operation conditions (such as fertilization and irrigation) in the pollution monitoring area.

[0070] As previously analyzed, considering the actual situation of the pollution of agricultural and forestry land by livestock and poultry breeding, after determining the livestock and poultry breeding area and the corresponding pollution monitoring area in the embodiments of the present disclosure, the pollution monitoring area is divided into a key monitoring area and a non-key monitoring area based on the geographical characteristics of the livestock and poultry breeding area and the pollution area. Sampling points are determined for the key monitoring area and the non-key monitoring area respectively, soil samples are obtained by sampling according to the sampling points, and then the soil pollution situation of the pollution monitoring area is inferred based on the pollutant data obtained from the detection of the soil samples. The solution of the embodiments of the present disclosure proposes a guiding sampling scheme for livestock and poultry breeding, and can make the determined soil pollution status reflect the influence of the distribution characteristics generated by geographical characteristics.

[0071] According to the existing livestock and poultry breeding surveys, large-scale industrial breeding areas generally adopt reasonable pollution control measures to avoid directly discharging the excrement of breeding livestock and poultry outward as much as possible (but conducting compost fermentation, sewage treatment, etc.). In this case, the size of the target monitoring area has no direct relationship with the livestock and poultry breeding quantity in the large-scale industrial breeding area, and there is no need to consider the problem of the pollution area area caused by the livestock and poultry breeding quantity. However, in the case where the livestock and poultry breeding area is a scattered intensive area (that is, the livestock and poultry breeding is small-scale scattered by individual households), due to scale and cost limitations, the livestock and poultry excrement may be discharged without harmless treatment. In this case, the livestock and poultry breeding scale directly determines the range that may be affected by pollution (the more livestock and poultry, the wider the affected range).

[0072] Based on the foregoing considerations, in the case where the livestock and poultry breeding area is a scattered intensive area, in some embodiments, the following S150 - S160 will also be executed.

[0073] S150: Calculate the maximum possible impact area based on the breeding quantity of various livestock and poultry in the free-range intensive area and the unit pollution discharge impact area of various livestock and poultry.

[0074] S160: Determine the regional scope of the target monitoring area based on the maximum possible impact area and the geographical characteristics of the area where the free-range intensive area is located.

[0075] The unit pollution discharge impact area of livestock and poultry is the pre-determined pollution discharge impact range of a single head / individual of livestock and poultry. In specific implementation, the area of fertilizable land with the annual manure and wastewater discharge of a single head / individual of livestock and poultry can be used as the unit pollution discharge impact area. Through rough estimation, the annual pollution discharge of 1 chicken can fertilize about 4 m 2 of land, the annual pollution discharge of 1 duck can fertilize about 5 m 2 of land, the annual pollution discharge of 1 pig can fertilize about 150 m 2 of land, the annual pollution discharge of 1 sheep can fertilize about 200 m 2 of land, and the annual pollution discharge of 1 cow can fertilize about 0.04 km 2 of land. By performing weighted summation using the unit pollution discharge impact areas of the aforementioned various livestock and poultry and the breeding quantities of various livestock and poultry in the free-range intensive area, the maximum possible impact area can be obtained. After obtaining the maximum possible impact area, the regional scope of the target monitoring area can also be determined based on the maximum possible impact area and the geographical characteristics of the area where the free-range intensive area is located.

[0076] As mentioned in S130 above, sampling is carried out according to the sampling points to obtain soil samples. In specific implementation, after determining the sampling points, how to carry out sampling to obtain soil samples has a great impact on the pollutant data in the soil samples obtained later, and a reasonable soil sampling strategy needs to be formulated.

[0077] In a specific implementation, the following S131 - S132 method can be used to carry out sampling according to the sampling points to obtain soil samples.

[0078] S131: Determine the root depth of typical crops in the pollution monitoring area, and determine the surface depth, intermediate depth, and bottom depth according to the root depth of typical crops.

[0079] From the perspective of agricultural planting, pollutants such as total nitrogen, total phosphorus, available phosphorus, ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen can be directly used as agricultural fertilizers or used as agricultural fertilizers after redox reactions. After the aforementioned pollutants enter the soil, when their content in the soil conforms to the actual situation of agricultural production, due to the absorption by agricultural and forestry crops, there will not be a large content. Based on this, except for the surface soil, the root depth of crops will directly affect the content of the aforementioned types of pollutants in the corresponding soil layer. Based on this, in the embodiments of the present disclosure, it is necessary to combine the root depth of typical crops to determine the surface depth, intermediate depth, and bottom depth. The surface depth is the depth above the main roots of typical crops, the intermediate depth is the depth where the main roots of typical crops are located, and the bottom depth is the depth that cannot be reached by the roots of typical crops.

[0080] For example, in a specific application, according to the root depth of typical crops determined by on-site excavation and analysis, the surface depth is determined to be 0 - 20 cm, the intermediate depth is 20 - 40 cm, and the bottom depth is 40 - 60 cm.

[0081] S132: At the sampling points, sample the soil at the corresponding depth positions according to the surface depth, intermediate depth, and bottom depth to obtain soil samples at the corresponding depths.

[0082] After determining the surface depth, intermediate depth, and bottom depth, a reasonable soil sampling method can be adopted to sample the soil at the determined sampling depths to obtain soil samples at the corresponding depths.

[0083] When the soil samples are determined by using the methods of S131 - S132 and the pollutant data are obtained by detecting the soil samples, S140 specifically is to determine the migration situation of pollutants in the soil depth direction based on the pollutant data corresponding to the soil samples at different depths of each sampling point. Determining the migration situation of pollutants in the soil depth direction based on the pollutant data corresponding to the soil samples at different depths of each sampling point can inversely deduce whether the emissions of pollutants such as nitrogen and phosphorus are seriously excessive, and further estimate whether there is a situation of pollutant over - emission or even emission without treatment.

[0084] In addition to the diffusion migration caused by concentration differences, the migration of pollutants in soil also includes passive migration under the action of water. In order to obtain the migration of pollutants caused by rainwater, in specific implementation, when specifically executing S132, soil samples corresponding to the corresponding depths can be collected from each sampling point according to the surface depth, middle depth, and bottom depth before rainfall, after rainfall, after the rainwater recedes, and when there is no water accumulation at the sampling point, so as to obtain soil samples at the corresponding depths before and after rainfall. Correspondingly, in S140, by comparing and analyzing the pollutant data corresponding to the soil samples at different depths of each sampling point in sequence, the migration of pollutants caused by rainwater leakage can be determined, and then the impact of pollutant emissions during the rainy season and flood season on groundwater, as well as the enrichment of pollutants in the deep soil, can be considered.

[0085] As previously analyzed, pollutants such as nitrogen and phosphorus are pollutants that can be absorbed by crops to achieve removal. It is not appropriate to use the concentration data of such pollutants to identify the diffusion path of pollutants in the pollution monitoring area. Based on this, in some embodiments of the present disclosure, considering the data of specific types of pollutants to determine the diffusion path and other situations of pollutants in the pollution monitoring area, specifically including S170 as follows.

[0086] S170: Determine characteristic pollutants according to the types of livestock and poultry raised in the livestock and poultry breeding area, the feed additives for raising livestock and poultry, and the agricultural land type in the pollution monitoring area; the characteristic pollutants are pollutants that are difficult to be absorbed by crops or biodegraded.

[0087] The characteristic pollutants in the embodiments of the present disclosure are pollutants that are difficult to be absorbed by crops or naturally degraded. Different types of livestock and poultry have different feeding value goals, and the feed types and breeding cycles of different livestock and poultry are different. Correspondingly, the feeding strategies, feed additives, antibiotics, etc. used are also different. Correspondingly, it is necessary to determine the characteristic pollutants according to the types of livestock and poultry raised in the livestock and poultry breeding area and the feed additives. For example, in the case of raising laying hens in the livestock and poultry breeding area, in order to ensure a high egg production efficiency of the laying hens, there will be estrogen in the feed additives; in the case of raising meat chickens in the livestock and poultry breeding area, there will be no estrogen in the feed additives. For another example, livestock and poultry such as chickens, ducks, and pigs are mainly grain-fed livestock and poultry, while livestock and poultry such as cattle and sheep are mainly grass-fed livestock and poultry. Different types of pollutants are enriched in the two different types of feeds, and the types of corresponding characteristic pollutants will also be different.

[0088] In addition, different types of agricultural land are used to grow different types of crops (here crops include forest trees). The root systems of crops and their enrichment effects on pollutants are different. Accordingly, it is also necessary to consider the type of agricultural land to determine characteristic pollutants. In a specific application, when the pollution monitoring area is arable land, rubber plantation, or tea garden, the characteristic pollutants may include antibiotics and estrogens; when the pollution monitoring area is an orchard or vegetable plot, the characteristic pollutants may include antibiotics, phthalate esters, microplastics, estrogens, and alkylphenols.

[0089] When performing the foregoing S170, when performing S140, it also includes detecting the characteristic pollutants in the soil sample to obtain the concentration data of the characteristic pollutants. When the concentration data of the characteristic pollutants is obtained, the soil pollution status caused by the sewage discharge from the livestock and poultry breeding area in the pollution monitoring area can be inferred based on the concentration data of the characteristic pollutants. Specifically, it is to determine the diffusion path, severity, etc. of the inferred pollutants in the pollution monitoring area.

[0090] It is undeniable that the pollutants in the pollution monitoring area may not only be caused by the sewage discharge from the livestock and poultry breeding area, but may also be caused by the discharge from other pollution sources upstream. When determining the pollution status caused by the sewage discharge from the livestock and poultry breeding area based on the pollution data, other reasons need to be excluded. For agricultural and forestry land, except for the application of fertilizers and pesticides, there are not many other pollutants. The application of fertilizers and pesticides can be inferred through the corresponding pollutant data of the soil. The core issue is to exclude the pollutants brought by other pollution sources.

[0091] As Figure 2 shown, in some embodiments of the present disclosure, in addition to determining the sampling points in the target monitoring area, the upstream monitoring area of the target monitoring area is also determined according to the geographical characteristics, and sampling control points are determined in the upstream monitoring area. In specific implementation, the sampling control points can be set in the area adjacent to the edge of the target monitoring area. When the sampling control points are determined, it is also necessary to perform grid sampling at the sampling control points to obtain control soil samples, and monitor the pollutants in the control soil samples to obtain control data. When there is control data, the determination of the soil pollution status in S140 above is specifically to use the control data as a reference to infer the soil pollution status caused by the sewage discharge from the livestock and poultry breeding area in the pollution monitoring area according to the pollutant data of each sampling point.

[0092] The above are only specific implementation manners of the present disclosure, enabling those skilled in the art to understand or implement the present disclosure. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to these embodiments herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for determining the soil pollution status caused by livestock and poultry breeding sewage discharge, characterized in that, Including: Determine the livestock and poultry breeding areas in the target monitoring area and the pollution monitoring areas associated with the livestock and poultry breeding areas; Based on the location of the livestock and poultry breeding areas in the pollution monitoring areas and the geographical features of the pollution monitoring areas, divide the pollution monitoring areas into key monitoring areas and non-key monitoring areas, where the key monitoring areas are the areas significantly affected by livestock and poultry breeding pollution emissions; Determine sampling points in the key monitoring areas according to the first sampling point layout method, determine sampling points in the non-key monitoring areas according to the second sampling point layout method, and perform sampling according to the sampling points to obtain soil samples; the sampling point density in the first sampling point layout method is greater than the sampling point density in the second sampling point layout method; Detect pollutants in the soil samples to obtain pollutant data for each sampling point, and infer the soil pollution status in the pollution monitoring areas caused by pollution discharge from the livestock and poultry breeding areas based on the pollutant data.

2. The method according to claim 1, characterized in that, Based on the location of the livestock and poultry breeding areas in the pollution monitoring areas and the geographical features of the pollution monitoring areas, divide the pollution monitoring areas into key monitoring areas and non-key monitoring areas, including: Based on the location of the livestock and poultry breeding areas in the pollution monitoring areas and the geographical features of the pollution monitoring areas, determine the downstream area of the livestock and poultry breeding areas; Define the key monitoring areas in the downstream area, and use the areas in the pollution monitoring areas other than the key monitoring areas as the non-key monitoring areas.

3. The method according to claim 1, wherein The determination of the livestock and poultry breeding areas in the target monitoring area and the pollution monitoring areas associated with the livestock and poultry breeding areas includes: In the case where the livestock and poultry breeding area is a large-scale industrial breeding area, determine the area range of the livestock and poultry breeding area based on the boundary of the large-scale industrial breeding area; In the case where the livestock and poultry breeding area is a scattered breeding intensive area, determine the area of the scattered breeding intensive area based on the breeding volume of various livestock and poultry in the scattered breeding intensive area and the unit breeding density of pollution discharge of various livestock and poultry, determine the central position of the scattered breeding intensive area based on the distribution characteristics of the scattered breeding intensive area, and determine the area range of the livestock and poultry breeding area based on the central position and the area of the scattered breeding intensive area; And use the remaining areas in the target monitoring area or the areas affected by the livestock and poultry breeding areas as the pollution monitoring areas.

4. The method according to claim 3, characterized in that, It also includes: In the case where the livestock and poultry breeding area is a scattered breeding intensive area, the method further includes: Calculate the maximum possible impact area based on the breeding volume of various livestock and poultry in the scattered breeding intensive area and the unit pollution impact area of various livestock and poultry; Determine the area range of the target monitoring area based on the maximum possible impact area and the geographical features of the location of the scattered breeding intensive area.

5. The method according to any one of claims 1-4, characterized in that, Determine sampling points in the key monitoring areas according to the first sampling point layout method, including: In the key monitoring areas, determine sampling points in a way that the sampling point spacing gradually increases from near the livestock and poultry breeding areas to far from the livestock and poultry breeding areas according to the surface runoff direction.

6. The method according to any one of claims 1 to 4, characterized in that Perform sampling according to the sampling points to obtain soil samples, including: Determine the root depth of typical crops in the pollution monitoring area, and determine the surface depth, middle depth, and bottom depth according to the root depth of typical crops; the surface depth is the depth above the main roots of typical crops; the middle depth is the depth where the main roots of typical crops are located, and the bottom depth is the depth that cannot be reached by the roots of typical crops; At the sampling points, sample the soil at the corresponding depth positions according to the surface depth, middle depth, and bottom depth respectively to obtain soil samples at the corresponding depths; Based on the pollutant data, infer the soil pollution status in the pollution monitoring area caused by the sewage discharge from the livestock and poultry breeding area, including: determining the migration of pollutants in the soil depth direction based on the pollutant data corresponding to the soil samples at different depths at each sampling point.

7. The method according to claim 6, wherein At the sampling points, sample the soil at the corresponding depth positions according to the surface depth, middle depth, and bottom depth respectively to obtain soil samples at the corresponding depths, including: Before rainfall, after rainfall, when the rainwater has receded and there is no water accumulation at the sampling points, sample the soil at the corresponding depths at each sampling point according to the surface depth, middle depth, and bottom depth respectively to obtain soil samples at the corresponding depths before and after rainfall; The determining the migration of pollutants in the soil depth direction based on the pollutant data corresponding to the soil samples at different depths at each sampling point includes: determining the migration of pollutants formed by rainwater leakage based on the pollutant data corresponding to the soil samples before and after rainfall at each sampling point.

8. The method according to any one of claims 1 to 4, characterized in that, It also includes: Determine the characteristic pollutants according to the types of livestock and poultry raised in the livestock and poultry breeding area, the feed additives used for raising livestock and poultry, and the agricultural land type in the pollution monitoring area; The characteristic pollutants are pollutants that are difficult to be absorbed by crops or naturally degraded; Detect the pollutants in the soil samples to obtain the pollutant data at each sampling point, including: detecting the characteristic pollutants in the soil samples to obtain the concentration data of the characteristic pollutants; The inferring the soil pollution status in the pollution monitoring area caused by the sewage discharge from the livestock and poultry breeding area based on the pollutant data includes: inferring the soil pollution status in the pollution monitoring area caused by the sewage discharge from the livestock and poultry breeding area based on the concentration data of the characteristic pollutants.

9. The method according to any one of claims 1-3, characterized in that, It also includes: Determine the upstream monitoring area of the target monitoring area according to the geographical features, and determine the sampling control points in the upstream monitoring area; Conduct spot sampling at the sampling control points to obtain control soil samples, and detect the pollutants in the control soil samples to obtain control data; The inferring the soil pollution status in the pollution monitoring area caused by the sewage discharge from the livestock and poultry breeding area based on the pollutant data includes: taking the control data as a reference, and inferring the soil pollution status in the pollution monitoring area caused by the sewage discharge from the livestock and poultry breeding area according to the pollutant data at each sampling point.

10. The method according to any one of claims 1-4, characterized in that, Determine the sampling points in the non-key monitoring area according to the second sampling method, including: determining the sampling points according to the possible pollution degree estimated by the terrain features of the key area, using one of the diagonal method, plum blossom point method, checkerboard method or serpentine method and the corresponding sampling density.

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