Cooperative source analysis method for nitrogen and phosphorus pollutants of land-sea system

Abstract

The invention discloses a land-sea system nitrogen and phosphorus pollutant collaborative source analysis method, and particularly relates to the field of environmental governance and water pollution traceability, which comprises a comprehensive method based on a multi-isotope tracer technology, an isotope mixed model and nitrogen and phosphorus molar ratio verification, and comprises the following steps: acquiring isotope characteristics of nitrogen sources and phosphorus sources in various forms of a land-sea system; in combination with hydrology and water quality monitoring data, the polymorphic contribution of river water, underground water, coastal terrestrial sources and estuary endogenesis to estuary nitrogen and phosphorus pollutants is quantitatively analyzed; through accurate calibration of underground water input, dynamic quantification of pollution flux and cooperative analysis of nitrogen and phosphorus pollutant sources, the problem of insufficient systematicness and accuracy in tracing of complex multi-source pollutants in the prior art is solved, and a basis is provided for drainage basin-estuary-bay integrated treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental governance and water pollution source tracing, and more specifically, to a method for coordinated source analysis of nitrogen and phosphorus pollutants in land-sea systems. Background Art

[0002] Nitrogen and phosphorus pollution is a major challenge in the ecological and environmental governance of the land-sea system. Its source analysis involves land sources (rivers, groundwater), sea sources (estuary sources), and complex migration and transformation processes. Existing research mainly focuses on the analysis of single sources or single forms of nitrogen and phosphorus pollutants, usually using pollution statistics or model simulation methods, lacking overall consideration of the land-sea coordinated system. In addition, most technologies can only estimate the flux distribution of pollutants, and it is difficult to accurately identify the contribution of groundwater input, estuary internal release and other hidden sources of pollutants, especially when dealing with complex multi-source pollution.

[0003] There is no patent for river-estuary nitrogen and phosphorus pollutant source tracing technology based on coordinated land and sea. In the existing technology, for example, CN114384224A discloses a basin nitrogen and phosphorus pollutant analysis method and system based on multi-isotope joint tracing, which can only calculate the pollutant flux transported by rivers entering the sea to the estuary, but cannot accurately identify the dynamic impact of groundwater input and coastal land sources, especially the lack of analytical means for the contribution of pollution released inside the estuary. For phosphorus pollutants, traditional methods usually calculate their sources based on a single phosphate oxygen isotope, but due to the complex morphology and incomplete data, the uncertainty of the analysis results is relatively large. These problems limit the application of existing technologies in large-scale complex environmental governance. Summary of the invention

[0004] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides a method for collaborative source analysis of nitrogen and phosphorus pollutants in land-sea systems, which solves the problems raised in the above-mentioned background technology through the collaborative application of a multi-isotope tracing technology system and an isotope mixing model.

[0005] To achieve the above object, the present invention provides the following technical solution: A method for collaborative source apportionment of nitrogen and phosphorus pollutants in land-sea systems, comprising:

[0006] S1. Obtain the isotopic characteristics of various forms of nitrogen and phosphorus sources in the land-sea system, and use the element and stable isotope tracing technology system and isotope mixing model to quantitatively analyze the contribution of river water, groundwater, coastal land sources and estuarine endogenous sources to different forms of nitrogen and active phosphate in estuarine seawater; different forms of nitrogen include ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, dissolved organic nitrogen, and particulate organic nitrogen;

[0007] S2. Based on hydrological monitoring data and water quality monitoring data, quantitatively calculate the flux of nitrogen and phosphorus pollutants in various forms entering the sea from rivers and their temporal and spatial variations; based on the flux of nitrogen and phosphorus pollutants in rivers and the results of seawater source analysis at the estuary, calibrate the flux of nitrogen and phosphorus pollutants input into groundwater;

[0008] S3. Quantitatively analyze the contribution ratio of different forms of nitrogen pollutants and phosphorus pollutants in rivers and groundwater;

[0009] S4. Based on the source analysis results of various forms of nitrogen pollutants and phosphorus pollutants in rivers and groundwater, calculate the input flux of different forms of nitrogen pollutants and phosphorus pollutants from various sources into the seawater of the bay through river water and groundwater;

[0010] S5. Combining the above results, the preliminary source analysis results of various forms of nitrogen and phosphorus pollutants in the estuary are formed;

[0011] S6. Verify the accuracy of the nitrogen source analysis results based on the source analysis results of different forms of nitrogen pollutants and the composition percentage of each form of nitrogen content in each pollution source;

[0012] S7. Verify the accuracy of phosphate source analysis results based on the source analysis results of active phosphate and the nitrogen-phosphorus ratios of various pollution sources;

[0013] S8. Based on the percentage of phosphorus content in each form and the source apportionment results of active sulfate from different pollution sources, calibrate the input of dissolved organic phosphorus and particulate organic phosphorus from each pollution source;

[0014] S9. Complete the source analysis of various forms of nitrogen and phosphorus pollutants in the estuary based on the idea of ​​coordinated development of land and sea.

[0015] In a preferred embodiment, according to step S1, the isotopic characteristics of nitrogen and phosphorus sources are obtained and the contributions are analyzed; is the isotopic contribution ratio of nitrogen or phosphorus form i in pollution source j, which corresponds to area k; through the weight of each sample point and isotope abundance ratio Calculate the contribution of source j;

[0016]

[0017] in is the isotopic abundance weight of morphology i at the mth sample point, considering the characteristics of region k; is the characteristic isotope ratio; is the total flow contribution of the mth sample point, combined with the monitoring data of the sample points in area k; N, M, and P are the number of pollution sources, the number of sample points, and the number of forms, respectively.

[0018] In a preferred embodiment, according to step S2, the flux into the sea and its temporal and spatial variations are quantitatively calculated; T i (t,z) is the total flux of nitrogen or phosphorus form i into the sea at time t and depth layer z; Φ i (x, t, z) represents the three-dimensional distribution of pollutant concentration, and combined with the dynamic changes of flow rate Q(x, t), the contribution of each location to the total flux is calculated;

[0019]

[0020] where Φ i (x, t, z) is the concentration distribution function of form i at position x, time t, and depth layer z; Q(x, t) is the flow distribution of the river at position x and time t; K z (x) is the depth correction coefficient, which represents the influence weight of different depth layers on flow at position x; L is the total length of the river.

[0021] In a preferred embodiment, a groundwater input rating model is established according to step S3; is the input flux of nitrogen or phosphorus form i from groundwater at depth z;

[0022]

[0023] T i (z) is the total flux of form i into the sea at depth z; C i,j The contribution ratio of pollution source j to form i; L j is the total load of pollution source j; is the total pollutant load of form i at depth layer z; J represents the total number of pollution sources.

[0024] In a preferred embodiment, the contribution ratios of different sources are quantitatively analyzed according to step S4; i,j is the quantitative contribution ratio of pollution source j to nitrogen or phosphorus form i;

[0025]

[0026] where Θ j is the regional characteristic factor of pollution source j; j is the environmental impact factor of pollution source j; K is the total number of pollution sources; Θ k is the regional characteristic factor of pollution source k; k Environmental impact factor of pollution source k;

[0027] According to step S5, a preliminary source analysis result is formed; R i,j is the preliminary analytical result of pollution source j on nitrogen or phosphorus form i;

[0028] R i,j =F i,j ·T i

[0029] where F i,j is the quantitative contribution ratio of pollution source j to nitrogen or phosphorus form i; T i is the total flux into the sea of ​​form i.

[0030] In a preferred embodiment, the accuracy of the source analysis of nitrogen pollutants is verified according to step S6; V i,j is the error ratio of nitrogen pollutant form i from source j;

[0031]

[0032] Where R i,j This is the preliminary analysis result; This is the result of actual analysis.

[0033] In a preferred embodiment, according to step S7, the accuracy of phosphorus pollutant source analysis is verified; Q i,j is the accuracy factor of phosphorus pollutant form i source j; the analytical results are verified by nitrogen-phosphorus ratio and measured phosphorus load;

[0034]

[0035] in is the measured load of phosphorus pollutant form i in source j; N i,j is the nitrogen-phosphorus ratio calibration value of source j to form i; k is the index of the pollution source; K is the total number of pollution sources; By combining the measured phosphorus loads from all sources and its corresponding nitrogen-phosphorus ratio N i,k The weighted sum is used to obtain the overall calibration benchmark.

[0036] In a preferred embodiment, according to step S8, the sources of other forms of phosphorus are determined; i,j is the input of dissolved organic phosphorus and particulate organic phosphorus from source j to form i; the remaining phosphorus forms are calibrated based on the reactive phosphate results;

[0037] L i,j =Q i,j α i,j

[0038] Where Q i,j is the accuracy factor of phosphorus pollutant form i source j; α i,j is the conversion factor, which is used to indicate the rate at which active phosphate is converted into other forms of phosphorus;

[0039] Complete the final source analysis according to step 9; formulate S i Precise source analysis results for nitrogen or phosphorus pollutants in final form i

[0040]

[0041] Where R i,j is the preliminary source analysis result; L i,j is the input of dissolved organic phosphorus and particulate organic phosphorus in form i from source j; J is the total number of pollution sources.

[0042] Technical effects and advantages of the present invention:

[0043] 1. Accurately trace the source of polymorphic nitrogen and phosphorus pollutants in land and sea systems. The present invention constructs a multi-isotope tracing system and an isotope mixing model. It targets the polymorphic characteristics of nitrogen and phosphorus pollutants, such as ammonia nitrogen, nitrate nitrogen, dissolved organic phosphorus, etc., and coordinates land-based, sea-based and internal release factors to establish a comprehensive and accurate source analysis method. Compared with traditional technologies, the present invention can not only quantitatively analyze the polymorphic contributions of rivers, groundwater and estuaries to nitrogen and phosphorus pollutants, but also verify the analysis results by combining the nitrogen-phosphorus molar ratio and composition of different pollution sources, thereby improving the analysis accuracy and providing a scientific basis for pollution control in complex watersheds and estuaries.

[0044] 2. Dynamically quantify the spatiotemporal changes of river and groundwater pollution fluxes; the present invention combines hydrological and water quality monitoring data to construct a dynamic quantification model of pollutant fluxes, which can accurately reflect the spatiotemporal evolution characteristics of nitrogen and phosphorus pollutant fluxes in rivers and groundwater; by quantitatively calculating the input of pollutants of different forms in different periods and regions, this technology provides multi-scale data support for dynamic pollution control; compared with existing static methods, the dynamic characteristics of the present invention significantly improve the adaptability and pertinence of pollutant control strategies;

[0045] 3. Strengthening groundwater input calibration and hidden pollution identification: In view of the fact that traditional technologies are difficult to identify hidden groundwater input, this invention, based on the residual amount extrapolation method and dynamic calibration model, can efficiently identify the dynamic input flux of endogenous pollutants in groundwater and estuaries, and quantify their contribution to the total pollution load; it improves the sensitivity of the analytical model to hidden pollution sources, and provides key data support for comprehensive pollution control;

[0046] 4. Collaborative analysis of nitrogen and phosphorus pollutants and establishment of a cross-validation mechanism: The present invention constructs a collaborative analysis system for nitrogen and phosphorus pollutants, incorporates the nitrogen and phosphorus molar ratio of the pollution source and the composition of each form content into the verification process, and realizes multi-level cross-validation of the analysis results; compared with traditional methods, the present invention is more systematic in verification means, which can ensure the scientificity and credibility of the source analysis results, and is particularly suitable for research and application in complex polluted environments;

[0047] 5. Dynamically calibrate the multi-form sources of phosphorus pollutants. In view of the complexity of tracing the source of phosphorus pollutants, the present invention establishes the transformation relationship and dynamic calibration model between active phosphate and other phosphorus forms, such as dissolved organic phosphorus and particulate phosphorus. Combined with source analysis and verification mechanism, this method improves the comprehensiveness and accuracy of phosphorus pollutant tracing, and provides strong technical support for refined governance.

[0048] 6. Provide a scientific basis for coordinated land-sea pollution control; by integrating the input, migration and transformation of multi-source pollution in the land-sea system, the present invention proposes a source analysis technology framework based on land-sea coordination; this method can effectively identify the key contribution ratios of river, groundwater, estuary endogenous and marine pollution, and dynamically reflect their role paths in governance, providing a reliable basis for the formulation of regional and large-scale basin-estuary-bay integrated governance strategies; compared with traditional single-form or single-source analysis technologies, the present invention has obvious advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] Refer to the instruction manual Figure 1 A method for coordinated source apportionment of nitrogen and phosphorus pollutants in a land-sea system according to an embodiment of the present invention comprises:

[0052] S1. Obtain the isotopic characteristics of various forms of nitrogen and phosphorus sources in the land-sea system, and use the element and stable isotope tracing technology system and isotope mixing model to quantitatively analyze the contribution of river water, groundwater, coastal land sources and estuarine endogenous sources to different forms of nitrogen and active phosphate in estuarine seawater; different forms of nitrogen include ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, dissolved organic nitrogen, and particulate organic nitrogen;

[0053] S2. Based on hydrological monitoring data and water quality monitoring data, quantitatively calculate the flux of nitrogen and phosphorus pollutants in various forms entering the sea from rivers and their temporal and spatial variations; according to the flux of nitrogen and phosphorus pollutants in rivers and the results of seawater source analysis at the estuary, calculate the flux of nitrogen and phosphorus pollutants input into groundwater in percentage;

[0054] S3. Quantitatively analyze the contribution ratio of different forms of nitrogen pollutants and phosphorus pollutants in rivers and groundwater;

[0055] S4. Based on the source analysis results of various forms of nitrogen pollutants and phosphorus pollutants in rivers and groundwater, calculate the input flux of different forms of nitrogen pollutants and phosphorus pollutants from various sources into the seawater of the bay through river water and groundwater;

[0056] S5. Combining the above results, the preliminary source analysis results of various forms of nitrogen and phosphorus pollutants in the estuary are formed;

[0057] S6. Verify the accuracy of the nitrogen source analysis results based on the source analysis results of different forms of nitrogen pollutants and the composition percentage of each form of nitrogen content in each pollution source;

[0058] S7. Verify the accuracy of phosphate source analysis results based on the source analysis results of active phosphate and the nitrogen-phosphorus ratios of various pollution sources;

[0059] S8. Based on the percentage of phosphorus content in each form and the source apportionment results of active sulfate from different pollution sources, calibrate the input of dissolved organic phosphorus and particulate organic phosphorus from each pollution source;

[0060] S9. Complete the source analysis of various forms of nitrogen and phosphorus pollutants in the estuary based on the idea of ​​coordinated development of land and sea.

[0061] According to step S1, obtain the isotopic characteristics of nitrogen and phosphorus sources and analyze their contributions; formulate is the isotopic contribution ratio of nitrogen or phosphorus form i in pollution source j, which corresponds to area k; through the weight of each sample point and isotope abundance ratio Calculate the contribution of source j;

[0062]

[0063] in is the isotopic abundance weight of morphology i at the mth sample point, considering the characteristics of region k; is the isotope characteristic ratio, which represents the stable isotope ratio of source j in the mth sample in region k, such as δ 15 N; is the total flow contribution of the mth sample point, combined with the monitoring data of the sample points in area k; N, M, and P are the number of pollution sources, the number of sample points, and the number of forms, respectively; the denominator in the above formula is normalized for all samples of all pollution sources to ensure that the total contribution ratio is 1.

[0064] According to step S2, the flux into the sea and its temporal and spatial variations are quantitatively calculated; T i (t,z) is the total flux of nitrogen or phosphorus form i into the sea at time t and depth layer z; Φ i(x, t, z) represents the three-dimensional distribution of pollutant concentration, and combined with the dynamic changes of flow rate Q(x, t), the contribution of each location to the total flux is calculated;

[0065]

[0066] where Φ i (x, t, z) is the concentration distribution function of form i at position x, time t, and depth layer z; Q(x, t) is the flow distribution of the river at position x and time t; K z (x) is the depth correction coefficient, which indicates the weight of the influence of different depth layers on the flow at position x; L is the total length of the river; dx is the integral variable over the river length, ensuring that the formula is extended from local and segment calculations to the entire river length; the correction coefficient K z (x) is used to take into account the uneven distribution of river channel depth.

[0067] According to step S3, a groundwater input rating model is established; is the input flux of nitrogen or phosphorus form i from groundwater at depth z;

[0068]

[0069] T i (z) is the total flux of form i into the sea at depth z, which comes from step S2; C i,j The contribution ratio of pollution source j to form i, which comes from step S1; L j is the total load of pollution source j, determined in combination with monitoring data; is the total pollutant load of form i at depth z; J represents the total number of pollution sources; the above formula estimates the implicit input of groundwater by subtracting the contribution of known pollution sources.

[0070] According to step S4, quantitative analysis is performed on the contribution ratios of different sources; F i,j is the quantitative contribution ratio of pollution source j to nitrogen or phosphorus form i;

[0071]

[0072] where Θ j is the regional characteristic factor of pollution source j, which indicates the pollution distribution characteristics of this source; j is the environmental impact factor of pollution source j, determined by combining climate and hydrodynamic impacts; K is the total number of pollution sources; Θ k is the regional characteristic factor of pollution source k, which is used to represent the geographical distribution and emission characteristics of pollution source k and to quantify the impact of the environmental characteristics of the area where the pollution source is located on the diffusion and migration of pollutants; kThe environmental impact factor of pollution source k is used to adjust the relative influence of pollution sources. The above formula adjusts the contribution ratio of groundwater input through characteristic factors and impact factors to determine the specific source.

[0073] According to step S5, a preliminary source analysis result is formed; R i,j is the preliminary analytical result of pollution source j on nitrogen or phosphorus form i;

[0074] R i,j =F i,j ·T i

[0075] where F i,j is the quantitative contribution ratio of pollution source j to nitrogen or phosphorus form i, according to the result of step S4; T i is the total flux of form i into the sea, according to the result of step S2; the above formula obtains a preliminary analysis by combining the proportion of each source with the total flux.

[0076] Verify the accuracy of the source analysis of nitrogen pollutants according to step S6; propose V i,j is the error ratio of nitrogen pollutant form i from source j;

[0077]

[0078] Where R i,j This is the preliminary analysis result; is the measured analytical result; the above formula is used to compare the relative error between the model analytical result and the measured value.

[0079] According to step S7, the accuracy of phosphorus pollutant source analysis is verified; Q i,j is the accuracy factor of phosphorus pollutant form i source j; the analytical results are verified by nitrogen-phosphorus ratio and measured phosphorus load;

[0080]

[0081] in is the measured load of phosphorus pollutant form i in source j; N i,j is the nitrogen-phosphorus ratio calibration value of source j to form i; k is the index of the pollution source, which is used to represent different pollution sources; K is the total number of pollution sources, which represents the sum of all pollution sources involved in the formula; By combining the measured phosphorus loads from all sources and its corresponding nitrogen-phosphorus ratio N i,k The weighted sum is used to obtain the overall calibration benchmark.

[0082] According to step S8, determine the sources of other forms of phosphorus; propose L i,j is the input of dissolved organic phosphorus and particulate organic phosphorus from source j to form i; the remaining phosphorus forms are calibrated based on the reactive phosphate results;

[0083] L i,j =Q i,j α i,j

[0084] Where Q i,j is the accuracy factor of phosphorus pollutant form i source j; α i,j is the conversion factor, which is used to indicate the rate at which active phosphate is converted into other forms of phosphorus;

[0085] Complete the final accurate source analysis according to step 9; formulate S i Precise source analysis results for nitrogen or phosphorus pollutants in final form i

[0086]

[0087] Where R i,j is the preliminary source analysis result, according to step S5; L i,j is the input of dissolved organic phosphorus and particulate organic phosphorus in form i from source j; J is the total number of pollution sources; the final result is completed by comprehensive preliminary analysis and supplementary amounts.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A collaborative source apportionment method for nitrogen and phosphorus pollutants in land-sea systems, characterized in that: include: S1. Obtain the isotopic characteristics of various forms of nitrogen and phosphorus sources in the land-sea system, and use the element and stable isotope tracing technology system and isotope mixing model to quantitatively analyze the contribution of river water, groundwater, coastal land sources and estuarine endogenous sources to different forms of nitrogen and active phosphate in estuarine seawater; different forms of nitrogen include ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, dissolved organic nitrogen, and particulate organic nitrogen; S2. Based on hydrological monitoring data and water quality monitoring data, quantitatively calculate the flux of nitrogen and phosphorus pollutants in various forms entering the sea from rivers and their temporal and spatial variations; based on the flux of nitrogen and phosphorus pollutants in rivers and the results of seawater source analysis at the estuary, calibrate the flux of nitrogen and phosphorus pollutants input into groundwater; S3. Quantitatively analyze the contribution ratio of different forms of nitrogen pollutants and phosphorus pollutants in rivers and groundwater; S4. Based on the source analysis results of various forms of nitrogen pollutants and phosphorus pollutants in rivers and groundwater, calculate the input flux of different forms of nitrogen pollutants and phosphorus pollutants from various sources into the seawater of the bay through river water and groundwater; S5. Combining the above results, the preliminary source analysis results of various forms of nitrogen and phosphorus pollutants in the estuary are formed; S6. Verify the accuracy of the nitrogen source analysis results based on the source analysis results of different forms of nitrogen pollutants and the composition percentage of each form of nitrogen content in each pollution source; S7. Verify the accuracy of phosphate source analysis results based on the source analysis results of active phosphate and the nitrogen-phosphorus ratios of various pollution sources; S8. Based on the percentage of phosphorus content in each form and the source apportionment results of active sulfate from different pollution sources, calibrate the input of dissolved organic phosphorus and particulate organic phosphorus from each pollution source; S9. Complete the source analysis of various forms of nitrogen and phosphorus pollutants in the estuary based on the idea of ​​coordinated development of land and sea.

2. The method for coordinated source apportionment of nitrogen and phosphorus pollutants in land-sea systems according to claim 1, characterized in that: According to step S1, obtain the isotopic characteristics of nitrogen and phosphorus sources and analyze their contributions; formulate is the isotopic contribution ratio of nitrogen or phosphorus form i in pollution source j, which corresponds to area k; through the weight of each sample point and isotope abundance ratio Calculate the contribution of source j; in is the isotopic abundance weight of morphology i at the mth sample point, considering the characteristics of region k; is the characteristic isotope ratio; is the total flow contribution of the mth sample point, combined with the monitoring data of the sample points in area k; N, M, and P are the number of pollution sources, the number of sample points, and the number of forms, respectively.

3. The method for coordinated source apportionment of nitrogen and phosphorus pollutants in land-sea systems according to claim 2, characterized in that: According to step S2, the flux into the sea and its temporal and spatial variations are quantitatively calculated; T i (t,z) is the total flux of nitrogen or phosphorus form i into the sea at time t and depth layer z; Φ i (x, t, z) represents the three-dimensional distribution of pollutant concentration, and combined with the dynamic changes of flow rate Q(x, t), the contribution of each location to the total flux is calculated; where Φ i (x, t, z) is the concentration distribution function of form i at position x, time t, and depth layer z; Q(x, t) is the flow distribution of the river at position x and time t; K z (x) is the depth correction coefficient, which represents the influence weight of different depth layers on flow at position x; L is the total length of the river.

4. The method for coordinated source apportionment of nitrogen and phosphorus pollutants in land-sea systems according to claim 3, characterized in that: According to step S3, a groundwater input rating model is established; is the input flux of nitrogen or phosphorus form i from groundwater at depth z; T i (z) is the total flux of form i into the sea at depth z; C i,j The contribution ratio of pollution source j to form i; L j is the total load of pollution source j; is the total pollutant load of form i at depth layer z; J represents the total number of pollution sources.

5. The method for coordinated source apportionment of nitrogen and phosphorus pollutants in land-sea systems according to claim 4, characterized in that: According to step S4, quantitative analysis is performed on the contribution ratios of different sources; F i,j is the quantitative contribution ratio of pollution source j to nitrogen or phosphorus form i; where Θ j is the regional characteristic factor of pollution source j; j is the environmental impact factor of pollution source j; K is the total number of pollution sources; Θ k is the regional characteristic factor of pollution source k; k Environmental impact factor of pollution source k; According to step S5, a preliminary source analysis result is formed; R i,j is the preliminary analytical result of pollution source j on nitrogen or phosphorus form i; R i,j =F i,j ·T i Among them, F i,j is the quantitative contribution ratio of pollution source j to nitrogen or phosphorus form i; T i is the total flux into the sea of ​​form i.

6. The method for coordinated source apportionment of nitrogen and phosphorus pollutants in land-sea systems according to claim 5, characterized in that: Verify the accuracy of the source analysis of nitrogen pollutants according to step S6; propose V i,j is the error ratio of nitrogen pollutant form i from source j; Where R i,j This is the preliminary analysis result; This is the result of actual analysis.

7. The method for coordinated source apportionment of nitrogen and phosphorus pollutants in land-sea systems according to claim 6, characterized in that: According to step S7, the accuracy of phosphorus pollutant source analysis is verified; Q i,j is the accuracy factor of phosphorus pollutant form i source j; the analytical results are verified by nitrogen-phosphorus ratio and measured phosphorus load; in is the measured load of phosphorus pollutant form i in source j; N i,j is the nitrogen-phosphorus ratio calibration value of source j to form i; k is the index of the pollution source; K is the total number of pollution sources; By combining the measured phosphorus loads from all sources and its corresponding nitrogen-phosphorus ratio N i,k The weighted sum is used to obtain the overall calibration benchmark.

8. The method for coordinated source apportionment of nitrogen and phosphorus pollutants in land-sea systems according to claim 7, characterized in that: According to step S8, determine the sources of other forms of phosphorus; propose L i,j is the input of dissolved organic phosphorus and particulate organic phosphorus from source j to form i; based on Reactive phosphate results are calibrated for other P species sources; 50 i,j =Q i,j ·α i,j Where Q i,j is the accuracy factor of phosphorus pollutant form i source j; α i,j is the conversion factor, which is used to indicate the rate at which active phosphate is converted into other forms of phosphorus; Complete the final source analysis according to step 9; formulate S i Precise source analysis results for nitrogen or phosphorus pollutants in final form i Where R i,j is the preliminary source analysis result; L i,j is the input of dissolved organic phosphorus and particulate organic phosphorus in form i from source j; J is the total number of pollution sources.

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