Rapid quantitative tracing method, medium and equipment for water pollution of tree-shaped river network area

Abstract

The invention discloses a rapid quantitative tracing method for water pollution of a tree-shaped river network area, a medium and equipment, and relates to the field of water pollution tracing, the rapid quantitative tracing method for water pollution of the tree-shaped river network area mainly comprises the following steps: constructing a river network upstream and downstream relationship and a river reach code according to basin information; establishing a pollution discharge relation matrix according to the point and non-point source pollution, the number and the position of the drain outlet and the river channel; the method comprises the following steps: acquiring a key monitored river section position, and establishing a traceability target set of a control section-pollution source; according to the traceability target set, the emission amount and the river entering amount of the non-point source pollution of the related points are calculated, and an alternative pollution source library is established; and obtaining contribution rates of different pollution sources according to the total pollution flux, and finally forming a pollution contribution rate list of a specific traceability target. According to the rapid quantitative traceability method, medium and equipment for water pollution in the tree-shaped river network area, the pollution source of a control section can be effectively traced, and a rapid pollution source analysis method is particularly provided for a drainage basin with a complex water system and difficult modeling.

Description

Technical Field

[0001] The present invention relates to the field of water pollution source tracing, and more specifically, to a method, medium and equipment for rapid quantitative source tracing of water pollution in a tree-like river network area. Background Art

[0002] Tracing the source of pollution is the key to achieving water quality standards. Exploring the causal relationship between water quality sections and pollution sources can clarify the source, intensity and impact range of river pollution, thereby providing a basis for formulating more targeted water quality management measures.

[0003] The commonly used methods for tracing the source of water pollution currently include the following two aspects. The first is to use a variety of technical means to qualitatively identify the source type and location of water pollutants, such as isotope tracing technology, linear correlation source identification method, spectral analysis, etc. This type of method mainly relies on identifying and determining the chemical composition and relative content of water bodies for source analysis. It often provides the source of pollutants and discusses the contribution rate of pollution less. The second is to apply environmental assessment, water quality parameter analysis and other methods to quantify the causal relationship between pollutants and sources through statistical or mathematical models, so as to calculate the contribution rate of pollution from each source. This type of method tends to analyze the ratio of pollution discharge / load into the river to the total pollution load of the water body in the area, and lacks a detailed analysis of the actual contribution of different pollution sources to the control section.

[0004] In the assessment of pollution contribution rate, a common technique is to construct a river network model to simulate the attenuation coefficient of different river sections, which has high requirements for data. In river basins with large altitude differences and complex river networks, in addition to conventional hydrological and water quality monitoring data, data such as riverbed slope, underwater topography, and aquatic organisms are also required. These data will significantly affect the accuracy and credibility of the model. In addition, the complex river network structure will increase the difficulty of model calculation and consume a long time cost. Summary of the invention

[0005] The purpose of the present invention is to provide a method, medium and equipment for rapid quantitative tracing of water pollution in a tree-like river network area. By investigating and analyzing the relationship between river networks in the watershed, a tracing relationship between pollution source-sewage outlet-river section is constructed. According to the two key factors affecting water pollution reduction, namely flow velocity and distance, a pollution flux ratio formula based on the comprehensive attenuation coefficient is established to quickly realize the analysis of pollution contribution rates of different water quality sections.

[0006] The present invention provides a method for rapid quantitative source tracing of water pollution in a tree-like river network area, comprising the following steps: S1: obtaining watershed information, and coding the river channel according to the watershed information to obtain a tree-like river network area; S2: obtaining point source pollution information, and obtaining a point source pollution matrix according to the point source pollution information and the tree-like river network area; S3: performing non-point source pollution statistics according to the tree-like river network area and the administrative division level as a unit to obtain a non-point source pollution relationship set; S4: obtaining the river section location of the key water quality monitoring area according to the watershed information, and obtaining the source tracing matrix according to the river section location of the key water quality monitoring area. Target set; S5: According to the tracing target set and the topological structure of the tree-like river network area, carry out pollution tracing step by step and section by section to obtain the relationship between the tracing target and the pollution source; S6: According to the environmental statistical data, the relationship between the tracing target and the pollution source and the non-point source pollution relationship set, the pollution sources affecting the target section are collected and the emissions and the amount of pollution entering the river of point source pollution and non-point source pollution are calculated respectively to obtain the alternative pollution source library; S7: According to the distance and flow velocity between the alternative pollution source library and the target section, the pollution residual amount and the pollution source contribution rate when the pollution source reaches the target section are calculated to obtain a refined pollution tracing list.

[0007] Furthermore, the watershed information of the above-mentioned rapid quantitative source tracing method for water pollution in the tree-like river network area includes the administrative division scope, digital elevation model, river data, and river network contained in the watershed; river channel coding includes: judging the direction of the river, and labeling from upstream to downstream, from tributaries to the main stream in order from small to large; point source pollution information includes the number and location of point source pollution and the number and location of sewage outlets; the point source pollution matrix is ​​the relationship matrix of point source pollution-sewage outlets-river channels; key water quality monitoring areas include control sections and water sources; and the tracing target set includes the geographical location of key water quality monitoring areas, river section codes, and water quality monitoring parameters.

[0008] Furthermore, step S2 of the method for rapid quantitative tracing of water pollution in the above-mentioned tree-like river network area specifically includes: S21: obtaining point source pollution information based on environmental statistical data, enterprise-filled information forms, and survey data, wherein the point source pollution information includes the number and location of point source pollution and the number and location of sewage outlets; S22: according to the point source pollution information and the tree-like river network area, the statistical point source emission pathways are matched one by one with the actual sewage outlets into the river according to the matching relationship, and a point source pollution-sewage outlet relationship table is obtained; among them, point sources that are difficult to match with sewage outlets are generalized based on remote sensing images and spatial relationships, and the environmental characteristics around the point sources are judged by remote sensing images to obtain sewage discharge information; the spatial relationship between point source pollution and the river channel is established using a geographic information system, and the nearest neighbor point in the river channel is selected as the sewage outlet according to the distance; S23: the river section code corresponding to the location of the point source pollution outlet is determined to form a relationship matrix to obtain a point source pollution matrix.

[0009] Furthermore, step S3 of the method for rapid quantitative tracing of water pollution in a tree-like river network area specifically includes:

[0010] S31: Based on the tree-like river network area, the administrative area and the river network are superimposed to obtain the spatial relationship between the administrative unit and the river channel; S32: Based on the spatial relationship between the administrative unit and the river channel, the administrative unit with a river channel flowing through it is recorded as "yes"; the administrative unit without a river channel flowing through it is recorded as "no"; S33: The administrative unit recorded as "yes" is regarded as the source of non-point source pollution, and the non-point source pollution is converted into a point source inflow format using the river channel generalization method, and the discharge port location is uniformly set to obtain a non-point source pollution relationship set.

[0011] Furthermore, step S33 of the method for rapid quantitative tracing of water pollution in the above-mentioned tree-like river network area specifically includes: taking the administrative unit recorded as "yes" as the source of non-point source pollution; when the administrative unit does not contain the source of the river and only has a single tributary or main stream flowing through it, it is evenly segmented and coded according to the distance of the river flowing through the administrative unit, and the center point of each sub-segment is set as the pollution discharge port to obtain the first non-point source pollution inflow generalization set; when the administrative unit contains the source of the river and only has a single tributary or main stream flowing through it, the administrative unit is divided, and the area without the river flowing through it is segmented as a whole to flow into the river, and the river source is used as the discharge port; for the area through which the river flows, the method of average segmentation along the river is used to determine the pollution inflow path, and the center point of each sub-segment is set as the pollution discharge port; each segment is uniformly coded and integrated to obtain the second non-point source pollution inflow generalization set; when the administrative unit does not contain the source of the river and only has a single tributary or main stream flowing through it, the administrative unit is divided, and the area without the river flowing through it is segmented as a whole to flow into the river, and the river source is used as the discharge port; for the area through which the river flows, the method of average segmentation along the river is used to determine the pollution inflow path, and the center point of each sub-segment is set as the pollution discharge port; each segment is uniformly coded and integrated to obtain the second non-point source pollution inflow generalization set; When a river source is included and there are multiple tributaries or main streams flowing through it, the river source is taken as the location of the discharge port and the third non-point source pollution inflow generalization set is obtained after aggregation. When an administrative unit contains a river source and there are multiple tributaries or main streams flowing through it, the part above the source is taken as a whole and merged into the river section, and the river source is taken as the discharge port location. The part through which multiple tributaries or main streams flow is segmented and coded respectively by the average distribution method, and the discharge port is set at the center point of the sub-segment. The fourth non-point source pollution inflow generalization set is obtained after aggregation. The first non-point source pollution inflow generalization set, the second non-point source pollution inflow generalization set, the third non-point source pollution inflow generalization set and the fourth non-point source pollution inflow generalization set are integrated to obtain the non-point source pollution relationship set. The non-point source pollution relationship set includes the relationship between non-point source pollution, discharge ports and corresponding river sections.

[0012] Furthermore, step S5 of the method for rapid quantitative tracing of water pollution in the above-mentioned tree-like river network area specifically includes: S51: according to the tracing target set and the topological structure of the tree-like river network area, the river channel is traced and recorded step by step from downstream to upstream to obtain the river section code; S52: according to the river section code, the point source pollution matrix and the non-point source pollution relationship set, the pollution transmission path, sewage outlets and potential pollution sources are tracked, and according to the river section code, the sewage outlet locations of point source and non-point source pollution are traced back in turn, recorded and screened, and the screening results are obtained; S53: according to the screening results, according to the relationship between the point and non-point source sewage outlets and the administrative units, the administrative unit of pollution emission is obtained; according to the administrative unit of pollution emission and the tracing target set, the relationship between the tracing target and the pollution source is obtained.

[0013] Furthermore, step S6 of the above-mentioned method for rapid quantitative source tracing of water pollution in the tree-like river network area specifically includes: S61: according to environmental statistical data and the relationship between tracing targets and pollution sources, the emission of point source pollution and non-point source pollution are calculated using the pollution production and emission coefficient method; S62: according to the point source pollution emission, a preset point source pollution inflow coefficient is selected in the form of direct emission and indirect emission for calculation to obtain the point source pollution inflow into the river; S63: according to the non-point source pollution emission and non-point source pollution relationship set, the corresponding preset non-point pollution inflow coefficient is selected for different types of non-point pollution sources, and the non-point source pollution inflow coefficient is calculated according to the non-point source pollution emission and non-point source pollution relationship set. For the generalized situation of non-point source pollution in rivers, the method of calculating the amount of pollution entering the river is selected: when the administrative unit that is the source of non-point source pollution does not include the source of the river and only has a single tributary or main stream flowing through it, the pollution emissions are evenly distributed according to the number of segments, and the pollution entering the river is calculated in the form of sub-segments to obtain the first non-point source pollution entering the river; when the administrative unit that is the source of non-point source pollution includes the source of the river and only has a single tributary or main stream flowing through it, the area ratio of the administrative unit above the source is obtained, the pollution emissions are distributed according to the area ratio method, and the amount entering the river is calculated as a whole; the remaining part is evenly distributed according to the number of segments The amount of pollution discharged is calculated in the form of sub-segments to calculate the amount of pollution discharged into the river, and the second amount of non-point source pollution discharged into the river is obtained; when the administrative unit as the source of non-point source pollution does not contain the source of the river and has multiple tributaries or main streams flowing through it, the pollution discharge is first evenly distributed according to the number of tributaries or main streams, and then the pollution discharge is evenly distributed according to the number of corresponding tributaries or main stream segments to obtain the third amount of non-point source pollution discharged into the river; when the administrative unit as the source of non-point source pollution contains the source of the river and has multiple tributaries or main streams flowing through it, the pollution discharge is first evenly distributed according to the number of tributaries or main streams; then the pollution discharge is evenly distributed according to the number of tributaries or main streams containing the source; The administrative units of the main stream allocate the pollution emissions of the areas above the source according to the area proportion method, and calculate their amount of input into the river as a whole; finally, the remaining rivers evenly distribute the pollution emissions according to the number of sections, and calculate the pollution amounts entering the river in the form of sub-segments to obtain the fourth non-point source pollution input into the river; the non-point source pollution input into the river is obtained based on the first non-point source pollution input into the river, the second non-point source pollution input into the river, the third non-point source pollution input into the river and the fourth non-point source pollution input into the river; the alternative pollution source library is obtained based on the point source pollution emissions, non-point source pollution emissions, point source pollution input into the river and non-point source pollution input into the river.

[0014] Furthermore, step S7 of the above-mentioned method for rapid quantitative source tracing of water pollution in the tree-like river network area specifically includes: according to the candidate pollution source library, considering the two specific factors of distance and flow rate that affect the amount of pollutant reduction, based on the comprehensive attenuation coefficient of the river, calculating the pollution residual amount of the pollution source reaching the target section; combining the total pollution flux, calculating the pollution source contribution rate, forming a pollution contribution rate list of a specific tracing target, and obtaining a refined pollution source tracing list, such as the formula:

[0015]

[0016] Among them, W is the remaining amount of pollution source reaching the target section, W in is the amount of pollution entering the river, K is the comprehensive attenuation coefficient of a certain pollutant, X is the length of the pollution source from the sewage outlet to the target section; u is the flow rate of the river, M ps is the contribution rate of point source pollution to the target section, W ps is the amount of point source pollution entering the river, c is the pollutant concentration in the target section, q is the flow rate in the target section, M nps is the contribution rate of the surface source to the target section, W nps is the inflow of surface sources.

[0017] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for rapid quantitative tracing of water pollution in the tree-like river network area are implemented.

[0018] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps of the above-mentioned method for rapid quantitative tracing of water pollution in a tree-like river network area are implemented.

[0019] The method, medium and equipment for rapid quantitative tracing of water pollution in a tree-like river network area provided by the present invention have the following beneficial effects:

[0020] According to the topological structure of the river network, the present invention constructs a rapid tracing relationship of different pollution sources-sewage outlets-rivers, and establishes a pollution flux ratio formula based on the comprehensive attenuation coefficient based on two specific factors that determine the amount of pollutant reduction, namely flow velocity and distance, to achieve flexible generalization of pollutant contribution rate calculation. It can quickly and effectively realize the quantification of the entire source analysis process, refine the types of pollution sources, provide clear and intuitive analysis results for scientific management of water environment, effectively solve the problem of difficult water pollution source tracing modeling in complex watersheds, and help managers quickly locate pollution sources and take corresponding control measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0022] Figure 1 It is a flow chart of the method for rapid quantitative tracing of water pollution in a tree-like river network area provided by the present invention;

[0023] Figure 2 It is a generalized schematic diagram of non-point source pollution provided by the present invention;

[0024] Figure 3 This is a comparison chart of the pollutant contribution calculation results of the Mangxi Bridge section using the two source analysis methods provided by the present invention;

[0025] Figure 4 It is a comparison chart of the pollutant contribution calculation results of the Simong River estuary section by the two source analysis methods provided by the present invention;

[0026] Figure 5 It is a comparison chart of the pollutant contribution calculation results of the two source analysis methods provided by the present invention to the Liangheshui section;

[0027] Figure 6 It is a structural block diagram of the computer device provided by the present invention. DETAILED DESCRIPTION

[0028] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0029] Figure 1 A schematic diagram of the method for rapid quantitative tracing of water pollution in a tree-like river network area of ​​this embodiment is shown.

[0030] In this embodiment, the method for rapid quantitative tracing of water pollution in a tree-like river network area includes the following steps:

[0031] S1: Obtain watershed information, encode the river channel according to the watershed information, and obtain the tree-like river network area;

[0032] Specifically, the basin information includes the administrative division scope, digital elevation model, river data, and river network of the basin; river channel coding includes: determining the direction of the river, and coding the labels from small to large from upstream to downstream and from tributaries to main stream;

[0033] Specifically, step S1 includes: determining the administrative division scope of the basin through investigation and statistics; collecting DEM and river data, extracting the river network of the basin using GIS software, establishing the upstream and downstream relationship of the river network, and encoding the river sections to obtain the tree-like river network area;

[0034] S2: Obtain point source pollution information, and obtain the point source pollution matrix based on the point source pollution information and the tree-like river network area;

[0035] Specifically, the point source pollution information includes the number and location of point source pollution and the number and location of sewage outlets; the point source pollution matrix is ​​the relationship matrix of point source pollution-sewage outlet-river channel;

[0036] Specifically, step S2 includes: determining the number and location of point sources based on the collected point source pollution information, matching point source pollution with sewage outlets one by one according to the discharge pathway, and constructing a relationship matrix of point source pollution-sewage outlets-river channels according to the river section codes to which the sewage outlets belong; the steps specifically include: S21: obtaining point source pollution information based on environmental statistical data, enterprise information forms, and survey data, the point source pollution information includes the number and location of point source pollution and the number and location of sewage outlets; S22: according to the point source pollution information and the tree-like river network area, According to the matching relationship, the statistical point source emission pathways are matched with the actual sewage outlets into the river one by one, and a relationship table of point source pollution-sewage outlets is obtained; among them, the point sources that are difficult to match with the sewage outlets are generalized based on remote sensing images and spatial relationships, and the environmental characteristics around the point sources are judged through remote sensing images to obtain sewage information; the spatial relationship between point source pollution and the river channel is established using the geographic information system, and the nearest neighbor point in the river channel is selected as the sewage outlet according to the distance; S23: Determine the river section code corresponding to the location of the point source pollution sewage outlet, form a relationship matrix, and obtain the point source pollution matrix;

[0037] S3: According to the tree-like river network area, non-point source pollution statistics are carried out according to the administrative division level to obtain the non-point source pollution relationship set;

[0038] Specifically, step S3 includes: taking the required administrative division level as a unit for non-point source pollution statistics, and constructing a non-point source pollution-sewage outlet-river relationship set according to the sewage outlet setting rules of non-point source pollution; specifically including: S31: according to the tree-like river network area, the administrative area and the river network are superimposed to obtain the spatial relationship between the administrative unit and the river; S32: according to the spatial relationship between the administrative unit and the river, the administrative unit with the river flowing through is recorded as "yes"; the administrative unit without the river flowing through is recorded as "no"; S33: the administrative unit recorded as "yes" is regarded as the source of non-point source pollution, and the non-point source pollution is converted into the point source input format by adopting the method of river channel generalization, and the discharge outlet position is uniformly set to obtain the non-point source pollution relationship set;

[0039] Specifically, step S33 includes: taking the administrative unit recorded as "yes" as the source of non-point source pollution; when the administrative unit does not contain the source of the river and only has a single tributary or main stream flowing through it, it is evenly segmented and coded according to the distance of the river flowing through the administrative unit, and the center point of each sub-segment is set as the pollution discharge port to obtain the first non-point source pollution inflow generalization set; when the administrative unit contains the source of the river and only has a single tributary or main stream flowing through it, the administrative unit is divided, and the area without the river flowing through it is segmented as a whole to flow into the river, and the river source is used as the discharge port; for the area where the river flows through, the method of average segmentation along the river is used to determine the pollution inflow path, and the center point of each sub-segment is set as the pollution discharge port; each segment is uniformly coded and integrated to obtain the second non-point source pollution inflow generalization set; when the administrative unit does not contain the source of the river and has multiple tributaries or main stream flows through, the tributaries or main streams are evenly segmented and coded according to the length of each tributary or main stream, and the center point of each sub-segment is set as the pollution discharge port, and the third non-point source pollution inflow generalization set is obtained after aggregation; when the administrative unit contains the source of the river and there are multiple tributaries or main streams flowing through, the part above the source is taken as a whole to flow into the river section, and the river source is taken as the discharge port location; the part through which multiple tributaries or main streams flow is segmented and coded respectively by the average distribution method, and the discharge port is set at the center point of the sub-segment, and the fourth non-point source pollution inflow generalization set is obtained after aggregation; the first non-point source pollution inflow generalization set, the second non-point source pollution inflow generalization set, the third non-point source pollution inflow generalization set and the fourth non-point source pollution inflow generalization set are integrated to obtain the non-point source pollution relationship set; the non-point source pollution relationship set includes the relationship between non-point source pollution, discharge ports and corresponding river sections;

[0040] S4: According to the watershed information, the river section location of the key water quality monitoring area is obtained, and according to the river section location of the key water quality monitoring area, the source tracing target set is obtained;

[0041] Specifically, the key water quality monitoring areas include control sections and water sources; the source tracing target set includes the geographical location, river section code, and water quality monitoring parameters of the key water quality monitoring areas;

[0042] S5: According to the source tracing target set and the topological structure of the tree-like river network area, carry out pollution source tracing step by step and section by section to obtain the relationship between the source tracing target and the pollution source;

[0043] Specifically, step S5 includes: S51: according to the source tracing target set and the topological structure of the tree-like river network area, the river channel is traced and recorded step by step from downstream to upstream to obtain the river section code; S52: according to the river section code, point source pollution matrix and non-point source pollution relationship set, the pollution transmission path, sewage outlet and potential pollution source are tracked, and the sewage outlet positions of point source and non-point source pollution are traced back in turn according to the river section code, recorded and screened to obtain the screening result; S53: according to the screening result, according to the relationship between the point and non-point source sewage outlets and the administrative unit, the administrative unit of pollution emission is obtained; according to the administrative unit of pollution emission and the source tracing target set, the relationship between the source tracing target and the pollution source is obtained;

[0044] S6: Based on the environmental statistical data, the relationship between the source tracing target and the pollution source, and the non-point source pollution relationship set, the pollution sources affecting the target section are collected and the discharge and river discharge of point source pollution and non-point source pollution are calculated respectively to obtain the candidate pollution source library;

[0045] Specifically, step S6 includes: S61: according to environmental statistical data and the relationship between tracing targets and pollution sources, the pollution production and emission coefficient method is used to calculate the point source pollution emissions and non-point source pollution emissions; S62: according to the point source pollution emissions, the preset point source pollution inflow coefficient is selected in the form of direct emissions and indirect emissions to calculate and obtain the point source pollution inflow into the river; S63: according to the non-point source pollution emissions and the non-point source pollution relationship set, the corresponding preset non-point pollution inflow coefficient is selected for different types of non-point pollution sources, and the pollution inflow into the river is selected according to the generalization of the river channel of non-point source pollution. Calculation method: When the administrative unit that is the source of non-point source pollution does not contain the source of the river and only has a single tributary or main stream flowing through it, the pollution emissions are evenly distributed according to the number of segments, and the pollution inflows into the river are calculated in the form of sub-segments to obtain the first non-point source pollution inflow into the river; when the administrative unit that is the source of non-point source pollution contains the source of the river and only has a single tributary or main stream flowing through it, the area ratio of the administrative unit above the source is obtained, the pollution emissions are distributed according to the area ratio method, and the inflows into the river are calculated as a whole; for the remaining part, the pollution emissions are evenly distributed according to the number of segments, and the pollution inflows into the river are calculated in the form of sub-segments. The second non-point source pollution inflow into the river is calculated by the formula respectively; when the administrative unit as the non-point source pollution source does not contain the river source and has multiple tributaries or main streams flowing through, the pollution emissions are first evenly distributed according to the number of tributaries or main streams, and then the pollution inflow into the river is evenly distributed according to the number of corresponding tributaries or main stream sections to obtain the third non-point source pollution inflow into the river; when the administrative unit as the non-point source pollution source contains the river source and has multiple tributaries or main streams flowing through, the pollution emissions are first evenly distributed according to the number of tributaries or main streams; then, for the administrative unit containing the source tributaries or main streams, the pollution emissions are evenly distributed according to the number of tributaries or main streams; The pollution discharge of the area above the source is distributed according to the area proportion method, and its discharge into the river is calculated as a whole; finally, the pollution discharge of the remaining river channels is evenly distributed according to the number of sections, and the pollution discharge into the river channels is calculated in the form of sub-sections to obtain the fourth non-point source pollution discharge into the river; the non-point source pollution discharge into the river is obtained according to the first non-point source pollution discharge into the river, the second non-point source pollution discharge into the river, the third non-point source pollution discharge into the river and the fourth non-point source pollution discharge into the river; the alternative pollution source library is obtained according to the point source pollution discharge, non-point source pollution discharge, point source pollution discharge into the river and non-point source pollution discharge into the river;

[0046] S7: According to the distance and flow rate between the candidate pollution source library and the target section, the remaining pollution amount and the pollution source contribution rate of the pollution source reaching the target section are calculated to obtain a refined pollution source tracing list;

[0047] Specifically, step S7 includes: according to the candidate pollution source library, considering the two specific factors of distance and flow rate that affect the amount of pollutant reduction, based on the comprehensive attenuation coefficient of the river, calculating the pollution residual amount of the pollution source reaching the target section; combining the total pollution flux, calculating the pollution source contribution rate, forming a pollution contribution rate list of specific tracing targets, and obtaining a refined pollution tracing list, such as the formula:

[0048]

[0049] Among them, W is the remaining amount of pollution source reaching the target section, W in is the amount of pollution entering the river, K is the comprehensive attenuation coefficient of a certain pollutant, X is the length of the pollution source from the sewage outlet to the target section; u is the flow rate of the river, M ps is the contribution rate of point source pollution to the target section, W ps is the amount of point source pollution entering the river, c is the pollutant concentration in the target section, q is the flow rate in the target section, M nps is the contribution rate of the surface source to the target section, W nps is the inflow of surface sources.

[0050] In some embodiments, the above-mentioned method for rapid quantitative tracing of water pollution in a tree-like river network area can also be implemented in the following manner.

[0051] This example will take the Minjiang River Basin as an example to propose a rapid quantitative tracing method for water pollution in a tree-like river network area, including the following steps:

[0052] S01. Collect watershed information and construct a tree-like river network area:

[0053] Determine the administrative division scope of the basin through investigation and statistics; collect DEM and river data, use GIS software to extract the river network of the basin, establish the upstream and downstream relationship of the river network, and encode the river sections; the river section encoding process includes: determine the direction of the river, and encode the labels from small to large from upstream to downstream and from tributaries to the main stream; in this example, the basin scope of the Minjiang River is determined through field investigation and statistics in Chengdu, Deyang, Mianyang and other places, and ArcGIS software is used to extract river network information from the collected basin DEM and river vector data to generate the river network map of the Minjiang River; analyze the upstream and downstream relationship of the Minjiang River, and encode the river sections from upstream to downstream and from tributaries to the main stream;

[0054] S02. Establish point source pollution matrix:

[0055] Determine the number and location of point sources based on the collected point source pollution information, correspond point source pollution to sewage outlets one by one according to the emission pathway, and construct a point source pollution-sewage outlet-river channel relationship matrix based on the river section code to which the sewage outlet belongs; Step S02 specifically includes: S021, determine the number and location of point source pollution and sewage outlets based on environmental statistical data, enterprise information forms, survey data and other relevant information; S022, determine the emission method of point source pollution based on the matching relationship, correspond its location to the actual sewage outlet into the river one by one, and obtain a point source pollution-sewage outlet relationship table; Among them, the point sources that are difficult to match the sewage outlet are generalized based on remote sensing images and spatial relationships: judge the environmental characteristics around the point source through remote sensing images, and obtain the sewage outlet. Then, the spatial relationship between point source pollution and the river is established by using GIS tools, and the nearest neighbor point in the river is selected as the sewage outlet according to the distance. In this embodiment, environmental statistical data in the Minjiang River Basin, information forms reported by enterprises, and point source pollution data and sewage outlet information of factories, sewage treatment plants, large-scale livestock and poultry breeding, etc. are collected in the survey data to determine their quantity and geographical location. For point source pollution with sewage outlet information, the pollution source is matched with the sewage outlet location to construct a point source pollution-sewage outlet relationship table. For point source pollution with missing sewage outlet information, the environmental characteristics of the surrounding area are judged by remote sensing images, and then the distance between the pollution source and the river is calculated by using GIS tools, and the nearest neighbor point is selected as the sewage outlet location.

[0056] S03. Establish a non-point source pollution relationship set:

[0057] The non-point source pollution is counted at the required administrative level, and the relationship set of non-point source pollution-sewage outlet-river is constructed according to the sewage outlet setting rules of the non-point source pollution; step S03 specifically includes: S031, non-point source pollution is counted at the required administrative level, and the administrative area and the river network are superimposed to obtain the spatial relationship between the administrative unit and the river; S032, the spatial relationship is judged, and the administrative unit with the river flowing through is recorded as "yes"; the administrative unit without the river flowing through is recorded as "no"; S033, the administrative unit recorded as "yes" "The administrative unit is taken as the source of non-point source pollution. The method of river channel generalization is used to convert non-point source pollution into point source inflow format, and the location of the discharge port is uniformly set: the first type does not include the river source and only a single tributary or main stream flows through; in this case, the distance of the river flowing through the administrative unit is evenly segmented and coded, and the center point of each sub-segment is set as the pollution discharge port to obtain a generalized set of non-point source pollution inflows; the second type includes the river source and only a single tributary or main stream flows through; in this case, the administrative unit needs to be segmented, and no river flows through The region as a whole is divided into sections and flows into the river, with the source of the river as the discharge port; the area through which the river flows is divided into sections along the river to determine the pollution inflow path, and the center point of each sub-segment is set as the pollution discharge port; the above sections are uniformly coded and integrated to form a generalized set of non-point source pollution based on administrative units; the third type does not include the source of the river and has multiple tributaries or main streams flowing through; in this case, the sections are evenly segmented and coded according to the length of each tributary or main stream, and the center point of each sub-segment is set as the pollution discharge port, which is summarized to form a generalized set of non-point source pollution based on administrative units. The fourth type includes the source of the river and multiple tributaries or main streams flowing through it. In this case, the part above the source is taken as a whole and merged into the river section, and the source of the river is taken as the discharge port location. The part through which multiple tributaries or main streams flow is segmented and coded respectively by the average distribution method, and the discharge port is set at the center point of the sub-segment, and finally summarized into the generalized set of non-point source pollution based on administrative units. S034. The generalized results of different administrative units are integrated to obtain the relationship set of non-point source pollution, discharge ports and corresponding river sections. Figure 2 The figure shows a schematic diagram of the generalization of non-point source pollution in this embodiment. In this example, the non-point source pollution data such as agricultural life sources, urban life sources, and agricultural planting sources are counted in the Minjiang River Basin with county-level cities as units; the position relationship of the administrative districts through which the Minjiang River flows is obtained based on the superposition results of the county-level administrative divisions and the river network data; the relationship between the non-point source pollution in the Minjiang River Basin and the river section is determined based on the method of generalizing the river channel; wherein, for the administrative divisions including the source, the source is set as the sewage outlet; the part through which the tributary or main stream flows is segmented by an average distribution method, and in the Minjiang River example, an average division of 15 to 30 sections is adopted, and the center point of the river section adjacent to the river bank is taken as the sewage outlet position; according to the above setting results, the relationship set of non-point source pollution-sewage outlet-river channel in the Minjiang River Basin is sorted out;

[0058] S04. Construct a source tracing target set for key water quality monitoring areas including control sections and water sources:

[0059] According to the river section location of key water quality monitoring areas such as control sections and water sources, a source tracing target set including the geographical location of the monitoring area, river section code, water quality monitoring parameters and other information is constructed according to the river basin information identification control sections, water sources and other key water quality monitoring areas. In this embodiment, the geographical location, river section code, water quality monitoring parameters and other information of the three excessive sections of Simeng River Estuary, Mangxi Bridge and Liangheshui in the Minjiang River Basin are mainly obtained, and the Minjiang River Basin source tracing target set containing the above information is established.

[0060] S05. Establish the relationship between traceability targets and pollution sources:

[0061] According to the topological structure of the tree-like river network area, carry out pollution source tracing step by step and section by section, track the pollution transmission path, sewage outlets and potential pollution sources, and use GIS tools to draw a generalized map of pollution source-tracing target; Step S05 specifically includes: S051, according to the geographical location of the control section and water source in the tracing target set, the river channel is traced step by step from downstream to upstream, and the river section code is recorded; S052, according to the river section code, the sewage outlet locations of point source and non-point source pollution are traced back in turn, and the screening results are recorded; S053, according to the relationship between the point and non-point source sewage outlets and administrative units, the administrative unit of pollution emission is obtained; in this example, according to the topological structure of the tree-like river network area in the Minjiang River Basin, the geographical location of the control section and water source in the tracing target set of the Minjiang River Basin is traced back step by step, and the river section code is recorded; according to the river section code, the sewage outlet locations of the point source and non-point source and the administrative division to which they belong are traced, and finally all the screening results of pollution sources under different tracing targets are formed;

[0062] S06. Establish a database of alternative pollution sources:

[0063] According to the set of pollution sources affecting the target section, the pollution emissions and river discharges of relevant point sources and non-point sources are counted and calculated respectively, and an alternative pollution source library is established; step S06 specifically includes: S061, using environmental statistical data and the pollution production and emission coefficient method to calculate the pollution emissions of point sources and non-point sources respectively; S062, calculating the pollution discharge into the river in the form of direct and indirect discharge for point sources; S063, according to the different generalization situations of river channels with non-point source pollution, select the corresponding method of calculating the pollution discharge into the river: the first method is the method of calculating the pollution discharge into the river when the river source is not included and only a single tributary or main stream flows through; according to the number of sections The first method is to evenly distribute the pollution emissions and calculate the pollution entering the river in the form of sub-segments; the second method is to calculate the pollution entering the river for a river that contains the source and has only a single tributary or main stream flowing through it; the area ratio of the administrative units above the source is obtained, the pollution emissions are distributed according to the area ratio method, and the pollution entering the river is calculated as a whole; the pollution emissions are evenly distributed for the remaining part according to the number of segments, and the pollution entering the river is calculated in the form of sub-segments; the third method is to calculate the pollution entering the river for a river that does not contain the source and has multiple tributaries or main streams flowing through it; first, the pollution emissions are evenly distributed according to the number of tributaries or main streams; second, according to The pollution inflow into the river is evenly distributed according to the number of tributaries or main stream sections; the fourth type is to calculate the pollution inflow into the river that contains the source of the river and has multiple tributaries or main streams flowing through; first, the pollution emissions are evenly distributed according to the number of tributaries or main streams; secondly, for the administrative units containing the source tributaries or main streams, the pollution emissions in the areas above the source are distributed according to the area ratio method, and the pollution inflow into the river is calculated as a whole; finally, the pollution emissions are evenly distributed for the remaining rivers according to the number of sections, and the pollution amounts flowing into the river are calculated in the form of sub-segments; in this embodiment, environmental statistical data and the pollution generation and emission coefficient method are used to generalize the pollution from different sources. The pollution discharge of point sources and non-point sources in the Minjiang River Basin is calculated respectively according to the situation; then the corresponding pollution discharge coefficient is selected according to the relationship between direct and indirect discharge of point source pollution; in this embodiment, the river discharge coefficient of 0.9 is selected for the point source of indirect discharge in the Minjiang River Basin; the river discharge coefficient of 0.5 is selected for the point source of direct discharge considering the infiltration and degradation effect in the process of entering the environmental water body; for non-point source pollution, the literature review method is used to determine that the pollution discharge coefficients of urban living sources, rural living sources, livestock and poultry breeding sources, and agricultural planting sources in the Minjiang River Basin are 0.75, 0.6, 0.5 and 0.4 respectively, and the river discharge of different types of non-point source pollution is calculated;

[0064] S07. Calculate the pollution contribution rate and form a refined pollution source traceability list:

[0065] Considering the two specific factors of distance and flow velocity that affect the amount of pollutant reduction, based on the comprehensive attenuation coefficient of the river, a calculation formula for the pollution residual when the pollution source reaches the target section is established, and the pollution source contribution rate is calculated in combination with the total pollution flux, and finally a pollution contribution rate list for specific tracing targets is formed; the pollution residual calculation equation is:

[0066]

[0067] Where W is the remaining amount of pollution source reaching the target section; W in is the amount of pollution entering the river; k is the comprehensive attenuation coefficient of a certain pollutant; X is the length of the pollution source from the sewage outlet to the target section; u is the flow rate of the river;

[0068] The calculation method of pollution contribution rate is:

[0069]

[0070] Among them, M ps is the contribution rate of the point source to the target section; W ps is the inflow of the point source; c is the pollutant concentration of the target section; q is the flow rate of the target section; M nps is the contribution rate of the surface source to the target section; W nps is the inflow of surface sources;

[0071] In this embodiment, the comprehensive attenuation coefficient of the Minjiang River Basin is determined according to the literature method and the field investigation method, and the pollution residual amount and contribution rate in each water quality section are calculated according to the pollution residual amount and contribution rate equation; finally, a list of contribution rates of water quality sections exceeding the standard for different pollution sources and administrative divisions is constructed based on the calculation results;

[0072] To further demonstrate the effectiveness of this method, this example compares the analytical results of the rapid quantitative source tracing method for water pollution in the Minjiang River Basin with the results of the conventional source analysis method - absolute principal component-multivariate linear regression model. Figure 3 The figure shows the comparison of the pollutant contribution calculation results of the two source analysis methods of this embodiment to the cross section of Mangxi Bridge. Figure 4 The figure shows the comparison of the pollutant contribution calculation results of the two source analysis methods in this embodiment for the Simong River estuary section. Figure 5 Shown is a comparison chart of the calculation results of pollutant contributions of two source analysis methods of the present embodiment for two combined water sections; the results show that the rapid quantitative source tracing method for water pollution in the tree-like river network area adopted in the present embodiment has achieved good analysis effect, and has a complementary relationship with the conventional method, indicating that the invented rapid quantitative source tracing method for water pollution in the tree-like river network area has certain feasibility and innovation.

[0073] This embodiment provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above-mentioned method for rapid quantitative tracing of water pollution in a tree-like river network area are implemented. Among them, the storage medium can be a disk, an optical disk, a read-only memory (ROM), a random access memory (RAM), a flash memory, a hard disk drive (HDD) or a solid-state drive (SSD), etc.; the storage medium can also include a combination of the above-mentioned types of memory.

[0074] This embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps of the above-mentioned method for rapid quantitative tracing of water pollution in a tree-like river network area are implemented.

[0075] like Figure 6 As shown, the computer device may include: at least one processor 121, such as a CPU (Central Processing Unit), at least one communication interface 123, a memory 124, and at least one communication bus 122. Among them, the communication bus 122 is used to realize the connection and communication between these components. Among them, the communication interface 123 may include a display screen (Display), a keyboard (Keyboard), and the optional communication interface 123 may also include a standard wired interface and a wireless interface. The memory 124 may be a high-speed RAM memory (Random Access Memory, volatile random access memory) or a non-volatile memory (non-volatile memory), such as at least one disk memory. The memory 124 may also be at least one storage device located away from the aforementioned processor 121. Among them, the memory 124 stores an application program, and the processor 121 calls the program code stored in the memory 124 to perform any of the above method steps. Among them, the communication bus 122 may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The communication bus 122 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 6Only one line is used to represent it, but it does not mean that there is only one bus or one type of bus. Among them, the memory 124 may include a volatile memory (English: volatile memory), such as a random access memory (English: random-access memory, abbreviated: RAM); the memory may also include a non-volatile memory (English: non-volatile memory), such as a flash memory (English: flash memory), a hard disk drive (English: hard disk drive, abbreviated: HDD) or a solid-state drive (English: solid-state drive, abbreviated: SSD); the memory 124 may also include a combination of the above-mentioned types of memory. Among them, the processor 121 may be a central processing unit (English: central processing unit, abbreviated: CPU), a network processor (English: network processor, abbreviated: NP) or a combination of CPU and NP. Among them, the processor 121 may further include a hardware chip. The above-mentioned hardware chip may be an application-specific integrated circuit (English: application-specific integrated circuit, abbreviated: ASIC), a programmable logic device (English: programmable logic device, abbreviated: PLD) or a combination thereof. The PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. Optionally, the memory 124 is also used to store program instructions. The processor 121 can call program instructions to implement the water pollution rapid quantitative source tracing method in the tree-like river network area of ​​the present embodiment.

[0076] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A method for rapid quantitative tracing of water pollution in a tree-like river network area, characterized in that: The following steps are involved: S1: Acquire watershed information, and perform river channel coding according to the watershed information to obtain a tree-like river network area; S2: obtaining point source pollution information, and obtaining a point source pollution matrix according to the point source pollution information and the tree-like river network area; S3: According to the tree-like river network area, non-point source pollution statistics are performed according to the administrative division level to obtain a non-point source pollution relationship set; S4: obtaining the river section location of the key water quality monitoring area according to the river basin information, and obtaining the source tracing target set according to the river section location of the key water quality monitoring area; S5: According to the tracing target set and the topological structure of the tree-like river network area, pollution tracing is carried out step by step and section by section to obtain the relationship between the tracing target and the pollution source; S6: According to the environmental statistical data, the relationship between the source tracing target and the pollution source, and the non-point source pollution relationship set, the pollution sources affecting the target section are collected and the discharge and river discharge of point source pollution and non-point source pollution are calculated respectively, so as to obtain a candidate pollution source library; S7: Based on the distance and flow rate between the candidate pollution source library and the target section, the remaining pollution amount and the pollution source contribution rate when the pollution source reaches the target section are calculated to obtain a refined pollution source tracing list.

2. The method for rapid quantitative tracing of water pollution in a tree-like river network area according to claim 1 is characterized in that: The watershed information includes the administrative division scope, digital elevation model, river data, and river network contained in the watershed; the river channel coding includes: determining the direction of the river, and coding labels from upstream to downstream and from tributaries to main stream in order from small to large; the point source pollution information includes the number and location of point source pollution and the number and location of sewage outlets; the point source pollution matrix is ​​a relationship matrix of point source pollution-sewage outlets-river channels; the key water quality monitoring area includes control sections and water sources; the tracing target set includes the geographical location of the key water quality monitoring area, river section code, and water quality monitoring parameters.

3. The method for rapid quantitative tracing of water pollution in a tree-like river network area according to claim 1 is characterized in that: Step S2 specifically includes: S21: Obtain point source pollution information based on environmental statistical data, enterprise information forms, and survey data, wherein the point source pollution information includes the number and location of point source pollution and the number and location of sewage outlets; S22: According to the point source pollution information and the tree-like river network area, the statistical point source emission pathways are matched one by one with the actual sewage outlets into the river according to the matching relationship, and a relationship table of point source pollution-sewage outlets is obtained; wherein, the point sources that are difficult to match with the sewage outlets are generalized based on remote sensing images and spatial relationships, and the environmental characteristics around the point sources are judged through remote sensing images to obtain sewage information; the spatial relationship between point source pollution and the river channel is established by using a geographic information system, and the nearest neighbor point in the river channel is selected as the sewage outlet according to the distance; S23: Determine the river section code corresponding to the location of the point source pollution discharge outlet, form a relationship matrix, and obtain a point source pollution matrix.

4. The method for rapid quantitative tracing of water pollution in a tree-like river network area according to claim 1 is characterized in that: Step S3 specifically includes: S31: According to the tree-like river network area, the administrative area and the river network are superimposed to obtain the spatial relationship between the administrative unit and the river; S32: According to the spatial relationship between the administrative unit and the river, the administrative unit with the river flowing through is recorded as "yes"; the administrative unit without the river flowing through is recorded as "no"; S33: The administrative units recorded as "yes" are regarded as the sources of non-point source pollution. The non-point source pollution is converted into a point source inflow format by using the river channel generalization method. The locations of the discharge outlets are uniformly set to obtain the non-point source pollution relationship set.

5. The method for rapid quantitative tracing of water pollution in a tree-like river network area according to claim 4 is characterized in that: Step S33 specifically includes: taking the administrative unit recorded as "yes" as the source of non-point source pollution, When the administrative unit does not contain the source of the river and only has a single tributary or main stream flowing through it, it is evenly segmented and coded according to the distance the river flows through the administrative unit, and the center point of each sub-segment is set as the pollution discharge port to obtain the first non-point source pollution inflow generalization set; When the administrative unit contains a river source and only a single tributary or main stream flows through it, the administrative unit is divided, and the area without the river flowing through it is divided into sections as a whole and flows into the river, with the river source as the discharge port; the area where the river flows through is determined by the average segmentation method along the river to determine the pollution inflow path, and the center point of each sub-segment is set as the pollution discharge port; each segment is uniformly coded and integrated to obtain the second non-point source pollution inflow generalization set; When the administrative unit does not contain the source of the river and has multiple tributaries or main streams flowing through it, the tributaries or main streams are evenly segmented and coded according to their lengths, and the center point of each sub-segment is set as the pollution discharge port, and the third non-point source pollution inflow generalization set is obtained after aggregation; When the administrative unit contains a river source and has multiple tributaries or main streams flowing through it, the part above the source is merged into the river section as a whole, and the river source is used as the discharge port location; the part through which multiple tributaries or main streams flow is segmented and coded respectively using the average distribution method, and the discharge port is set at the center point of the sub-segment, and the fourth non-point source pollution inflow generalization set is obtained after aggregation; Integrate the first non-point source pollution inflow generalization set, the second non-point source pollution inflow generalization set, the third non-point source pollution inflow generalization set, and the fourth non-point source pollution inflow generalization set to obtain a non-point source pollution relationship set; The non-point source pollution relationship set includes the relationship between non-point source pollution, discharge outlets and corresponding river sections.

6. The method for rapid quantitative tracing of water pollution in a tree-like river network area according to claim 1 is characterized in that: Step S5 specifically includes: S51: According to the source tracing target set and the topological structure of the tree-like river network area, the river channel is traced back and recorded step by step and section by section from downstream to upstream to obtain the river section code; S52: According to the river section code, the point source pollution matrix and the non-point source pollution relationship set, the pollution transmission path, the sewage outlet and the potential pollution source are tracked, and the locations of the sewage outlets of the point source and non-point source pollution are traced back in sequence according to the river section code, recorded and screened to obtain the screening results; S53: According to the screening results, the administrative unit of pollution emission is obtained according to the relationship between the point and surface source discharge outlets and the administrative unit; according to the administrative unit of pollution emission and the tracing target set, the relationship between the tracing target and the pollution source is obtained.

7. The method for rapid quantitative tracing of water pollution in a tree-like river network area according to claim 1 is characterized in that: Step S6 specifically includes: S61: Based on environmental statistical data and the relationship between the source tracing target and the pollution source, the emission of point source pollution and non-point source pollution are calculated using the pollution production and emission coefficient method; S62: According to the point source pollution discharge, a preset point source pollution inflow coefficient is selected for calculation in the form of direct discharge and indirect discharge to obtain the point source pollution inflow into the river; S63: According to the non-point source pollution emission and the non-point source pollution relationship set, select corresponding preset non-point pollution inflow coefficients for different non-point pollution source types, and select a method for calculating the pollution inflow according to the generalized river channel of non-point source pollution: When the administrative unit that is the source of non-point source pollution does not contain the source of the river and only has a single tributary or main stream flowing through it, the pollution discharge is evenly distributed according to the number of segments, and the pollution discharge into the river is calculated in the form of sub-segments to obtain the first non-point source pollution discharge into the river; When the administrative unit that is the source of non-point source pollution includes the source of the river and only has a single tributary or main stream flowing through it, the area ratio of the administrative unit above the source is obtained, the pollution emissions are allocated according to the area ratio method, and the amount of pollution entering the river is calculated as a whole; the pollution emissions are evenly distributed for the remaining part according to the number of segments, and the pollution amount entering the river is calculated in the form of sub-segments to obtain the second non-point source pollution entering the river; When the administrative unit that is the source of non-point source pollution does not contain the source of the river and has multiple tributaries or main streams flowing through it, the pollution discharge is first evenly distributed according to the number of tributaries or main streams, and then the pollution inflow into the river is evenly distributed according to the number of corresponding tributaries or main stream sections to obtain the third non-point source pollution inflow into the river; When the administrative unit that is the source of non-point source pollution contains the source of the river and has multiple tributaries or main streams flowing through it, the pollution emissions are first evenly distributed according to the number of tributaries or main streams; then, for the administrative unit containing the source tributaries or main streams, the pollution emissions of the area above the source are distributed according to the area ratio method, and the amount of pollution entering the river is calculated as a whole; finally, the pollution emissions of the remaining rivers are evenly distributed according to the number of sections, and the pollution amount entering the river is calculated in the form of sub-segments, and the fourth non-point source pollution inflow into the river is obtained; Obtaining the amount of non-point source pollution entering the river according to the first amount of non-point source pollution entering the river, the second amount of non-point source pollution entering the river, the third amount of non-point source pollution entering the river, and the fourth amount of non-point source pollution entering the river; A library of alternative pollution sources is obtained based on the point source pollution emissions, non-point source pollution emissions, point source pollution inflow into rivers, and non-point source pollution inflow into rivers.

8. The method for rapid quantitative tracing of water pollution in a tree-like river network area according to claim 1 is characterized in that: Step S7 specifically includes: according to the candidate pollution source library, considering two specific factors that affect the amount of pollutant reduction, namely distance and flow rate, and calculating the remaining amount of pollution when the pollution source reaches the target section based on the comprehensive attenuation coefficient of the river; combining the total pollution flux, calculating the pollution source contribution rate, forming a pollution contribution rate list for a specific tracing target, and obtaining a refined pollution tracing list, such as the formula: Among them, W is the remaining amount of pollution source reaching the target section, W in is the amount of pollution entering the river, K is the comprehensive attenuation coefficient of a certain pollutant, X is the length of the pollution source from the sewage outlet to the target section; u is the flow rate of the river, M ps is the contribution rate of point source pollution to the target section, W ps is the amount of point source pollution entering the river, c is the pollutant concentration in the target section, q is the flow rate in the target section, M nps is the contribution rate of the surface source to the target section, W nps is the inflow of surface sources.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for rapid quantitative tracing of water pollution in a tree-like river network area as described in any one of claims 1 to 8 are implemented.

10. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the method for rapid quantitative tracing of water pollution in any tree-like river network area as described in claims 1-8 are implemented.

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