A method and device for pollution source tracing of rainwater outlets

Abstract

A pollution source tracing method and device for a rainwater drainage outlet, which relates to the technical field of computer-aided pollution source tracing. A pollution source tracing method for a rainwater drainage outlet includes the following steps: obtaining pipe network data and first drainage outlet data; determining monitoring factors according to the first drainage outlet data; determining an encrypted monitoring area according to the pipe network data and the monitoring factors, and obtaining the coordinates of the pollution source; obtaining the pollution source data corresponding to the coordinates of the pollution source and second drainage outlet data; calculating the pollution load of the pollution source and the pollution load of the drainage outlet according to the pollution source data and the second drainage outlet data; calculating the determination coefficient between the pollution source and the drainage outlet according to the pollution load of the pollution source and the pollution load of the drainage outlet, and judging whether the source tracing is completed according to the determination coefficient. This application calculates the determination coefficient between the pollution source and the drainage outlet to determine the correlation between the pollution load of the pollution source and the pollution load of the rainwater drainage outlet, and solves the problem that the current sewage source tracing method cannot verify the accuracy of the results.

Description

Technical Field

[0001] The present invention belongs to the technical field of computer-aided pollution source tracing, and particularly relates to a method and device for pollution source tracing of rainwater outlets. Background Art

[0002] Urban rainwater pipe networks are an important part of the urban drainage system, mainly used for collecting and discharging rainwater runoff in the city, including rainwater inlets for collecting rainwater on the ground, branch pipes and main pipes for transporting rainwater, and rainwater outlets for discharging the collected rainwater into rivers and lakes. Their operating status directly affects the flood control and drainage capacity of the city, the quality of residents' lives, and the ecological environment.

[0003] However, at present, urban rainwater pipe networks are facing many challenges. For example, due to serious aging, insufficient design standards, inadequate maintenance management, and rain-sewage combined drainage problems, there are still a large number of functional defects such as blockage, sediment accumulation, and full pipe flow, as well as structural defects such as rain-sewage mixed connection in the drainage pipe network, resulting in a large amount of pollutants being directly discharged into water bodies, and thus frequent problems of urban water body blackening and odoring.

[0004] Existing pollution source tracing methods for rainwater outlets mainly include: manual investigation and tracing, that is, tracing is carried out by technicians observing or sampling and analyzing one by one by opening manhole covers on site; pipeline detection equipment tracing, that is, mainly using equipment such as closed-circuit television monitoring systems, pipeline periscopes, sonars, and ground-penetrating radars to comprehensively detect pipelines; and computer-aided tracing, etc.

[0005] For example, Chinese Patent with publication number CN113947033B discloses an artificial intelligence-based pollution source tracing system and method for drainage pipe networks. The method steps include: distributing monitoring points in the drainage pipe network and obtaining pollutant concentration value data monitored at the monitoring points; a pollutant simulation operation module, according to the pollutant concentration value data, simulating the state of pollutants in the drainage pipe through the SWMM simulator to obtain a simulation result; the drainage pipe network pollution analysis module, processing the data in the drainage pipe network to obtain the flow direction with the maximum pollution concentration in the drainage pipe network; a sewage flow direction processing module, obtaining the pollutant concentration value data closest to the sewage treatment plant, and predicting the pollutant concentration value data when the drainage flows into the sewage treatment plant; it uses the method of machine learning decision trees to classify the flow direction of the maximum pollutants in the drainage pipe network, realizing the full-automatic prediction and classification analysis of the drainage pipe network without manual intervention.

[0006] However, current sewage source tracing methods do not verify the accuracy of the results. For example, when there are multiple pollutants in the pipe network, it is easy to miss pollution sources, resulting in poor accuracy of the tracing results and reliability of the tracing methods.

[0007] Therefore, it is urgent to develop a pollution source tracing method for rainwater outlets to solve the problems in the existing technology. Summary of the Invention

[0008] The purpose of the present invention is to provide a pollution source tracing method for rainwater outlets. By calculating the determination coefficient between the pollution source and the outlet, the correlation between the pollution source and the rainwater outlet is compared to solve the problem of poor tracing accuracy and reliability caused by the lack of verification of the result accuracy in the current sewage source tracing method as proposed in the above background technology.

[0009] To solve the above technical problems, the specific technical solution of the present invention is as follows:

[0010] A pollution source tracing method for rainwater outlets includes the following steps:

[0011] Obtain pipe network data and first outlet data;

[0012] Determine the monitoring factors according to the first outlet data;

[0013] Determine the encrypted monitoring area according to the pipe network data and the monitoring factors, and obtain the coordinates of the pollution source;

[0014] Obtain the pollution source data corresponding to the coordinates of the pollution source and the second outlet data;

[0015] Calculate the pollution load of the pollution source and the pollution load of the outlet according to the pollution source data and the second outlet data;

[0016] Calculate the determination coefficient between the pollution source and the outlet according to the pollution load of the pollution source and the pollution load of the outlet, and determine whether the source tracing is completed according to the determination coefficient.

[0017] Furthermore, the pollution load is calculated by the following formula:

[0018] ;

[0019] Wherein, is the pollution load, with the unit of t / d; is the discharge flow rate, with the unit of m³ / s; is the concentration of the monitoring factor, with the unit of mg / L;

[0020] The determination coefficient is calculated by the following formula:

[0021] ;

[0022] Wherein, is the determination coefficient, is the pollution load of the pollution source in the i-th time period; is the pollution load of the outlet corresponding to the time period corresponding to the i-th time period of the pollution source; is the average pollution load of the pollution source in n time periods.

[0023] Furthermore, it also includes:

[0024] Before calculating the determination coefficient between the pollution source and the outfall, it also includes calculating the relative error;

[0025] Among them, the calculation formula of the relative error is as follows:

[0026] ;

[0027] Among them, is the relative error, is the pollution load of the pollution source, is the pollution load of the outfall.

[0028] Furthermore, the determining the monitoring factors according to the first outfall data includes the following steps:

[0029] Determine the pollution factors according to the first outfall data;

[0030] When there is only one pollution factor, the monitoring factor is the pollution factor;

[0031] When there are multiple pollution factors, the monitoring factors are determined by the optimization selection index of the pollution factors;

[0032] Among them, the optimization selection index is calculated by the following formula:

[0033] ;

[0034] Among them, is the optimization selection index of the i-th pollution factor, is the concentration of the i-th pollution factor, is the discharge flow of the i-th pollution factor, is the river flow or related normalization factor, is the related adjustment coefficient.

[0035] Furthermore, the determining the encrypted monitoring area and obtaining the coordinates of the pollution source according to the pipeline network data and the monitoring factors includes the following steps:

[0036] Obtain the monitoring factor data of the key nodes;

[0037] Calculate the concentration change rate of the monitoring factors;

[0038] Determine the encrypted monitoring area according to the concentration change rate of the monitoring factors;

[0039] Obtain the area monitoring data of the encrypted monitoring area.

[0040] Further, the steps of determining the encrypted monitoring area based on the pipe network data and monitoring factors and obtaining the coordinates of the pollution sources further include the following steps:

[0041] Perform Kriging interpolation analysis on several coordinate positions in the encrypted monitoring area according to the regional monitoring data to obtain the predicted concentrations of the monitoring factors at several coordinate positions;

[0042] Determine the predicted coordinates of the pollution source according to the predicted concentrations of the monitoring factors.

[0043] A pollution source tracing device for a rainwater outlet includes:

[0044] A data acquisition module for acquiring pipe network data and first outlet data;

[0045] A monitoring factor determination module for determining monitoring factors according to the first outlet data;

[0046] A pollution source coordinate determination module for determining the encrypted monitoring area according to the pipe network data and monitoring factors and obtaining the coordinates of the pollution source;

[0047] A tracing completion judgment module for obtaining the pollution source data and second outlet data corresponding to the coordinates of the pollution source, calculating the pollution load of the pollution source and the pollution load of the outlet according to the pollution source data and the second outlet data, calculating the determination coefficient between the pollution source and the outlet according to the pollution load of the pollution source and the pollution load of the outlet, and judging whether the tracing is completed according to the determination coefficient.

[0048] Further, the tracing completion judgment module is further used to calculate the relative error before calculating the determination coefficient between the pollution source and the outlet.

[0049] A computer program product includes a computer program, and when the computer program is executed by a processor, the steps of the method are implemented.

[0050] A computer device includes a memory, a processor, and a computer program stored on the memory, and the processor executes the computer program to implement the steps of the method.

[0051] The present invention has the following advantages:

[0052] (1) In this application, the pollution loads of the pollution source and the rainwater outlet are calculated, and the fitting degree between the pollution load of the pollution source and the pollution load of the rainwater outlet is measured by the determination coefficient to evaluate the contribution degree of the pollution source to the pollution of the rainwater outlet, so as to determine the correlation between the pollution load of the pollution source and the pollution load of the rainwater outlet, more efficiently screen out possible pollution sources, avoid misjudgment and missed judgment, improve the accuracy and reliability of pollution source tracing, and thus provide reliable data support for subsequent illegal discharge evidence collection and pollution control. At the same time, the calculation of the pollution load can also provide data support for subsequent pollution control.

[0053] (2) The present application applies an optimized selection index formula to evaluate the relative importance of each pollution factor during the source tracing process. By comprehensively considering the concentration of the pollution factor, the discharge flow rate, and the flow rate or normalization factor of the river, and combining relevant adjustment coefficients, this optimized selection index formula can screen out the most representative characteristic pollution factors, improving the pertinence and efficiency of monitoring. With limited monitoring resources, preferentially monitoring pollution factors with a high optimized selection index can lock in the pollution source faster and reduce unnecessary monitoring work.

[0054] (3) The present application uses Kriging interpolation to analyze the predicted concentration of the monitored factors at the coordinate positions to predict the water quality status of unmonitored areas, thereby assisting in finding the actual coordinate position of the pollution source. At the same time, applying Kriging interpolation can also optimize the layout of the intensive monitoring to more scientifically divide the monitoring blocks and improve the coverage rate and accuracy of monitoring.

[0055] Other features and advantages of the present invention will be disclosed in detail in the following specific embodiments and the accompanying drawings. Brief Description of the Drawings

[0056] Figure 1 is a schematic flow chart of the present invention;

[0057] Figure 2 is a schematic diagram of the predicted concentration of the monitored factors of the present invention. Detailed Description of the Specific Embodiments

[0058] To better understand the purpose, structure, and function of the present invention, the following provides a more detailed description of the present invention in conjunction with the accompanying drawings.

[0059] A method for tracing the pollution source of a rainwater outlet, as Figure 1 shown, includes the following steps:

[0060] S1: Obtain pipe network data and first outlet data;

[0061] S2: Determine the monitored factors according to the first outlet data;

[0062] S3: Determine the intensive monitoring area according to the pipe network data and the monitored factors, and obtain the pollution source coordinates;

[0063] S4: Obtain the pollution source data and second outlet data corresponding to the pollution source coordinates;

[0064] S5: Calculate the pollution load of the pollution source and the pollution load of the outlet according to the pollution source data and the second outlet data;

[0065] S6: Calculate the determination coefficient between the pollution source and the outlet according to the pollution load of the pollution source and the pollution load of the outlet, and determine whether the source tracing is completed according to the determination coefficient.

[0066] In this embodiment, the pipeline network data in S1 includes a drainage pipeline network topology map, etc., which is used to understand the overall layout and connection relationship of the pipeline network. Specifically, relevant pipeline network archive materials can be consulted to obtain information such as the distribution of pipelines with different diameters, the locations of inspection wells, and the connection directions of each pipe section, so as to obtain the pipeline network data.

[0067] The first outfall data in S1 includes the detection data of the sewage at the outfall site, the river flow rate at this time, and the outfall discharge volume.

[0068] In this embodiment, at the rainwater outfall site, a portable multi-parameter water quality tester is used to quickly detect the water sample. The measured pH value is 6.5, the conductivity is 1200 μS / cm, and the dissolved oxygen is 5 mg / L. The water sample is sent to the laboratory, and chemical analysis methods such as GC-MS or ICP-MS are used to accurately determine the composition and concentration of pollutants. It is found that the ammonia nitrogen concentration in the water sample is 15 mg / L, and the total phosphorus concentration is 2 mg / L. The outfall discharge volume when taking the water sample is 0.5 m³ / s, and the river flow rate is 100 m³ / s.

[0069] Combining the results of on-site rapid detection and laboratory analysis, it is found that the concentrations of ammonia nitrogen and total phosphorus are relatively high. Combining the characteristics of known pollution sources, it can be preliminarily judged that the pollution source may be domestic sewage or agricultural wastewater.

[0070] In S2, according to the first outfall data, the monitoring factors are determined, including the following steps:

[0071] According to the first outfall data, the pollution factors are determined;

[0072] When there is one pollution factor, the monitoring factor is the pollution factor;

[0073] When there are multiple pollution factors, the monitoring factors are determined by the optimized selection index of the pollution factors.

[0074] In this embodiment, the pollution factors in the water sample include ammonia nitrogen (NH 3 -N) and total phosphorus (TP).

[0075] The optimized selection index is obtained through the following formula:

[0076] ;

[0077] Among them, is the optimized selection index of the i-th pollution factor, which is used to represent the relative importance of the i-th pollution factor in the process of tracing the source of the river outfall;

[0078] is the concentration of the i-th pollution factor, which is used to reflect the actual content of the pollution factor in the outfall;

[0079] is the discharge flow rate of the i-th pollution factor, which is used to represent the rate at which the pollution factor enters the river;

[0080] is the river flow or related normalization factor, which is used to compare and normalize the pollution factor selection indices of different outfalls or different time periods;

[0081] is the relevant adjustment coefficient, which is an optional adjustment coefficient used to consider toxicity or other factors that may affect the selection of pollution factors other than toxicity, such as the persistence, detectability, regulatory restrictions, etc. of the pollution factor. In practical applications, if these factors have little impact on the comparison results or can be ignored, can be set to 1 or omitted.

[0082] Optionally, the relevant adjustment coefficient can also be directly set to 1 or adjusted according to experience.

[0083] In this embodiment, the concentration of ammonia nitrogen (NH 3 -N) in the water sample is 15 mg / L, and the concentration of total phosphorus (TP) is 2 mg / L. The outfall discharge is 0.5 m³ / s, and the river flow is 100 m³ / s; since the difference between ammonia nitrogen pollution and total phosphorus pollution is not significant, the relevant adjustment coefficients of the two are the same, both being 1.

[0084] The calculation process of the optimized selection index of ammonia nitrogen (NH 3 -N) is as follows:

[0085] ;

[0086] The calculation process of the optimized selection index of total phosphorus (TP) is as follows:

[0087] ;

[0088] It can be seen that the optimized selection index of ammonia nitrogen is significantly higher than that of total phosphorus, which means that under the current monitoring conditions, ammonia nitrogen is relatively more important as a pollution factor. Therefore, ammonia nitrogen is used as the monitoring factor to more effectively trace the pollution source.

[0089] In step S3, according to the pipe network data and the monitoring factors, the encrypted monitoring area is determined, and the coordinates of the pollution source are obtained, including the following steps:

[0090] S31: Obtain the monitoring factor data of the key nodes;

[0091] Among them, the key nodes can be the intersection points of the rainwater pipe network, etc., such as the intersection point between the main pipe and the branch pipe of the drainage outlet. The monitoring factor data includes the concentration of the monitoring factor and the flow rate of the monitoring factor.

[0092] In this embodiment, a flow and water quality integrated monitoring device is arranged in the rainwater pipe network. The monitoring factor is selected as ammonia nitrogen, and the reference value of ammonia nitrogen in a stable and pollution-free state is measured to be 0.5 mg / L. Through real-time monitoring, the ammonia nitrogen concentration at a certain key node is 15 mg / L, and the flow rate is 0.5 m³ / s.

[0093] S32: Calculate the concentration change rate of the monitoring factor;

[0094] In this embodiment, the concentration change rate of the monitoring factor is calculated by the following formula:

[0095] ;

[0096] Among them, is the concentration change rate of the monitoring factor at the kth key node, is the water quality parameter value at the kth key node, is the reference value of this parameter in a stable and pollution-free state.

[0097] In this embodiment, the calculation process of the concentration change rate of ammonia nitrogen at this place is as follows:

[0098] ;

[0099] It can be seen that the concentration change rate of ammonia nitrogen at this place has reached 29 times.

[0100] This concentration change rate calculation formula is used to calculate the change rate of the water quality parameter at the key node relative to the stable and pollution-free state, so as to quickly judge the pollution source direction. This calculation formula can quickly narrow down the investigation scope and locate the possible pollution source area. This has important guiding significance for subsequent intensive monitoring and pipeline inspection.

[0101] S33: Determine the intensive monitoring area according to the concentration change rate of the monitoring factor.

[0102] In this embodiment, the concentration change rate of ammonia nitrogen in the previous place has reached 29 times, which is a very significant increase, strongly indicating that the pollution may come from the upstream direction of this key node. This result provides a clear indication for subsequent intensive monitoring, that is, the rainwater pipe network area upstream of this node should be focused on, and the rainwater pipe network area upstream of this node is determined as the intensive monitoring area.

[0103] Optionally, if the range of the determined intensive monitoring area is small, the pollution source can be locked by directly manually checking in the intensive monitoring area.

[0104] S35: Obtain the regional monitoring data of the encrypted monitoring area. Among them, the regional monitoring data includes the coordinate positions, flow data, and water quality parameters of each monitoring point in the encrypted monitoring area.

[0105] In this embodiment, taking the key nodes in the encrypted monitoring area as monitoring points, a flow and water quality integrated monitoring device is continuously arranged to obtain the coordinate positions, flow data, and water quality parameters of each monitoring point for subsequent spatial interpolation and prediction analysis. Among them, the water quality parameter is the concentration of the monitoring factor.

[0106] S36: Perform Kriging interpolation analysis based on the regional monitoring data to obtain the coordinates of the pollution source.

[0107] Specifically, it includes the following steps:

[0108] Perform Kriging interpolation analysis on several coordinate positions in the encrypted monitoring area according to the regional monitoring data to obtain the predicted concentrations of the monitoring factors at several coordinate positions;

[0109] Determine the predicted coordinates of the pollution source according to the predicted concentrations of the monitoring factors.

[0110] In this embodiment, the coordinates of the pollution source refer to the predicted coordinates of the pollution source.

[0111] In this embodiment, the regional monitoring data includes Table 1 below, and the predicted concentrations of the monitoring factors at several coordinate positions after Kriging interpolation analysis are as Figure 2 shown.

[0112] Table 1:

[0113]

[0114] According to Table 1, if it is necessary to predict the ammonia nitrogen concentration at a point with a longitude of 116.41 and a latitude of 39.93, it includes the following steps:

[0115] Calculate the weight coefficients of each monitoring point according to the Kriging equations as follows:

[0116] ;

[0117] Calculate the predicted concentration of the monitoring factor at the coordinate position according to the weight coefficients of each monitoring point as follows:

[0118] .

[0119] The predicted ammonia nitrogen concentration at the coordinate position with a longitude of 116.41 and a latitude of 39.93 is 15.45 mg / L.

[0120] The coordinates of the pollution source are the predicted coordinates where a pollution source may exist. When there is one or more pollution sources, the predicted concentration of the monitoring factors at the coordinate position where the pollution source is located is generally higher than the predicted concentration of the monitoring factors at the coordinate positions around the pollution source. Based on this, the coordinates of one or more pollution sources can be obtained.

[0121] Optionally, if the encrypted monitoring area in S33 is large, making it difficult to determine the coordinates of the pollution source in S36, the encrypted monitoring area can be re-determined according to the predicted concentration of the monitoring factors, and S35 and S36 can be repeated.

[0122] If the range of the encrypted monitoring area is small, the pipeline inspection of the problem pipe section can be directly carried out to lock the pollution source by manual investigation, skipping S36.

[0123] After obtaining the coordinates of the pollution source, the pipeline inspection of the problem pipe section can be carried out to lock the pollution source by manual investigation, such as using equipment such as CCTV, QV, sonar, and ground-penetrating radar to comprehensively detect the pipeline. The CCTV equipment can put the camera into the pipeline and observe the internal situation of the pipeline through video transmission, such as whether the pipeline is damaged, leaking, or there are foreign objects. The sonar equipment can detect whether there are cavities inside the pipeline, and the ground-penetrating radar can detect the soil conditions around the pipeline to judge whether there are external impacts caused by pipeline problems.

[0124] By observing the internal situation of the pipeline, the relationship between pipeline problems and pollution can be analyzed. For example, if it is found that there is a damaged part in the pipeline and there are signs of sewage seeping out around the damaged part, it can be judged that the pollution source may enter the pipeline through the damaged part, so as to lock the specific location of the pollution source.

[0125] After locking the pollution source, it is necessary to check the pollution load of the drainage household and the pollution load of the rainwater outlet.

[0126] In this embodiment, the pollution source data corresponding to the pollution source coordinates in S4 is the pollution source data at the position of the actual coordinates of the pollution source obtained according to the predicted coordinates of the pollution source. The pollution source data includes the concentration and emission flow of the monitoring factors at the pollution source. The second outlet data includes the concentration and emission flow of the monitoring factors at the outlet.

[0127] The pollution load in S5 is calculated by the following formula:

[0128] ;

[0129] Where, is the pollution load at this coordinate position, with the unit of t / d; is the emission flow at this coordinate position, with the unit of m³ / s; is the concentration of the monitoring factor at this coordinate position, with the unit of mg / L.

[0130] The coefficient of determination in S6 is calculated by the following formula:

[0131] ;

[0132] where is the coefficient of determination, is the pollution load of the pollution source in the i-th time period; is the pollution load of the outfall corresponding to the time period corresponding to the i-th time period of the pollution source; is the average value of the pollution loads of the pollution sources in n time periods. Wherein, n is determined according to needs. Optionally, the time period corresponding to the i-th time period of the pollution source can be obtained by means such as predicting the water flow velocity in the pipe network, which is an existing technology and will not be elaborated in this application.

[0133] In this embodiment, the pollution loads of the rainwater outfalls are: 8 t / h, 10 t / h, and 12 t / h; the pollution loads of the pollution sources are: 7.5 t / h, 10.2 t / h, and 11.8 t / h.

[0134] The calculation process of the coefficient of determination is as follows:

[0135] ;

[0136] ;

[0137] ;

[0138] .

[0139] In this embodiment, the threshold range of the coefficient of determination is from 0.9 to 1, if it is within the threshold range, the tracing is completed.

[0140] In this embodiment, when there are multiple pollution sources, the pollution load of the pollution source in the calculation of the coefficient of determination is the sum of the pollution loads of all pollution sources.

[0141] This application calculates the pollution loads of the pollution sources and the rainwater outfalls, and measures the fitting degree between the pollution load of the pollution source and the pollution load of the rainwater outfall through the coefficient of determination, so as to evaluate the contribution degree of the pollution source to the pollution of the rainwater outfall, thereby determining the correlation between the pollution load of the pollution source and the pollution load of the rainwater outfall, more efficiently screening out possible pollution sources, avoiding misjudgment and missed judgment, improving the accuracy and reliability of pollution source tracing, and thus providing reliable data support for subsequent illegal discharge evidence collection and pollution control. At the same time, the calculation of the pollution load can also provide data support for subsequent pollution control.

[0142] A pollution tracing device for a rainwater outfall, comprising:

[0143] A data acquisition module, configured to acquire pipe network data and first outfall data;

[0144] A monitoring factor determination module, configured to determine monitoring factors according to the first outfall data;

[0145] A pollution source coordinate determination module, configured to determine an encrypted monitoring area according to the pipe network data and the monitoring factors, and acquire pollution source coordinates;

[0146] A tracing completion judgment module, configured to acquire pollution source data and second outfall data corresponding to the pollution source coordinates, calculate the pollution load of the pollution source and the pollution load of the outfall according to the pollution source data and the second outfall data, calculate the determination coefficient between the pollution source and the outfall according to the pollution load of the pollution source and the pollution load of the outfall, and judge whether tracing is completed according to the determination coefficient.

[0147] A computer program product, including a computer program, which implements the steps of the method when executed by a processor.

[0148] A computer device, including a memory, a processor, and a computer program stored on the memory, where the processor executes the computer program to implement the steps of the method.

[0149] Embodiment 2

[0150] The difference between this embodiment and Embodiment 1 is that before calculating the determination coefficient between the pollution source and the outfall, it further includes calculating a relative error. If the relative error is less than a threshold error, then calculate the determination coefficient between the pollution source and the outfall.

[0151] The calculation formula of the relative error is as follows:

[0152] ;

[0153] Wherein, is the relative error, is the pollution load of the pollution source; is the pollution load of the outfall.

[0154] The data shows that the drainage flow rate of the pollution source is 2 m³ / s. In this embodiment, the relative error is calculated through the pollution load of 10 h. Among them, the ammonia nitrogen concentration of the drainage water measured by the water quality monitoring equipment in the first 5 h is 10 mg / L, and linearly increases to 20 mg / L in the next 5 h.

[0155] ;

[0156] .

[0157] Meanwhile, for the locked rainwater outlet corresponding to the pollution source, continuous monitoring was carried out for 10 hours using flow and water quality monitoring equipment. The pollution load of the outlet corresponding to the pollution load period of the above pollution source was calculated, and the pollution load of the 10-hour rainwater outlet was obtained as 255 tons. Among them, the calculation formula is the same as above.

[0158] Calculate the relative error based on the pollution load of the pollution source and the pollution load of the outlet , as follows:

[0159] ;

[0160] The relative error is only 1.96%, indicating that the pollution load at the pollution source is very close to the pollution load of the rainwater outlet, and the tracing result is accurate and reliable. Optionally, the error threshold can be less than 5%.

[0161] During the tracing process, by calculating the RE between the pollution load of the pollution source and the pollution load of the rainwater outlet, the difference between the two can be quantified. The smaller the RE value, the smaller the difference between the monitoring values of the pollution source and the rainwater outlet, the higher the accuracy of the tracing result, and it helps to identify and correct possible prediction deviations.

[0162] In this embodiment, there is only one pollution source and one outlet. If there are multiple pollution sources, It is the sum of the pollution loads of all pollution sources corresponding to the outlet, and the same applies to the outlet.

[0163] In a complex and changeable urban drainage system, a single index may not accurately reflect the true situation of the pollution source. This application uses both the relative error and the coefficient of determination R² for data verification. The relative error is used to verify the tracing result from the aspect of error, and the coefficient of determination R² is used to verify the tracing result from the aspect of correlation, so as to reduce the risk of tracing errors caused by misjudgment of a single index and ensure that the tracing result performs well in different dimensions.

[0164] Meanwhile, the calculation process of the relative error is relatively simple, and it can quickly compare the pollution loads for a long time period or multiple time periods. Setting the calculation of the relative error before the calculation of the coefficient of determination helps to quickly verify the connection between the pollution source and the outlet, quickly obtain the calculation result, and save calculation resources.

[0165] Optionally, the calculation of the relative error can also be set after the calculation of the coefficient of determination or carried out simultaneously with the calculation of the coefficient of determination.

[0166] A pollution tracing device for a rainwater outlet, comprising:

[0167] A data acquisition module, configured to acquire pipe network data and first outlet data;

[0168] A monitoring factor determination module, configured to determine monitoring factors according to the first outfall data;

[0169] A pollution source coordinate determination module, configured to determine an encrypted monitoring area according to the pipe network data and the monitoring factors, and obtain the pollution source coordinates;

[0170] A tracing completion judgment module, configured to obtain the pollution source data corresponding to the pollution source coordinates and the second outfall data, calculate the pollution load of the pollution source and the pollution load of the outfall according to the pollution source data and the second outfall data, and calculate the determination coefficient between the pollution source and the outfall according to the pollution load of the pollution source and the pollution load of the outfall, and judge whether the tracing is completed according to the determination coefficient.

[0171] Wherein, before calculating the determination coefficient between the pollution source and the outfall, the tracing completion judgment module is further configured to calculate the relative error.

[0172] It can be understood that the present invention is described by some embodiments. Those skilled in the art know that without departing from the spirit and scope of the present invention, these features and embodiments can be variously changed or equivalently replaced. In addition, under the teaching of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present invention.

[0173] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for tracing the pollution source of a rainwater outlet, characterized in that: The steps include: Obtain pipe network data and first outlet data; Determine the monitoring factor based on the first row of data; According to the pipe network data and monitoring factors, determine the encrypted monitoring area and obtain the coordinates of the pollution source; Obtain pollution source data and second outlet data corresponding to the pollution source coordinates; Calculate the pollution load of the pollution source and the pollution load of the outlet according to the pollution source data and the second outlet data; According to the pollution load of the pollution source and the pollution load of the outlet, calculate the determination coefficient of the pollution source and the outlet, and judge whether the tracing is completed according to the determination coefficient; The method of determining the encrypted monitoring area and obtaining the coordinates of the pollution source according to the pipe network data and monitoring factors includes the following steps: Acquire monitoring factor data of key nodes, where the key nodes are intersection points of the rainwater pipe network; Calculate the concentration change rate of the monitoring factor; Determine the intensified monitoring area based on the concentration change rate of the monitoring factor; Obtain regional monitoring data of the encrypted monitoring area; Based on the regional monitoring data, Kriging interpolation analysis is performed on several coordinate positions in the encrypted monitoring area to obtain the predicted concentration of monitoring factors at several coordinate positions; Predict concentrations based on monitoring factors and determine the predicted coordinates of pollution sources; The determination coefficient is calculated by the following formula: ； in, is the coefficient of determination, is the pollution load of the pollution source in the i-th time period; is the outlet pollution load in the time period corresponding to the i-th time period of the pollution source; is the average value of the pollution load of the pollution source in n time periods.

2. The method for tracing the pollution source of a rainwater outlet according to claim 1, characterized in that: The pollution load of the pollution source and the pollution load of the discharge outlet are calculated by the following formula: ； in, is the pollution load, in t / d; is the discharge flow rate, in m³ / s; It is the concentration of monitoring factor, the unit is mg / L.

3. The method for tracing the pollution source of a rainwater outlet according to claim 2, characterized in that: Also includes: Before calculating the coefficient of determination of pollution sources and outlets, it also includes calculating relative errors; The calculation formula of the relative error is as follows: ； is the relative error, is the pollution load of the pollution source, It is the pollution load at the outlet.

4. The method for tracing the pollution source of a rainwater outlet according to claim 1, characterized in that: Determining the monitoring factor according to the first row of data comprises the following steps: Determine the pollution factor based on the first outlet data; When there is only one pollution factor, the monitoring factor is the pollution factor; When there are multiple pollution factors, the monitoring factor is determined by the optimization selection index of the pollution factor; The optimization selection index is calculated by the following formula: ； in, is the optimal selection index of the ith pollution factor, is the concentration of the ith pollution factor, is the emission flow of the ith pollution factor, is the river discharge or related normalization factor, is the relevant adjustment coefficient.

5. A pollution source tracing device for a rainwater outlet, characterized in that: include: A monitoring factor determination module, used to determine the monitoring factor according to the first row of port data; The pollution source coordinate determination module is used to determine the encrypted monitoring area and obtain the pollution source coordinates based on the pipe network data and monitoring factors; A source tracing completion judgment module is used to obtain the pollution source data and the second outlet data corresponding to the pollution source coordinates, and calculate the pollution load of the pollution source and the outlet pollution load based on the pollution source data and the second outlet data, and calculate the determination coefficient of the pollution source and the outlet based on the pollution load of the pollution source and the outlet pollution load, and judge whether the source tracing is completed based on the determination coefficient; The method of determining the encrypted monitoring area and obtaining the coordinates of the pollution source according to the pipe network data and monitoring factors includes the following steps: Acquire monitoring factor data of key nodes, where the key nodes are intersection points of the rainwater pipe network; Calculate the concentration change rate of the monitoring factor; Determine the intensified monitoring area based on the concentration change rate of the monitoring factor; Obtain regional monitoring data of the encrypted monitoring area; Based on the regional monitoring data, Kriging interpolation analysis is performed on several coordinate positions in the encrypted monitoring area to obtain the predicted concentration of monitoring factors at several coordinate positions; Predict concentrations based on monitoring factors and determine the predicted coordinates of pollution sources; The determination coefficient is calculated by the following formula: ； in, is the coefficient of determination, is the pollution load of the pollution source in the i-th time period; is the outlet pollution load in the time period corresponding to the i-th time period of the pollution source; is the average value of the pollution load of the pollution source in n time periods.

6. The pollution source tracing device for a rainwater outlet according to claim 5, characterized in that: The source tracing completion judgment module is also used to calculate the relative error before calculating the determination coefficient of the pollution source and the outlet.

7. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

8. A computer device comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 4.

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