Water quality pollution event tracing method and terminal

Abstract

The application discloses a water quality pollution event tracing method and a terminal. When a pollution event is monitored, a monitoring site is determined as a target water quality section. A pollution curve of the target water quality section is obtained, and a pollution path pollution curve, a non-point source pollution curve and an internal source pollution curve corresponding to the target water quality section are calculated. The pollution dominant probability of each pollution path in the pollution event is calculated. The pollution source is determined based on the pollution dominant probability. The pollution source is simply and effectively positioned considering the multi-source water quality pollution, so that the pollution event source is accurately and quickly positioned.

Description

Technical Field

[0001] The present invention relates to the technical field of water environment monitoring and management, and in particular to a method and terminal for tracing the source of a water pollution incident. Background Art

[0002] Existing water pollution source analysis methods are mainly based on contribution rate calculations. That is, based on the water quality sections and pollution source lists of the target river basin, the inflow and outflow of water quality pollution indicators at the section are estimated. For water pollution incidents, it is described as the pollution contribution rate, which represents the contribution of emissions from each pollution source to the current water pollution incident.

[0003] The traditional method of tracing the source of water pollution has the following steps:

[0004] (1) Divide the monitoring sections based on the upstream and downstream relationship and establish the spatiotemporal relationship between the water quality sections and the pollution sources;

[0005] (2) Based on the water environment of each section, a model is established to estimate the inflow and outflow of pollutants in the section;

[0006] (3) For pollution incidents, when the pollution source is clear, the emission and diffusion process of the pollution source is simulated based on the model to evaluate the pollutant concentration under different circumstances;

[0007] (4) Calculate the contribution rate of each pollution source to the target water quality section, sort them by size, and determine the main cause of the pollution incident.

[0008] However, the quantitative analysis method of water pollution contribution rate in the above method is relatively complicated. It mainly calculates the contribution rate of pollution source emissions. It is limited by the requirements of model and data quality, requires sufficient monitoring of water quality parameters of the target river basin, and the condition setting is cumbersome, and the calculation cost and time cost are high. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a method and terminal for tracing the source of water pollution incidents, which can accurately and quickly locate the source of the pollution incident.

[0010] In order to solve the above technical problems, a technical solution adopted by the present invention is:

[0011] A method for tracing the source of a water pollution incident, comprising the steps of:

[0012] Drawing a water environment map of the target watershed, wherein the water environment map includes monitoring sites;

[0013] Determining whether the monitoring site detects a pollution event, and if so, determining the monitoring site as a target water quality section;

[0014] Obtaining the pollution curve of the target water quality section, and calculating the pollution path pollution curve, nonpoint source pollution curve, and internal source pollution curve corresponding to the target water quality section;

[0015] The pollution dominance probability of each pollution path is calculated based on the pollution curve of the target water quality section, the pollution path pollution curve, the non-point source pollution curve and the internal source pollution curve, and the pollution source is determined based on the pollution dominance probability of each pollution path.

[0016] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0017] A water pollution incident tracing terminal includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the following steps are implemented:

[0018] Drawing a water environment map of the target watershed, wherein the water environment map includes monitoring sites;

[0019] Determining whether the monitoring site detects a pollution event, and if so, determining the monitoring site as a target water quality section;

[0020] Obtaining the pollution curve of the target water quality section, and calculating the pollution path pollution curve, nonpoint source pollution curve, and internal source pollution curve corresponding to the target water quality section;

[0021] The pollution dominance probability of each pollution path is calculated based on the pollution curve of the target water quality section, the pollution path pollution curve, the non-point source pollution curve and the internal source pollution curve, and the pollution source is determined based on the pollution dominance probability of each pollution path.

[0022] The beneficial effects of the present invention are: when a pollution event is monitored, the monitoring site is determined as the target water quality section, and the pollution curve of the target water quality section is obtained, and the pollution path pollution curve, non-point source pollution curve and endogenous pollution curve corresponding to the target water quality section are calculated, the pollution dominance probability of each pollution path in the pollution event is calculated, and the pollution source is determined based on the pollution dominance probability, taking into account multi-source water quality pollution, and simply and effectively locating the pollution source, thereby achieving accurate and rapid positioning of the pollution event source. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a flowchart of the steps of a method for tracing the source of a water pollution incident according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic structural diagram of a water pollution incident tracing terminal according to an embodiment of the present invention;

[0025] Figure 3A water environment context diagram in a method for tracing the source of a water pollution incident according to an embodiment of the present invention;

[0026] Figure 4 Schematic diagram of analysis of dominant factors of pollution incidents in a method for tracing the source of water pollution incidents according to an embodiment of the present invention;

[0027] Figure 5 Schematic diagram of a pollutant concentration curve of a target water quality section in a method for tracing the source of a water pollution incident according to an embodiment of the present invention;

[0028] Figure 6 Schematic diagram of the pollution dominance probability of each pollution path in the water pollution incident tracing method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] To illustrate the technical content, achieved objectives and effects of the present invention in detail, the following description is given in conjunction with the embodiments and accompanying drawings.

[0030] Please refer to Figure 1 The embodiment of the present invention provides a method for tracing the source of a water pollution incident, comprising the steps of:

[0031] Drawing a water environment map of the target watershed, wherein the water environment map includes monitoring sites;

[0032] Determining whether the monitoring site detects a pollution event, and if so, determining the monitoring site as a target water quality section;

[0033] Obtaining the pollution curve of the target water quality section, and calculating the pollution path pollution curve, nonpoint source pollution curve, and internal source pollution curve corresponding to the target water quality section;

[0034] The pollution dominance probability of each pollution path is calculated based on the pollution curve of the target water quality section, the pollution path pollution curve, the non-point source pollution curve and the internal source pollution curve, and the pollution source is determined based on the pollution dominance probability of each pollution path.

[0035] From the above description, it can be seen that the beneficial effects of the present invention are: when a pollution event is monitored, the monitoring site is determined as the target water quality section, and the pollution curve of the target water quality section is obtained, and the pollution path pollution curve, surface source pollution curve and endogenous pollution curve corresponding to the target water quality section are calculated, the pollution dominance probability of each pollution path in the pollution event is calculated, and the pollution source is determined based on the pollution dominance probability, taking into account multi-source water quality pollution, and simply and effectively locating the pollution source, thereby achieving accurate and rapid positioning of the pollution event source.

[0036] Furthermore, obtaining the pollution curve of the target water quality section includes:

[0037] Obtaining a pollutant concentration curve of the target water quality section;

[0038] Determine the start time of the last increase in the pollutant concentration before the pollutant concentration exceeds the water quality standard for the first time and the end time of the first decrease in the pollutant concentration after the pollutant concentration exceeds the water quality standard for the last time in the pollutant concentration curve;

[0039] Determine the start time as the starting point, and determine the end time as the end point;

[0040] A pollution curve of the target water quality section is intercepted from the pollutant concentration curve according to the starting point and the end point.

[0041] From the above description, it can be seen that the pollution curve of the target water quality section can be accurately extracted, thereby improving the subsequent calculation efficiency.

[0042] Furthermore, the calculation of the pollution path pollution curve, the non-point source pollution curve, and the internal source pollution curve corresponding to the target water quality section includes:

[0043] Determining the pollution path of the target water quality section according to the water environment context map;

[0044] Obtaining the pollution index concentration and water flow of the pollution path;

[0045] Calculating a pollution path pollution curve corresponding to the target water quality section according to the pollution index concentration, the water flow rate and the target water quality section;

[0046] Determine a rainfall event corresponding to the target water quality section, and determine the rainfall amount, the accumulated rainfall amount over a preset time, and the rainfall month of the rainfall event;

[0047] Obtaining pollution curves of the target water quality section at a plurality of moments before a time period corresponding to the pollution curve of the target water quality section;

[0048] Fitting the pollution curves of the target water quality sections at the previous multiple moments, the rainfall of the rainfall event, the accumulated rainfall over the preset time, and the rainfall month to obtain a nonpoint source pollution curve corresponding to the target water quality section;

[0049] A plurality of pollution curves of various monitoring indicators of the target watershed are obtained, and an average value of the plurality of pollution curves of various monitoring indicators is calculated to obtain an endogenous pollution curve corresponding to the target water quality section.

[0050] From the above description, we can see that traditional methods usually evaluate the contribution rate based on the inflow volume and determine the source of pollutants from a numerical level. However, in actual application, there may be a gap between this and the needs of determining pollution incidents. By calculating different types of pollution curves to analyze the dominant factors of pollution incidents, the comprehensiveness and reliability of pollution incident tracing are improved.

[0051] Furthermore, the calculating of the pollution path pollution curve corresponding to the target water quality section according to the pollution index concentration, the water flow rate and the target water quality section includes:

[0052] ;

[0053] ;

[0054] Where, represents the pollution path pollution curve corresponding to the target water quality section, express t i The pollution index concentration at the time, express t i The water flow at the time, h represents the sampling time interval, t i Indicates the pollution source of the pollution path i The transmission lag time between the target water quality section, t 0 represents the pollution moment of the target water quality section, l i Indicates the pollution source of the pollution path i The distance to the target water quality section, v i Indicates the average water flow velocity.

[0055] From the above description, it can be seen that the pollution path pollution curve corresponding to the target water quality section is calculated based on the pollution index concentration, water flow and target water quality section, taking into account the point source pollution of the pollution event.

[0056] Furthermore, the non-point source pollution curve corresponding to the target water quality section is obtained by fitting the pollution curves of the target water quality section at the previous multiple moments, the rainfall of the rainfall event, the accumulated rainfall in the preset time, and the rainfall month, including:

[0057] ;

[0058] Where, The pollution curve of the target water quality section is t The value at time 0, Represents the first parameter, Represents the second parameter, Represents the third parameter, Represents the fourth parameter, Represents the fifth parameter, Indicates that the pollution curve of each pollution path is t i The value of the moment, represents the autoregression of the pollution curve of the target water quality section at the previous multiple moments, express t The rainfall amount of the rainfall event at time 0, Indicates the cumulative rainfall during the preset time of the rainfall event, M Indicates the rainfall month of the rainfall event.

[0059] From the above description, it can be seen that since non-point source pollution can also affect water quality, a non-point source pollution curve is obtained by fitting based on the pollution curve of the target water quality section at multiple previous moments, the rainfall of the rainfall event, the cumulative rainfall in the preset time, and the rainfall month. This fully considers the non-point source pollution caused by rainfall and improves the comprehensiveness of subsequent tracing.

[0060] Furthermore, the calculation of the pollution dominance probability of each pollution path based on the pollution curve of the target water quality section, the pollution path pollution curve, the non-point source pollution curve, and the internal source pollution curve includes:

[0061] Determining a numerical curve corresponding to each pollution curve, the pollution curves including the pollution curve of the target water quality section, the pollution path pollution curve, the nonpoint source pollution curve, and the endogenous pollution curve;

[0062] determining a standard low value and a standard high value from each of said value curves;

[0063] Determine the minimum and maximum values ​​for each pollution curve;

[0064] If the minimum value is higher than the standard low value, the standard low value is replaced by the minimum value; if the maximum value is higher than the standard high value, the standard high value is replaced by the maximum value, to obtain each pollution curve after replacement;

[0065] performing a standardization process on each of the replaced pollution curves to obtain each standardized pollution curve;

[0066] Calculating the variance of each pollution curve after the standardization process, and calculating the difference between the variance of each pollution curve after the standardization process and the variance of the pollution curve of the target water quality section;

[0067] Obtaining a fluctuation difference coefficient based on the difference;

[0068] Using a dynamic time warping algorithm, the minimum cumulative distances between the pollution path pollution curve, the nonpoint source pollution curve, the endogenous pollution curve and the pollution curve of the target water quality section are calculated respectively;

[0069] Percentilizing the minimum cumulative distance to obtain a fluctuation correlation coefficient;

[0070] The pollution dominance probability of each pollution path is obtained according to the fluctuation correlation coefficient and the fluctuation difference coefficient.

[0071] From the above description, it can be seen that, unlike the traditional inflow statistical method, based on the pollution curve and after standardization, the dominant probability of each pollution path to the pollution event is estimated according to the fluctuation difference coefficient and the fluctuation correlation coefficient, which is conducive to the accurate positioning of the pollution source.

[0072] Furthermore, the step of performing standardization on each of the replaced pollution curves to obtain each of the standardized pollution curves includes:

[0073] ;

[0074] Where, C represents the pollution curve, C min Indicates the lower value of the standard, C max Indicates the high value of the standard;

[0075] The fluctuation difference coefficient obtained according to the difference includes:

[0076] ;

[0077] Where, D i Indicates pollution source i The fluctuation difference coefficient of the pollution curve, represents the sum of the differences of all pollution curves, Indicates pollution source i the difference in the pollution curves of

[0078] The method of obtaining the pollution dominant probability of each pollution path according to the fluctuation correlation coefficient and the fluctuation difference coefficient includes:

[0079] ;

[0080] Where, P i Indicates pollution source i The pollution dominance probability of the pollution path, W i Indicates pollution sourcei The fluctuation correlation coefficient of the pollution curve, Indicates all pollution sources i The sum of the product of the fluctuation difference coefficient and the fluctuation correlation coefficient of the pollution curve.

[0081] From the above description, it can be seen that the dominant probability of each pollution path on the pollution incident is calculated by multiplying the fluctuation difference coefficient and the fluctuation correlation coefficient. The dominant probability can accurately reflect the degree of influence of each pollution path on the pollution incident, so as to accurately trace the source.

[0082] Furthermore, the determining of the pollution source based on the pollution dominance probability of each pollution path includes:

[0083] Determine the pollution dominant probability of the pollution path that is greater than or equal to a preset threshold as the target pollution dominant probability;

[0084] sorting the target pollution dominant probabilities in descending order to obtain sorted target pollution dominant probabilities;

[0085] Determine whether the pollution path corresponding to the largest target pollution dominant probability among the sorted target pollution dominant probabilities is the upstream water quality section; if not, determine the pollution path corresponding to the largest target pollution dominant probability as the primary pollution source; if so, determine the pollution path corresponding to the largest target pollution dominant probability as the latest target water quality section, calculate the pollution dominant probabilities of each pollution path corresponding to the latest target water quality section, and determine the pollution path corresponding to the largest target pollution dominant probability as the primary pollution source;

[0086] Determine in turn whether the pollution paths corresponding to the other pollution dominant probabilities except the largest target pollution dominant probability among the sorted target pollution dominant probabilities are upstream water quality sections. If not, determine the pollution paths corresponding to the other target pollution dominant probabilities as secondary pollution sources. If so, determine the pollution paths corresponding to the other target pollution dominant probabilities as the latest target water quality sections, calculate the pollution dominant probabilities of each pollution path corresponding to the latest target water quality section, and determine the pollution path corresponding to the largest target pollution dominant probability as a secondary pollution source.

[0087] From the above description, it can be seen that the pollution sources are located from the perspective of the dominant probability of pollution. The pollution sources finally determined include primary pollution sources and secondary pollution sources, which enables clear and accurate tracing of pollution incidents.

[0088] Furthermore, the drawing of the water environment context map of the target watershed includes:

[0089] Collect relevant data of the target watershed;

[0090] Identify monitoring sites in the target watershed;

[0091] Obtaining pollution source data of the target watershed;

[0092] A water environment context map of the target watershed is drawn based on the relevant data, the monitoring sites and the pollution source data.

[0093] From the above description, it can be seen that by drawing a water environment context map of the target river basin, we can accurately understand each pollution path, providing a data basis for tracing the source of subsequent pollution incidents.

[0094] Please refer to Figure 2 Another embodiment of the present invention provides a water pollution incident tracing terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, each step in the above-mentioned water pollution incident tracing method is implemented.

[0095] The water pollution incident tracing method and terminal of the present invention can be applied to application scenarios where water pollution occurs, and the following is an explanation through specific implementation methods:

[0096] Example 1

[0097] Please refer to Figure 1 、 Figure 3-Figure 6 A method for tracing the source of a water pollution incident in this embodiment includes the following steps:

[0098] S1. Draw a water environment map of the target basin, which includes monitoring sites, i.e. Figure 3 The water quality monitoring stations in the project include:

[0099] S1-1. Collect relevant data of the target watershed;

[0100] In an optional embodiment, the relevant data includes but is not limited to real-time water quality data, historical water quality data, pollution emission inventory and land use, etc.

[0101] S1-2. Determine the monitoring sites in the target watershed, use each monitoring site as an analysis unit, refine the water quality network to the greatest extent, and analyze the pollution transmission between various water quality sections.

[0102] S1-3. Obtaining pollution source data of the target watershed;

[0103] In an optional embodiment, when obtaining the pollution source data, field survey results along the river section can also be obtained for drawing a water environment context map.

[0104] S1-4, draw a water environment diagram of the target basin based on the relevant data, the monitoring sites and the pollution source data, such as Figure 3 As shown, it includes water quality monitoring stations (i.e. the monitoring stations), pollution sources and inflow paths. The pollution sources include domestic sewage, sewage treatment plants, animal husbandry and agricultural land.

[0105] Specifically, the possible pollution inflow paths of each water quality section can be analyzed based on the water environment context diagram, for example, Figure 3 There are four pollution paths at the water quality monitoring site 1, namely upstream site 2, upstream site 4, sewage treatment plants along the line and livestock breeding along the line.

[0106] The most direct path of pollution is the upstream and downstream relationship of a water quality section. The inflow and outflow relationship is determined based on the direction of water flow. In addition to upstream and downstream, point source pollution along the route must also be considered, such as sewage treatment plants, industrial discharge, and direct household discharge. This type of pollution can be monitored in real time by deploying water quality monitoring equipment. Non-point source pollution comes from a wide range of sources, such as agricultural pollution caused by rainfall, aquaculture pollution, and surface runoff pollution from residential areas. This type of pollution is difficult to monitor through the deployment of equipment. Hydrological models, hydrodynamic models, or physical experimental observations are typically used to estimate the inflow of non-point source pollution under rainfall conditions.

[0107] S2. Determine whether the monitoring site detects a pollution event. If so, determine the monitoring site as a target water quality section.

[0108] In existing technologies, traditional methods usually evaluate the contribution rate based on the inflow volume and determine the source of pollutants from a numerical level. However, in actual application, there may be a gap between the requirements for determining pollution events, for example, Figure 4 As shown in the figure, an analysis of a pollutant exceeding the standard at a water quality monitoring station is conducted. From the perspective of contribution rate, most of the pollutants come from pollution path 2. However, in fact, the pollutants in pollution path 2 are in a relatively stable state. The main cause of this pollution incident should be the abnormal fluctuation of pollution path 1. Therefore, the present invention analyzes the main factors of the pollution incident by solving the pollution curve, as described below:

[0109] S3. Obtain the pollution curve of the target water quality section, and calculate the pollution path pollution curve, nonpoint source pollution curve, and endogenous pollution curve corresponding to the target water quality section, specifically including:

[0110] S3-1, obtain the pollutant concentration curve of the target water quality section, such as Figure 5 As shown;

[0111] S3-2, determining the start time of the last increase in the pollutant concentration before the pollutant concentration exceeds the water quality standard for the first time, and the end time of the first decrease in the pollutant concentration after the pollutant concentration exceeds the water quality standard for the last time;

[0112] S3-3, determine the start time as the starting point, and determine the end time as the end point, such as Figure 5 As shown;

[0113] S3-4, intercepting the pollution curve of the target water quality section from the pollutant concentration curve according to the starting point and the end point, such as Figure 5 As shown, the curve between the starting point and the end point is the pollution curve of the target water quality section.

[0114] S3-5, determining the pollution path of the target water quality section according to the water environment context map;

[0115] S3-6. Obtaining the pollution index concentration and water flow rate of the pollution path;

[0116] Specifically, the pollution index concentration and water flow of the pollution path are obtained through other monitoring data, such as upstream water quality sections and pipe network outlets.

[0117] S3-7. Calculate a pollution path pollution curve corresponding to the target water quality section based on the pollution index concentration, the water flow rate, and the target water quality section. Specifically:

[0118] ;

[0119] ;

[0120] Where, represents the pollution path pollution curve corresponding to the target water quality section, express t i The pollution index concentration at the time, express t i The water flow at the time, h represents the sampling time interval, t i Indicates the pollution source of the pollution path i The transmission lag time between the target water quality section, t 0 represents the pollution moment of the target water quality section, l i Indicates the pollution source of the pollution path i The distance to the target water quality section, v i Indicates the average water flow velocity.

[0121] S3-8. Determine a rainfall event corresponding to the target water quality section, and determine the rainfall amount, the accumulated rainfall amount within a preset time, and the rainfall month of the rainfall event, specifically including:

[0122] S3-8-1. Determine the last non-flooding point before the starting time of the pollution event as the start time of the rainfall event, and determine the ending time of the pollution event as the end time of the rainfall event;

[0123] The method for determining a non-flooding point is as follows:

[0124] Determine whether the cumulative rainfall within 24 hours corresponding to the moment before the starting moment of the pollution event is greater than or equal to 5 mm. If so, determine that the previous moment is a flood point, and continue to determine whether the cumulative rainfall within 24 hours corresponding to the two moments before the starting moment of the pollution event is greater than or equal to 5 mm, and so on. Otherwise, determine that the previous moment is not a flood point.

[0125] For example, if the starting point of the pollution event is 15:00 today, then 14:00 will be judged. Assuming that the cumulative rainfall from 13:00 yesterday to 14:00 today is 4mm, then 14:00 today is a non-flood point and is used as the starting time of the rainfall event. Otherwise, continue to judge whether 13:00 is a non-flood point, and so on.

[0126] S3-8-2. Generate a rainfall event corresponding to the target water quality section according to the rainfall event start time and the rainfall event end time;

[0127] S3-8-3. Determine the rainfall amount of the rainfall event, the accumulated rainfall amount within a preset time period, and the rainfall month.

[0128] Wherein, the preset time is 12 hours.

[0129] S3-9, obtaining the pollution curve of the target water quality section at a plurality of moments before the time period corresponding to the pollution curve of the target water quality section;

[0130] S3-10. Fitting the pollution curves of the target water quality sections at the previous multiple moments, the rainfall of the rainfall event, the accumulated rainfall during the preset time, and the rainfall month to obtain a nonpoint source pollution curve corresponding to the target water quality section, specifically:

[0131] ;

[0132] Where, represents the value of the pollution curve of the target water quality section at time t0, Represents the first parameter, Represents the second parameter, Represents the third parameter, Represents the fourth parameter, Represents the fifth parameter, Indicates that the pollution curve of each pollution path is t i The value of the moment, represents the autoregression of the pollution curve of the target water quality section at the previous multiple moments, express t The rainfall amount of the rainfall event at time 0, Indicates the cumulative rainfall during the preset time of the rainfall event, M Indicates the rainfall month of the rainfall event.

[0133] Unlike physical models that require more watershed environmental data to quantify pollution, such as elevation, land use, and meteorological data, and have higher model calculation costs, the present invention uses an intelligent algorithm to fit the impact trend of rainfall surface source pollution, which can effectively fit the impact trend of rainfall surface source pollution at a lower calculation cost.

[0134] S3-11. Obtain multiple pollution curves of various monitoring indicators of the target watershed, and calculate the average value of the multiple pollution curves of various monitoring indicators to obtain an endogenous pollution curve corresponding to the target water quality section.

[0135] For areas with obvious endogenous pollution, such as lake and bay basins, which are prone to pollutant adsorption, precipitation, and suspended release, it is necessary to focus on endogenous factors. By taking multi-point sampling in the target basin and using the laboratory control variable method, multiple pollution curves for each monitoring indicator can be obtained. For example, the change in sludge pollutant release corresponding to the change in water quality monitoring indicators, and the average value of the multiple pollution curves of each monitoring indicator is calculated to obtain the endogenous pollution curve corresponding to the target water quality section.

[0136] For example, data from five sampling points in the target watershed are used to calculate five pollution curves of ammonia nitrogen indicators, and the average value of these five pollution curves is taken as the endogenous pollution curve of ammonia nitrogen.

[0137] In an optional implementation, in order to take into account the influence of time, it is necessary to sample as much as possible in different time periods, such as monthly, seasonally, etc., with time as an important indicator. Finally, these data are put into intelligent algorithm training as samples to obtain a prediction model, such as a multivariate regression model, to achieve the simulation of the endogenous pollution curve.

[0138] S4. Calculating the pollution dominance probability of each pollution path based on the pollution curve of the target water quality section, the pollution path pollution curve, the non-point source pollution curve, and the internal source pollution curve, and determining the pollution source based on the pollution dominance probability of each pollution path, specifically including:

[0139] S4-1. Determine a numerical curve corresponding to each pollution curve, wherein the pollution curve includes the pollution curve of the target water quality section, the pollution path pollution curve, the non-point source pollution curve, and the internal source pollution curve;

[0140] Among them, the numerical curve is the numerical curve corresponding to the month before the pollution event, and the calculation method of the numerical curve is the same as that of the pollution curve, that is, the numerical curve corresponding to the pollution curve of the target water quality section is the same as its calculation method, the numerical curve corresponding to the pollution path pollution curve is the same as its calculation method, the numerical curve corresponding to the non-point source pollution curve is the same as its calculation method, and the numerical curve corresponding to the endogenous pollution curve is the same as its calculation method, which will not be repeated here.

[0141] By calculating the corresponding numerical curve within the month before the pollution incident, the present invention can use percentiles to standardize the pollution curve and evaluate the abnormality of the pollution curve in this pollution incident. The greater the fluctuation of the standardized pollution curve, the more abnormal the value compared with the previous month, and the more likely it is to dominate the pollution, thereby improving the accuracy of tracing the source.

[0142] S4-2, determining a standard low value and a standard high value from each of the numerical curves;

[0143] Specifically, the 25% quantile of each of the numerical curves is used as the standard low value, and the 75% quantile of each of the numerical curves is used as the standard high value.

[0144] S4-3. Determine the minimum and maximum values ​​of each pollution curve;

[0145] S4-4. If the minimum value is higher than the standard low value, the standard low value is replaced by the minimum value; if the maximum value is higher than the standard high value, the standard high value is replaced by the maximum value, to obtain each pollution curve after replacement;

[0146] S4-5, performing standardization processing on each of the replaced pollution curves to obtain each pollution curve after standardization processing, specifically:

[0147] ;

[0148] Where, C represents the pollution curve, C min Indicates the lower value of the standard,C max Indicates the high value of the standard;

[0149] S4-6. Calculate the variance of each pollution curve after the standardization process, and calculate the difference between the variance of each pollution curve after the standardization process and the variance of the pollution curve of the target water quality section, specifically:

[0150] ;

[0151] Where, represents the difference, S i Indicates pollution source i The variance of the pollution curve, S 0 represents the variance of the pollution curve of the target water quality section.

[0152] S4-7. Obtaining a fluctuation difference coefficient based on the difference;

[0153] ;

[0154] Where, D i Indicates pollution source i The fluctuation difference coefficient of the pollution curve, represents the sum of the differences of all pollution curves, Indicates pollution source i The difference in the pollution curves.

[0155] S4-8. Use a dynamic time warping algorithm to calculate the minimum cumulative distances between the pollution curve of the pollution path, the nonpoint source pollution curve, the endogenous pollution curve and the pollution curve of the target water quality section.

[0156] S4-9. Percentile the minimum cumulative distance to obtain a fluctuation correlation coefficient. Specifically:

[0157] ;

[0158] Where, W i Indicates pollution source i The fluctuation correlation coefficient of the pollution curve, H i Indicates pollution source i The minimum cumulative distance between the pollution curve of the target water quality section and the pollution curve of the target water quality section, Represents the sum of the minimum cumulative distances.

[0159] S4-10. Obtain the pollution dominance probability of each pollution path based on the fluctuation correlation coefficient and the fluctuation difference coefficient. Specifically:

[0160] ;

[0161] Where, P i Indicates pollution source i The pollution dominance probability of the pollution path, W i Indicates pollution source i The fluctuation correlation coefficient of the pollution curve, Indicates all pollution sources i The sum of the product of the fluctuation difference coefficient and the fluctuation correlation coefficient of the pollution curve.

[0162] S4-11. Determine the pollution dominant probability of the pollution path that is greater than or equal to a preset threshold as the target pollution dominant probability;

[0163] In an optional implementation, the preset threshold is 30%.

[0164] S4-12. Sort the target pollution dominant probabilities in descending order to obtain sorted target pollution dominant probabilities;

[0165] S4-13. Determine whether the pollution path corresponding to the largest target pollution dominant probability among the sorted target pollution dominant probabilities is an upstream water quality section; if not, determine the pollution path corresponding to the largest target pollution dominant probability as the primary pollution source; if so, determine the pollution path corresponding to the largest target pollution dominant probability as the latest target water quality section, calculate the pollution dominant probabilities of each pollution path corresponding to the latest target water quality section, and determine the pollution path corresponding to the largest target pollution dominant probability as the primary pollution source;

[0166] Among them, the calculation method of the pollution dominance probability of each pollution path corresponding to the latest target water quality section is the same as S4-1 to S4-10, and will not be repeated here.

[0167] S4-14. Determine in turn whether the pollution paths corresponding to the other pollution dominant probabilities except the largest target pollution dominant probability among the sorted target pollution dominant probabilities are upstream water quality sections. If not, determine the pollution paths corresponding to the other target pollution dominant probabilities as secondary pollution sources. If so, determine the pollution paths corresponding to the other target pollution dominant probabilities as the latest target water quality sections, calculate the pollution dominant probabilities of each pollution path corresponding to the latest target water quality section, and determine the pollution path corresponding to the largest target pollution dominant probability as a secondary pollution source.

[0168] like Figure 6As shown in the figure, when solving the pollution dominant probability for water quality monitoring station 1, the pollution path with the highest probability is animal husbandry, which is listed as the primary pollution source. The second largest pollution dominant probability is the upstream water quality section. Therefore, taking water quality monitoring station 2 as the latest target water quality section, the pollution dominant probability is calculated again, and the pollution path with the highest probability is domestic sewage, which is listed as a secondary pollution source. From this, we can get the source of this pollution incident: the primary pollution source is animal husbandry, and the secondary pollution source is upstream domestic sewage.

[0169] Example 2

[0170] Please refer to Figure 2 A water pollution incident tracing terminal of this embodiment includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, each step of the water pollution incident tracing method in the first embodiment is implemented.

[0171] In summary, the present invention provides a method and terminal for tracing the source of water pollution incidents. When a pollution incident is monitored, the monitoring site is determined as the target water quality section. By obtaining the pollution curve of the target water quality section and calculating the pollution path pollution curve, surface source pollution curve and endogenous pollution curve corresponding to the target water quality section, the pollution dominance probability of each pollution path in the pollution incident is calculated, and the pollution source is determined based on the pollution dominance probability. Multi-source water pollution is taken into account, and the pollution source is simply and effectively located, thereby achieving accurate and rapid positioning of the source of the pollution incident. In addition, by calculating different types of pollution curves for analyzing the dominant factors of pollution incidents, the comprehensiveness and reliability of pollution incident tracing are improved. The pollution source is located from the perspective of the pollution dominance probability, and the pollution sources finally determined include primary pollution sources and secondary pollution sources, thereby achieving clear and accurate tracing of the pollution incident.

[0172] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's description and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for tracing the source of water pollution incidents, characterized in that: Including steps: Drawing a water environment map of the target watershed, wherein the water environment map includes monitoring sites; Determining whether the monitoring site detects a pollution event, and if so, determining the monitoring site as a target water quality section; Obtaining the pollution curve of the target water quality section, and calculating the pollution path pollution curve, nonpoint source pollution curve, and internal source pollution curve corresponding to the target water quality section; Calculating the pollution dominance probability of each pollution path based on the pollution curve of the target water quality section, the pollution path pollution curve, the non-point source pollution curve, and the internal source pollution curve, and determining the pollution source based on the pollution dominance probability of each pollution path; The step of obtaining the pollution curve of the target water quality section includes: Obtaining a pollutant concentration curve of the target water quality section; Determine the start time of the last increase in the pollutant concentration before the pollutant concentration exceeds the water quality standard for the first time and the end time of the first decrease in the pollutant concentration after the pollutant concentration exceeds the water quality standard for the last time in the pollutant concentration curve; Determine the start time as the starting point, and determine the end time as the end point; intercepting a pollution curve of the target water quality section from the pollutant concentration curve according to the starting point and the end point; The calculation of the pollution path pollution curve, the non-point source pollution curve, and the internal source pollution curve corresponding to the target water quality section includes: Determining the pollution path of the target water quality section according to the water environment context map; Obtaining the pollution index concentration and water flow of the pollution path; Calculating a pollution path pollution curve corresponding to the target water quality section according to the pollution index concentration, the water flow rate and the target water quality section; Determine a rainfall event corresponding to the target water quality section, and determine the rainfall amount, the accumulated rainfall amount over a preset time, and the rainfall month of the rainfall event; Obtaining pollution curves of the target water quality section at a plurality of moments before a time period corresponding to the pollution curve of the target water quality section; Fitting the pollution curves of the target water quality sections at the previous multiple moments, the rainfall of the rainfall event, the accumulated rainfall over the preset time, and the rainfall month to obtain a nonpoint source pollution curve corresponding to the target water quality section; A plurality of pollution curves of various monitoring indicators of the target watershed are obtained, and an average value of the plurality of pollution curves of various monitoring indicators is calculated to obtain an endogenous pollution curve corresponding to the target water quality section.

2. A method for tracing the source of a water pollution incident according to claim 1, characterized in that: The calculating of the pollution path pollution curve corresponding to the target water quality section according to the pollution index concentration, the water flow rate and the target water quality section includes: ； ； Where, represents the pollution path pollution curve corresponding to the target water quality section, express t i The pollution index concentration at the time, express t i The water flow at the time, h represents the sampling time interval, t i Indicates the pollution source of the pollution path i The transmission lag time between the target water quality section, t 0 represents the pollution moment of the target water quality section, l i Indicates the pollution source of the pollution path i The distance to the target water quality section, v i Indicates the average water flow velocity.

3. A method for tracing the source of a water pollution incident according to claim 1, characterized in that: The non-point source pollution curve corresponding to the target water quality section is obtained by fitting the pollution curves of the target water quality section at the previous multiple moments, the rainfall of the rainfall event, the accumulated rainfall in the preset time, and the rainfall month, including: ； Where, The pollution curve of the target water quality section is t The value at time 0, Represents the first parameter, Represents the second parameter, Represents the third parameter, Represents the fourth parameter, Represents the fifth parameter, Indicates that the pollution curve of each pollution path is t i The value of the moment, represents the autoregression of the pollution curve of the target water quality section at the previous multiple moments, express t The rainfall amount of the rainfall event at time 0, Indicates the cumulative rainfall during the preset time of the rainfall event, M Indicates the rainfall month of the rainfall event.

4. A method for tracing the source of a water pollution incident according to claim 1, characterized in that: The calculation of the pollution dominance probability of each pollution path based on the pollution curve of the target water quality section, the pollution path pollution curve, the non-point source pollution curve, and the internal source pollution curve includes: Determining a numerical curve corresponding to each pollution curve, the pollution curves including the pollution curve of the target water quality section, the pollution path pollution curve, the nonpoint source pollution curve, and the endogenous pollution curve; Determine a standard low value and a standard high value from each of the numerical curves, wherein the standard low value is the 25% quantile of each of the numerical curves, and the standard high value is the 75% quantile of each of the numerical curves; Determine the minimum and maximum values ​​for each pollution curve; If the minimum value is higher than the standard low value, the standard low value is replaced by the minimum value; if the maximum value is higher than the standard high value, the standard high value is replaced by the maximum value, to obtain each pollution curve after replacement; performing a standardization process on each of the replaced pollution curves to obtain each standardized pollution curve; Calculating the variance of each pollution curve after the standardization process, and calculating the difference between the variance of each pollution curve after the standardization process and the variance of the pollution curve of the target water quality section; Obtaining a fluctuation difference coefficient based on the difference; Using a dynamic time warping algorithm, the minimum cumulative distances between the pollution path pollution curve, the nonpoint source pollution curve, the endogenous pollution curve and the pollution curve of the target water quality section are calculated respectively; Percentilizing the minimum cumulative distance to obtain a fluctuation correlation coefficient; The pollution dominance probability of each pollution path is obtained according to the fluctuation correlation coefficient and the fluctuation difference coefficient.

5. A method for tracing the source of a water pollution incident according to claim 1, characterized in that: The determining of the pollution source based on the pollution dominant probability of each pollution path includes: Determine the pollution dominant probability of the pollution path that is greater than or equal to a preset threshold as the target pollution dominant probability; sorting the target pollution dominant probabilities in descending order to obtain sorted target pollution dominant probabilities; Determine whether the pollution path corresponding to the largest target pollution dominant probability among the sorted target pollution dominant probabilities is the upstream water quality section; if not, determine the pollution path corresponding to the largest target pollution dominant probability as the primary pollution source; if so, determine the pollution path corresponding to the largest target pollution dominant probability as the latest target water quality section, calculate the pollution dominant probabilities of each pollution path corresponding to the latest target water quality section, and determine the pollution path corresponding to the largest target pollution dominant probability as the primary pollution source; Determine in turn whether the pollution paths corresponding to the other pollution dominant probabilities except the largest target pollution dominant probability among the sorted target pollution dominant probabilities are upstream water quality sections. If not, determine the pollution paths corresponding to the other pollution dominant probabilities as secondary pollution sources. If so, determine the pollution paths corresponding to the other pollution dominant probabilities as the latest target water quality sections, calculate the pollution dominant probabilities of each pollution path corresponding to the latest target water quality section, and determine the pollution path corresponding to the largest target pollution dominant probability as a secondary pollution source.

6. A method for tracing the source of a water pollution incident according to claim 1, characterized in that: Drawing the water environment context map of the target basin includes: Collect relevant data of the target watershed; Identify monitoring sites in the target watershed; Obtaining pollution source data of the target watershed; A water environment context map of the target watershed is drawn based on the relevant data, the monitoring sites and the pollution source data.

7. A water pollution incident tracing terminal, 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 computer program, each step of the method for tracing the source of a water pollution incident according to any one of claims 1 to 6 is implemented.

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