Method and system for groundwater pollution source tracing based on sewage pipeline data

Abstract

The present application relates to the technical field of pollution tracing, and particularly relates to a groundwater pollution tracing method and system based on sewage pipeline data, which comprises: obtaining water flow and mineral dissolution content of monitoring wells; obtaining all suspected downstream monitoring wells of each monitoring well; analyzing fluctuation similarity of water flow combined with mineral dissolution content to obtain a plurality of monitoring wells contained in each underground river section; analyzing intersection conditions of underground river sections to obtain a plurality of tidal suspected connecting points and a plurality of marker wells thereof; obtaining high water flow dates of the marker wells of each tidal suspected connecting point; judging independence of trends of mineral dissolution content to obtain a plurality of tidal well channels and connecting river sections thereof; and connecting underground river sections to perform pollution tracing. The present application aims to solve the problems of unclear upstream and downstream of underground rivers and the influence of well channels between different underground river sections on tracing, and realizes accurate groundwater pollution tracing.

Description

Technical Field

[0001] The present invention relates to the technical field of pollution source tracing, and in particular to a method and system for groundwater pollution source tracing based on sewage pipeline data. Background Art

[0002] Groundwater is the primary water resource for people's livelihoods and production worldwide. Its sustainability and water safety directly impact social development and resident health. Groundwater resources in karst cities account for over 70% of their total water resources. Therefore, groundwater contamination severely impacts urban water security. The primary cause of urban groundwater contamination is sewage pipe leakage. Therefore, tracing the source of groundwater pollution in karst cities primarily relies on sewage pipelines as the primary data source. Isotope tracing of groundwater allows identification of the sewage pipelines through which the groundwater has passed, ultimately pinpointing the source of the leak.

[0003] Different groundwater layers are driven by gravity, density difference and heat to form water layers that do not interfere with each other. However, domestic and industrial water in cities in karst areas mainly rely on extracting groundwater by drilling wells. Drilling wells will connect multiple different levels of groundwater layers in the karst area. If the groundwater in one layer is polluted due to sewage pipe leakage, the interconnection of multi-layer water structures will affect multiple water layers, causing water pollution in other water layers, resulting in the inability to determine the source of pollution and increasing the difficulty of tracing the source of pollution. Summary of the Invention

[0004] The present invention provides a method and system for tracing the source of groundwater pollution based on sewage pipeline data to solve existing problems.

[0005] The groundwater pollution source tracing method and system based on sewage pipeline data of the present invention adopts the following technical solutions:

[0006] In a first aspect, an embodiment of the present invention provides a method for tracing the source of groundwater pollution based on sewage pipeline data, the method comprising the following steps:

[0007] Use the locations of groundwater monitoring wells, sewage pipelines, and their inspection wells to construct a sewage pipeline map; collect water flow and mineral dissolved content at each sampling time of the monitoring wells each day;

[0008] Analyze the peak-shift correlation of water flow between monitoring wells to obtain all suspected downstream monitoring wells of each monitoring well; analyze the similarity of water flow fluctuations between each monitoring well and its suspected downstream monitoring wells over a short distance, and combine the coordinated changes in the increase in mineral dissolved content and the flow distance to obtain the number of monitoring wells included in each underground river section;

[0009] Connect the monitoring wells included in each underground river section in the sewage pipeline map to obtain the underground river section pipeline network map; analyze the intersection of the underground river sections to obtain several suspected tidal connection points and several marked wells; select the dates when the water flow of each marked well is higher than its average daily flow rate to obtain the high water flow date of each marked well at each suspected tidal connection point;

[0010] Determine the independence of the trends of mineral dissolution content of all marker wells at each suspected tidal connection point on all high-flow dates, and obtain several tidal well channels and their connected river sections;

[0011] All connected river sections of the same tidal well channel in the underground river section pipeline network diagram are connected to obtain several through-river sections, and pollution source tracing is carried out through the intersection of the through-river sections and various sewage pipelines and their checkpoints.

[0012] Preferably, the specific steps for all suspected downstream monitoring wells of each monitoring well include:

[0013] Using the water flow of each monitoring well at each sampling time of each day, a historical water flow sequence of each monitoring well is constructed;

[0014] Any monitoring well is recorded as the target monitoring well, and any monitoring well other than the target monitoring well is recorded as the first monitoring well;

[0015] Performing dynamic time warping on the historical water flow sequences of the target monitoring well and the first monitoring well to obtain a matching water flow in the historical water flow sequence of the first monitoring well for each water flow in the historical water flow sequence of the target monitoring well;

[0016] If a water flow rate in the historical water flow sequence of the target monitoring well satisfies a one-to-one match with its matching water flow rate in the historical water flow sequence of the first monitoring well, the water flow rate in the historical water flow sequence of the target monitoring well is recorded as a fluctuation-characterized water flow rate of the target monitoring well;

[0017] Calculate the time interval between each fluctuation-characterized water flow rate of the target monitoring well and its matching water flow rate in the historical water flow sequence of the first monitoring well, and record it as the peak time difference between each fluctuation-characterized water flow rate of the target monitoring well and the first monitoring well;

[0018] The number of positive peak-to-peak time differences between all the fluctuation-representing water flow rates of the target monitoring well and the first monitoring well is recorded as the positive peak-to-peak value of the target monitoring well and the first monitoring well; the number of negative peak-to-peak time differences between all the fluctuation-representing water flow rates of the target monitoring well and the first monitoring well is recorded as the negative peak-to-peak value of the target monitoring well and the first monitoring well;

[0019] If the positive error peak values ​​of the target monitoring well and the first monitoring well are smaller than the negative error peak values, the first monitoring well is recorded as a suspected downstream monitoring well of the target monitoring well.

[0020] Preferably, the specific steps of the each monitoring well and its several suspected downstream monitoring wells include:

[0021] The inverse proportion normalized value of the distance between each monitoring well and its each suspected downstream monitoring well is recorded as the spatial difference weight of each monitoring well and its each suspected downstream monitoring well;

[0022] The approximate situation of the water flow trend of each monitoring well and its each suspected downstream monitoring well at each sampling time of each day is analyzed, and the spatial difference weight of each monitoring well and its each suspected downstream monitoring well is combined to obtain the water flow fluctuation similarity of each monitoring well and its each suspected downstream monitoring well;

[0023] The difference of the mineral dissolution content of each monitoring well and its each suspected downstream monitoring well at each sampling time of each day is analyzed, and the spatial difference weight of each monitoring well and its each suspected downstream monitoring well is combined to record the solution product connection degree of each monitoring well and its each suspected downstream monitoring well;

[0024] The water flow fluctuation similarity and the solution product connection degree of each monitoring well and its each suspected downstream monitoring well are integrated to obtain the connection possibility of each monitoring well and its each suspected downstream monitoring well, which is in a positive proportional relationship with the water flow fluctuation similarity and the solution product connection degree;

[0025] The suspected downstream monitoring well with the largest connection possibility among all suspected downstream monitoring wells of each monitoring well is recorded as the judged downstream monitoring well of each monitoring well;

[0026] A connection threshold is preset, and when the connection possibility of a monitoring well and its judged downstream monitoring well is greater than or equal to the connection threshold, the monitoring well is recorded as the first monitoring well of an underground river section, and the judged downstream monitoring well is recorded as the second monitoring well of the underground river section;

[0027] The current judged downstream monitoring well is taken as a new monitoring well, and the new judged downstream monitoring well of the new monitoring well is obtained, and the process is repeated until there is no judged downstream monitoring well for the new monitoring well, and all monitoring wells included in the underground river section are obtained.

[0028] Preferably, the specific steps of the water flow fluctuation similarity include:

[0029] Any one suspected downstream monitoring well of the target monitoring well is recorded as a second monitoring well, and the water flow fluctuation similarity of the target monitoring well and the second monitoring well includes:

[0030] The inverse proportion normalized value of the DTW distance of the historical water flow sequence of the target monitoring well and the second monitoring well after dynamic time warping is recorded as the water flow trend approximation degree of the target monitoring well and the second monitoring well;

[0031] The product of the water flow trend approximation between the target monitoring well and the second monitoring well and the spatial difference weight between the target monitoring well and the second monitoring well is recorded as the water flow fluctuation similarity between the target monitoring well and the second monitoring well.

[0032] Preferably, the specific steps of determining the degree of connection of the solution product include:

[0033] The sum of the difference in mineral dissolution content between the target monitoring well and the second monitoring well at each sampling time of the day is recorded as the mineral dissolution content increment between the target monitoring well and the second monitoring well;

[0034] The product of the inversely proportional normalized value of the increment of the mineral dissolution content and the spatial difference weight of the target monitoring well and the second monitoring well is recorded as the solution product connection degree between the target monitoring well and the second monitoring well.

[0035] Preferably, analyzing the intersection of underground river sections to obtain a number of suspected tidal connection points and a number of marked wells includes:

[0036] Obtain the intersection points of all underground river sections and the underground river sections corresponding to each intersection point in the underground river section pipe network map;

[0037] If the location distance of multiple intersection points is less than or equal to the preset location distance threshold, the centroid of these multiple intersection points is recorded as a tidal suspected connection point, and the tidal suspected connection point inherits the underground river sections corresponding to these multiple intersection points;

[0038] If the distance between a junction and all other junctions is greater than the preset distance threshold, the junction is recorded as a suspected tidal connection point, and the suspected tidal connection point inherits the underground river section corresponding to the junction;

[0039] Among all the monitoring wells in each underground river section corresponding to each suspected tidal connection point, the monitoring well closest to the location of the suspected tidal connection point is recorded as the marker well of each suspected tidal connection point.

[0040] Preferably, the specific steps of the high water flow date include:

[0041] Obtain the average of the water flow of each marker well at each suspected tidal connection point at all sampling times on all days, and record it as the average daily water flow of each marker well at each suspected tidal connection point;

[0042] Obtain the mean of the water flow of each marker well at each suspected tidal connection point at all sampling times of each day, and record it as the average water flow of each marker well at each suspected tidal connection point on each day;

[0043] The date when the average water flow of each marked well at each suspected tidal connection point is greater than the average daily water flow is recorded as the high water flow date of each marked well at each suspected tidal connection point.

[0044] Preferably, the specific steps of the plurality of tidal well channels and the connected river sections include:

[0045] The mineral dissolution content of all the marker wells at each suspected tidal connection point at each sampling time on all high water flow dates was used to construct the mineral dissolution content matrix of each suspected tidal connection point.

[0046] Calculating the covariance matrix of the mineral dissolution matrix of each tidal suspected connection point, and obtaining the eigenvector of the covariance matrix by principal component analysis algorithm;

[0047] Arrange the eigenvalues ​​of the eigenvectors of the covariance matrix in descending order and record them as the principal component descending sequence of each tidal suspected connected point;

[0048] The difference between the eigenvalue of each eigenvector and the eigenvalue of the next eigenvector in the descending sequence of the principal components of each tidal suspected connection point is recorded as the principal component decision coefficient of each eigenvector of each tidal suspected connection point;

[0049] The sequence number of the eigenvector with the largest principal component decision coefficient in the descending sequence of the principal components is recorded as the number of principal component directions of the mineral dissolution matrix of each tidal suspected connection point;

[0050] If the number of principal component directions of the mineral dissolution matrix of each suspected tidal connection point is greater than or equal to the number of marked wells of each suspected tidal connection point, the suspected tidal connection point is recorded as a tidal well channel, and the underground river section corresponding to the marked well of the suspected tidal connection point is recorded as the connected river section of the tidal well channel.

[0051] Preferably, all connected river sections of the same tidal well channel in the underground river section pipe network diagram are connected to obtain a number of through river sections, and pollution source tracing is performed based on the intersection of the through river sections and each sewage pipeline and its checkpoint, including:

[0052] Connect all connected river sections of the same tidal well channel in the underground river section pipe network diagram to obtain several through-channel sections;

[0053] The through-stream and underground river sections are regarded as traceable rivers. All sewage pipelines that intersect with existing traceable rivers with pollution are recorded as suspected sewage pipelines. The nearest inspection point upstream of the suspected sewage pipeline at the intersection of the traceable river with pollution and each suspected sewage pipeline is recorded as the tracing inspection point of each suspected sewage pipeline.

[0054] Starting from the suspected sewage pipeline at the downstream end of the traceable river with pollution, isotopes are released at the tracer checkpoint of the suspected sewage pipeline at the downstream end, and tracers are monitored in the monitoring well closest to the tracer checkpoint. If tracers are detected, the tracer checkpoint is recorded as a leakage checkpoint; if no tracers are detected, the tracer checkpoint is judged towards the adjacent suspected sewage pipeline upstream of the traceable river with pollution until a leakage checkpoint is obtained.

[0055] In the second aspect, the present invention also proposes a groundwater pollution tracing system based on sewage pipeline data, which includes a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the steps of the above method are implemented.

[0056] The beneficial effects of the technical solution of the present invention are: the present invention utilizes the positions of groundwater monitoring wells and the positions of sewage pipelines and their inspection wells to construct a sewage pipeline map; collects and obtains the water flow and mineral dissolved content of the monitoring wells at each sampling time of the day; analyzes the peak-shifting correlation of water flow between monitoring wells, and obtains all suspected downstream monitoring wells of each monitoring well; obtains the downstream monitoring wells of the monitoring well by analyzing the peak-shifting relationship of water flow between each monitoring well; analyzes the similarity of fluctuations of water flow between each monitoring well and its suspected downstream monitoring wells in a short distance, and combines the coordinated changes of the increase in mineral dissolved content and the flow distance to obtain several monitoring wells contained in each underground river section; by analyzing the similarity of water flow fluctuations in the same underground river section, and the characteristics that the increase in dissolved mineral content is small in adjacent monitoring wells in the same river channel under short-distance flow, connects each monitoring well to obtain several underground river sections; connects the monitoring wells contained in each underground river section in the sewage pipeline map to obtain an underground river section pipeline network map; analyzes the intersection of underground river sections to obtain several tidal suspected Connecting points and several marked wells; after visualizing the location information of underground river sections, determine their intersections and use them as suspected tidal connecting points, which serve as the location coordinate basis for analyzing tidal well channels; screen the dates when each marked well is higher than its average daily water flow, and obtain the high water flow dates of each marked well at each suspected tidal connecting point; use the tidal well channel to cause the blending characteristics of different river sections under large water volume conditions to screen the high water flow dates of each river channel; determine the independence of the trends of mineral dissolved content of all marked wells at each suspected tidal connecting point on all high water flow dates, and obtain several tidal well channels and their connected river sections; by analyzing the independence of the trends of mineral dissolved content in the water flow of the marked wells corresponding to the same suspected tidal connecting point, determine the consistency between the independent trends and the number of underground river sections, and determine whether the suspected tidal connecting point belongs to the tidal well channel; connect all the connected river sections of the same tidal well channel in the underground river section pipeline network map to obtain several through river sections, and trace the pollution source through the intersection of the through river sections and various sewage pipelines and their inspection points. The present invention aims to solve the problem of unclear upstream and downstream of underground rivers and the impact of well channels between different underground river sections on source tracing, and to achieve accurate groundwater pollution source tracing. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0058] Figure 1 This is a flowchart of the steps of the groundwater pollution source tracing method based on sewage pipeline data of the present invention. DETAILED DESCRIPTION

[0059] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the following, in combination with the accompanying drawings and preferred embodiments, describes in detail the specific implementation methods, structures, features and effects of the groundwater pollution source tracing method and system based on sewage pipeline data proposed by the present invention. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0060] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0061] The specific scheme of the groundwater pollution source tracing method and system based on sewage pipeline data provided by the present invention is described in detail below with reference to the accompanying drawings.

[0062] See also Figure 1 , which shows a flowchart of a method for tracing the source of groundwater pollution based on sewage pipeline data provided by an embodiment of the present invention, the method comprising the following steps:

[0063] Step S001: construct a sewage pipeline map using the locations of groundwater monitoring wells, sewage pipelines and their inspection well locations; collect and obtain the water flow and mineral dissolved content of the monitoring wells at each sampling time every day.

[0064] Since sewage pipelines are installed manually, inspection wells are set up at regular intervals underground. When tracing the source of pollution, if a sewage pipeline section is suspected of leaking, isotope tracers are placed in the corresponding upstream inspection well to determine whether the corresponding isotopes appear in the underground river, thereby determining the location of the leak point. This embodiment is based on groundwater pollution tracing based on sewage pipeline data, so it is first necessary to collect and obtain the locations of the sewage pipelines and each inspection well.

[0065] Specifically, the direction of the sewage pipeline and the geographical location of each inspection well along the sewage pipeline are obtained through public information from the municipal drainage management department to construct a sewage pipeline original map. The location of each inspection well in the sewage pipeline original map described in this embodiment is described by its latitude and longitude coordinates. Other embodiments may use other representation methods.

[0066] When tracing the source of groundwater pollution, it is usually necessary to obtain the location of each underground river and obtain water samples from each underground river through sampling for isotope analysis. However, in this process, due to the complex structure of underground caves, water layers and rivers in karst cities, the existing geological radar method has a small detection depth when detecting underground rivers and caves due to the influence of radar penetration and underground structure, usually less than 50 meters. Underground rivers exist in multiple layers in karst cities, and multiple underground rivers are intertwined, resulting in the existence of multiple underground rivers at the same depth in different locations. It is difficult to determine the underground river to which each location belongs from all the monitored groundwater layers.

[0067] Therefore, this embodiment samples and monitors the groundwater that can be monitored, and then analyzes the correlation between water samples from monitoring wells at different locations, thereby obtaining the monitorable points belonging to each underground river. Since the channel diameter of the same underground river is fixed, its flow rate is related to the speed compared to surface water, and the groundwater in the karst area is rich in 、 Therefore, in this embodiment, after selecting the location of the monitoring well, the water flow rate and mineral dissolution content of each monitoring well at the sampling node are obtained.

[0068] Specifically, the location of groundwater in the karst area is detected by geological radar, and monitoring wells are drilled at locations where groundwater can be detected;

[0069] In the preset historical sampling range, the water flow rate and mineral dissolved content of each monitoring well at each sampling time of each day are obtained. It should be noted that the historical sampling range of this embodiment takes the most recent month as an example, and the sampling time is sampled at an interval of 1 hour. The water flow rate is obtained by installing a water flow sensor in each monitoring well to obtain the water flow rate at each sampling time, and after extracting water samples from the monitoring well at each sampling time, the ion concentration detection method is used to obtain the water flow rate of each monitoring well at each sampling time of each day. Concentration is recorded as the dissolved mineral content of each monitoring well at each sampling time of each day.

[0070] Furthermore, the location of each monitoring well is mapped to the original sewage pipeline map to obtain a sewage pipeline map.

[0071] Step S002: Analyze the peak-shifting correlation of water flow between monitoring wells to obtain all suspected downstream monitoring wells of each monitoring well; analyze the similarity of water flow fluctuations between each monitoring well and its suspected downstream monitoring wells in a short distance, and combine the coordinated changes of the increase in mineral dissolved content and the flow distance to obtain the number of monitoring wells contained in each underground river section.

[0072] For each monitoring well, since the diameter of the underground river is fixed, when the water volume upstream changes, the water volume downstream will also change accordingly. Therefore, for two adjacent monitoring wells belonging to the same underground river section, the changes in their water flow are the same after a certain period of time. Therefore, this embodiment determines the suspected downstream monitoring wells suspected to belong to each monitoring well through the staggered correlation of water flow between different monitoring wells.

[0073] Preferably, the specific steps of analyzing the peak-shift correlation of water flow between monitoring wells and obtaining all suspected downstream monitoring wells of each monitoring well include:

[0074] Using the water flow of each monitoring well at each sampling time of each day, a historical water flow sequence of each monitoring well is constructed;

[0075] Perform time series alignment on the historical water flow sequences of each monitoring well and other monitoring wells, and obtain the matching water flow of each water flow in the historical water flow sequence of each monitoring well in the historical water flow sequence of each other monitoring well;

[0076] The temporal dislocation relationship between each water flow in the historical water flow sequence of each monitoring well and the matching water flow in the historical water flow sequence of each other monitoring well is analyzed to obtain all suspected downstream monitoring wells of each monitoring well.

[0077] Specifically, using the water flow of each monitoring well at each sampling time every day, constructing the historical water flow sequence of each monitoring well specifically includes:

[0078] The sequence of water flow of each monitoring well at each sampling time of each day is recorded as the historical water flow sequence of each monitoring well.

[0079] Furthermore, the historical water flow sequences of each monitoring well and other monitoring wells are time-series aligned to obtain each water flow in the historical water flow sequence of each monitoring well. The matching water flow in the historical water flow sequence of each other monitoring well specifically includes:

[0080] It should be noted that the historical water flow sequences of the suspected upstream and downstream monitoring wells in the same river section have staggered correlations, that is, the peak values ​​of the water flow changes at different times are similar. Therefore, by performing time series alignment on the suspected upstream and downstream monitoring wells, the alignment of the aligned matching times can be determined to obtain all the suspected downstream monitoring wells of each monitoring well.

[0081] Any monitoring well is recorded as the target monitoring well, and any monitoring well other than the target monitoring well is recorded as the first monitoring well;

[0082] Performing dynamic time warping on the historical water flow sequences of the target monitoring well and the first monitoring well to obtain a matching water flow in the historical water flow sequence of the first monitoring well for each water flow in the historical water flow sequence of the target monitoring well;

[0083] Similarly, each water flow in the historical water flow sequence of each monitoring well is obtained, and the matching water flow in the historical water flow sequence of each other monitoring well is obtained.

[0084] Furthermore, the temporal dislocation relationship between each water flow in the historical water flow sequence of each monitoring well and the matching water flow in the historical water flow sequence of each other monitoring well is analyzed to obtain all suspected downstream monitoring wells of each monitoring well, including:

[0085] Count the positive and negative times of each water flow in the historical water flow sequence of each monitoring well and the matching water flow in the historical water flow sequence of each other monitoring well after a one-to-one matching is achieved, and record them as the positive and negative peak values ​​of each monitoring well and each other monitoring well;

[0086] It should be noted that since there are a lot of matching situations in dynamic time warping, which are mainly for sequences with no obvious change trend, this embodiment does not consider them when performing analysis.

[0087] If the positive error peak value between a monitoring well and a monitoring well other than the monitoring well is smaller than the negative error peak value, the monitoring well other than the monitoring well will be recorded as the suspected downstream monitoring well of the monitoring well.

[0088] As an example, for the target monitoring well and the first monitoring well, the steps of obtaining the positive error peak value and the negative error peak value of the target monitoring well and the first monitoring well are:

[0089] If a water flow rate in the historical water flow sequence of the target monitoring well satisfies a one-to-one match with its matching water flow rate in the historical water flow sequence of the first monitoring well, the water flow rate in the historical water flow sequence of the target monitoring well is recorded as a fluctuation-characterized water flow rate of the target monitoring well;

[0090] Calculate the time interval between each fluctuation-characterized water flow rate of the target monitoring well and its matching water flow rate in the historical water flow sequence of the first monitoring well, and record it as the peak-offset time difference between each fluctuation-characterized water flow rate of the target monitoring well and the first monitoring well; the time interval is the result of subtracting the time of the matching water flow rate in the historical water flow sequence of the first monitoring well from the time of the water flow rate in the historical water flow sequence of the target monitoring well;

[0091] It should be noted that when the off-peak time difference is negative, it means that the water flow in the historical water flow sequence of the target monitoring well undergoes the same change as the matching water flow in the historical water flow sequence of the first monitoring well, and is before the timing of the matching water flow in the historical water flow sequence of the first monitoring well, which means that the first monitoring well is downstream of the target monitoring well.

[0092] Furthermore, the number of positive peak-to-peak time differences between all fluctuation-representing water flow rates of the target monitoring well and the first monitoring well is recorded as the positive peak-to-peak value of the target monitoring well and the first monitoring well, and the number of negative peak-to-peak time differences between all fluctuation-representing water flow rates of the target monitoring well and the first monitoring well is recorded as the negative peak-to-peak value of the target monitoring well and the first monitoring well.

[0093] Preferably, the specific steps of analyzing the similarity of water flow fluctuations between each monitoring well and its suspected downstream monitoring wells over a short distance and combining the coordinated changes in the increment of dissolved mineral content and the flow distance to obtain the number of monitoring wells included in each underground river section are as follows:

[0094] The inverse proportional normalized value of the distance between each monitoring well and its suspected downstream monitoring wells is recorded as the spatial difference weight of each monitoring well and its suspected downstream monitoring wells;

[0095] The similarity of water flow trends between each monitoring well and its suspected downstream monitoring wells at each sampling time of the day was analyzed. The similarity of water flow fluctuations between each monitoring well and its suspected downstream monitoring wells was obtained by combining the spatial difference weights of each monitoring well and its suspected downstream monitoring wells.

[0096] Analyze the difference in mineral dissolved content between each monitoring well and its suspected downstream monitoring wells at each sampling time of the day, and combine the spatial difference weights between each monitoring well and its suspected downstream monitoring wells to record the degree of connection between each monitoring well and its suspected downstream monitoring wells;

[0097] Based on the similarity of water flow fluctuations and the degree of connection between solution products of each monitoring well and its suspected downstream monitoring wells, the connection probability of each monitoring well and its suspected downstream monitoring wells is obtained. The connection probability is positively proportional to the similarity of water flow fluctuations and the degree of connection between solution products.

[0098] Each monitoring well is connected to each suspected downstream monitoring well through the connection possibility to obtain a number of monitoring wells included in each underground river section.

[0099] Specifically, the water flow trend similarity between each monitoring well and its suspected downstream monitoring wells at each sampling time of each day is analyzed. Combined with the spatial difference weights of each monitoring well and its suspected downstream monitoring wells, the water flow fluctuation similarity between each monitoring well and its suspected downstream monitoring wells is obtained. Specifically, the following are the results:

[0100] As an example, any suspected downstream monitoring well of the target monitoring well is recorded as the second monitoring well. For the target monitoring well and the second monitoring well, obtaining the similarity of water flow fluctuations between the target monitoring well and the second monitoring well includes:

[0101] The inverse proportional normalized value of the DTW distance between the historical water flow series of the target monitoring well and the second monitoring well after dynamic time warping is recorded as the water flow trend approximation between the target monitoring well and the second monitoring well;

[0102] The product of the water flow trend approximation between the target monitoring well and the second monitoring well and the spatial difference weight between the target monitoring well and the second monitoring well is recorded as the water flow fluctuation similarity between the target monitoring well and the second monitoring well.

[0103] It should be noted that the DTW distance can reflect the difference in the changing trends of historical water flow series. The smaller the value, the smaller the difference. The closer the distance between a monitoring well and its suspected downstream monitoring well, the smaller the difference in the water flow trend, and the closer the water flow trend between the monitoring well and its suspected downstream monitoring well. The method of obtaining the DTW distance through dynamic time warping is a well-known technique and will not be further described in this embodiment.

[0104] Furthermore, the differences in the dissolved mineral content of each monitoring well and its suspected downstream monitoring wells at each sampling time of each day were analyzed. Combined with the spatial difference weights of each monitoring well and its suspected downstream monitoring wells, the degree of connection between the solution products of each monitoring well and its suspected downstream monitoring wells was recorded as follows:

[0105] It should be noted that since the mineral dissolved content in the underground river is constantly increasing due to the scouring of the karst area by the water flow, the mineral dissolved content in the adjacent monitoring wells is constantly increasing. Therefore, this embodiment obtains the degree of connection between the solution products of each monitoring well and its suspected downstream monitoring wells by analyzing the coordinated changes in the increase in mineral dissolved content and the flow distance.

[0106] The term "synergistic change" refers to the change in the common parameters of the mineral dissolution increment and the flow distance. As the flow distance changes, the mineral dissolution increment can also produce a certain degree of synergistic change. It can be understood that the mineral dissolution increment represents the difference in the change in mineral dissolution content, while the flow distance characterizes the location distance. Therefore, based on the values ​​of these two, the degree of connection between solution products can be synergistically calculated.

[0107] As an example, for the target monitoring well and the second monitoring well, obtaining the degree of connection between the solution products of the target monitoring well and the second monitoring well includes:

[0108] The sum of the difference in mineral dissolution content between the target monitoring well and the second monitoring well at each sampling time of the day is recorded as the mineral dissolution content increment between the target monitoring well and the second monitoring well;

[0109] The product of the inversely proportional normalized value of the increment of the mineral dissolution content and the spatial difference weight of the target monitoring well and the second monitoring well is recorded as the solution product connection degree between the target monitoring well and the second monitoring well.

[0110] The solution product connection degree indicates the degree of association between the target monitoring well and the second monitoring well in terms of solution products.

[0111] It should be noted that the smaller the increment of dissolved mineral content in two monitoring wells and the closer the distance between them, the more likely it is that the two monitoring wells belong to the same underground river section.

[0112] In the embodiment of the present invention, since the aforementioned includes "normalizing the inverse proportion of the position distance between each monitoring well and its suspected downstream monitoring wells as the spatial difference weight between each monitoring well and its suspected downstream monitoring wells", that is, the spatial difference weight has a distance characteristic, the flow distance can be represented by the spatial difference weight. The larger the value of the spatial difference weight, the closer the position distance, which further represents the higher the value of the degree of connection between the solution products.

[0113] Since the smaller the increment of mineral dissolution content, the smaller the difference in mineral dissolution content between the two monitoring wells at different sampling times, the higher the similarity of the change in mineral dissolution content in the two monitoring wells in time series, that is, the higher the degree of connection between the solution products.

[0114] Furthermore, the connection probability of each monitoring well with each suspected downstream monitoring well is obtained by comprehensively considering the similarity of water flow fluctuation and the degree of connection of solution products between each monitoring well and each suspected downstream monitoring well. The connection probability is positively proportional to the similarity of water flow fluctuation and the degree of connection of solution products, specifically including:

[0115] As an example, the target monitoring well and the second monitoring well are considered as a monitoring well group. The connection possibilities of the target monitoring well and the second monitoring well include:

[0116] The second norm of the similarity of water flow fluctuations and the degree of connection between solution products of the monitoring well group is recorded as the connection possibility of the monitoring well group.

[0117] In other words, the target monitoring well and the second monitoring well have the characteristics of similar water flow fluctuations and the degree of connection between solution products. The two characteristics are integrated through the calculation method of the second norm to obtain the connection possibility of the monitoring well group.

[0118] Furthermore, each monitoring well is connected with each suspected downstream monitoring well through the connection possibility to obtain a number of monitoring wells included in each underground river section, including:

[0119] The suspected downstream monitoring well with the greatest possibility of connection among all suspected downstream monitoring wells of each monitoring well is recorded as the determined downstream monitoring well of each monitoring well;

[0120] A connection threshold is preset. When the connection possibility between a monitoring well and its downstream monitoring well is greater than or equal to the connection threshold, the monitoring well is recorded as the first monitoring well of an underground river section, and the downstream monitoring well is recorded as the second monitoring well of this underground river section.

[0121] The currently judged downstream monitoring well is used as a new monitoring well to obtain a new judged downstream monitoring well of the new monitoring well, and so on, until the new monitoring well no longer has a judged downstream monitoring well, and all the monitoring wells contained in this underground river section are obtained.

[0122] It should be noted that the connection threshold in this embodiment is described by taking 0.6 as an example.

[0123] As an example, the suspected downstream monitoring well with the greatest connection possibility among the target monitoring well and all its suspected downstream monitoring wells is recorded as the third monitoring well; if the connection possibility between the target monitoring well and the third monitoring well is greater than or equal to the connection threshold, the target monitoring well is recorded as the first monitoring well of an underground river section, the third monitoring well is recorded as the second monitoring well of this underground river section, and the second monitoring well is used as the new target monitoring well to obtain the judged downstream monitoring well of the new target monitoring well, and so on, until the new target monitoring well no longer has a judged downstream monitoring well, and all the monitoring wells contained in this underground river section are obtained.

[0124] Step S003: Connect the monitoring wells included in each underground river section in the sewage pipeline map to obtain an underground river section pipeline network map; analyze the intersection of the underground river sections to obtain several suspected tidal connection points and several marked wells; screen the dates when each marked well is higher than its average daily water flow, and obtain the high water flow dates of each marked well of each suspected tidal connection point; determine the independence of the trends of the mineral dissolved content of all marked wells of each suspected tidal connection point on all high water flow dates, and obtain several tidal well channels and their connected river sections.

[0125] Due to the complex structure of the groundwater layer in the karst area and the existence of natural channels, and the fact that the main water used in cities in the karst area is groundwater, there are connected well channels between the multiple underground water structures, which enables the exchange of water flow and ions between different water layers. These well channels are mainly divided into regular well channels and tidal well channels. Regular well channels are caused by the collapse of caves and artificial well drilling, which directly connect the underground river sections of different water layers; the other is tidal well channels, which are usually located at high positions in the underground river sections, or due to the pressure difference between the underground river sections that are penetrated, large amounts of water and ion exchange cannot be carried out by gravity.

[0126] For the two underground river sections at the upper and lower levels that are connected by the tidal well channel, when the water flow of the upper underground river section increases, the water flow burden of the upper river section increases and the water level rises, which will cause the water in the upper underground river section to enter the lower underground river section; when tracing the source of groundwater pollution, the tidal well channel makes the pollution characteristics of the isotope tracer incoherent. Therefore, this embodiment analyzes the intersection of different underground rivers, and then analyzes the flow trend of the intersecting underground rivers on high water flow days, and then obtains several tidal well channels and their connected river sections.

[0127] Specifically, in the sewage pipeline map, each monitoring well is connected in the order of the underground river section to which it belongs, so as to obtain the underground river section pipeline network map.

[0128] It should be noted that tidal well channels will only appear when underground river sections converge at the same location. Therefore, the intersection of underground river sections is analyzed to obtain suspected tidal connection points and several marked wells.

[0129] Preferably, the specific steps of analyzing the intersection of underground river sections to obtain several suspected tidal connection points and several marked wells are:

[0130] Obtain the intersection points of all underground river sections and the underground river sections corresponding to each intersection point in the underground river section pipe network map; filter all intersection points to obtain several suspected tidal connection points and their corresponding underground river sections;

[0131] Among all the monitoring wells in each underground river section corresponding to each suspected tidal connection point, the monitoring well closest to the location of the suspected tidal connection point is recorded as the marker well of each suspected tidal connection point.

[0132] It should be noted that, since the flow area of ​​the underground river section may be large, although multiple underground river sections do not intersect at the same location, the locations of their intersections are close. Therefore, this embodiment screens the close intersections to obtain suspected tidal connection points.

[0133] Specifically, all intersection points are screened to obtain several suspected tidal connection points and their corresponding underground river sections, including:

[0134] If the location distance of multiple intersection points is less than or equal to the preset location distance threshold, the centroid of these multiple intersection points is recorded as a tidal suspected connection point, and the tidal suspected connection point inherits the underground river sections corresponding to these multiple intersection points;

[0135] If the location distance between a junction and all other junctions is greater than the preset location distance threshold, the junction is recorded as a suspected tidal connection point, and the suspected tidal connection point inherits the underground river section corresponding to the junction.

[0136] It should be noted that the location distance threshold in this embodiment is described using 2 kilometers as an example.

[0137] Preferably, the specific steps of screening the dates when the water flow of each marked well is higher than its average daily flow to obtain the high water flow dates of each marked well of each suspected tidal connection point include:

[0138] Obtain the average of the water flow of each marker well at each suspected tidal connection point at all sampling times on all days, and record it as the average daily water flow of each marker well at each suspected tidal connection point;

[0139] Obtain the mean of the water flow of each marker well at each suspected tidal connection point at all sampling times of each day, and record it as the average water flow of each marker well at each suspected tidal connection point on each day;

[0140] The date when the average water flow of each marked well at each suspected tidal connection point is greater than the average daily water flow is recorded as the high water flow date of each marked well at each suspected tidal connection point.

[0141] It should be noted that the flow paths in each underground river section are different, and rocks will be dissolved during the flow of the underground river section, resulting in the presence of dissolved minerals in the water flow. Since the river channels in the same underground river section are the same, while the river channels in different underground river sections are different, the dissolved mineral content in the same underground river section has the same trend, while the change trends of minerals in different underground river sections are different. If the trends of mineral dissolution content in the marked wells of multiple underground river sections corresponding to a suspected tidal connection point are independent of each other, then there is no water flow confluence caused by well channels. When the number of independent change trends of mineral dissolution content is less than the number of underground river sections corresponding to the suspected tidal connection point, it means that there is water flow confluence, that is, there is a well channel at the suspected tidal connection point.

[0142] Preferably, the independence of the trends of mineral dissolution content of all marked wells at each suspected tidal connection point on all high water flow dates is determined, and the specific steps for obtaining several tidal well channels and their connected river sections are as follows:

[0143] The mineral dissolution content of all the marker wells at each suspected tidal connection point at each sampling time on all high water flow dates was used to construct the mineral dissolution content matrix of each suspected tidal connection point.

[0144] It should be noted that the mineral dissolution matrix is ​​a three-dimensional matrix, the X-axis is the serial number of the marked well, the Y-axis is the high water flow date of each marked well, and the Z-axis is the mineral dissolution content of each marked well at each sampling time on each high water flow date.

[0145] Calculating the covariance matrix of the mineral dissolution matrix of each tidal suspected connection point, and obtaining the eigenvector of the covariance matrix by principal component analysis algorithm;

[0146] It should be noted that the calculation of the covariance matrix and eigenvectors of the mineral dissolution matrix, as well as the principal component analysis algorithm are well-known technologies and will not be described in detail in this embodiment.

[0147] Arrange the eigenvalues ​​of the eigenvectors of the covariance matrix in descending order and record them as the principal component descending sequence of each tidal suspected connected point;

[0148] The difference between the eigenvalue of each eigenvector and the eigenvalue of the next eigenvector in the descending sequence of the principal components of each tidal suspected connection point is recorded as the principal component decision coefficient of each eigenvector of each tidal suspected connection point;

[0149] The sequence number of the eigenvector with the largest principal component decision coefficient in the descending sequence of the principal components is recorded as the number of principal component directions of the mineral dissolution matrix of each tidal suspected connection point;

[0150] If the number of principal component directions of the mineral dissolution matrix of each suspected tidal connection point is greater than or equal to the number of marked wells of each suspected tidal connection point, the suspected tidal connection point is recorded as a tidal well channel, and the underground river section corresponding to the marked well of the suspected tidal connection point is recorded as the connected river section of the tidal well channel.

[0151] When the number of principal component directions of the mineral dissolution matrix of each suspected tidal connection point is greater than or equal to the number of marked wells of each suspected tidal connection point, it indicates that there is no mixing of carbonate solution products in the underground river section corresponding to the marked wells of each suspected tidal connection point, and the change trends between the carbonate solution products are independent of each other; otherwise, it indicates that there is mixing of carbonate solution products at the suspected tidal connection point, resulting in a decrease in independent characteristics, thus proving the existence of a tidal well channel at the suspected tidal connection point.

[0152] Step S004: Connect all connected river sections of the same tidal well channel in the underground river section pipe network diagram to obtain several through-link river sections, and trace the pollution source through the intersection of the through-link river sections and each sewage pipeline and its checkpoint.

[0153] Currently, the source of groundwater pollution is mainly traced through the isotope tracing method. Isotopes are released into the nearest inspection well upstream of the suspected leaking sewage pipeline, and samples are then collected through the monitoring wells of the underground river section to analyze whether they contain isotopes. If they do, it means that sewage has leaked here. Otherwise, it is judged that sewage has leaked upstream, thereby tracing the source of groundwater pollution.

[0154] This embodiment uses the underground river section pipe network map to analyze the tidal well channels and connected river sections between the underground river sections, so that when tracing the source of sewage, the underground river sections connected by the tidal well channels can be connected to avoid tracing errors caused by the tidal well channels.

[0155] Specifically, all connected river sections of the same tidal well channel are connected in the underground river section pipe network diagram to obtain several through-channel sections;

[0156] The through-stream and underground river sections are regarded as traceable rivers. All sewage pipelines that intersect with existing traceable rivers with pollution are recorded as suspected sewage pipelines. The nearest inspection point upstream of the suspected sewage pipeline at the intersection of the traceable river with pollution and each suspected sewage pipeline is recorded as the tracing inspection point of each suspected sewage pipeline.

[0157] Starting from the suspected sewage pipeline at the downstream end of the traceable river with pollution, isotopes are released at the tracer checkpoint of the suspected sewage pipeline at the downstream end, and the tracer is monitored in the monitoring well closest to the tracer checkpoint. If the tracer is detected, the tracer checkpoint is recorded as a leakage checkpoint; if the tracer is not detected, the suspected sewage pipeline adjacent to the upstream of the traceable river with pollution is judged until a leakage checkpoint is obtained, proving that pollution exists at the tracer checkpoint, thereby realizing the tracing of groundwater pollution.

[0158] Another embodiment of the present invention provides a groundwater pollution tracing system based on sewage pipeline data, which includes a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, steps S001 to S004 of the above method are implemented.

[0159] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A groundwater pollution source tracing method based on sewage pipeline data is characterized by: The method comprises the following steps: Use the locations of groundwater monitoring wells, sewage pipelines, and their inspection wells to construct a sewage pipeline map; collect water flow and mineral dissolved content at each sampling time of the monitoring wells each day; Analyze the peak-shift correlation of water flow between monitoring wells to obtain all suspected downstream monitoring wells of each monitoring well; analyze the similarity of water flow fluctuations between each monitoring well and its suspected downstream monitoring wells over a short distance, and combine the coordinated changes in the increase in mineral dissolved content and the flow distance to obtain the number of monitoring wells included in each underground river section; Connect the monitoring wells included in each underground river section in the sewage pipeline map to obtain the underground river section pipeline network map; analyze the intersection of the underground river sections to obtain several suspected tidal connection points and several marked wells; select the dates when the water flow of each marked well is higher than its average daily flow rate to obtain the high water flow date of each marked well at each suspected tidal connection point; Determine the independence of the trends of mineral dissolution content of all marker wells at each suspected tidal connection point on all high-flow dates, and obtain several tidal well channels and their connected river sections; Connect all connected river sections of the same tidal well channel in the underground river section pipeline network diagram to obtain several through-river sections, and trace the pollution source through the intersection of the through-river sections and various sewage pipelines and their checkpoints; The specific steps of the monitoring wells in each underground river section include: The inverse proportional normalized value of the distance between each monitoring well and its suspected downstream monitoring wells is recorded as the spatial difference weight of each monitoring well and its suspected downstream monitoring wells; The similarity of water flow trends between each monitoring well and its suspected downstream monitoring wells at each sampling time of the day was analyzed. The similarity of water flow fluctuations between each monitoring well and its suspected downstream monitoring wells was obtained by combining the spatial difference weights of each monitoring well and its suspected downstream monitoring wells. Analyze the difference in mineral dissolved content between each monitoring well and its suspected downstream monitoring wells at each sampling time of the day, and combine the spatial difference weights between each monitoring well and its suspected downstream monitoring wells to record the degree of connection between each monitoring well and its suspected downstream monitoring wells; Based on the similarity of water flow fluctuations and the degree of connection between solution products of each monitoring well and its suspected downstream monitoring wells, the connection probability of each monitoring well and its suspected downstream monitoring wells is obtained. The connection probability is positively proportional to the similarity of water flow fluctuations and the degree of connection between solution products. The suspected downstream monitoring well with the greatest possibility of connection among all suspected downstream monitoring wells of each monitoring well is recorded as the determined downstream monitoring well of each monitoring well; A connection threshold is preset. When the connection possibility between a monitoring well and its downstream monitoring well is greater than or equal to the connection threshold, the monitoring well is recorded as the first monitoring well of an underground river section, and the downstream monitoring well is recorded as the second monitoring well of this underground river section. The currently judged downstream monitoring well is used as a new monitoring well to obtain a new judged downstream monitoring well of the new monitoring well, and so on, until the new monitoring well no longer has a judged downstream monitoring well, and all the monitoring wells contained in this underground river section are obtained.

2. The method for tracing the source of groundwater pollution based on sewage pipeline data according to claim 1 is characterized in that: The specific steps for all suspected downstream monitoring wells of each monitoring well include: Using the water flow of each monitoring well at each sampling time of each day, a historical water flow sequence of each monitoring well is constructed; Any monitoring well is recorded as the target monitoring well, and any monitoring well other than the target monitoring well is recorded as the first monitoring well; Performing dynamic time warping on the historical water flow sequences of the target monitoring well and the first monitoring well to obtain a matching water flow in the historical water flow sequence of the first monitoring well for each water flow in the historical water flow sequence of the target monitoring well; If a water flow rate in the historical water flow sequence of the target monitoring well satisfies a one-to-one match with its matching water flow rate in the historical water flow sequence of the first monitoring well, the water flow rate in the historical water flow sequence of the target monitoring well is recorded as a fluctuation-characterized water flow rate of the target monitoring well; Calculate the time interval between each fluctuation-characterized water flow rate of the target monitoring well and its matching water flow rate in the historical water flow sequence of the first monitoring well, and record it as the peak time difference between each fluctuation-characterized water flow rate of the target monitoring well and the first monitoring well; The number of positive peak-to-peak time differences between all the fluctuation-representing water flow rates of the target monitoring well and the first monitoring well is recorded as the positive peak-to-peak value of the target monitoring well and the first monitoring well; the number of negative peak-to-peak time differences between all the fluctuation-representing water flow rates of the target monitoring well and the first monitoring well is recorded as the negative peak-to-peak value of the target monitoring well and the first monitoring well; If the positive error peak values ​​of the target monitoring well and the first monitoring well are smaller than the negative error peak values, the first monitoring well is recorded as a suspected downstream monitoring well of the target monitoring well.

3. The method for tracing the source of groundwater pollution based on sewage pipeline data according to claim 1 is characterized in that: The specific steps of the water flow fluctuation similarity include: Any suspected downstream monitoring well of the target monitoring well is recorded as the second monitoring well. For the target monitoring well and the second monitoring well, the similarity of water flow fluctuation between the target monitoring well and the second monitoring well is obtained by: The inverse proportional normalized value of the DTW distance between the historical water flow series of the target monitoring well and the second monitoring well after dynamic time warping is recorded as the water flow trend approximation between the target monitoring well and the second monitoring well; The product of the water flow trend approximation between the target monitoring well and the second monitoring well and the spatial difference weight between the target monitoring well and the second monitoring well is recorded as the water flow fluctuation similarity between the target monitoring well and the second monitoring well.

4. The method for tracing the source of groundwater pollution based on sewage pipeline data according to claim 3 is characterized in that: The specific steps of the solution product connection degree include: The sum of the difference in mineral dissolution content between the target monitoring well and the second monitoring well at each sampling time of the day is recorded as the mineral dissolution content increment between the target monitoring well and the second monitoring well; The product of the inversely proportional normalized value of the increment of the mineral dissolution content and the spatial difference weight of the target monitoring well and the second monitoring well is recorded as the solution product connection degree between the target monitoring well and the second monitoring well.

5. The method for tracing the source of groundwater pollution based on sewage pipeline data according to claim 1 is characterized in that: The analysis of the intersection of underground river sections to obtain several suspected tidal connection points and several marker wells includes: Obtain the intersection points of all underground river sections and the underground river sections corresponding to each intersection point in the underground river section pipe network map; If the location distance of multiple intersection points is less than or equal to the preset location distance threshold, the centroid of these multiple intersection points is recorded as a tidal suspected connection point, and the tidal suspected connection point inherits the underground river sections corresponding to these multiple intersection points; If the distance between a junction and all other junctions is greater than the preset distance threshold, the junction is recorded as a suspected tidal connection point, and the suspected tidal connection point inherits the underground river section corresponding to the junction; Among all the monitoring wells in each underground river section corresponding to each suspected tidal connection point, the monitoring well closest to the location of the suspected tidal connection point is recorded as the marker well of each suspected tidal connection point.

6. The method for tracing the source of groundwater pollution based on sewage pipeline data according to claim 1 is characterized in that: The specific steps for the high water date include: Obtain the average of the water flow of each marker well at each suspected tidal connection point at all sampling times on all days, and record it as the average daily water flow of each marker well at each suspected tidal connection point; Obtain the mean of the water flow of each marker well at each suspected tidal connection point at all sampling times of each day, and record it as the average water flow of each marker well at each suspected tidal connection point on each day; The date when the average water flow of each marked well at each suspected tidal connection point is greater than the average daily water flow is recorded as the high water flow date of each marked well at each suspected tidal connection point.

7. The method for tracing the source of groundwater pollution based on sewage pipeline data according to claim 1 is characterized in that: The specific steps of the plurality of tidal well channels and the connected river sections include: The mineral dissolution content of all the marker wells at each suspected tidal connection point at each sampling time on all high water flow dates was used to construct the mineral dissolution content matrix of each suspected tidal connection point. Calculating the covariance matrix of the mineral dissolution matrix of each tidal suspected connection point, and obtaining the eigenvector of the covariance matrix by principal component analysis algorithm; Arrange the eigenvalues ​​of the eigenvectors of the covariance matrix in descending order and record them as the principal component descending sequence of each tidal suspected connected point; The difference between the eigenvalue of each eigenvector and the eigenvalue of the next eigenvector in the descending sequence of the principal components of each tidal suspected connection point is recorded as the principal component decision coefficient of each eigenvector of each tidal suspected connection point; The sequence number of the eigenvector with the largest principal component decision coefficient in the descending sequence of the principal components is recorded as the number of principal component directions of the mineral dissolution matrix of each tidal suspected connection point; If the number of principal component directions of the mineral dissolution matrix of each suspected tidal connection point is greater than or equal to the number of marked wells of each suspected tidal connection point, the suspected tidal connection point is recorded as a tidal well channel, and the underground river section corresponding to the marked well of the suspected tidal connection point is recorded as the connected river section of the tidal well channel.

8. The method for tracing the source of groundwater pollution based on sewage pipeline data according to claim 1 is characterized in that: The above-mentioned underground river network diagram connects all connected river sections of the same tidal well channel to obtain several through-river sections. The pollution source is traced through the intersection of the through-river sections and each sewage pipeline and its checkpoint, including: Connect all connected river sections of the same tidal well channel in the underground river section pipe network diagram to obtain several through-channel sections; The through-stream and underground river sections are regarded as traceable rivers. All sewage pipelines that intersect with existing traceable rivers with pollution are recorded as suspected sewage pipelines. The nearest inspection point upstream of the suspected sewage pipeline at the intersection of the traceable river with pollution and each suspected sewage pipeline is recorded as the tracing inspection point of each suspected sewage pipeline. Starting from the suspected sewage pipeline at the downstream end of the traceable river with pollution, isotopes are released at the tracer checkpoint of the suspected sewage pipeline at the downstream end, and tracers are monitored in the monitoring well closest to the tracer checkpoint. If tracers are detected, the tracer checkpoint is recorded as a leakage checkpoint; if no tracers are detected, the tracer checkpoint is judged towards the adjacent suspected sewage pipeline upstream of the traceable river with pollution until a leakage checkpoint is obtained.

9. A groundwater pollution tracing system based on sewage pipeline data, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the groundwater pollution tracing method based on sewage pipeline data as described in any one of claims 1 to 8 are implemented.

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