Karst region city groundwater pollution source tracing method and system

Abstract

The present application relates to the technical field of electric digital data processing, in particular to a karst area city groundwater pollution source tracing method and system, the method comprising: determining the main node on the sewage pipeline, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the pollution tracing supply area, the

Description

Technical Field

[0001] This invention relates to the field of electronic digital data processing technology, specifically to a method and system for tracing the source of urban groundwater pollution in karst areas. Background Technology

[0002] Karst areas are unique geological regions formed by the dissolution of soluble rocks such as limestone and dolomite by water. The groundwater system in karst areas is highly permeable, making it extremely vulnerable. Due to the heterogeneity of the karst aquifer, its pollution-resistant properties are poor. The close hydraulic connection between surface water and groundwater allows pollutants to easily enter the groundwater directly from the surface through sinkholes and karst fissures. Once contaminated, pollutants spread rapidly. Source tracing allows for precise location of the pollution source, enabling timely measures to prevent further spread and thus protect the groundwater environment.

[0003] The tracer method is a traditional approach for tracing groundwater pollution sources. When a groundwater outcrop is contaminated but the source is unknown, a tracer is released from a sewage pipeline upstream of the outcrop. Tracer devices are installed at the contaminated outcrop to receive the signal. The source of pollution is then determined by receiving the signal. However, in karst areas, the flow path of the tracer is difficult to predict accurately due to the complexity of groundwater channels. Furthermore, when there are many sewage pipelines upstream of the contaminated outcrop, the time required for the tracer to reach the detection point from the injection point increases with distance. During long-distance migration, the tracer is affected by more factors, such as diffusion and dilution. When the tracer concentration is too low, it may fall below the detection threshold and cannot be accurately detected, thus affecting its path tracing and reducing the accuracy of source tracing. Summary of the Invention

[0004] To address the technical problem of low accuracy in tracing groundwater pollution sources in karst areas, the present invention aims to provide a method and system for tracing urban groundwater pollution sources in karst areas. The specific technical solution adopted is as follows:

[0005] This invention provides a method for tracing the source of urban groundwater pollution in karst areas, the method comprising:

[0006] Identify the main drainage ditches and manholes in the pollution source replenishment area, as well as the main nodes on the sewage pipelines relative to the main drainage ditches.

[0007] Determine the tracer concentration change curve at the main node corresponding to the inspection well in the main ditch, and determine the tracer aggregation degree change curve at the main node;

[0008] Determine the trend similarity between the tracer concentration change curve and the tracer convergence degree change curve, and use the trend similarity to determine the degree of tracer concentration anomaly at the master node;

[0009] The corrected tracer concentration is obtained by using the degree of tracer concentration anomaly and the original tracer concentration of the inspection well in the large trench;

[0010] The concentration of the groundwater outburst tracer at the outburst point was determined by using the corrected tracer concentration.

[0011] The possibility of leakage in the sewage pipeline corresponding to the inspection well in the ditch was determined by using the concentration of tracer at the dew point.

[0012] The tracer is placed in the inspection well of the sewage pipeline, and the main node represents the main node inspection well.

[0013] Further steps in determining the main nodes on the sewage pipeline relative to the main sewage ditch include:

[0014] Identify the sewage inspection well that is furthest from the main sewage ditch;

[0015] The manhole on the shortest path between the main sewage ditch and the farthest pipeline manhole is identified as the main node.

[0016] Further, the steps for determining the tracer concentration change curve at the main node corresponding to the inspection well in the large trench include:

[0017] Obtain the tracer concentration values ​​on the main nodes corresponding to the inspection wells in the trench according to the preset sequence;

[0018] Using the various tracer concentration values, tracer concentration change curves are generated.

[0019] Further, the steps for determining the tracer aggregation degree change curve at the master node include:

[0020] Determine the master node information of the master node, and use the master node information to determine the tracer convergence degree value of each master node;

[0021] By using the aggregation degree values ​​of each tracer, the curve of tracer aggregation degree change is determined.

[0022] Furthermore, the master node information includes: the number of parent nodes of the master node, and the physical distance between the parent nodes and the master node; the step of determining the tracer aggregation degree value of each master node using the master node information includes:

[0023] Using the number of parent nodes and the physical distance, the tracer aggregation degree value of each master node is calculated.

[0024] Furthermore, the steps of determining the trend similarity between the tracer concentration change curve and the tracer convergence degree change curve, and using the trend similarity to determine the degree of tracer concentration anomaly at the master node, include:

[0025] Determine the difference in tracer concentration values ​​between adjacent principal nodes on the tracer concentration change curve;

[0026] Determine the difference in tracer aggregation degree values ​​between adjacent principal nodes on the tracer aggregation degree change curve;

[0027] The degree of tracer concentration anomaly at the master node is calculated by using the differences in tracer concentration values ​​and the differences in tracer aggregation degree values.

[0028] Furthermore, the step of obtaining a corrected tracer concentration based on the degree of tracer concentration anomaly and the original tracer concentration of the inspection well in the large trench includes:

[0029] Determine the number of abnormal master nodes and the abnormality coefficient value of the master nodes;

[0030] By using the number of abnormal master nodes, the abnormal coefficient value of master nodes, and the degree of abnormality in tracer concentration, the original tracer concentration of the Dagou inspection well is corrected to obtain the corrected tracer concentration.

[0031] Furthermore, the step of determining the outburst tracer concentration at the groundwater outburst point using a modified tracer concentration includes:

[0032] Determine the first inspection well on the sewage pipeline that is closest to the inspection well in the ditch and its first tracer concentration;

[0033] Determine the first physical distance and the second physical distance between the main ditch inspection well and the first inspection well and the groundwater outburst point, respectively;

[0034] The groundwater outburst tracer concentration is calculated using the corrected tracer concentration, the first tracer concentration, the first physical distance, and the second physical distance.

[0035] Furthermore, the step of determining the likelihood of leakage in the sewage pipeline corresponding to the inspection well in the ditch by utilizing the concentration of the dew point tracer includes:

[0036] By using the concentration of tracer at the dew point and a preset detection threshold, the likelihood of leakage in the sewage pipeline corresponding to the inspection well in the ditch can be determined.

[0037] This invention also provides a source tracing system for urban groundwater pollution in karst areas, the system being used to implement the source tracing method for urban groundwater pollution in karst areas as described in any of the preceding claims; the system includes:

[0038] The regional planning module is used to determine the main drainage ditches and manholes in the pollution source replenishment area, as well as the main nodes on the sewage pipelines relative to the main drainage ditches.

[0039] The tracer analysis module is used to determine the tracer concentration change curve at the main node corresponding to the inspection well in the large trench, and to determine the tracer convergence degree change curve at the main node; to determine the trend similarity between the tracer concentration change curve and the tracer convergence degree change curve, and to determine the degree of tracer concentration anomaly at the main node using the trend similarity; to obtain the corrected tracer concentration using the degree of tracer concentration anomaly and the original tracer concentration of the inspection well in the large trench; and to determine the outburst tracer concentration at the groundwater outburst point using the corrected tracer concentration.

[0040] The pipeline leak detection module uses the concentration of tracer at the dew point to determine the likelihood of leakage in the sewage pipeline corresponding to the inspection well in the ditch.

[0041] The present invention has the following beneficial effects:

[0042] This invention determines the tracer concentration and aggregation level of each main node in a sewage ditch and its corresponding manhole by calculating the distribution of tracer concentrations at each main node on the sewage pipeline. Then, it determines the degree of anomaly in the tracer concentration at each main node by analyzing the fluctuations in the tracer concentration and aggregation level curves. The original tracer concentration values ​​of the manholes in the sewage ditch are then corrected based on the degree of anomaly in the tracer concentration values ​​of each main node. Finally, the leakage probability of the corresponding sewage pipeline is calculated based on the corrected tracer concentration values ​​of the manholes. The actual leakage situation of the manholes in the sewage ditch is determined based on the leakage probability. Compared to existing methods, this invention can more accurately detect leakage in each manhole and its corresponding sewage pipeline, thereby improving the accuracy of source tracing. Attached Figure Description

[0043] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a flowchart illustrating the steps of a method for tracing the source of urban groundwater pollution in karst areas, provided in one embodiment of the present invention.

[0045] Figure 2 This is a detailed flowchart of step S2 in a method for tracing the source of urban groundwater pollution in karst areas, provided in an embodiment of the present invention.

[0046] Figure 3 This is a detailed flowchart of step S3 in a method for tracing the source of urban groundwater pollution in karst areas, provided in an embodiment of the present invention.

[0047] Figure 4 This is a detailed flowchart of step S5 in a method for tracing the source of urban groundwater pollution in karst areas, provided in an embodiment of the present invention.

[0048] Figure 5 A schematic diagram of the pollution source recharge area involved in a method for tracing urban groundwater pollution sources in karst areas, provided in an embodiment of the present invention;

[0049] Figure 6 This is a schematic diagram of the main node tracer concentration change curves involved in a method for tracing urban groundwater pollution sources in karst areas, provided in an embodiment of the present invention.

[0050] Figure 7 This is a schematic diagram of the hardware operating environment of the source tracing device for urban groundwater pollution in karst areas involved in the embodiments of the present invention.

[0051] Figure 8 This is a schematic diagram of the framework structure of the urban groundwater pollution source tracing system in karst areas involved in the embodiments of the present invention. Detailed Implementation

[0052] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a method for tracing the source of urban groundwater pollution in karst areas proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0053] Unless otherwise defined, 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 pertains.

[0054] The specific scheme of the method for tracing the source of urban groundwater pollution in karst areas provided by the present invention will be described in detail below with reference to the accompanying drawings.

[0055] Example 1:

[0056] This invention provides a method for tracing the source of urban groundwater pollution in karst areas. Please refer to [link / reference needed]. Figure 1 The diagram illustrates a flowchart of the source tracing method for urban groundwater pollution sources in karst areas provided by an embodiment of the present invention.

[0057] The method includes:

[0058] Step S1: Determine the main drainage ditches and manholes in the pollution source replenishment area, as well as the main nodes on the sewage pipelines relative to the main drainage ditches;

[0059] In one embodiment, the step of determining the main node on the sewage pipeline relative to the main sewage ditch includes:

[0060] Identify the sewage inspection well that is furthest from the main sewage ditch;

[0061] The manhole on the shortest path between the main sewage ditch and the farthest pipeline manhole is identified as the main node.

[0062] Please refer to Figure 5 An example is provided for the pollution source recharge area:

[0063] First, based on a thorough analysis of existing data, a hydrogeological survey was conducted to delineate the boundary of the recharge area for urban groundwater outcrops in the karst region to be analyzed, and to determine the upstream recharge area of ​​the contaminated groundwater outcrops. Maps of sewage ditches and pipelines within the recharge area were collected, and inspection wells on these ditches and pipelines were examined one by one to determine the flow and number of sewage pipelines, thereby generating a pollution source recharge area map. Figure 5 As shown, those labeled J1 belong to sewage pipeline No. 1 and manhole number; those labeled J2 belong to sewage pipeline No. 2 and manhole number; those labeled J3 belong to sewage pipeline No. 3 and manhole number; those labeled J4 belong to sewage pipeline No. 4 and manhole number; those labeled J5 belong to sewage pipeline No. 5 and manhole number; and those labeled P belong to the main sewage ditch and manhole number.

[0064] Then, tracers are simultaneously released into multiple manholes (single-connected manholes) along the same sewage pipeline. Sensors (such as those for real-time monitoring of tracer concentration) are installed at the main nodes of the same sewage pipeline. Figure 5 In the No. 5 sewage pipeline, the main nodes are manholes numbered 1, 4, 5, 7, and 9 (also referred to as main node manholes). For example, if the tracer contains heavy metal ions, an ion-selective electrode sensor is installed. If the tracer is a fluorescent dye, a fluorescent sensor is installed. The appropriate sensor can be selected according to the type of tracer.

[0065] Further explanation is needed here:

[0066] For tracer application, it can be started from the inspection well in the sewage ditch closest to the contaminated groundwater outcrop. ( Figure 5The process begins by considering P1 first, followed by other sewage ditch inspection wells in sequence, and then starting with the corresponding sewage pipelines for tracer release. Tracer signals are then received at the contaminated groundwater outcrop using installed tracer equipment. In traditional methods, receiving a tracer signal indicates a potential leak in the sewage pipeline. However, tracers are affected by more factors during long-distance migration, such as diffusion and dilution. During long-distance flow, the tracer diffuses in different directions, resulting in a more uneven concentration distribution. Simultaneously, the large volume of groundwater flow and mixing with other water bodies leads to tracer dilution. When the tracer concentration is too low, it may fall below the detection threshold, making it undetectable. Therefore, traditional methods may miss leaks in sewage pipelines.

[0067] Therefore, if no tracer signal is detected at the contaminated groundwater outcrop by the installed tracer equipment, it can be detected through the inspection well in the sewage ditch. The concentration change of the tracer at the main node of the corresponding sewage pipeline is used to determine the possibility of leakage in the sewage pipeline, thus avoiding the situation described in the traditional method.

[0068] Step S2: Determine the tracer concentration change curve on the main node corresponding to the inspection well in the large trench, and determine the tracer aggregation degree change curve on the main node;

[0069] Specifically, the steps for determining the tracer concentration change curve at the main node corresponding to the inspection well in the large trench include:

[0070] Obtain the tracer concentration values ​​on the main nodes corresponding to the inspection wells in the trench according to the preset sequence;

[0071] Using the various tracer concentration values, tracer concentration change curves are generated.

[0072] Due to the sewage ditch inspection well The groundwater in the corresponding sewage pipelines will eventually converge into the inspection well of the sewage ditch. Therefore, the first step was to analyze the inspection wells in the sewage ditch. The change curve of tracer concentration at the main node on the corresponding sewage pipeline is used to determine the inspection wells passing through the sewage ditch. The effectiveness of tracer concentration.

[0073] Specifically, the distance from the main node to the inspection well of the sewage ditch can be used as a guide. The tracer concentration values ​​at the master node are obtained in order from farthest to nearest, and then the change curve is obtained, denoted as curve 1, as shown in the schematic diagram. Figure 6 As shown.

[0074] Specifically, please refer to Figure 2 The steps for determining the tracer aggregation change curve at the master node include:

[0075] Step S21: Determine the master node information of the master node, and use the master node information to determine the tracer aggregation degree value of each master node;

[0076] More specifically, the master node information includes: the number of parent nodes of the master node, and the physical distance between the parent nodes and the master node; the steps for determining the tracer convergence degree value of each master node using the master node information include:

[0077] Using the number of parent nodes and the physical distance, the tracer aggregation degree value of each master node is calculated.

[0078] Step S22: Use the aggregation degree values ​​of each tracer to determine the tracer aggregation degree change curve.

[0079] Since the number of parent nodes connected to each master node is different, the more parent nodes a particular master node connects to, and the closer their physical distance, the more tracer accumulates on that master node, and the higher the tracer concentration should be on that master node. Therefore, statistical analysis of sewage ditch inspection wells is necessary. The number of parent nodes connected to each main node on the corresponding sewage pipeline (specifically: if a main node has branches, the corresponding parent node count is incremented by 1; the number of nodes on the branches does not affect the count of parent nodes). For example: Figure 5 Taking the No. 5 sewage pipeline as an example, with J5-1 as the main node, the corresponding superior nodes are J5-4, J5-2 and J5-3. Since J5-2 and J5-3 are branches, the number of superior nodes is only increased by 1, so the total number of superior nodes of this main node is 2.

[0080] Inspection wells in sewage ditches The m-th main node on the corresponding sewage pipeline. Its corresponding tracer aggregation degree value is:

[0081]

[0082] In the formula, Indicates the inspection well of the sewage ditch The tracer aggregation degree value of the m-th main node on the corresponding sewage pipeline. Indicates the inspection well of the sewage ditch The number of parent nodes of the m-th main node on the corresponding sewage pipeline. Indicates the inspection well of the sewage ditch The physical distance between the m-th main node and the r-th parent node of the corresponding sewage pipeline (in particular: if the r-th parent node contains multiple nodes, the physical distance between the node with the farthest physical distance and the m-th main node is represented).

[0083] Based on the above calculation method, the inspection well of the sewage ditch can be calculated. The tracer aggregation level value for each main node on the corresponding sewage pipeline. This can also be calculated based on the distance of the main node from the sewage ditch inspection well. The tracer aggregation degree values ​​of the master node are obtained in order from far to near, and the change curve is obtained, which is denoted as curve 2.

[0084] Step S3: Determine the trend similarity between the tracer concentration change curve and the tracer convergence degree change curve, and use the trend similarity to determine the degree of tracer concentration anomaly at the master node;

[0085] Specifically, please refer to Figure 3 Step S3 includes:

[0086] Step S31: Determine the difference in tracer concentration values ​​between adjacent principal nodes on the tracer concentration change curve;

[0087] Step S32: Determine the difference in tracer aggregation degree values ​​between adjacent master nodes on the tracer aggregation degree change curve;

[0088] Step S33: Calculate the degree of tracer concentration anomaly on the master node using the difference in tracer concentration and the difference in tracer aggregation degree.

[0089] By analyzing the trend similarity between curves 1 and 2, the degree of anomaly in the tracer concentration value of each master node can be obtained. When the tracer convergence value of a master node is larger than that of the previous master node, it indicates that more tracer is flowing into that master node, and a higher tracer concentration value at that node is more reasonable. Using the next master node as the baseline node, if the trends (slopes of the line segments formed by the two points) of the two master nodes at the same position on fluctuation curves 1 and 2 are different, it indicates an anomaly in the tracer concentration value of the baseline node. When the trends of the two master nodes at the same position on fluctuation curve 2 are positive, while the trends of the two master nodes at the same position on fluctuation curve 1 are negative, it indicates a negative anomaly at the baseline node. When the trends of the two master nodes at the same position on fluctuation curve 2 are negative, while the trends of the two master nodes at the same position on fluctuation curve 1 are positive, it indicates a positive anomaly at the baseline node.

[0090] Therefore, the inspection well in the sewage ditch The mathematical formula for the degree of anomaly in the tracer concentration value of the m-th main node on the corresponding sewage pipeline is:

[0091]

[0092] In the formula, Indicates the inspection well of the sewage ditch The degree of anomaly in the tracer concentration at the m-th main node on the corresponding sewage pipeline (degree of anomaly in tracer concentration). This represents the normalization function. Indicates the inspection well of the sewage ditch The tracer concentration value of the m-th main node on the corresponding sewage pipeline. Indicates the inspection well of the sewage ditch The tracer concentration value of the (m-1)th main node on the corresponding sewage pipeline. Indicates the inspection well of the sewage ditch The tracer aggregation degree value of the m-th main node on the corresponding sewage pipeline. Indicates the inspection well of the sewage ditch The tracer aggregation degree value of the (m-1)th main node on the corresponding sewage pipeline.

[0093] Step S4: Obtain the corrected tracer concentration by using the degree of tracer concentration anomaly and the original tracer concentration of the inspection well in the large trench;

[0094] Specifically, step S4 includes:

[0095] Determine the number of abnormal master nodes and the abnormality coefficient value of the master nodes;

[0096] By using the number of abnormal master nodes, the abnormal coefficient value of master nodes, and the degree of abnormality in tracer concentration, the original tracer concentration of the Dagou inspection well is corrected to obtain the corrected tracer concentration.

[0097] Due to the sewage ditch inspection well The tracer at each main node of the corresponding sewage pipeline will flow into the inspection well of the sewage ditch. Therefore, based on the degree of abnormality of the tracer concentration value of the master node that exhibits the anomaly. Inspection wells for sewage drainage ditches The corresponding original tracer concentration value is corrected.

[0098] Specifically: When a master node shows a negative anomaly, it indicates that the tracer concentration value of that master node is too low, and it should be corrected to a higher value. Conversely, when a master node shows a positive anomaly, it indicates that the tracer concentration value of that master node is too high, and it should be corrected to a lower value.

[0099] Therefore, the revised sewage ditch inspection well The mathematical formula for the corresponding tracer concentration value is:

[0100]

[0101] In the formula, Indicates the inspection well of the sewage ditch Corrected tracer concentration value. Indicates the inspection well of the sewage ditch The original tracer concentration value. This indicates the number of master nodes that experienced anomalies. Indicates the inspection well of the sewage ditch The degree of abnormality of the tracer concentration value of the y-th main node on the corresponding sewage pipeline where an anomaly occurs. Indicates the inspection well of the sewage ditch The anomaly coefficient value of the y-th main node on the corresponding sewage pipeline where an anomaly occurs is 1 when it is a negative anomaly and -1 when it is a positive anomaly. This indicates the adjustment of the parameter value, which is an empirical value. It can be set to 30 or other values ​​as needed.

[0102] Step S5: Determine the outburst tracer concentration at the groundwater outburst point using the corrected tracer concentration.

[0103] Specifically, please refer to Figure 4 Step S5 includes:

[0104] Step S51: Determine the first inspection well on the sewage pipeline that is closest to the inspection well in the ditch and its first tracer concentration;

[0105] Step S52: Determine the first physical distance and the second physical distance between the large ditch inspection well and the first inspection well and the groundwater outburst point, respectively;

[0106] Step S53: Calculate the outburst tracer concentration at the groundwater outburst point using the corrected tracer concentration, the first tracer concentration, the first physical distance, and the second physical distance.

[0107] Specifically: First, the inspection wells in the sewage drainage ditch The inspection well on the nearest sewage pipeline is directly connected to it. Meanwhile, the inspection well in the main sewage ditch... It is also directly connected to the contaminated groundwater outcrop. Therefore, it can be accessed through the sewage ditch and inspection well. The diffusion rate of the tracer towards the contaminated groundwater outcrop is determined by the change in tracer concentration between the tracer and the nearest manhole on the sewage pipeline. The corresponding mathematical formula is:

[0108]

[0109] In the formula, Indicates the inspection well of the sewage ditch The degree of diffusion of the tracer per unit length towards the outcrop of contaminated groundwater. Indicates the inspection well of the sewage ditch Corrected tracer concentration value. This indicates the distance between the sewage pipeline and the inspection well in the sewage ditch. The concentration of tracer on the most recent inspection well (referred to as inspection well 1, also known as the first inspection well) (first tracer concentration). Indicates the inspection well of the sewage ditch The physical distance to manhole 1 (first physical distance). Indicates the inspection well of the sewage ditch The difference in tracer concentration between well 1 and inspection well 1.

[0110] Then we can estimate the amount of sewage discharge ditch inspection wells. The concentration of the tracer flowing to the outcrop of the contaminated groundwater. The corresponding mathematical formula is:

[0111]

[0112] In the formula, This indicates the estimated number of inspection wells in the sewage ditch. The concentration of the tracer flowing to the outcrop of the contaminated groundwater (outcrop tracer concentration). Indicates the inspection well of the sewage ditch The degree of diffusion of the tracer per unit length towards the outcrop of contaminated groundwater. Indicates the inspection well of the sewage ditch The physical distance to the point where the contaminated groundwater emerges (second physical distance).

[0113] Step S6: Use the concentration of the tracer at the dew point to determine the possibility of leakage in the sewage pipeline corresponding to the inspection well in the ditch.

[0114] Specifically, step S6 includes:

[0115] By using the concentration of tracer at the dew point and a preset detection threshold, the likelihood of leakage in the sewage pipeline corresponding to the inspection well in the ditch can be determined.

[0116] If calculated If the value is less than the preset detection threshold (set according to actual needs), it indicates that the result that the contaminated groundwater outcrop did not receive a tracer signal is correct. If the calculated value is less than the preset detection threshold (set according to actual needs), it indicates that the result is correct. If the value is greater than or equal to the detection threshold, it indicates that the result of no tracer signal being received at the contaminated groundwater outcrop may be inaccurate, possibly due to abnormal dilution of the tracer concentration caused by other reasons. Therefore, the inspection well in the sewage ditch should be checked at this time. The mathematical formula for the probability of leakage in the corresponding sewage pipeline is:

[0117]

[0118] In the formula, Indicates the inspection well of the sewage ditch The possibility of leakage in the corresponding sewage pipeline. This indicates the estimated number of inspection wells in the sewage ditch. The concentration of the tracer flowing to the outcrop of the contaminated groundwater (outcrop tracer concentration). This indicates the preset detection threshold.

[0119] Among them when The value is greater than 2 At that time, it indicated the inspection well of the sewage ditch. The corresponding sewage pipeline has an excessively high probability of leakage. (Sewage ditch inspection well) The corresponding sewage pipeline is considered to be leaking.

[0120] According to the steps of the above embodiments, tracers can be used to detect the leakage of sewage pipelines corresponding to each inspection well on the sewage ditch, thereby obtaining all leaking pipelines. Then, based on the identified leaking pipelines, groundwater connectivity tests are used to further accurately locate the polluted leakage sections or points. Based on the distance between the inspection wells in the leakage pipelines and the exposed points of the polluted groundwater, connectivity tests are conducted sequentially in the inspection wells, starting from the nearest and moving further away, to accurately locate the specific leakage sections or points in the sewage pipelines. After locating the leakage section or point, repair measures are immediately implemented, and connectivity tests are used to verify the repair effect until all identified leakage sections or points are completely repaired. This process is repeated until all leakage sections and points located in the same sewage pipeline are repaired. Then, the process is repeated again to locate and repair all leakage sections and points in all sewage pipelines within the recharge area.

[0121] The above steps establish a method for tracing the source of urban groundwater pollution in karst areas, providing a rapid approach for tracing the source and remediating urban groundwater pollution in karst areas. This significantly reduces the time and cost of tracing the source and remediating urban groundwater pollution in karst areas, and effectively alleviates the pressure on urban ecological environment protection and groundwater pollution prevention and control in karst areas.

[0122] This invention determines the tracer concentration and aggregation level of each main node in a sewage ditch and its corresponding manhole by calculating the distribution of tracer concentrations at each main node on the sewage pipeline. Then, it determines the degree of anomaly in the tracer concentration at each main node by analyzing the fluctuations in the tracer concentration and aggregation level curves. The original tracer concentration values ​​of the manholes in the sewage ditch are then corrected based on the degree of anomaly in the tracer concentration values ​​of each main node. Finally, the leakage probability of the corresponding sewage pipeline is calculated based on the corrected tracer concentration values ​​of the manholes. The actual leakage situation of the manholes in the sewage ditch is determined based on the leakage probability. Compared to existing methods, this invention can more accurately detect leakage in each manhole and its corresponding sewage pipeline, thereby improving the accuracy of source tracing.

[0123] Example 2:

[0124] This invention also proposes a source tracing device for urban groundwater pollution in karst areas. The source tracing device can be a computer, a server, or other data processing equipment, or a combination of multiple devices.

[0125] like Figure 7 As shown, Figure 7 This is a schematic diagram of the hardware operating environment of the source tracing device for urban groundwater pollution in karst areas involved in the embodiments of the present invention.

[0126] like Figure 7 As shown, the karst area urban groundwater pollution source tracing device may include: a processor 1001, such as a CPU, a network interface 1004, a user interface 1003, a memory 1005, and a communication bus 1002. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display or an input unit such as a control panel; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a WIFI interface). The memory 1005 may be a high-speed RAM or a stable, non-volatile memory, such as a disk drive. Optionally, the memory 1005 may also be a storage device independent of the aforementioned processor 1001. The memory 1005, as a computer storage medium, may include a karst area urban groundwater pollution source tracing program.

[0127] Those skilled in the art will understand that Figure 7 The hardware structure shown does not constitute a limitation on the device and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0128] Continue to refer to Figure 7 , Figure 7 The memory 1005, which is a computer-readable storage medium, may include an operating system, a user interface module, a network communication module, and a source tracing program for urban groundwater pollution in karst areas.

[0129] exist Figure 7 In this embodiment, the network communication module is mainly used to connect to the server and can communicate with the server for data; while the processor 1001 can call the source tracing program for urban groundwater pollution in karst areas stored in the memory 1005 and execute the steps in the above embodiments.

[0130] Based on the hardware structure of the above-mentioned karst urban groundwater pollution source tracing device, various embodiments of the karst urban groundwater pollution source tracing method of the present invention are implemented.

[0131] In addition, this invention also provides a source tracing system for urban groundwater pollution in karst areas, please refer to... Figure 8 The karst area urban groundwater pollution source tracing system includes:

[0132] Regional planning module A10 is used to determine the main drainage ditches and manholes in the pollution source replenishment area, as well as the main nodes on the sewage pipelines relative to the main drainage ditches.

[0133] The tracer analysis module A20 is used to determine the tracer concentration change curve at the main node corresponding to the inspection well in the large trench, and to determine the tracer convergence degree change curve at the main node; to determine the trend similarity between the tracer concentration change curve and the tracer convergence degree change curve, and to determine the degree of tracer concentration anomaly at the main node using the trend similarity; to obtain the corrected tracer concentration using the degree of tracer concentration anomaly and the original tracer concentration of the inspection well in the large trench; and to determine the outburst tracer concentration at the groundwater outburst point using the corrected tracer concentration.

[0134] The pipeline leak detection module A30 uses the concentration of tracer at the dew point to determine the likelihood of leakage in the sewage pipeline corresponding to the inspection well in the ditch.

[0135] Furthermore, the regional planning module A10 is also used for:

[0136] Identify the sewage inspection well that is furthest from the main sewage ditch;

[0137] The manhole on the shortest path between the main sewage ditch and the farthest pipeline manhole is identified as the main node.

[0138] Furthermore, the tracer analysis module A20 is also used for:

[0139] Obtain the tracer concentration values ​​on the main nodes corresponding to the inspection wells in the trench according to the preset sequence;

[0140] Using the various tracer concentration values, tracer concentration change curves are generated.

[0141] Furthermore, the tracer analysis module A20 is also used for:

[0142] Determine the master node information of the master node, and use the master node information to determine the tracer convergence degree value of each master node;

[0143] By using the aggregation degree values ​​of each tracer, the curve of tracer aggregation degree change is determined.

[0144] Furthermore, the tracer analysis module A20 is also used for:

[0145] Using the number of parent nodes and the physical distance, the tracer aggregation degree value of each master node is calculated.

[0146] Furthermore, the tracer analysis module A20 is also used for:

[0147] Determine the difference in tracer concentration values ​​between adjacent principal nodes on the tracer concentration change curve;

[0148] Determine the difference in tracer aggregation degree values ​​between adjacent principal nodes on the tracer aggregation degree change curve;

[0149] The degree of tracer concentration anomaly at the master node is calculated by using the differences in tracer concentration values ​​and the differences in tracer aggregation degree values.

[0150] Furthermore, the tracer analysis module A20 is also used for:

[0151] Determine the number of abnormal master nodes and the abnormality coefficient value of the master nodes;

[0152] By using the number of abnormal master nodes, the abnormal coefficient value of master nodes, and the degree of abnormality in tracer concentration, the original tracer concentration of the Dagou inspection well is corrected to obtain the corrected tracer concentration.

[0153] Furthermore, the tracer analysis module A20 is also used for:

[0154] Determine the first inspection well on the sewage pipeline that is closest to the inspection well in the ditch and its first tracer concentration;

[0155] Determine the first physical distance and the second physical distance between the main ditch inspection well and the first inspection well and the groundwater outburst point, respectively;

[0156] The groundwater outburst tracer concentration is calculated using the corrected tracer concentration, the first tracer concentration, the first physical distance, and the second physical distance.

[0157] Furthermore, the pipeline leak detection module A30 is also used for:

[0158] By using the concentration of tracer at the dew point and a preset detection threshold, the likelihood of leakage in the sewage pipeline corresponding to the inspection well in the ditch can be determined.

[0159] The specific implementation of the karst urban groundwater pollution source tracing system of the present invention is basically the same as the embodiments of the above-mentioned karst urban groundwater pollution source tracing method, and will not be repeated here.

[0160] Furthermore, the present invention also provides a computer-readable storage medium. The computer-readable storage medium stores a source tracing program for urban groundwater pollution in karst areas, wherein, when executed by a processor, the source tracing program for urban groundwater pollution in karst areas implements the steps of the source tracing method for urban groundwater pollution in karst areas as described above.

[0161] The method implemented when the source tracing procedure for urban groundwater pollution sources in karst areas is executed can be referred to in various embodiments of the source tracing method for urban groundwater pollution sources in karst areas of the present invention, and will not be repeated here.

[0162] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0163] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0164] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0165] The above description is only a preferred embodiment of the present invention and does not limit the scope of protection of the present invention. All equivalent structural / method transformations made under the inventive concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present invention.

Claims

1. A method for tracing a pollution source of urban groundwater in a karst area, characterized in that, The method comprises: determining the main nodes of the pollution trace supply area, including: determining the farthest pipeline inspection well of the pollution trace supply area; determining the inspection well on the shortest path between the pollution trace supply area and the farthest pipeline inspection well as the main node; determining the tracer concentration change curve on the main node corresponding to the inspection well of the pollution trace supply area, and determining the tracer convergence degree change curve on the main node, including: obtaining the tracer concentration value on the main node corresponding to the inspection well of the pollution trace supply area in a preset order; generating the tracer concentration change curve using each tracer concentration value; determining the main node information of the main node, and determining the tracer convergence degree value of each main node using the main node information; determining the tracer convergence degree change curve using each tracer convergence degree value; determining the trend similarity of the tracer concentration change curve and the tracer convergence degree change curve, and determining the tracer concentration anomaly degree on the main node using the trend similarity, including: determining the difference between the tracer concentration values of adjacent main nodes on the tracer concentration change curve; determining the difference between the tracer convergence degree values of adjacent main nodes on the tracer convergence degree change curve; calculating the tracer concentration anomaly degree on the main node using the tracer concentration value difference and the tracer convergence degree value difference; obtaining the corrected tracer concentration using the tracer concentration anomaly degree and the original tracer concentration of the inspection well of the pollution trace supply area; determining the outburst point tracer concentration of the groundwater outburst point using the corrected tracer concentration, including: determining the first inspection well closest to the inspection well of the pollution trace supply area on the pollution trace supply area and the first tracer concentration thereof; determining the first physical distance and the second physical distance between the inspection well of the pollution trace supply area and the first inspection well and the groundwater outburst point, respectively; calculating the outburst point tracer concentration of the groundwater outburst point using the corrected tracer concentration, the first tracer concentration, the first physical distance, and the second physical distance; determining the leakage possibility of the pollution trace supply area corresponding to the inspection well of the pollution trace supply area using the outburst point tracer concentration. The tracer is placed in the inspection well of the pollution trace supply area, and the main node represents the main node inspection well.

2. The karst city groundwater pollution source tracing method according to claim 1, characterized in that, The main node information includes: the number of upper nodes of the main node, and the physical distance between the upper nodes and the main node; the step of determining the tracer convergence degree value of each main node using the main node information comprises: calculating the tracer convergence degree value of each main node using the number of upper nodes and the physical distance.

3. The karst city groundwater pollution source tracing method according to claim 1, characterized in that, The step of obtaining the corrected tracer concentration using the tracer concentration anomaly degree and the original tracer concentration of the inspection well of the pollution trace supply area comprises: determining the number of abnormal main nodes and the main node anomaly coefficient value; correcting the original tracer concentration of the inspection well of the pollution trace supply area using the number of abnormal main nodes, the main node anomaly coefficient value, and the tracer concentration anomaly degree to obtain the corrected tracer concentration.

4. The karst city groundwater pollution source tracing method according to claim 1, characterized in that, The step of determining the leakage possibility of the pollution trace supply area corresponding to the inspection well of the pollution trace supply area using the outburst point tracer concentration comprises: determining the leakage possibility of the pollution trace supply area corresponding to the inspection well of the pollution trace supply area using the outburst point tracer concentration and the preset detection threshold.

5. A karst area city groundwater pollution source tracing system, characterized in that, The system is used for realizing the karst area city groundwater pollution source tracing method as claimed in any one of claims 1-4; the system comprises: A regional planning module, configured to determine a pollution tracing recharge area, a large pollution ditch, a large ditch inspection well, and a main node on a sewage pipeline relative to the large pollution ditch, comprising: determining a pipeline inspection well farthest from the large pollution ditch on the sewage pipeline; and determining an inspection well on a shortest path between the large pollution ditch and the farthest pipeline inspection well as the main node; A tracer analysis module, configured to determine a tracer concentration change curve on the main node corresponding to the large ditch inspection well, determine a tracer convergence degree change curve on the main node, determine a trend similarity of the tracer concentration change curve and the tracer convergence degree change curve, determine a tracer concentration anomaly degree on the main node by using the trend similarity, obtain a corrected tracer concentration by using the tracer concentration anomaly degree and an original tracer concentration of the large ditch inspection well, and determine an outburst point tracer concentration of a groundwater outburst point by using the corrected tracer concentration; A pipeline leakage determination module, configured to determine a leakage possibility of a sewage pipeline corresponding to the large ditch inspection well by using the outburst point tracer concentration.

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