River pollution monitoring method, system and device based on water quality change

Abstract

The application relates to a river pollution monitoring method, system and equipment based on water quality changes, and the method comprises the following steps: acquiring first-period remote sensing images and second-period remote sensing images of a target river; based on a preset water quality inversion model, water quality parameters of the first-period remote sensing images and the second-period remote sensing images are respectively inverted to obtain first water quality parameter spatial distribution data and second water quality parameter spatial distribution data, and difference calculation is performed to generate a water quality difference spatial distribution map; according to a preset pollution state judgment rule, the pollution state of the target river is acquired; and according to the pollution state of the target river, corresponding pollution monitoring strategies are adopted to perform pollution monitoring and source tracing. The method provided by the application can analyze the time-space differences of two-period water quality parameters by performing water quality parameter inversion on two-period remote sensing images of a river area, identify and judge the pollution state of the river, and trace the pollution source.

Description

Technical Field

[0001] This invention relates to the technical field of water quality remote sensing monitoring, and in particular to a method, system and equipment for monitoring river sewage discharge based on water quality changes. Background Technology

[0002] In the field of water pollution control, traditional water pollution source tracing mainly relies on a combination of manual sampling and ground surveys. This method requires staff to conduct on-site investigations along the river, collect water samples, and send them to the laboratory for analysis to determine the source of pollution. This requires a lot of manpower and resources, and it is difficult to achieve high-frequency and full-coverage patrols in river sections with complex terrain. On the other hand, traditional monitoring methods rely on the test results of static water samples, which cannot dynamically reflect real-time changes in water quality and cannot respond promptly to sudden sewage discharge events. In addition, manual testing methods also have problems such as low accuracy in source tracing.

[0003] With the rapid development of remote sensing technology, satellite or UAV-based remote sensing technology has been applied to the monitoring and source tracing of river pollution. However, there is a lack of existing technologies that use remote sensing images to dynamically analyze river pollution discharge, thereby identifying the state of river pollution discharge and conducting intelligent monitoring and source tracing. Summary of the Invention

[0004] Based on this, the purpose of the present invention is to provide a method, system and equipment for monitoring river sewage discharge based on water quality changes. The method uses a water quality inversion model to obtain spatial distribution data of water quality parameters from two periods of remote sensing images, generates a spatial distribution map of water quality differences, obtains the sewage discharge status of the river based on the spatial distribution map of water quality differences, and takes corresponding sewage discharge monitoring strategies to monitor and trace the source of sewage discharge based on the sewage discharge status.

[0005] Firstly, this application provides a method for monitoring river sewage discharge based on water quality changes, including: Acquire the first and second phases of remote sensing images of the target river; wherein, the first phase of remote sensing images is the remote sensing images during the period of normal water quality, and the second phase of remote sensing images is the remote sensing images of the sewage discharge status to be determined; Based on the preset water quality inversion model, water quality parameters are inverted on the first phase remote sensing image and the second phase remote sensing image respectively to obtain the spatial distribution data of the first water quality parameter corresponding to the first phase remote sensing image and the spatial distribution data of the second water quality parameter corresponding to the second phase remote sensing image. Spatial difference calculation is performed on the spatial distribution data of the first water quality parameter and the spatial distribution data of the second water quality parameter to generate a spatial distribution map of water quality differences; wherein, the spatial distribution map of water quality differences includes a number of grids and the concentration difference value corresponding to each grid; Based on the spatial distribution map of water quality differences, the sewage discharge status of the target river is obtained according to the preset sewage discharge status judgment rules. Based on the sewage discharge status of the target river, corresponding sewage discharge monitoring strategies are adopted for sewage discharge monitoring and source tracing.

[0006] Secondly, this application provides a river sewage discharge monitoring system based on water quality changes, including: a remote sensing image acquisition module, used to acquire a first-phase remote sensing image and a second-phase remote sensing image of the target river; wherein, the first-phase remote sensing image is a remote sensing image during a period of normal water quality, and the second-phase remote sensing image is a remote sensing image of the sewage discharge status to be determined; The inversion module is used to invert water quality parameters on the first phase remote sensing image and the second phase remote sensing image based on a preset water quality inversion model, to obtain the spatial distribution data of the first water quality parameter corresponding to the first phase remote sensing image and the spatial distribution data of the second water quality parameter corresponding to the second phase remote sensing image. A water quality difference spatial distribution map generation module is used to calculate the spatial difference between the first water quality parameter spatial distribution data and the second water quality parameter spatial distribution data to generate a water quality difference spatial distribution map; wherein, the water quality difference spatial distribution map includes a number of grids and the concentration difference value corresponding to each grid; The sewage discharge status identification module is used to obtain the sewage discharge status of the target river based on the spatial distribution map of water quality differences and according to the preset sewage discharge status judgment rules. The sewage discharge monitoring module is used to monitor and trace the source of sewage discharge by adopting corresponding sewage discharge monitoring strategies based on the sewage discharge status of the target river.

[0007] Thirdly, this application provides a computer device including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the river sewage monitoring method based on water quality changes as described above.

[0008] This application provides a method, system, and equipment for river pollution monitoring based on water quality changes. It utilizes multi-remote sensing technology to acquire first-phase remote sensing images of a period with normal water quality and second-phase remote sensing images of a period to be assessed for pollution discharge status, ensuring that the images cover the entire river cross-section. Water quality parameters are inverted using a water quality inversion model on both the first and second-phase images to obtain spatial distribution data for the first and second water quality parameters. Next, spatial differences are calculated between the spatial distribution data of the water quality parameters obtained from the inversion of the two remote sensing images to generate a spatial distribution map of water quality differences. Then, based on this spatial distribution map, and according to preset pollution discharge status judgment rules, the current pollution discharge status of the river is determined. Finally, based on the determined pollution discharge status, corresponding pollution monitoring strategies are adopted for pollution monitoring and source tracing. Compared to existing technologies, this application, by inverting water quality parameters from two phases of remote sensing images of a river area and analyzing the spatiotemporal differences of water quality parameters between the two phases, identifies and judges the pollution discharge status of the river, thereby tracing the pollution source. This application enables rapid and automated identification of sewage discharge status in a wide range of river bodies, significantly improving the timeliness and efficiency of water pollution monitoring. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 A flowchart illustrating the steps of a river sewage discharge monitoring method based on water quality changes, provided in this application embodiment; Figure 2 A flowchart illustrating the steps for obtaining spatial distribution data of water quality parameters is provided in this application embodiment. Figure 3 A flowchart illustrating the steps for generating a spatial distribution map of water quality differences, provided in this application embodiment; Figure 4 A flowchart illustrating the steps for determining the sewage discharge status of a river, as provided in this application embodiment; Figure 5 A schematic diagram of a river sewage discharge monitoring system based on water quality changes, provided as an embodiment of this application; Figure 6 This is a schematic diagram of the structure of a computer device provided in this application. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the protection scope of this application.

[0012] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0013] In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims. In the description of this application, it should be understood that the terms "first," "second," "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0014] Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0015] With the rapid development of remote sensing technology, satellite or UAV-based remote sensing technology has been applied to the monitoring and source tracing of river pollution. However, there is a lack of existing technologies that use remote sensing images to dynamically analyze river pollution discharge, thereby identifying the state of river pollution discharge and conducting intelligent monitoring and source tracing.

[0016] To this end, this application provides a method, system, and equipment for monitoring river sewage discharge based on water quality changes. By inverting water quality parameters from remote sensing images of the target river, performing spatiotemporal difference analysis on two periods of remote sensing images, calculating the spatial difference between the spatial distribution data of water quality parameters in the two periods, generating a spatial distribution map of water quality differences representing concentration changes, determining the sewage discharge status of the river according to preset sewage discharge status judgment rules, and adopting corresponding sewage discharge monitoring strategies to monitor the river and trace pollution sources based on the sewage discharge status, thereby realizing intelligent monitoring and identification of river sewage discharge status.

[0017] Please see Figure 1 , Figure 1 A flowchart illustrating the steps of a river sewage monitoring method based on water quality changes, provided in this application embodiment.

[0018] This application provides a method for monitoring river sewage discharge based on water quality changes, comprising: S101, acquire the first phase remote sensing image and the second phase remote sensing image of the target river; wherein, the first phase remote sensing image is a remote sensing image of the normal water quality period, and the second phase remote sensing image is a remote sensing image of the sewage discharge status to be determined. S102, Based on the preset water quality inversion model, water quality parameters are inverted on the first phase remote sensing image and the second phase remote sensing image respectively to obtain the spatial distribution data of the first water quality parameter corresponding to the first phase remote sensing image and the spatial distribution data of the second water quality parameter corresponding to the second phase remote sensing image. S103, calculate the spatial difference between the spatial distribution data of the first water quality parameter and the spatial distribution data of the second water quality parameter to generate a spatial distribution map of water quality differences; wherein, the spatial distribution map of water quality differences includes a number of grids and the concentration difference value corresponding to each grid. S104, Based on the spatial distribution map of water quality differences, the sewage discharge status of the target river is obtained according to the preset sewage discharge status judgment rules; S105, Based on the sewage discharge status of the target river, adopt corresponding sewage discharge monitoring strategies to monitor and trace the source of sewage discharge.

[0019] The river discharge monitoring method based on water quality changes provided in this application utilizes multi-remote sensing technology to acquire first-phase remote sensing images of normal water quality periods and second-phase remote sensing images of discharge status to be determined, ensuring that the images cover the complete river cross-section. Water quality parameters are inverted using a water quality inversion model on both the first and second-phase images to obtain spatial distribution data of the first and second water quality parameters. Next, spatial differences are calculated between the spatial distribution data of the water quality parameters obtained from the inversion of the two remote sensing images to generate a spatial distribution map of water quality differences. Then, based on this spatial distribution map, and according to preset discharge status judgment rules, the current discharge status of the river is determined. Finally, based on the determined discharge status, corresponding discharge monitoring strategies are adopted for discharge monitoring and source tracing. Compared to existing technologies, this application, by inverting water quality parameters from two phases of remote sensing images of a river region and analyzing the spatiotemporal differences of water quality parameters between the two phases, identifies and judges the discharge status of the river, thereby tracing the pollution source. This application enables rapid and automated identification of sewage discharge status in a wide range of river bodies, significantly improving the timeliness and efficiency of water pollution monitoring.

[0020] For step S101, acquire the first and second phases of remote sensing images of the target river.

[0021] The first and second phases of remote sensing imagery can be acquired using remote sensing technology, such as satellite remote sensing data or UAV remote sensing data. The first phase of remote sensing imagery represents a period of normal water quality. In one embodiment, the first phase of remote sensing imagery can be a historical remote sensing image of the target river where the water concentration is below a preset threshold, or it can be a remote sensing image taken before any river discharge. The second phase of remote sensing imagery represents a period where the discharge status needs to be determined. In one embodiment, the second phase of remote sensing imagery is a remote sensing image of the target river at the current time.

[0022] In one embodiment, the spatial resolution of the first-phase remote sensing image and the second-phase remote sensing image is consistent (e.g., both are 10-meter resolution, 30-meter resolution, etc.), and they can be acquired by the same type of remote sensing sensor.

[0023] In this embodiment, by acquiring two remote sensing images of the target river during its normal period and the current period, a data basis is provided for the spatiotemporal difference analysis of the target river's water quality parameters.

[0024] For step S102, based on the preset water quality inversion model, water quality parameters are inverted on the first phase remote sensing image and the second phase remote sensing image respectively to obtain the spatial distribution data of the first water quality parameter corresponding to the first phase remote sensing image and the spatial distribution data of the second water quality parameter corresponding to the second phase remote sensing image.

[0025] Please see Figure 2 , Figure 2 A flowchart illustrating the steps for acquiring spatial distribution data of water quality parameters is provided in an embodiment of this application. In one embodiment, step S102 includes: S201, Preprocess the first phase remote sensing image and the second phase remote sensing image.

[0026] The preprocessing refers to a series of correction and optimization operations performed on the original remote sensing image to eliminate sensor errors, atmospheric interference, and geometric distortion, in order to obtain data that can truly reflect the spectral information of ground features. In one embodiment, the preprocessing steps may include atmospheric correction, radiometric calibration, and geometric correction, so that the processed first-phase and second-phase remote sensing images are completely spatially registered, that is, the same geographic coordinate point corresponds to the same raster position in both phases of remote sensing images.

[0027] S202, extract the first water quality parameter feature data corresponding to the first phase of the preprocessed remote sensing image and the second water quality parameter feature data corresponding to the second phase of the remote sensing image.

[0028] The first water quality parameter characteristic data and the second water quality parameter characteristic data are the reflectance of spectral characteristic variables (such as red light, green light, near-infrared band, etc.) related to the concentration of substances in the river.

[0029] S203, construct a water quality inversion model.

[0030] The process of constructing the water quality inversion model may include: acquiring a historical water quality measured parameter dataset of the target river, which contains multiple sample points, each sample point including the true concentration values ​​of several water quality parameters (such as total phosphorus, total nitrogen, chemical oxygen demand, etc.) and water quality parameter feature data of the corresponding location extracted from preprocessed remote sensing images; then, using the water quality parameter feature data in the historical water quality measured parameter dataset as input variables and the corresponding true water quality parameter concentrations as target variables, training the model based on a preset machine learning algorithm (such as a random forest model) to construct the water quality inversion model.

[0031] S204, the first water quality parameter feature data and the second water quality parameter feature data are respectively input into the water quality inversion model to obtain the spatial distribution data of the first water quality parameter corresponding to the first phase remote sensing image and the spatial distribution data of the second water quality parameter corresponding to the second phase remote sensing image.

[0032] In one embodiment, the first water quality parameter feature data and the second water quality parameter feature data extracted from the preprocessed first-phase remote sensing image and the second-phase remote sensing image are respectively input into the constructed water quality inversion model to calculate the water quality concentration value corresponding to each grid position in the remote sensing image. The water quality concentration value can be the concentration value corresponding to one or more water quality parameters. The set of water concentration values ​​of all grids constitutes the spatially continuously distributed first water quality parameter spatial distribution data.

[0033] In this embodiment, by inputting the water quality parameter feature data extracted from the two remote sensing images into the water quality inversion model for calculation, the spatial distribution data of water quality parameters corresponding to the two remote sensing images are obtained, which can reflect the spatiotemporal changes of water quality.

[0034] For step S103, spatial difference calculation is performed on the spatial distribution data of the first water quality parameter and the spatial distribution data of the second water quality parameter to generate a spatial distribution map of water quality differences.

[0035] Please see Figure 3 , Figure 3 A flowchart illustrating the steps for generating a spatial distribution map of water quality differences, provided in an embodiment of this application. In one embodiment, step S103 includes: S301, based on the spatial distribution data of the first water quality parameter and the spatial distribution data of the second water quality parameter, obtain the water quality concentration values ​​of each grid in the first phase remote sensing image and the second phase remote sensing image respectively; wherein, the grids in the first phase remote sensing image and the second phase remote sensing image correspond one-to-one.

[0036] In this embodiment, after preprocessing the first and second phase remote sensing images through the steps described above, the grids in the first and second phase remote sensing images correspond one-to-one. Both the first and second phase remote sensing images include the same number of grids, each grid being a unit constituting the spatial distribution data of water quality parameters, with each grid representing a rectangular area. In one embodiment, the value of the grid represents the water quality concentration value corresponding to that location. This water quality concentration value can be the concentration value of a single water quality parameter, or it can be an integrated value obtained by weighting several water quality parameter concentration values ​​based on a preset weight.

[0037] In this embodiment, the water quality concentration value corresponding to each grid is obtained by reading the value of each grid in the two phases of remote sensing images of the target river.

[0038] S302, calculate the difference in water concentration values ​​for each group of corresponding grid cells to obtain the concentration difference value of the grid cells at each spatial location.

[0039] Wherein, the one-to-one corresponding grids are grids with the same spatial position in the two phases of remote sensing images; for each group of grids with the same spatial position, the water quality concentration value of the grid in the second water quality parameter spatial distribution data is subtracted by the water quality concentration value of the grid in the first water quality parameter spatial distribution data to obtain the concentration difference value of the spatial position.

[0040] In this embodiment, the concentration difference value generated by time series change is obtained by comparing the water quality concentration values in the two phases of water quality parameter spatial distribution data, which reflects the sewage discharge condition of the target river.

[0041] S303, generating a water quality difference spatial distribution map according to the concentration difference values.

[0042] Wherein, the range of the water quality difference spatial distribution map is consistent with that of the first-phase remote sensing image and the second-phase remote sensing image, and the positions of each grid correspond to each other respectively.

[0043] In another embodiment, after the step S302, the method further comprises the following steps: S302a, obtaining the concentration difference grade of the grid at each spatial position according to the concentration difference value of the grid at each spatial position based on a preset water quality difference division rule; wherein the concentration difference grades comprise a high value, a medium value and a low value.

[0044] S302b, generating a water quality difference spatial distribution map according to the concentration difference grading result.

[0045] Wherein, performing concentration difference grading on grids refers to a process of classifying the concentration difference values of each grid according to numerical value intervals. In one embodiment, the process of obtaining the concentration difference grade of a grid is as follows: presetting two concentration difference thresholds T1 and T2 (wherein T1<T2); when the concentration difference value is greater than T2, grading the grid as a high value; when the concentration difference value is between T1 and T2, grading the grid as a medium value; when the concentration difference value is less than T1, grading the grid as a low value. Wherein, the concentration difference thresholds T1 and T2 can be set based on the average value and standard deviation of the grid concentration difference values.

[0046] The water quality difference spatial distribution map generated in this embodiment comprises the concentration difference values of each grid and the corresponding concentration difference grades. In one embodiment, different concentration difference grades are marked with different colors respectively (for example, red indicates a high value, yellow indicates a medium value, and green indicates a low value).

[0047] In this embodiment, the concentration difference values ​​are divided into gradients, and a spatial distribution map of water quality differences is generated based on the concentration difference classification of each grid. This map can intuitively reflect water quality changes, highlight the polluted areas and their impact range and diffusion trend, thereby providing a data basis for determining the sewage discharge status of the target river.

[0048] For step S104, based on the spatial distribution map of water quality differences, the sewage discharge status of the target river is obtained according to the preset sewage discharge status judgment rules.

[0049] The two sides of the second phase of remote sensing imagery are the riverbanks of the target river, and the target river flows from top to bottom.

[0050] Please see Figure 4 , Figure 4 A flowchart illustrating the steps for determining the sewage discharge status of a river, provided in an embodiment of this application. In one embodiment, step S104 includes: S401, Based on the spatial distribution map of water quality differences, obtain the location information of the grid with the highest concentration difference value and the spatial morphological characteristics of the spatial distribution map of water quality differences.

[0051] Among them, the spatial morphological characteristics of the spatial distribution map of water quality differences refer to the shape, structure and other characteristics of the area formed by the grid with high concentration difference values ​​in spatial distribution, such as the gradient change of concentration difference values ​​along the river flow direction.

[0052] In one embodiment, in the spatial distribution map of water quality differences, the grid with the highest concentration difference value is marked in dark red.

[0053] S402, based on the positional relationship between the grid with the highest concentration difference value and the riverbank, and the spatial morphological characteristics of the spatial distribution map of water quality differences, determine the sewage discharge status of the target river.

[0054] In one embodiment, the sewage discharge status of the target river is determined by calculating the distance between the grid with the highest concentration difference value and the riverbank. For example, in the spatial distribution map of water quality differences, the coordinates of the center point of the grid with the highest concentration difference value are obtained, and the Euclidean distance between the center point coordinates and the two banks is calculated to obtain the positional relationship between the grid with the highest concentration difference value and the riverbank.

[0055] The discharge status includes both a discharge in progress state and a discharge stopped state.

[0056] In one embodiment, step S402 includes: If the distance between the grid with the highest concentration difference value and the riverbank is within a preset distance threshold, and the concentration difference value gradually decreases from the grid with the highest concentration difference value along the river's flow direction, then the target river is determined to be in a state of sewage discharge; otherwise, it is determined to be in a state of stopped sewage discharge.

[0057] Referring to the above embodiments, the Euclidean distance between the grid corresponding to the grid with the highest concentration difference value and the riverbanks on both sides is calculated. The side with the closer distance is retained as the distance between the grid and the riverbank. If the distance between the grid with the highest concentration difference value and the riverbank is less than a preset distance threshold, it is determined that the grid is located in the near-shore area. In one embodiment, the distance threshold can be set based on the river width, for example, set to one-fifth of the river width. The river width of the target river can be calculated based on the coordinate positions of the riverbanks on both sides.

[0058] When both of the above conditions are met simultaneously, the target river is determined to be in a state of discharging sewage; otherwise, the target river is determined to be in a state of ceasing to discharge sewage.

[0059] In this embodiment, the sewage discharge status of the target river is determined by combining the location of the maximum concentration difference value and the spatial morphological characteristics of the concentration difference value. When the river is in the process of sewage discharge, the sewage outlets near the bank will continuously discharge pollutants, resulting in a significant increase in concentration, and the location of the maximum concentration difference value will be near the bank. When the river is in the process of sewage discharge stopped, the pollution cloud as a whole begins to flow, causing the maximum concentration difference value to deviate from the bank.

[0060] For step S105, based on the sewage discharge status of the target river, a corresponding sewage discharge monitoring strategy is adopted to monitor and trace the source of sewage discharge.

[0061] In one embodiment, step S105 includes: S501, if the target river is currently discharging sewage, the location of the grid with the highest concentration difference value is determined as the location of the sewage outlet.

[0062] When the target river is in the process of discharging sewage, pollutants are continuously discharged from the sewage outlet. The concentration of its water quality parameters will change significantly compared to the normal water quality period, resulting in the maximum concentration difference value at the sewage outlet. The position of the grid with the highest concentration difference value is then determined as the location of the sewage outlet.

[0063] S502a, if the target river is in a state of no sewage discharge, a boundary line parallel to the river flow direction is constructed with the center point of the grid with the highest concentration difference value; the concentration difference values ​​of the grids on both sides of the boundary line are compared, and the river bank near the side with the higher concentration difference value is determined as the location of the sewage outlet.

[0064] The dividing line extends in the same direction as the target river, dividing the river into two regions (left and right) based on the highest concentration difference value. The concentration difference value on each side of the dividing line is calculated, where the concentration difference value can be the average of the concentration difference values ​​of all grid cells in the region. The side with the higher average value is identified as the source of the pollution, and further investigation is conducted to trace the discharge outlet. For example, in one embodiment, if the average concentration difference value on the left side of the dividing line is higher than the average value on the right side, the discharge outlet is determined to be located on the left bank of the river.

[0065] Alternatively, in S502b, based on the position of the grid with the highest concentration difference value, a preset concentration anomaly judgment rule is used to obtain the concentration difference value anomaly area, and the sewage outlet location is determined based on the concentration difference value anomaly area.

[0066] The concentration anomaly judgment rule is used to identify grids with abnormal concentration difference values ​​in the spatial distribution map of water quality differences, thereby obtaining anomaly regions. In one embodiment, starting from the grid with the highest concentration difference value, the search proceeds upstream along the target river (i.e., upstream direction) to obtain a continuous grid area where the concentration difference value is consistently higher than its downstream adjacent grid and significantly higher than the average concentration difference value, which is then regarded as anomaly regions.

[0067] In one embodiment, after obtaining the abnormal concentration difference area, the location of the sewage outlet is determined based on the positional relationship between the abnormal concentration difference area and the two sides of the bank.

[0068] In another embodiment, the location of the sewage outlet can be determined by combining the judgment method of step S502a above, thereby tracing the source of the sewage outlet.

[0069] In this embodiment, steps S502a and S502b can be used individually or in combination to trace and determine the location of the sewage outlet, effectively improving the reliability of the tracing results.

[0070] In one embodiment, S502b further includes: Based on the spatial distribution map of water quality differences, the leverage ratio of each grid is obtained using a preset leverage ratio calculation formula. The leverage ratio is calculated using the following formula:

[0071] In the formula, Let A be the leverage ratio of the i-th grid cell, and let A be the water quality parameter matrix, where the rows represent several grid cells and the columns represent several water quality parameters obtained through inversion. The transpose of the water quality parameter matrix A for The pseudo-inverse matrix; Extract the abnormal grid cells with a leverage ratio greater than 0.5, and obtain the overlapping area between the abnormal grid cells and the abnormal concentration difference value area; The location of the sewage outlet is determined based on the overlapping area.

[0072] The water quality parameter matrix A is a two-dimensional matrix with N grids as sample points. Each grid corresponds to a row in the water quality parameter matrix. Several (P) different water quality parameters obtained by inversion are used as feature variables. Each water quality parameter corresponds to a column in the water quality parameter matrix, forming an N*P water quality parameter matrix.

[0073] The leverage ratio is an indicator derived from multi-source statistical analysis, used to measure the "abnormality" or "influence" of a sample point in a multidimensional feature space composed of all sample points.

[0074] In this embodiment, the leverage ratio corresponding to each grid is calculated and compared with a preset discrimination threshold (e.g., 0.5). If the leverage ratio of a grid is higher than the discrimination threshold, the grid is determined to be an abnormal grid. Then, all abnormal grids are spatially superimposed with the abnormal concentration difference value area obtained in the above embodiment to obtain an overlapping area. Finally, the location of the sewage outlet is determined based on the overlapping area to complete the sewage monitoring and source tracing of the target river.

[0075] The river pollution monitoring method based on water quality changes provided in this application acquires a first-phase remote sensing image of the target river during a period of normal water quality and a second-phase remote sensing image under the current condition. A water quality inversion model is constructed, and water quality parameter feature data are extracted from the two-phase remote sensing images. These feature data are then input into the water quality inversion model to obtain the spatial distribution data of water quality parameters corresponding to the two-phase remote sensing images. Next, the water quality concentration values ​​of each grid in the two-phase remote sensing images are acquired, and the difference between the water quality concentration values ​​of the grids at the same spatial location in the two phases is calculated to obtain the concentration difference value of each grid. The concentration difference is then classified according to the magnitude of the concentration difference value, thereby generating a spatial distribution map of water quality differences. Based on the spatial morphological characteristics of the spatial distribution map of water quality differences and the positional relationship between the grid with the highest concentration difference value and the riverbank, the current pollution discharge status of the target river is determined, and corresponding pollution discharge monitoring strategies are adopted, ultimately realizing the monitoring of pollution discharge in the target river and the tracing of pollution outlets.

[0076] The method provided in this application, based on two remote sensing images of a target river during a period of normal water quality and the current period, obtains spatial distribution data of water quality parameters in the two periods through a water quality inversion model, generates a spatial distribution map of water quality differences, and automatically determines the river's sewage discharge status and pollution source tracing based on preset judgment rules. This solves the problems of wasted manpower and resources and low efficiency of traditional manual inspection and single-point sampling, significantly improving the timeliness, spatial accuracy and source tracing reliability of pollution monitoring, and providing effective remote sensing technology support for watershed water environment supervision and pollution source investigation.

[0077] Secondly, please refer to Figure 5 , Figure 5 This is a schematic diagram of a river sewage monitoring system based on water quality changes, provided as an embodiment of this application.

[0078] This application provides a river sewage discharge monitoring system based on water quality changes, including: The remote sensing image acquisition module 11 is used to acquire the first phase remote sensing image and the second phase remote sensing image of the target river; wherein, the first phase remote sensing image is the remote sensing image during the period of normal water quality, and the second phase remote sensing image is the remote sensing image of the sewage discharge status to be determined. Inversion module 12 is used to invert water quality parameters on the first phase remote sensing image and the second phase remote sensing image based on a preset water quality inversion model, to obtain the spatial distribution data of the first water quality parameter corresponding to the first phase remote sensing image and the spatial distribution data of the second water quality parameter corresponding to the second phase remote sensing image. The water quality difference spatial distribution map generation module 13 is used to calculate the spatial difference between the first water quality parameter spatial distribution data and the second water quality parameter spatial distribution data to generate a water quality difference spatial distribution map; wherein, the water quality difference spatial distribution map includes a plurality of grids and the concentration difference value corresponding to each grid; The sewage discharge status identification module 14 is used to obtain the sewage discharge status of the target river based on the spatial distribution map of water quality differences and according to the preset sewage discharge status judgment rules. The sewage monitoring module 15 is used to monitor and trace the source of sewage discharge by adopting corresponding sewage monitoring strategies based on the sewage discharge status of the target river.

[0079] It should be noted that the river sewage monitoring system based on water quality changes provided in the above embodiments is only illustrated by the division of the above functional modules when executing the river sewage monitoring method based on water quality changes. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the equipment can be divided into different functional modules to complete all or part of the functions described above. The river sewage monitoring system based on water quality changes provided in the above embodiments is used to execute the river sewage monitoring method based on water quality changes described in the above embodiments. Its operation method and principle are the same as the river sewage monitoring method based on water quality changes described above. That is, the river sewage monitoring system based on water quality changes provided in the above embodiments and the river sewage monitoring method based on water quality changes belong to the same concept. The implementation process is detailed in the above method embodiments and will not be repeated here.

[0080] Thirdly, this embodiment provides a computer device. Please refer to [link / reference needed]. Figure 6 , Figure 6 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Figure 6 As shown, the computer device 21 includes: a processor 210, a memory 211, and a computer program 212 stored in the memory 211 and executable on the processor 210, such as a river sewage monitoring program based on water quality changes; the processor 210 executes the computer program 212 to implement the methods described in the above embodiments.

[0081] The processor 210 may include one or more processing cores. The processor 210 connects to various parts within the computer device 21 using various interfaces and lines. It executes various functions of the computer device 21 and processes data by running or executing instructions, programs, code sets, or instruction sets stored in the memory 211, and by accessing data in the memory 211. Optionally, the processor 210 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 210 may integrate one or more of the following: a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), and a modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the content required for the touch screen; and the modem handles wireless communication. It is understood that the modem may also be implemented as a separate chip, rather than integrated into the processor 210.

[0082] The memory 211 may include random access memory (RAM) or read-only memory. Optionally, the memory 211 may include a non-transitory computer-readable storage medium. The memory 211 may be used to store instructions, programs, code, code sets, or instruction sets. The memory 211 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as touch instructions), instructions for implementing the various method embodiments described above, etc.; the data storage area may store data involved in the various method embodiments described above, etc. Optionally, the memory 211 may also be at least one storage device located remotely from the aforementioned processor 210.

[0083] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application 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.

[0084] Fourthly, embodiments of this application also provide a computer-readable storage medium that can store multiple instructions. These instructions are applicable to being loaded by a processor and executing the method steps of the above embodiments. For details of the execution process, please refer to the specific description of the above embodiments, which will not be repeated here.

[0085] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application 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.

[0086] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for monitoring river sewage discharge based on water quality changes, characterized in that, include: Acquire the first and second phases of remote sensing images of the target river; wherein, the first phase of remote sensing images is the remote sensing images during the period of normal water quality, and the second phase of remote sensing images is the remote sensing images of the sewage discharge status to be determined; Based on the preset water quality inversion model, water quality parameters are inverted on the first phase remote sensing image and the second phase remote sensing image respectively to obtain the spatial distribution data of the first water quality parameter corresponding to the first phase remote sensing image and the spatial distribution data of the second water quality parameter corresponding to the second phase remote sensing image. Spatial difference calculation is performed on the spatial distribution data of the first water quality parameter and the spatial distribution data of the second water quality parameter to generate a spatial distribution map of water quality differences; wherein, the spatial distribution map of water quality differences includes a number of grids and the concentration difference value corresponding to each grid; Based on the spatial distribution map of water quality differences, the sewage discharge status of the target river is obtained according to the preset sewage discharge status judgment rules. Based on the sewage discharge status of the target river, corresponding sewage discharge monitoring strategies will be adopted for sewage discharge monitoring and source tracing. The two sides of the second phase of remote sensing image are the riverbanks of the target river, and the target river flows from top to bottom; The step of obtaining the discharge status of the target river based on the spatial distribution map of water quality differences and according to preset discharge status judgment rules includes: Based on the spatial distribution map of water quality differences, obtain the location information of the grid with the highest concentration difference value and the spatial morphological characteristics of the spatial distribution map of water quality differences; Based on the positional relationship between the grid with the highest concentration difference value and the riverbank, and the spatial morphological characteristics of the spatial distribution map of water quality differences, the sewage discharge status of the target river is determined; wherein, the sewage discharge status includes the sewage discharge status in progress and the sewage discharge status stopped. The determination of the sewage discharge status of the target river based on the positional relationship between the grid with the highest concentration difference value and the riverbank, and the spatial morphological characteristics of the spatial distribution map of water quality differences, includes: If the distance between the grid with the highest concentration difference value and the riverbank is within a preset distance threshold, and the concentration difference value gradually decreases from the grid with the highest concentration difference value along the river's flow direction, then the target river is determined to be in a state of sewage discharge; otherwise, it is determined to be in a state of stopped sewage discharge.

2. The river sewage discharge monitoring method based on water quality changes according to claim 1, characterized in that, The water quality inversion model, based on a preset model, performs water quality parameter inversion on the first and second phases of remote sensing images, respectively, to obtain spatial distribution data of the first water quality parameter corresponding to the first phase of remote sensing images and spatial distribution data of the second water quality parameter corresponding to the second phase of remote sensing images, including: Preprocessing is performed on the first and second phases of remote sensing images; Extract the first water quality parameter feature data corresponding to the first phase of the preprocessed remote sensing image and the second water quality parameter feature data corresponding to the second phase of the remote sensing image; Construct a water quality inversion model; The first water quality parameter feature data and the second water quality parameter feature data are respectively input into the water quality inversion model to obtain the spatial distribution data of the first water quality parameter corresponding to the first phase remote sensing image and the spatial distribution data of the second water quality parameter corresponding to the second phase remote sensing image.

3. The river sewage discharge monitoring method based on water quality changes according to claim 1, characterized in that, The step of calculating the difference between the spatial distribution data of the first water quality parameter and the spatial distribution data of the second water quality parameter to generate a spatial distribution map of water quality differences includes: Based on the spatial distribution data of the first water quality parameter and the spatial distribution data of the second water quality parameter, the water quality concentration values ​​of each grid in the first phase remote sensing image and the second phase remote sensing image are obtained respectively; wherein, the grids in the first phase remote sensing image and the second phase remote sensing image correspond one-to-one; The difference in water concentration values ​​is calculated for each group of one-to-one corresponding grid cells to obtain the concentration difference value of the grid cells at each spatial location; Based on the concentration difference values, a spatial distribution map of water quality differences is generated.

4. The river sewage discharge monitoring method based on water quality changes according to claim 3, characterized in that, After the step of calculating the difference in water concentration values ​​for each group of corresponding grid cells to obtain the concentration difference value of the grid cells at each spatial location, the method further includes: Based on the preset water quality difference classification rules, the concentration difference classification of the grid at each spatial location is obtained according to the concentration difference value of the grid at each spatial location; wherein, the concentration difference classification includes high value, medium value and low value. Based on the concentration difference classification results, a spatial distribution map of water quality differences is generated.

5. The river sewage discharge monitoring method based on water quality changes according to claim 1, characterized in that, The step of adopting corresponding pollution monitoring strategies for pollution monitoring and source tracing based on the pollution discharge status of the target river includes: If the target river is currently discharging sewage, the location of the grid with the highest concentration difference value will be determined as the location of the sewage outlet; If the target river is in a state of no sewage discharge, a boundary line parallel to the river flow direction is constructed with the center point of the grid with the highest concentration difference value; the concentration difference values ​​of the grids on both sides of the boundary line are compared, and the river bank closer to the side with the higher concentration difference value is determined as the location of the sewage outlet. And / or, based on the position of the grid with the highest concentration difference value, a preset concentration anomaly judgment rule is used to obtain the concentration difference abnormality area, and the sewage outlet location is determined based on the concentration difference abnormality area.

6. The river sewage discharge monitoring method based on water quality changes according to claim 5, characterized in that, The step of determining the location of the sewage outlet based on the position of the grid with the highest concentration difference value, using a preset concentration anomaly judgment rule, to obtain the concentration difference anomaly region, and based on the concentration difference anomaly region, further includes: Based on the spatial distribution map of water quality differences, the leverage ratio of each grid is obtained using a preset leverage ratio calculation formula. The leverage ratio is calculated using the following formula: In the formula, Let A be the leverage ratio of the i-th grid cell, and let A be the water quality parameter matrix, where the rows represent several grid cells and the columns represent several water quality parameters obtained through inversion. The transpose of water quality parameter matrix A for The pseudo-inverse matrix; Extract the abnormal grid cells with a leverage ratio greater than 0.5, and obtain the overlapping area between the abnormal grid cells and the abnormal concentration difference value area; The location of the sewage outlet is determined based on the overlapping area.

7. A river sewage discharge monitoring system based on water quality changes, characterized in that, include: The remote sensing image acquisition module is used to acquire the first phase remote sensing image and the second phase remote sensing image of the target river; wherein, the first phase remote sensing image is the remote sensing image during the period of normal water quality, and the second phase remote sensing image is the remote sensing image of the sewage discharge status to be determined. The inversion module is used to invert water quality parameters on the first phase remote sensing image and the second phase remote sensing image based on a preset water quality inversion model, to obtain the spatial distribution data of the first water quality parameter corresponding to the first phase remote sensing image and the spatial distribution data of the second water quality parameter corresponding to the second phase remote sensing image. A water quality difference spatial distribution map generation module is used to calculate the spatial difference between the first water quality parameter spatial distribution data and the second water quality parameter spatial distribution data to generate a water quality difference spatial distribution map; wherein, the water quality difference spatial distribution map includes a number of grids and the concentration difference value corresponding to each grid; The sewage discharge status identification module is used to obtain the sewage discharge status of the target river based on the spatial distribution map of water quality differences and according to the preset sewage discharge status judgment rules, including: obtaining the location information of the grid with the highest concentration difference value and the spatial morphological features of the spatial distribution map of water quality differences based on the spatial distribution map of water quality differences. Based on the positional relationship between the grid with the highest concentration difference value and the riverbank, and the spatial morphological characteristics of the water quality difference spatial distribution map, the sewage discharge status of the target river is determined; wherein, the sewage discharge status includes an ongoing sewage discharge status and a stopped sewage discharge status, including: If the distance between the grid with the highest concentration difference value and the riverbank is within a preset distance threshold, and the concentration difference value gradually decreases from the grid with the highest concentration difference value along the river's flow direction, then the target river is determined to be in a state of sewage discharge; otherwise, it is determined to be in a state of stopped sewage discharge. The two sides of the second phase of remote sensing imagery represent the riverbanks of the target river, and the target river flows from top to bottom. The sewage discharge monitoring module is used to monitor and trace the source of sewage discharge by adopting corresponding sewage discharge monitoring strategies based on the sewage discharge status of the target river.

8. A computer device comprising a processor, a memory, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the river sewage monitoring method based on water quality changes as described in any one of claims 1 to 6.

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