Method for joint defense and control of water environment risk across administrative regions

Abstract

The present application relates to the technical field of environmental monitoring, in particular to a water environment risk joint defense and control partitioning method across administrative regions, comprising the following steps: obtaining a section parameter change direction, screening consistent trend sections, extracting cross-region water body connection relationships, identifying path continuity, judging boundary connectivity state, identifying water area coverage consistency, screening section arrangement offset regions, and delineating a joint defense partitioning structure table. In the present application, multi-parameter trend consistency screening is used to strengthen section response feature extraction, path construction standards are established in combination with water flow direction and accessibility continuity, the structural integrity of spatial connection and the rationality of hydrodynamic conduction are enhanced, water surface coverage continuity and section distribution coordination judgment is introduced in the boundary region, the cross-region water area range delineation basis is refined, the partitioning reconstruction is completed in accordance with the water flow connection order, the joint defense and control partitioning structure covering a coordinated range, having consistent water area boundary size and trend direction is constructed, and the orderly operation of the cross-region pollution control collaboration mechanism is promoted.

Description

Technical Field

[0001] This invention relates to the field of environmental monitoring technology, and in particular to a cross-administrative region water environment risk joint prevention and control zoning method. Background Technology

[0002] Environmental monitoring technology falls under the category of ecological environmental protection and governance. Its core aspects include monitoring the status of environmental elements such as water, air, soil, and noise; detecting pollutant indicators; data collection and analysis; constructing monitoring networks; and building an information-based regulatory system. This technology provides support for environmental quality assessment, pollution source tracing, environmental risk identification, and emergency management through the deployment of sensing terminals, data collection, real-time transmission, and intelligent analysis. It is a crucial pillar for achieving digital, systematic, and refined ecological environmental management. Among these, the traditional cross-administrative regional water environment risk joint prevention and control zoning method refers to using water environment monitoring results and historical water quality data within a single administrative region as the basis for risk assessment. Pollution risk levels are classified according to established local risk assessment rules, and a joint water pollution prevention and control mechanism is established between upstream and downstream areas or adjacent areas through administrative consultation.

[0003] Because it relies on historical data from a single region and only constructs a linkage division logic based on risk level, it lacks effective identification of the spatial continuity of water bodies and cross-regional connection structures. In scenarios where pollution spreads along water flow, path interruption or boundary identification deviation can easily lead to omissions in the control scope. The continuity relationship of water bodies has not been fully quantified and analyzed, making it difficult for pollution response to accurately cover high-risk sections. In actual joint control zoning, the mismatch between administrative boundaries and water body paths is evident, affecting the deployment of monitoring points and the establishment of pollution prevention and control coordination mechanisms, and reducing the overall consistency and management closed-loop effect between governance chains. Summary of the Invention

[0004] To address the technical problems existing in the prior art, embodiments of the present invention provide a cross-administrative regional water environment risk joint prevention and control zoning method, comprising the following steps:

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a cross-administrative region water environment risk joint prevention and control zoning method, comprising the following steps:

[0006] S1: Obtain the monitoring sections deployed in the watershed that flows through the administrative region, extract the changing direction of ammonia nitrogen, total phosphorus and dissolved oxygen in a continuous time period, screen the sections with consistent turning points, and obtain a list of monitoring sections with pollution trend response characteristics according to the administrative region.

[0007] S2: Based on the list of monitoring sections with the pollution trend response characteristics, extract the cross-regional connection relationship, determine whether the water body direction is continuous, remove interrupted segments, and obtain the continuous water body path information across administrative regions;

[0008] S3: Based on the coverage status of the continuous water body path information in the boundary area, determine whether the water body is completely connected at the boundary, remove segments with missing sections and non-connected segments, and obtain the boundary water area with water body continuity characteristics.

[0009] S4: Based on the cross-sectional arrangement within the boundary water area with the water body continuity characteristics, compare the cross-sectional distribution direction with the water body extension direction, remove areas with insufficient distribution and discontinuous arrangement, and obtain a list of administrative region water areas with connection offset.

[0010] S5: Based on the list of administrative region water areas under the aforementioned connection offset, extract uninterrupted water flow segments, divide the segment into cross-sectional directions and path directions, divide the joint defense zones, and obtain a cross-administrative region joint defense and control zone structure table.

[0011] As a further aspect of the present invention, the list of monitoring sections for pollution trend response characteristics includes section number, administrative region, ammonia nitrogen change trend, total phosphorus change trend, dissolved oxygen change trend, and trend change synchronicity. The continuous water body path information across administrative regions includes path start and end sections, section connection sequence, water flow direction, administrative region crossing sequence, and water body connectivity identifier. The boundary water area with water body continuity characteristics includes a boundary connection point list, water surface coverage continuity, water body accessibility, and waterway integrity identifier. The list of administrative region water areas with connection offset includes section spatial coverage density, boundary direction consistency, section distribution connection status, and water area coverage offset. The cross-administrative region joint prevention and control zoning structure table includes water body area number, upstream and downstream connection relationship, administrative region distribution structure, zoning boundary range, and section functional attributes.

[0012] As a further aspect of the present invention, the transition consistent section refers to a monitoring section in which multiple water quality monitoring parameters change in the same direction over a continuous time period.

[0013] The term "missing cross-section" refers to the absence of monitoring cross-sections at the boundaries or connecting areas of the water body path, making it impossible to determine whether the water body is continuous or whether the pollution trend continues.

[0014] As a further aspect of the present invention, the disconnected segment refers to a spatial and hydrodynamic fracture segment in the water path caused by discontinuous cross-sectional arrangement, inconsistent water flow direction, and physical obstruction.

[0015] The water body extension direction refers to the spatial extension trend of the water body along the natural flow direction and boundary direction, whether the arrangement spacing is less than a preset threshold, and whether the distribution covers the entire water area.

[0016] As a further aspect of the present invention, the specific steps of S1 are as follows:

[0017] S101: Obtain water quality monitoring sections that flow through multiple administrative regions, collect ammonia nitrogen, total phosphorus, and dissolved oxygen parameter data of the sections in a continuous time period, arrange the values ​​of each parameter in chronological order, determine the direction of increase or decrease between adjacent time points, and obtain a sequence of changes in multiple monitoring parameters.

[0018] S102: Based on the sequence of changes in the multiple monitoring parameters, screen the sections where the changes in ammonia nitrogen, total phosphorus, and dissolved oxygen parameters are all consistent, and remove sections where the changes in any parameter are inconsistent, to obtain a set of section numbers with consistent changes.

[0019] S103: Based on the set of cross-section numbers with consistent change direction, call the administrative region attribute of the corresponding cross-section, and assign the cross-section number to the region to obtain a list of monitoring cross-sections with pollution trend response characteristics.

[0020] As a further aspect of the present invention, the specific steps of S2 are as follows:

[0021] S201: Based on the list of monitoring sections with the pollution trend response characteristics, call the position index of the section in the water body and the water flow direction data, extract the sections that are located in different administrative regions and have upstream and downstream relationships, exclude the sections that are located in the same region or have discontinuous water flow directions, and obtain a list of cross-regional section connection numbers.

[0022] S202: Based on the cross-regional cross-section connection sequence number list, call the distance between cross-sections, water flow direction and river section continuity status, determine whether the water flow direction is consistent with the cross-section arrangement order, eliminate paths with reversed flow direction and spatial interruption, and obtain the set of water flow direction sequence path numbers.

[0023] S203: Based on the set of sequential path numbers in the direction of water flow, call the coordinate points of the path break sections and the water flow direction information, arrange the connection relationship of the sections in sequence according to the direction of water flow, extract the spatial path of the water body along the line, and obtain the continuous water body path information across administrative regions.

[0024] As a further aspect of the present invention, the specific steps of S3 are as follows:

[0025] S301: Based on the continuous water body path information across administrative regions, call the coordinate points of the path at the administrative region boundary and the administrative boundary line data, extract the boundary junctions of the areas traversed by the path, identify whether there are corresponding water quality monitoring sections on both sides of the junctions, exclude boundary locations lacking section distribution, and obtain a list of boundary junctions with section distribution.

[0026] S302: Based on the list of boundary nodes with cross-sectional distribution, call the remote sensing water surface layer data on both sides of the node, determine whether the water surface area maintains spatial connection, identify the boundary section of closed waterway or water body separation, remove the corresponding node, and obtain the set of boundary nodes that maintain connectivity.

[0027] S303: Based on the set of boundary nodes that maintain connectivity, call the linear data and cross-sectional spatial distribution information of the path segments associated with the nodes, extract the area covered by the boundary path segments that simultaneously have cross-sectional continuity and water surface connection, and obtain the boundary water area with water body continuity characteristics.

[0028] As a further aspect of the present invention, the specific steps of S4 are as follows:

[0029] S401: Based on the boundary water area with water body continuity characteristics, call the administrative region code information corresponding to the monitoring section, classify the section into the corresponding management scope according to the administrative division, extract the spatial coordinates of the section within the administrative region, and obtain the distribution coordinate set of the administrative region section.

[0030] S402: Based on the coordinate set of the cross-section distribution of the administrative region, call the cross-section coordinate points and the corresponding water boundary line shape, determine the arrangement state of the cross-section along the boundary direction in space, identify whether the cross-section distribution continuously covers the entire water edge, and extract the position segment of the blank spacing to obtain the length of the boundary direction distribution coverage interval.

[0031] S403: Based on the length of the boundary direction distribution coverage interval, call the spatial connection point of the interval position and the corresponding segment of the water area line, determine whether the cross-section arrangement has shifted in the adjacent area, extract the administrative division information of the spatial shift position, and obtain the list of administrative area water areas with connection shift.

[0032] As a further aspect of the present invention, the process of determining the arrangement of cross sections along the boundary direction in space specifically involves: measuring the distance between adjacent cross sections in the distribution coordinate set of cross sections in the administrative region, comparing it with a set reference distance, analyzing the positional segments between adjacent cross sections whose distances exceed the reference range, and extracting the positional segments as the range of blank spacing.

[0033] The process of determining whether the cross-section arrangement has shifted in adjacent areas specifically involves: analyzing the directional changes of the spatial connection points of the interval positions and the corresponding segments of the water area lines, analyzing the continuous trend in the boundary direction, and when the directional change angle between adjacent administrative regions is greater than a preset angle threshold, extracting the administrative region code information where the spatial position is located, and analyzing the list of administrative region water areas in the connection shift situation based on the information.

[0034] As a further aspect of the present invention, the specific steps of S5 are as follows:

[0035] S501: Based on the list of administrative region water areas under the connection offset, call the water flow direction data within the area, remove path segments with interrupted water flow direction, extract water bodies in areas where the flow direction is continuous, extract the cross-sectional position, water flow direction and administrative region name corresponding to the path segment within the range, and obtain continuous area cross-sectional path information.

[0036] S502: Based on the continuous section path information, call the section coordinates, water flow direction and boundary intersection point location data, arrange the upstream and downstream edge positions of the path segment according to the water flow sequence, extract the correspondence between the section sequence and the boundary intersection point, and obtain the upstream and downstream connection sequence relationship table.

[0037] S503: Based on the upstream and downstream connection sequence relationship table, call the cross-sectional spatial distribution, water flow path and administrative boundary range, divide the spatial range of continuous areas according to the connection sequence, and correspond the partition range with the administrative region to obtain the cross-administrative region joint prevention and control partition structure table.

[0038] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0039] In this invention, the extraction of cross-sectional response features is enhanced by screening for consistency of multi-parameter trends. Path construction standards are established by combining water flow direction and accessibility continuity, thereby enhancing the structural integrity of spatial connections and the rationality of hydrodynamic transmission. Water surface coverage continuity and cross-sectional distribution coordination are introduced in boundary areas to refine the criteria for delineating cross-regional water areas. The zoning reconstruction is completed according to the water flow connection sequence, constructing a joint prevention and control zoning structure with coordinated coverage, consistent water area boundary scale, and consistent trend direction, thus promoting the orderly operation of the cross-regional pollution control cooperation mechanism. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying 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.

[0041] Figure 1 This is a schematic diagram of the steps of the present invention;

[0042] Figure 2 This is a detailed schematic diagram of S1 of the present invention;

[0043] Figure 3 This is a detailed schematic diagram of S2 of the present invention;

[0044] Figure 4 This is a detailed schematic diagram of S3 of the present invention;

[0045] Figure 5 This is a detailed schematic diagram of S4 of the present invention;

[0046] Figure 6 This is a detailed schematic diagram of S5 of the present invention. Detailed Implementation

[0047] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0048] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0049] In the embodiments of this invention, the terms "image" and "picture" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning. Similarly, the terms "of," "corresponding (relevant)," and "corresponding" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning.

[0050] In this embodiment of the invention, sometimes a subscript such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, the meaning they express is the same.

[0051] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0052] Please see Figure 1 This invention provides a method for joint prevention and control of water environment risks across administrative regions, comprising the following steps:

[0053] S1: Obtain water quality monitoring sections deployed within the basin that flows through multiple administrative regions, extract ammonia nitrogen, total phosphorus, and dissolved oxygen parameter data for each section in a continuous time period, compare the changing direction of each parameter in the time period, filter sections that change continuously in the same time period, and map the sections to their respective regions according to their administrative scope to obtain a list of monitoring sections with pollution trend response characteristics.

[0054] S2: Based on the positional order of monitoring sections in the water flow path of the pollution trend response characteristics, extract the connection relationship of sections in different administrative regions, analyze whether there is a complete water body continuity for each connection, exclude water body interruption or direction reversal, delineate the path boundary along the water flow direction, and obtain continuous water body path information across administrative regions.

[0055] S3: Based on the continuous water body path information across administrative regions, conduct water body distribution checks at the administrative region boundaries. According to the boundary junctions of the areas traversed by the path, identify the continuity of water surface coverage, exclude areas with cross-sectional gaps, disconnected water bodies, and closed waterways, and obtain the boundary water area with water body continuity characteristics.

[0056] S4: Delineate the management scope of the administrative region to which the monitoring section within the boundary water area with water body continuity characteristics belongs, analyze the spatial distribution continuity of the section within each scope, conduct a matching analysis with the boundary extension direction of the water area, screen out cases of insufficient section coverage area and spatial connection break, and obtain a list of administrative region water areas with connection offset.

[0057] S5: Based on the list of administrative region water areas with connection offset, select water bodies in areas where the continuous water flow direction is not interrupted, divide the cross-sectional positions, water flow paths and administrative regions in the water body segments, and divide the edge positions of the water bodies at the boundary according to the upstream and downstream connection order to obtain the cross-administrative region joint prevention and control zoning structure table.

[0058] The list of monitoring sections for pollution trend response characteristics includes section number, administrative region, ammonia nitrogen change trend, total phosphorus change trend, dissolved oxygen change trend, and trend synchronicity. The information on continuous water body paths across administrative regions includes path start and end sections, section connection sequence, water flow direction, administrative region crossing sequence, and water connectivity identifier. The scope of boundary water areas with water body continuity characteristics includes a list of boundary junctions, water surface coverage continuity, water accessibility, and waterway integrity identifier. The list of administrative region water areas with connection offset includes section spatial coverage density, boundary direction consistency, section distribution connection status, and water area coverage offset. The cross-administrative region joint prevention and control zoning structure table includes water body area number, upstream and downstream connection relationship, administrative region distribution structure, zoning boundary range, and section functional attributes.

[0059] Please see Figure 2 The specific steps of S1 are as follows:

[0060] S101: Obtain water quality monitoring sections that flow through multiple administrative regions, collect ammonia nitrogen, total phosphorus, and dissolved oxygen parameter data of the sections in a continuous time period, arrange the values ​​of each parameter in chronological order, determine the direction of increase or decrease between adjacent time points, and obtain a sequence of changes in multiple monitoring parameters.

[0061] First, locate the nodes of the main streams and tributaries of the water system that cross two or more administrative boundaries within the watershed coverage area. Mark the location of each cross-section on the map and overlay it with the administrative region vector map. Extract the cross-section number and its corresponding administrative code one by one. For example, cross-section D001 is located in area A, and D002 is located at the boundary of area B. After confirming the cross-section affiliation, collect water quality parameter data such as ammonia nitrogen, total phosphorus, and dissolved oxygen for each cross-section during a specific observation period. The set time period should be continuous, such as selecting the daily average value for ten consecutive days as the parameter. The input data source is used to construct a date-sorted sequence for each water quality parameter. For example, the ammonia nitrogen concentration values ​​at section D001 are 1.2, 1.1, 0.9, 1.0, and 1.3. Adjacent values ​​are compared within this sequence. For each pair of consecutive data points, a subtraction operation is performed to determine the trend. If the result of subtracting the value at the next time point from the previous one is positive, it is marked as a decrease; if the result is negative, it is marked as an increase; and if the result is zero, it is marked as unchanged. This operation is applied to ammonia nitrogen and total phosphorus. The three parameters, dissolved oxygen, and total phosphorus, are executed independently to obtain three corresponding directional change sequences. The judgment result of each sequence should be interpreted in conjunction with the concentration change characteristics of its parameter. For example, an increase in dissolved oxygen usually corresponds to an improvement in water quality, so its change direction should be directly judged as positive. Ammonia nitrogen and total phosphorus are judged as a decrease in water risk and thus as a positive trend. Taking section D001 as an example, its ammonia nitrogen concentration sequence decreases continuously from 1.2 to 1.1 and then to 0.9, and the trend of water quality improvement is marked as positive. Similarly, if a section shows an increase in ammonia nitrogen from 1.0 to 1.3 and then a decrease to 1.1, the change direction is negative first and then positive, which does not constitute a continuous trend. It is necessary to further judge whether each trend segment forms a trend inflection point. Based on the continuity of trend changes in the section parameter sequence, trend chain identification is performed. The change direction results of the three parameters within the same section are stored in parallel in the same dataset. Finally, the trend direction sequence of multiple water quality parameters is output as the trend identification result of the section, thus obtaining the change direction sequence of multiple monitoring parameters.

[0062] S102: Based on the sequence of changes in multiple monitoring parameters, screen the sections where the changes in ammonia nitrogen, total phosphorus, and dissolved oxygen parameters are all consistent, and remove sections where the changes in any parameter are inconsistent, thus obtaining a set of section numbers with consistent changes.

[0063] First, extract the directional change signs of the three parameters—ammonia nitrogen, total phosphorus, and dissolved oxygen—for each cross-section, constructing a three-element combination sequence for each cross-section. A positive sequence is defined as all three parameters trending upwards, a negative sequence as all three trending downwards, and a mixed state if different directions exist among the three parameters. Before performing the screening operation, the criteria for determining the direction of each parameter need to be standardized. For example, the decreasing direction of ammonia nitrogen and total phosphorus is defined as positive, and the increasing direction of dissolved oxygen is defined as positive. Therefore, if cross-section D005 shows a decreasing trend in ammonia nitrogen, a decreasing trend in total phosphorus, and an increasing trend in dissolved oxygen, then all three trends are positive, meeting the screening requirements and entering the subsequent set. If cross-section D006 shows a decreasing trend in ammonia nitrogen, an increasing trend in total phosphorus, and an increasing trend in dissolved oxygen, then it is removed from the set because the direction of total phosphorus is inconsistent with the other two. For this direction determination, the classification boundary should be clearly defined. If expressed by symbols, let decreasing be "+", increasing be "+", and decreasing be "+". If the symbol is "-", then the consistent combination is in the form of "+++" or "---". All other cases are inconsistent combinations. The screening process should process each section independently and record them according to the section number. For example, D001 is "+++", D002 is "++-", and D003 is "+--". Only D001 meets the three consistent conditions. In actual processing scenarios, the symbol comparison operation can be performed in batches through a list. If the three directions are used to form a string, the Boolean judgment can be performed in script tools such as Python to determine whether the characters in the string are all equal. The judgment method is: if the length of set(string) is 1 and the symbols in the string are consistent with the direction standard, then it is determined that the three are consistent; otherwise, it is determined that they are inconsistent. Finally, the section numbers that meet the consistency of the three change directions are extracted and summarized into a set of numbers to obtain the set of section numbers with consistent change directions.

[0064] S103: Based on the set of cross-section numbers with consistent change direction, call the administrative region attribute of the corresponding cross-section, and match the cross-section numbers according to their respective regions to obtain a list of monitoring cross-sections with pollution trend response characteristics.

[0065] First, the administrative region attribute data corresponding to each cross-section number is retrieved. Spatial coordinates are overlaid with the administrative boundary layer to identify the spatial overlap between the cross-section's location and the administrative boundary polygon, determining the administrative region to which the cross-section belongs. If a cross-section point D023 is located within the boundary polygon of administrative region B, then the cross-section number is associated with administrative region B. This process is repeated until all cross-sections are properly labeled. During implementation, it is crucial to ensure that the resolution accuracy of the administrative boundary data matches the cross-section coordinates to avoid misjudgment due to scale inconsistencies. For cases of boundary overlap, priority rules can be set, such as using the shortest distance between the cross-section and the nearest point on the administrative region boundary line as the basis for assignment. If cross-section D023... Section 5 overlaps with the boundaries of both Area A and Area B, but the nearest point on the administrative boundary line of Area A is 110 meters away, while that of Area B is 220 meters away. Therefore, this section belongs to Area A. Subsequently, all section numbers are classified and organized according to their respective areas, and a mapping table between section numbers and administrative areas is established. For example, section numbers D001, D003, and D007 belong to Area A, D002 and D004 belong to Area B, and D005 belongs to Area C. In actual operation, the section code column and the administrative boundary attribute column can be concatenated through spatial join operations to finally form a section classification result table according to the region. The results can be output as a list structure for subsequent calls to obtain a list of monitoring sections with pollution trend response characteristics.

[0066] Please see Figure 3 The specific steps of S2 are as follows:

[0067] S201: A list of monitoring sections based on pollution trend response characteristics. It calls the position index of the section in the water body and the water flow direction data, extracts the sections located in different administrative regions and with upstream and downstream relationships, excludes the sections located in the same region or with discontinuous water flow directions, and obtains a list of cross-regional section connection numbers.

[0068] First, the spatial location information of each cross-section in the list and the flow direction data of the water body in which it is located are retrieved. The downstream or upstream sorting position of each cross-section in the main channel and tributary path of the river is extracted. Determining this sorting requires a comparison operation between the cross-section's latitude and longitude and the direction of the flow arrow. If cross-section A and cross-section B are in the same river segment and the coordinate value of A is in the direction of the flow starting point while that of B is in the direction of the flow ending point, then cross-section A is the upstream cross-section and cross-section B is the downstream cross-section. In actual calculation, a flow direction comparison matrix between cross-sections can be constructed, setting the direction of the water body as the basis. After sorting along the coordinate axis, the order sequence between cross-sections can be obtained. Next, it is necessary to determine whether each pair of cross-sections is located in different administrative regions. This operation requires calling the administrative division code field corresponding to the cross-section number. By matching the field, it is determined whether there are differences in administrative regions. For example, cross-section A belongs to administrative region X, and cross-section B belongs to... If the administrative region is Y, and X≠Y, then the cross-sections are recorded as cross-regional cross-sections; otherwise, they are discarded. It should be noted that if cross-sections belong to the same region or have no clear flow direction (e.g., the flow direction is marked as 0 or missing), such data will not participate in the subsequent judgment process. In addition, at the confluence of tributaries and main streams, it is also necessary to identify whether there is a real water path connection between the cross-sections to avoid misidentifying them as upstream and downstream relationships due to short straight-line distances on the map. In this case, the continuity can be judged based on the water body coding logic of the river network structure. If there is an upstream path number logical number before and after the cross-section coding, it is considered as continuous water body; otherwise, it is not counted as a connection relationship. Finally, all cross-sections that meet the conditions of continuous upstream and downstream flow and cross-administrative region are paired and numbered, and the numbering identifiers are uniformly recorded according to the order of the cross-section number pairs to obtain a list of cross-regional cross-section connection numbers.

[0069] S202: Based on the cross-regional cross-section connection sequence list, the distance between cross-sections, the direction of water flow and the continuity status of the river section are called to determine whether the direction of water flow is consistent with the order of cross-sections. Paths with reversed flow direction and spatial interruption are eliminated to obtain the set of sequential path numbers of the direction of water flow.

[0070] First, for each upstream and downstream cross-section, the spatial coordinates between the starting and ending points of the cross-section are extracted. The straight-line distance between the two points is calculated and compared with the actual river path length to determine whether the spatial connectivity conforms to the natural flow structure of the river. If the straight-line distance is much smaller than the linear length of the river segment, there may be a meandering river but continuous water. If the distance error is greater than half of the total length of the river segment, it can be preliminarily judged that there is a spatial disconnect. At the same time, the water flow direction data of the path segment is retrieved and compared with the cross-section sorting order for consistency judgment. If the upstream cross-section is ranked first, the corresponding water flow direction arrow points from it to the downstream cross-section, and it is determined that the direction is consistent. If the direction of the water flow arrow is opposite to the cross-section order, it is determined that the direction is reversed and it is not included in the subsequent path set. For example, cross-section numbered P021 has upstream cross-section number D011 and downstream cross-section number D013. The coordinates show that D011 is located on the north side. D013 is located on the south side, and the water flow direction arrow is from north to south, consistent with the cross-section sequence. Therefore, this path direction is valid. If there is another set of numbers, P022, where D021 is upstream and D023 is downstream, but the water flow direction is from south to north, which is opposite to the cross-section sequence, then this path is considered to have a reverse flow direction and should be removed from the path data. In addition, the judgment of the continuity of the river segment also needs to check whether there is a jump in the water body code between cross-sections on the path segment. If there is a break in the numbering or missing water body data between cross-sections, it should also be considered a spatially interrupted path and removed. In the process of removal judgment, the judgment criteria need to be clearly set. For example, the consistency of the river segment flow direction needs to meet the requirement that the direction of the flow arrow is consistent with the cross-section number sequence, and the spatial continuity needs to meet the requirement that there is a corresponding river segment code between cross-sections without jumps. Finally, the path numbers that meet the dual consistency of flow direction and spatial arrangement are retained to obtain the set of path numbers in the order of water flow direction.

[0071] S203: Based on the set of sequential path numbers in the direction of water flow, call the coordinate points of the path break section and the water flow direction information, arrange the connection relationship of the section in sequence according to the direction of water flow, extract the spatial path of the water body along the line, and obtain the continuous water body path information across administrative regions;

[0072] First, extract the coordinate data of each cross-section and simultaneously obtain the water flow direction parameters. Combine the spatial coordinates and flow direction information to construct an ordered sequence of cross-sections. When performing the sorting operation, the cross-sections need to be arranged along the water flow direction, numbered sequentially from upstream to downstream. For example, path number P015 includes cross-sections D001, D004, and D007, with corresponding spatial coordinates of (X1, Y1), (X2, Y2), and (X3, Y3), respectively. The water flow direction is from D001 to D007, so the sorting order is D001→D004→D007. During the sorting process, vector angle judgment needs to be performed on each pair of adjacent cross-section points to ensure that their arrangement conforms to the natural flow trend of the river. For river sections with flow direction deviation or bends, the consistency of flow direction needs to be judged by whether the angle difference is less than a set threshold. It is recommended to set the flow direction deviation tolerance angle threshold to 30 degrees. If it exceeds, it is judged as inconsistent flow direction and the path is removed. After sorting is completed, the path is extracted. For all cross sections arranged in sequence, the corresponding river segment code data and river spatial shape line data between each cross section are called. The water body paths between the cross sections are connected in sequence by splicing line segments. For example, the river segment code R12 is called from D001 to D004, and the corresponding line segment is L1. The corresponding line segment is R13 from D004 to D007, and the corresponding line segment is L2. The path splicing is L1+L2. At the joint, the spatial coordinate error range is called to determine whether the connection point of the two line segments falls within the unified watershed. If the error does not exceed 2 meters, it is considered a connectable line segment. If it exceeds, the path is not included in the result output. All path line segments that pass the connection judgment are accumulated and superimposed in sequence to form a complete water body path line layer. At the same time, the cross section number label and the code of the administrative region to which it belongs are added to the layer. Finally, all path numbers and line segment sets that meet the water flow sequence arrangement and spatial connectivity judgment are recorded as output items to obtain continuous water body path information across administrative regions.

[0073] Please see Figure 4 The specific steps of S3 are as follows:

[0074] S301: Based on the continuous water body path information across administrative regions, call the coordinate points of the path at the administrative region boundary and the administrative boundary line data, extract the boundary junctions of the areas traversed by the path, identify whether there are corresponding water quality monitoring sections on both sides of the junctions, exclude boundary locations with missing section distribution, and obtain a list of boundary junctions with section distribution.

[0075] First, extract the intersection points of the path segments with the administrative boundary layer on the map. Identifying these intersection points can be done through spatial overlay. Perform geometric intersection calculations on the path layer and the administrative boundary layer. Each intersection point is a key node where the path crosses the administrative boundary line, called a boundary junction. Next, perform a buffer query on each boundary junction, setting a radius of 500 meters. Search within this range for the existence of water quality monitoring section coordinates. Determine whether a valid section distribution is formed by spatial distance calculation. For example, if boundary point P001 is located on the boundary line between administrative regions A and B, and section D013 is found within the buffer at a distance of 180 meters, it is determined to cover this boundary junction. Record its section number and boundary point. Coordinate pairing: If no cross-section point is found within the buffer zone for a certain junction point P002, it is considered that the boundary location is not monitored and is removed, and will not participate in the subsequent path continuity judgment. To avoid the judgment result being affected by the difference in boundary line accuracy or coordinate error, a spatial matching tolerance can be set. For example, an error range of less than 100 meters is considered a valid hit. At the same time, it is necessary to ensure that the extracted cross-sections are the actual cross-section points laid out on the water body path line, and to exclude interference items such as human error or cross-sections not in this watershed. Finally, all boundary junction points covered by valid cross-section points are included in a list. The list items include fields such as junction point coordinates, corresponding cross-section number, and administrative division identifier, resulting in a list of boundary junction points with cross-section distribution.

[0076] S302: Based on the list of boundary nodes with cross-sectional distribution, call the remote sensing water surface layer data on both sides of the node, determine whether the water surface area maintains spatial connection, identify the boundary segments of closed waterways or water body barriers, remove the corresponding nodes, and obtain the set of boundary nodes that maintain connectivity.

[0077] First, the coordinate information of each boundary node is retrieved to extract its geographical location and obtain the remote sensing water surface layer data of the corresponding administrative regions on both sides. The layer source must maintain consistent resolution to avoid water surface identification errors due to inconsistent image granularity. During the operation, a fixed radius buffer is constructed with the node as the center, typically ranging from 300 to 500 meters. This area is divided into left and right parts, corresponding to the image ranges of administrative region A and administrative region B. The water mask area within this range is extracted from the layer, and its pixel values ​​are judged. Water is usually marked with a value of 1, and non-water is marked with 0. The number of water pixels on both sides of the buffer is calculated, and it is determined whether a continuous water surface area is formed on both sides. If there are discontinuous blanks between the two water surface areas or they are cut off by non-water patches, it is determined that the water surface is interrupted. If a boundary node P014 has a water area of ​​1250 square meters on side A and 1320 square meters on side B of the buffer zone, and there is a building block with a length of 40 meters and a width of 8 meters or a waterless area in the middle connecting area, then the node does not meet the water surface connectivity condition. Such nodes are marked as "disconnected" in the results and are not included in the subsequent path extension calculation. For boundary nodes that do not have an interruption, that is, in the water body layer that is continuously distributed in the buffer zone, if the pixels are continuous and the water body identification value is always 1 in the direction of extension from the node along the flow direction, it is considered as a continuous water surface state and marked as "connected". Finally, the coordinate numbers of all nodes that meet the requirement of continuous water body distribution are extracted and collected into a result set to obtain the set of boundary nodes that maintain the connectivity state.

[0078] S303: Based on the set of boundary nodes that maintain connectivity, call the linear data and cross-sectional spatial distribution information of the path segments associated with the nodes, extract the area covered by the boundary path segments that simultaneously have cross-sectional continuity and water surface connection, and obtain the boundary water area with water body continuity characteristics.

[0079] First, the path number associated with each node is called. The linear data of the path segment is extracted using the path number, and the coordinate information of all monitored cross-sections on the path segment is obtained. The linear data must be a spatial trajectory set composed of a continuous sequence of line segments. Each path segment must have start and end point information. The cross-section coordinates are then used to determine if the path segment has cross-section coverage. Specifically, the path segment is sliced ​​into 50-meter sections to generate a cross-section search buffer. The buffer is then searched to see if at least two or more cross-section points are present. If a path segment has only one cross-section, it is considered discontinuous and not included in subsequent processing. Based on the cross-section continuity requirement, the boundary nodes corresponding to both ends of the path segment are called to obtain their coordinates. The previous water surface connectivity judgment results are used to confirm whether they are marked as connected. If both the start and end nodes of the path are in the connected state set, it indicates that the path segment is spatially connected. In terms of morphology, these path segments possess the ability to seamlessly transition from one administrative region's water surface to another, meeting the requirements for water body continuity. Such path segments are selected and retained. After selection, each eligible path segment is converted into a spatial extent graphic. A boundary water area layer can be formed by buffering and expanding the path segments on both sides. The buffer distance is set based on the average width of the river channel, and the buffer distance is set equal to the average width of the river channel for that path segment. The value of this average value is limited to between 25 and 100 meters. For example, if the starting and ending points of path segment P041 are P041A and P041B, connecting sections D030 and D034 respectively, and the average width of the river segment is 60 meters, then the buffer is expanded along the path line based on this value to construct the spatial extent and form a complete boundary water area graphic. All path segments that meet this condition are merged into a result set to obtain a boundary water area with water body continuity characteristics.

[0080] Please see Figure 5 The specific steps of S4 are as follows:

[0081] S401: Based on the boundary water area with water body continuity characteristics, call the administrative region code information corresponding to the monitoring section, classify the section into the corresponding management scope according to the administrative division, extract the spatial coordinates of the section within the administrative region, and obtain the distribution coordinate set of the administrative region section.

[0082] First, extract the monitoring section numbers within the coverage area. Then, sequentially call the administrative division code field corresponding to each section. The field content is usually a standard administrative code or division name. Use spatial overlay to determine the spatial overlap between the section's location and the administrative boundary layer, ensuring the accuracy of administrative division attribution. If the coordinates of section D022 are within the boundary of District A and the administrative code field displays 110101, then it is classified under the jurisdiction of District A. Repeat this operation until all sections have been identified. Then, use the administrative division code as the grouping basis to classify all section numbers. Each classification result represents a set of monitoring sections under a management unit. In the example, District A includes D00... 1. For each set of cross-sections, D003 and D022 are included. Area B contains D002 and D005, and Area C contains D007 and D009. Further extract the spatial coordinate information of each cross-section set, matching the cross-section number with its corresponding latitude and longitude coordinates. For example, the coordinates of D001 are (116.32, 39.98), and those of D003 are (116.35, 40.01). This information is used for subsequent spatial distribution density and boundary direction determination. In practice, the coordinate format needs to be standardized to ensure that all points are represented by the same projection method, avoiding the accumulation of errors that could affect subsequent analysis. Ultimately, a set of cross-section distribution spatial data is formed based on administrative regions, resulting in a set of cross-section distribution coordinates for administrative regions.

[0083] S402: Based on the coordinate set of cross-section distribution in administrative regions, call the cross-section coordinate points and the corresponding water boundary line shape, determine the spatial arrangement of the cross-section along the boundary direction, identify whether the cross-section distribution continuously covers the entire water edge, and extract the location segment of the blank spacing to obtain the length of the boundary direction distribution coverage interval.

[0084] First, extract the spatial coordinates of each cross-section and retrieve the boundary line data of its corresponding water area. The line data should be a set of closed or semi-closed polylines to represent the actual outline of the water area. When extracting the boundary line data, the query range needs to be limited to avoid path mixing caused by retrieving adjacent water areas. Perform a spatial projection operation on the cross-section coordinates and the boundary line data to determine whether each cross-section is distributed within the boundary buffer zone. The boundary buffer zone is set as a strip area with a width of 50 meters. If a cross-section falls into this buffer zone area, it is considered a valid point arranged along the boundary. After performing this judgment operation, obtain the sequence of all cross-sections arranged along the boundary within the current administrative region. Sort the cross-sections according to the direction of water flow to obtain a list of continuous coordinate points from upstream to downstream. Then, calculate the coordinates of adjacent cross-sections. If the distance between two sections is less than the set boundary continuous coverage judgment benchmark value, then the boundary area is considered to be continuously monitored and covered. The benchmark distance is set to 300 meters. For example, if the distance between D015 and D016 is 250 meters, it is considered continuous. If the distance between D016 and D017 is 520 meters, it is considered that there is a coverage discontinuity. Record the section number and the coordinates between the two points, and mark the discontinuity position as the boundary gap section. Continue to complete the traversal and pairing between all sections, form a continuous coverage judgment matrix for all sections within the boundary line range, output the start and end positions and spacing values ​​of the coverage break area of ​​all sections, and use the interval distance as the quantitative indicator of boundary monitoring coverage. Finally, the coverage interval length of the boundary direction distribution is obtained.

[0085] S403: Based on the length of the coverage interval in the boundary direction, call the spatial connection point between the interval position and the corresponding segment of the water area line, determine whether the cross-section arrangement has shifted in the adjacent area, extract the administrative division information of the spatial shift position, and obtain the list of administrative area water areas with connection shift.

[0086] First, extract the coordinates of the boundary segments corresponding to the start and end points of each identified spatial interval. Then, retrieve the boundary line data of that water body segment to extract the curve contour of the water body boundary line in space. Next, calculate the shortest projection path between the start and end points of the interval on this contour. Based on the path direction, determine whether there is a lateral or longitudinal deviation in the spatial arrangement of the cross-section. If the original arrangement axis of the cross-section is consistent with the direction of the boundary line, it indicates that the spatial structure is stable. If the deviation angle exceeds the set judgment threshold, it is considered that there is a spatial offset. The offset judgment threshold is set to 30 degrees. The offset direction can be calculated by the angle between the cross-section deflection angle and the boundary normal. In actual operation, it is necessary to construct left and right extension analysis lines for each interval segment and retrieve the connecting boundary nodes of the line segment upstream and downstream. Combined with the coordinate positions of the cross-sections on both sides, it is determined whether there is a deviation of the centroid of the cross-section. The direction of the water body's central axis or its misaligned extension is as follows: For example, a certain water body boundary segment forms a continuous arrangement in zone A, but in the adjacent zone B, due to non-standard cross-section layout, the entire cross-section shifts to 150 meters inside the water body, forming an oblique distribution structure. This situation can be judged by the offset between the midpoint of the path and the center point of the opposite cross-section. If the offset distance exceeds 100 meters, it is recorded as a significant offset. This distance can be regarded as a phenomenon of asymmetrical monitoring coverage on the administrative region boundary. Further, the administrative region code to which the offset cross-section belongs is extracted, and the corresponding region name is determined by field reverse lookup. For example, if cross-sections D028 and D029 both belong to the region coded 330105, then this region is marked as having a connection offset. Finally, the identifiers of all administrative regions with cross-section arrangement offset phenomena are output to obtain a list of administrative region water bodies with connection offset.

[0087] Please see Figure 6 The specific steps of S5 are as follows:

[0088] S501: Based on the list of administrative region water areas with connection offset, call the water flow direction data within the area, remove path segments with interrupted water flow direction, extract water bodies in areas with continuous flow direction, extract the cross-sectional location, water flow direction and administrative region name corresponding to the path segment within the range, and obtain the cross-sectional path information of continuous area.

[0089] First, using the region identifier field as an index, the corresponding path segments within the target region are extracted from the complete water body path data. Then, for each path segment, its associated water flow direction field is called to determine whether there is a break in the water flow direction label between the start and end points. A break refers to a situation where the flow direction code is undirected or backflow. If so, the path segment is removed from the subsequent processing scope to ensure that all retained path segments extend downstream from the start point without directional interruption. For example, if path P048 has a segment labeled "0" in its coding sequence, it is recorded as a broken segment, and this segment or the entire path needs to be removed from P048. Then, for the path segments that are retained after removal, the cross-section number corresponding to each path segment is called, and its location in the spatial database is extracted through the cross-section number. The location coordinates of the cross-section are determined by combining them with the path direction to determine whether the cross-section is located upstream, midstream, or downstream of the water flow. For example, if cross-section D112 is located in the middle of path P048 and its downstream direction is northeast, the direction of the cross-section is marked as NE. At the same time, the administrative region code associated with the cross-section is extracted, and the region name field is looked up. For example, if the administrative code 370902 corresponds to the region "Taishan District", then cross-section D112 is associated with "Taishan District". The above processing is performed cyclically on each path segment that maintains continuous water flow until all valid path segments in the region have been processed. The final output result should include the cross-section number, corresponding coordinates, water flow direction, and the name of the administrative region, thus obtaining the continuous area cross-section path information.

[0090] S502: Based on the continuous section path information, call the section coordinates, water flow direction and boundary intersection point location data, arrange the upstream and downstream edge positions of the path segment according to the water flow sequence, extract the correspondence between the section sequence and the boundary intersection point, and obtain the upstream and downstream connection sequence relationship table;

[0091] First, the cross-section numbers within each path segment are read sequentially. For each cross-section, its corresponding spatial coordinate field and water flow direction field are retrieved. The coordinates are converted into two-dimensional coordinate points for comparison in latitude and longitude form. Simultaneously, the water flow direction is converted into an angular encoding representation as a direction vector. When processing the two cross-sections before and after each path segment, their relative positions in spatial coordinates are calculated. For example, the starting point coordinates of cross-section D103 on path P021 are (116.30, 35.12), with a southeast direction, while the ending point coordinates of cross-section D104 are (116.35, 35.08), with a southeast direction. It is determined whether the direction vector direction is consistent with the coordinate changes. If they are consistent, the path direction is retained unchanged. Next, the position coordinate data of the boundary intersection points are retrieved, and the coordinates of all boundary intersection points are also converted into two-dimensional points in a unified coordinate system. Euclidean coordinates are calculated for the starting and ending cross-section coordinates in the path segment and for all intersection points. For distance, select boundary points less than the set spatial limit of 200 meters as candidate intersection points. Then, based on the water flow direction, compare the relative positions of the cross-section and the intersection point in the main direction to determine whether the intersection point corresponds to the upstream or downstream direction in the cross-section sequence. For example, if the direction of path P021 is southeast, then the endpoint coordinates should be located at the boundary position southeast of the intersection point. If the boundary point number is J037 and its coordinates are (116.36, 35.07), then it is the downstream intersection point corresponding to the endpoint of P021. At the same time, mark the cross-section D104 and the intersection point J037 as upstream and downstream connection relationships. Process each path segment in this way, and perform spatial judgment and direction judgment operations on the relationship between the start and end points and the intersection points of each path segment. Finally, pair the starting cross-section, ending cross-section and their corresponding intersection points of each path segment in the upstream and downstream order to form a sequence comparison table in the path direction, and obtain the upstream and downstream connection sequence relationship table.

[0092] S503: Based on the upstream and downstream connection sequence table, the cross-sectional spatial distribution, water flow path and administrative boundary range are called, the spatial range of continuous areas is divided according to the connection sequence, and the zoning range is matched with the administrative region to obtain the cross-administrative region joint prevention and control zoning structure table.

[0093] First, the start and end section numbers associated with the path segment are read, and the spatial coordinate information of the sections contained in each connection sequence pair is retrieved. The coordinates between the continuous start and end sections are formed into a set of line segments. Next, the water flow path data where the section is located is read, and the section line segments are projected onto the path line. If both the start and end points of the section intersect with the path line, the path line segment is extracted as a valid continuous segment. All valid continuous segments are spliced ​​together one by one according to the connection sequence to form a continuous area. During the splicing process, it is necessary to determine whether the start and end sections of adjacent segments overlap or the spacing is within an acceptable range. For example, if the end section of segment A is D032, and the start section of the next segment is D033, the coordinates of D032 are (114.35, 30.28), and the coordinates of D033 are (114.35, 30.28), then... If the distance between two points is less than 0.2 kilometers, the two segments can be merged into one area; otherwise, they are marked as discontinuous and divided into independent areas. Then, the outermost line segment set of the path is extracted for each area to form the outer boundary line of the area. The boundary line is buffered and expanded to form the coverage area. Then, the administrative boundary layer is called to spatially overlay each area with the administrative boundary and extract the name of the administrative unit that the area falls into. If an area crosses multiple administrative code areas, the corresponding administrative names are recorded and used as joint control areas. Finally, each area is numbered according to the path direction and its start and end sections, the administrative name to which it belongs, and the boundary outline information are marked to obtain the cross-administrative region joint prevention and control zoning structure table.

[0094] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A cross-administrative region water environment risk joint prevention and control zoning method, characterized in that, Includes the following steps: S1: Obtain the monitoring sections deployed in the watershed that flows through the administrative region, extract the changing direction of ammonia nitrogen, total phosphorus and dissolved oxygen in a continuous time period, screen the sections with consistent turning points, and obtain a list of monitoring sections with pollution trend response characteristics according to the administrative region. S2: Based on the list of monitoring sections with the pollution trend response characteristics, extract the cross-regional connection relationship, determine whether the water body direction is continuous, remove interrupted segments, and obtain the continuous water body path information across administrative regions; S3: Based on the coverage status of the continuous water body path information in the boundary area, determine whether the water body is completely connected at the boundary, remove segments with missing sections and non-connected segments, and obtain the boundary water area with water body continuity characteristics. S4: Based on the cross-sectional arrangement within the boundary water area with the water body continuity characteristics, compare the cross-sectional distribution direction with the water body extension direction, remove areas with insufficient distribution and discontinuous arrangement, and obtain a list of administrative region water areas with connection offset. S5: Based on the list of administrative region water areas under the connection offset, extract the uninterrupted water flow segments, divide the segment into cross-section directions and path directions, divide the joint defense zones, and obtain the cross-administrative region joint defense and control zone structure table. The specific steps of S2 are as follows: S201: Based on the list of monitoring sections with the pollution trend response characteristics, call the position index of the section in the water body and the water flow direction data, extract the sections that are located in different administrative regions and have upstream and downstream relationships, exclude the sections that are located in the same region or have discontinuous water flow directions, and obtain a list of cross-regional section connection numbers. S202: Based on the cross-regional cross-section connection sequence number list, call the distance between cross-sections, water flow direction and river section continuity status, determine whether the water flow direction is consistent with the cross-section arrangement order, eliminate paths with reversed flow direction and spatial interruption, and obtain the set of water flow direction sequence path numbers. S203: Based on the set of sequential path numbers in the direction of water flow, call the coordinate points of the path break sections and the water flow direction information, arrange the connection relationship of the sections in sequence according to the direction of water flow, extract the spatial path of the water body along the line, and obtain the continuous water body path information across administrative regions; The specific steps for S3 are as follows: S301: Based on the continuous water body path information across administrative regions, call the coordinate points of the path at the administrative region boundary and the administrative boundary line data, extract the boundary junctions of the areas traversed by the path, identify whether there are corresponding water quality monitoring sections on both sides of the junctions, exclude boundary locations lacking section distribution, and obtain a list of boundary junctions with section distribution. S302: Based on the list of boundary nodes with cross-sectional distribution, call the remote sensing water surface layer data on both sides of the node, determine whether the water surface area maintains spatial connection, identify the boundary section of closed waterway or water body separation, remove the corresponding node, and obtain the set of boundary nodes that maintain connectivity. S303: Based on the set of boundary nodes that maintain connectivity, call the linear data and cross-sectional spatial distribution information of the path segments associated with the nodes, extract the area covered by the boundary path segments that simultaneously have cross-sectional continuity and water surface connection, and obtain the boundary water area range with water body continuity characteristics. The specific steps of S4 are as follows: S401: Based on the boundary water area with water body continuity characteristics, call the administrative region code information corresponding to the monitoring section, classify the section into the corresponding management scope according to the administrative division, extract the spatial coordinates of the section within the administrative region, and obtain the distribution coordinate set of the administrative region section. S402: Based on the coordinate set of the cross-section distribution of the administrative region, call the cross-section coordinate points and the corresponding water boundary line shape, determine the arrangement state of the cross-section along the boundary direction in space, identify whether the cross-section distribution continuously covers the entire water edge, and extract the position segment of the blank spacing to obtain the length of the boundary direction distribution coverage interval. S403: Based on the length of the boundary direction distribution coverage interval, call the spatial connection point of the interval position and the corresponding segment of the water area line, determine whether the cross-section arrangement has shifted in the adjacent area, extract the administrative division information of the spatial shift position, and obtain the list of administrative area water areas with connection shift.

2. The cross-administrative region water environment risk joint prevention and control zoning method according to claim 1, characterized in that, The list of monitoring sections for pollution trend response characteristics includes section number, administrative region, ammonia nitrogen change trend, total phosphorus change trend, dissolved oxygen change trend, and trend change synchronicity. The continuous water body path information across administrative regions includes path start and end sections, section connection sequence, water flow direction, administrative region crossing sequence, and water body connectivity identifier. The boundary water area with water body continuity characteristics includes a boundary connection point list, water surface coverage continuity, water body accessibility, and waterway integrity identifier. The list of administrative region water areas with connection offset includes section spatial coverage density, boundary direction consistency, section distribution connection status, and water area coverage offset. The cross-administrative region joint prevention and control zoning structure table includes water body area number, upstream and downstream connection relationship, administrative region distribution structure, zoning boundary range, and section functional attributes.

3. The cross-administrative region water environment risk joint prevention and control zoning method according to claim 1, characterized in that, The term "consistent turning section" refers to a monitoring section in which multiple water quality monitoring parameters change in the same direction over a continuous time period. The term "missing cross-section" refers to the absence of monitoring cross-sections at the boundaries or connecting areas of the water body path, making it impossible to determine whether the water body is continuous or whether the pollution trend continues.

4. The cross-administrative region water environment risk joint prevention and control zoning method according to claim 1, characterized in that, The discontinuous segments refer to spatial and hydrodynamic breaks in the water path caused by discontinuous cross-sectional arrangement, inconsistent water flow direction, and physical obstruction. The water body extension direction refers to the spatial extension trend of the water body along the natural flow direction and boundary direction, whether the arrangement spacing is less than a preset threshold, and whether the distribution covers the entire water area.

5. The cross-administrative region water environment risk joint prevention and control zoning method according to claim 1, characterized in that, The specific steps of S1 are as follows: S101: Obtain water quality monitoring sections that flow through multiple administrative regions, collect ammonia nitrogen, total phosphorus, and dissolved oxygen parameter data of the sections in a continuous time period, arrange the values ​​of each parameter in chronological order, determine the direction of increase or decrease between adjacent time points, and obtain a sequence of changes in multiple monitoring parameters. S102: Based on the sequence of changes in the multiple monitoring parameters, screen the sections where the changes in ammonia nitrogen, total phosphorus, and dissolved oxygen parameters are all consistent, and remove sections where the changes in any parameter are inconsistent, to obtain a set of section numbers with consistent changes. S103: Based on the set of cross-section numbers with consistent change direction, call the administrative region attribute of the corresponding cross-section, and assign the cross-section number to the region to obtain a list of monitoring cross-sections with pollution trend response characteristics.

6. The cross-administrative region water environment risk joint prevention and control zoning method according to claim 1, characterized in that, The process of determining the spatial arrangement of cross sections along the boundary direction is as follows: measuring the distance between adjacent cross sections in the distribution coordinate set of cross sections in the administrative region, comparing it with the set reference distance, analyzing the positional segments between adjacent cross sections whose distance exceeds the reference range, and extracting the positional segments as the range of blank distances. The process of determining whether the cross-section arrangement has shifted in adjacent areas specifically involves: analyzing the directional changes of the spatial connection points of the interval positions and the corresponding segments of the water area lines, analyzing the continuous trend in the boundary direction, and when the directional change angle between adjacent administrative regions is greater than a preset angle threshold, extracting the administrative region code information where the spatial position is located, and analyzing the list of administrative region water areas in the connection shift situation based on the information.

7. The cross-administrative region water environment risk joint prevention and control zoning method according to claim 1, characterized in that, The specific steps of S5 are as follows: S501: Based on the list of administrative region water areas under the connection offset, call the water flow direction data within the area, remove path segments with interrupted water flow direction, extract water bodies in areas where the flow direction is continuous, extract the cross-sectional position, water flow direction and administrative region name corresponding to the path segment within the range, and obtain continuous area cross-sectional path information. S502: Based on the continuous section path information, call the section coordinates, water flow direction and boundary intersection point location data, arrange the upstream and downstream edge positions of the path segment according to the water flow sequence, extract the correspondence between the section sequence and the boundary intersection point, and obtain the upstream and downstream connection sequence relationship table. S503: Based on the upstream and downstream connection sequence relationship table, call the cross-sectional spatial distribution, water flow path and administrative boundary range, divide the spatial range of continuous areas according to the connection sequence, and correspond the partition range with the administrative region to obtain the cross-administrative region joint prevention and control partition structure table.

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