Urban blue line delineation method, device, equipment, medium and computer program product

Abstract

The application discloses a kind of urban blue line demarcation method, device, equipment, medium and computer program product, the method comprises: obtaining remote sensing image and DEM data, river center line and river boundary line are extracted from remote sensing image;According to DEM data, river center line and river boundary line, river catchment area and corresponding waterlogging risk grade are demarcated;According to river discharge capacity, river grade is divided, and according to river grade, river section type is determined, according to river section type and river discharge capacity, river drainage width under drainage standard is calculated, and river planning water area boundary is generated;According to the three zones and three lines of land space planning, waterlogging risk grade and river grade, the river planning water area boundary is extended by a first distance, and the river blue line is generated.The present application fully considers the waterlogging risk, connects the three zones and three lines of land space planning, reduces the planning conflict of river blue line and other land, is more conducive to promoting the integration of city and water development, and is more operable and implementable.

Description

Technical Field

[0001] This invention relates to the field of urban planning technology, and in particular to a method, apparatus, equipment, medium, and computer program product for delineating urban blue lines. Background Technology

[0002] The delineation of river blue lines is an important measure for implementing ecological civilization construction and a key component of territorial spatial planning. Since the Ministry of Housing and Urban-Rural Development issued the "Urban Blue Line Management Measures" in 2005, various regions across the country have attempted to delineate river blue lines. However, due to the lack of refined blue line delineation methods, the results of river blue line delineation have resulted in serious planning conflicts and significant disagreements among relevant water management departments, making implementation difficult.

[0003] The current method of delineating blue lines is primarily based on the single objective of river protection, combining the type of river embankment and the design flood level. This method represents a typical pre-emptive spatial control approach, defining a large and wide area to protect the river and prevent illegal construction. However, this method fails to consider the risk of flooding in the river's catchment area and does not align with national land use planning. It focuses solely on river protection, hindering the intensive and economical use of land and ultimately rendering the blue line delineation results unenforceable. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method, device, equipment, medium and computer program product for delineating urban blue lines, which fully considers the risk of urban flooding, connects the three zones and three lines of the national land space planning, reduces the planning conflict between the river blue line and other land use, is more conducive to promoting the integrated development of urban and water, and is more operable and feasible.

[0005] To achieve the above objectives, embodiments of the present invention provide a method for delineating urban blue lines, comprising:

[0006] Acquire remote sensing images and DEM data, and extract the river centerline and river edge line from the remote sensing images;

[0007] The catchment area of ​​the river is delineated based on the DEM data, the center line of the river channel, and the edge line of the river channel, and the waterlogging risk level of the catchment area is determined.

[0008] Rivers are classified into different grades based on their discharge capacity under self-drainage conditions, and the cross-sectional shape of the river is determined based on the river grade. The drainage width of the river under the drainage standard is calculated based on the cross-sectional shape of the river and the discharge capacity of the river. The planned water area boundary of the river is generated based on the drainage width of the river, the center line of the river, and the edge line of the river.

[0009] Based on the three zones and three lines of the national land space plan, the aforementioned waterlogging risk level, and the aforementioned river level, the river planning water area boundary is extended by a first distance to generate the river blue line.

[0010] As an improvement to the above scheme, the step of delineating the river catchment area based on the DEM data, the river centerline, and the river edge, and determining the flood risk level of the river catchment area, specifically includes:

[0011] The catchment area of ​​the river channel was delineated based on the DEM data;

[0012] The catchment area of ​​the river is corrected based on the river centerline and the river edge line so that the river centerline and the river catchment area do not overlap.

[0013] The flood risk level of the river catchment area is determined based on the water depth at historical flood points; wherein the flood risk level includes high risk and low risk.

[0014] As an improvement to the above scheme, the classification of river levels based on the river's discharge capacity under gravity drainage conditions specifically includes:

[0015] Based on the preset river hydrodynamic model, the river discharge capacity of each section of the river under the self-drainage condition is calculated.

[0016] The discharge capacity of each river segment is normalized, and the standard value of the discharge capacity is calculated.

[0017] Based on the standard flow rate and the preset flow rate range, the river class of each section of the river is determined.

[0018] As an improvement to the above scheme, the step of determining the river cross-section type based on the river grade, calculating the river drainage width under the drainage standard based on the river cross-section type and the river's discharge capacity, and generating the planned water area boundary of the river based on the river drainage width, the river centerline, and the river edge line specifically includes:

[0019] The river cross-sectional type is determined according to the river grade; wherein, the river cross-sectional type includes trapezoidal cross-section and rectangular cross-section;

[0020] Based on the river cross-sectional shape and the river discharge capacity, the river drainage width under the drainage standard is calculated by trial calculation.

[0021] A preliminary planned water area boundary for the river channel is generated by extending a second distance outward from both sides of the river channel centerline; wherein, the second distance is determined based on the drainage width of the river channel;

[0022] The preliminary planned water area boundary is superimposed on the river edge line, and the outer boundary line is taken as the final planned water area boundary.

[0023] As an improvement to the above scheme, the step of extending the boundary of the planned water area of ​​the river by a first distance based on the three zones and three lines of the national land spatial planning, the waterlogging risk level, and the river level, specifically includes:

[0024] If the river is located in the agricultural or ecological space of the national land space plan, then according to the river level, the boundary of the planned water area of ​​the river is extended by different first distances to generate the river blue line;

[0025] If the river is located in the urban space of the national land space plan, then according to the waterlogging risk level and the river level, the boundary of the planned water area of ​​the river will be extended by different first distances to generate the river blue line.

[0026] The first distance is directly proportional to the level of waterlogging risk.

[0027] As an improvement to the above solution, the method further includes:

[0028] Overlay the river blue line with the existing control detailed plan to determine whether the land use within the river blue line area is entirely water area or green space.

[0029] If so, then there is no need to modify the aforementioned blue line of the river channel;

[0030] If not, the first distance is adjusted based on the width of the waterfront green space and the aforementioned waterlogging risk level to correct the blue line of the river channel.

[0031] This invention also provides an urban blue line delineation device, comprising:

[0032] The data acquisition module is used to acquire remote sensing images and DEM data, and extract the river centerline and river edge line from the remote sensing images.

[0033] The grading module is used to delineate the river catchment area based on the DEM data, the river centerline, and the river edge line, and to determine the waterlogging risk level of the river catchment area.

[0034] The boundary delineation module is used to classify river levels according to the river discharge capacity under the self-drainage condition, determine the river cross-sectional type according to the river level, calculate the river drainage width under the drainage standard according to the river cross-sectional type and the river discharge capacity, and generate the planned water area boundary of the river according to the river drainage width, the river centerline and the river edge line.

[0035] The blue line delineation module is used to generate a river blue line by extending the boundary of the planned water area of ​​the river by a first distance based on the three zones and three lines of the national land space plan, the waterlogging risk level, and the river level.

[0036] This invention also provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor executes the computer program to implement the urban blue line delineation method described above.

[0037] This invention also provides a computer-readable storage medium, which includes a stored computer program, wherein the computer program, when running, controls the device where the computer-readable storage medium is located to execute the urban blue line delineation method described above.

[0038] This invention also provides a computer program product, which includes a computer program or computer instructions. When the computer program or computer instructions are executed by a processor, they implement the urban blue line delineation method described above.

[0039] Compared with existing technologies, the beneficial effects of the urban blue line delineation method, apparatus, equipment, medium, and computer program product provided by the embodiments of the present invention are as follows: By acquiring remote sensing images and DEM data, the river centerline and river edge line are extracted from the remote sensing images; the river catchment area is delineated based on the DEM data, the river centerline, and the river edge line, and the waterlogging risk level of the river catchment area is determined; the river level is classified according to the river discharge under self-drainage conditions, and the river cross-sectional type is determined based on the river level; the river drainage width under the drainage standard is calculated based on the river cross-sectional type and the river discharge; the planned water area boundary of the river is generated based on the river drainage width, the river centerline, and the river edge line; and the planned water area boundary of the river is extended outward by a first distance according to the three zones and three lines of the national land spatial planning, the waterlogging risk level, and the river level to generate the river blue line. The embodiments of the present invention fully consider the risk of urban flooding, connect the three zones and three lines of the national land space planning, reduce the planning conflicts between the river blue line and other land uses, are more conducive to promoting the integrated development of urban and water, and are more operable and feasible. Attached Figure Description

[0040] Figure 1 This is a flowchart illustrating a preferred embodiment of a method for delineating urban blue lines provided by the present invention;

[0041] Figure 2 This is a schematic diagram illustrating the generation of the waterway planning boundary in a method for delineating urban blue lines provided by this invention.

[0042] Figure 3 This is a schematic diagram of a preferred embodiment of an urban blue line delineation device provided by the present invention;

[0043] Figure 4 This is a schematic diagram of a preferred embodiment of a terminal device provided by the present invention. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] Please see Figure 1 , Figure 1 This is a schematic flowchart of a preferred embodiment of the urban blue line delineation method provided by the present invention. The urban blue line delineation method includes:

[0046] S1, acquire remote sensing images and DEM data, and extract the river centerline and river edge line from the remote sensing images;

[0047] S2, Determine the catchment area of ​​the river based on the DEM data, the center line of the river channel, and the edge line of the river channel, and determine the waterlogging risk level of the catchment area of ​​the river channel.

[0048] S3. Classify the river level according to the river discharge under the self-drainage condition, determine the river cross-section type according to the river level, calculate the river drainage width under the drainage standard according to the river cross-section type and the river discharge, and generate the planned water area boundary of the river according to the river drainage width, the river centerline and the river edge.

[0049] S4. Based on the three zones and three lines of the national land space plan, the waterlogging risk level, and the river level, extend the boundary of the planned water area of ​​the river by a first distance to generate the river blue line.

[0050] Specifically, this embodiment of the invention first utilizes remote sensing imagery and high-precision DEM data to establish a basic database of river systems within the research area. Remote sensing imagery and DEM data are acquired, and the river centerline and river boundary lines are extracted from the remote sensing imagery. For example, this embodiment of the invention uses remote sensing imagery to extract river system patches and form vector data in Shapefile format. For instance, the research area is selected using the Bigmap all-in-one map software, a commonly used local coordinate system is chosen, and the highest-level remote sensing imagery and DEM data are downloaded. The imagery is imported into GIS software, and various water bodies in the imagery are initially identified. Training sample points for each water body's threshold range are generated. These training sample points are used to determine the water bodies in the entire research area imagery using a threshold method and generate raster data. In GIS, the water body raster data is converted into surface data, and the river system surface data is filtered out. The connecting lines between the upstream and downstream sections of the river surface data are identified and deleted. The river vector surface data is then converted into two independent boundary lines, forming a vector database of the current river boundary lines. Then, the river centerline is extracted using the line segment mean method, and a "River ID" field is added to the river centerline with an assigned code. For example, the riverbank database is converted into a CAD file, and the PathAverage.lsp file is loaded into the CAD file; the pav command is entered, the number of segment divisions is defined, the existing river boundary is selected, and vector data of the river centerline is generated; the river centerline is imported into the existing river boundary vector database, a "River ID" field is added to the river centerline, and codes A, B, C, ... are assigned according to the element order. Then, the river catchment area is delineated based on the DEM data, the river centerline, and the river boundary, and the waterlogging risk level of the river catchment area is determined. The river level is classified according to the river discharge under self-drainage conditions, and the river cross-sectional type is determined according to the river level. The river drainage width under the drainage standard is calculated based on the river cross-sectional type and the river discharge. The planned water area boundary of the river is generated based on the river drainage width, the river centerline, and the river boundary. Finally, according to the "Urban Blue Line Management Measures" issued by the Ministry of Housing and Urban-Rural Development, the blue line refers to the geographical boundary for the protection and control of urban surface water bodies such as rivers, lakes, reservoirs, canals, and wetlands as determined by urban planning. In other words, the river blue line needs to be extended a certain distance beyond the planned river water boundary. Therefore, this embodiment of the invention combines the three zones and three lines of the national land spatial planning, the urban flooding risk level, and the river level to generate river blue lines by extending the planned river water boundary by different first distances.

[0051] As a preferred option, if the river is located in the agricultural or ecological space of the national land space plan, then according to the river level, the boundary of the planned water area of ​​the river is extended by different first distances to generate the river blue line.

[0052] If the river is located in the urban space of the national land space plan, then according to the waterlogging risk level and the river level, the boundary of the planned water area of ​​the river will be extended by different first distances to generate the river blue line.

[0053] The first distance is directly proportional to the level of waterlogging risk.

[0054] For example:

[0055] (1) For rivers located in agricultural and ecological spaces in the national land space planning, the planned water area boundaries of Class I, II and III rivers will be extended by 20m, 15m and 10m respectively as the preliminary river blue lines.

[0056] (2) For waterways located within urban areas in the national land use plan, the blue lines for the waterways shall be delineated according to the following rules:

[0057] 1) For rivers that receive rainwater from high-risk catchment areas, the planned water area boundaries of Class I, II and III rivers will be extended by 20m, 15m and 10m respectively as the preliminary blue lines for the river channels.

[0058] 2) For rivers that receive rainwater from low-risk catchment areas, the planned water area boundaries of Class I, II and III rivers will be extended by 15m, 10m and 5m respectively as the preliminary blue lines for the river channels.

[0059] The embodiments of the present invention fully consider the risk of urban flooding, connect the three zones and three lines of the national land space planning, reduce the planning conflicts between the river blue line and other land uses, are more conducive to promoting the integrated development of urban and water, and are more operable and feasible.

[0060] In another preferred embodiment, step S2, delineating the river catchment area based on the DEM data, the river centerline, and the river edge, and determining the flood risk level of the river catchment area, specifically includes:

[0061] S201, Delineate the river catchment area based on the DEM data;

[0062] S202, the catchment area of ​​the river is corrected according to the river centerline and the river edge line so that the river centerline and the river catchment area do not overlap.

[0063] S203, the flood risk level of the river catchment area is determined based on the water depth of historical flood points; wherein, the flood risk level includes high risk and low risk.

[0064] Specifically, in this embodiment of the invention, DEM data is imported into GIS software. The catchment area of ​​each river is generated through processes such as basin determination, inlet / outlet determination, and catchment zone segmentation within the GIS hydrological analysis module. Then, by combining topographic data and imagery with the river centerline vector line, any potential overlap between the river centerline and the catchment area line is adjusted to correct the catchment area, ensuring that each river centerline falls independently within a single catchment area without overlap. Finally, based on the collected and established register of historical flooding points within the research area, the flooding risk level of the river catchment area is determined according to the water depth of these historical flooding points. For example, the catchment area of ​​a river containing flooding points with a water depth exceeding 0.2m is defined as a high-risk catchment area, and the others are low-risk catchment areas. The flooding risk level includes both high and low risk.

[0065] In yet another preferred embodiment, the step of classifying river levels based on the river's discharge capacity under self-drainage conditions specifically includes:

[0066] Based on the preset river hydrodynamic model, the river discharge capacity of each section of the river under the self-drainage condition is calculated.

[0067] The discharge capacity of each river segment is normalized, and the standard value of the discharge capacity is calculated.

[0068] Based on the standard flow rate and the preset flow rate range, the river class of each section of the river is determined.

[0069] Specifically, in this embodiment of the invention, the discharge capacity Q of each river segment under the self-drainage condition is first calculated based on the preset river hydrodynamic model Mike. I (m 3 / s). It should be noted that in plain river network areas, the river systems are interconnected. Under the low-probability backwater effect of high tides from external rivers, the river flow direction and flow rate are significantly and not uniquely influenced by artificially operated hydraulic structures. However, under the high-probability self-drainage effect, the amount of floodwater discharged by the river can more fully reflect the river's flood drainage function. For example, in this embodiment of the invention, the specific steps for calculating the river's discharge capacity under self-drainage conditions using the river hydrodynamic model Mike are as follows:

[0070] 1) Model generalization: Import the river centerline into the model, add a cross section every 100-150m for each river segment, and mark the cross section as "river ID-Arabic number". For example, cross section A-1 represents the first cross section with river ID A. The generalized river network area is not less than the area of ​​the river water area extracted in the first step.

[0071] 2) Inflow treatment: Within the river catchment area, the inflow of water into the river is treated to ensure uniform inflow into the river network at a unit width along the sides, i.e., q = 0.278 × F × H / L, where: 0.278 is the unit conversion factor, and q is the inflow rate per unit length of the river channel (m³). 3 / s·m), F is the catchment area of ​​the river (km). 2 H represents the runoff depth (mm) of the river during the inflow period of the river zone under the design drainage standard conditions, and L represents the river length (m).

[0072] 3) Self-drainage operation mode setting: the tide level of the outer river and the initial water level of the river channel are consistent, generally the average tide level of the outer river.

[0073] 4) Simulation calculation: Calculate the peak flow of each river section in 5-minute increments. The peak flow of the j-th section of the river with ID I is denoted as Q. I-j (m 3 / s).

[0074] 5) Select the section with the largest peak flood discharge as the discharge capacity of that section of the river, i.e., Q. I =max(Q I-1 Q I-2 ,…,Q I-j In the Shapefile file representing the river centerline, add a "discharge capacity" field attribute and use GIS spatial analysis functions to associate and match the discharge capacity with the river centerline.

[0075] Then, the discharge capacity of each river segment is normalized and a standard value of discharge is calculated. Based on the standard value of discharge and the preset discharge range, the river class of each river segment is determined.

[0076] For example, the upper and lower limits of the river's discharge capacity within the study area are extracted and denoted as [Q], respectively. min Q max Add a "Flow Standardization" field to the river centerline. The field type is double precision, and the specific flow value is assumed to be Q. i The corresponding standard flow rate is q, which is calculated using the formula q = (Q i -Q min ) / (Q max -Q minCalculate the standard value of the "Flow Standardization" field. Add a "Flow Grade" field to the river centerline. When the standard value q∈[0,0.33), assign the "Flow Grade" field "Class III River" (indicating that the river handles a small flood flow, has a weak function, and belongs to a micro-river in the watershed zoning); when the standard value q∈[0.33,0.67], assign the "Flow Grade" field "Class II River" (indicating that the river handles a moderate flood flow, has a strong function, and belongs to a small to medium-sized river); when the standard value q∈(0.67,1.0], assign the "Flow Grade" field "Class I River" (indicating that the river handles a large flood flow, has a high functional positioning, and belongs to a large river).

[0077] The embodiments of the present invention classify river levels according to the river's discharge capacity under self-drainage conditions, which can fully reflect the level of the river's drainage function. The blue lines drawn according to the river level reflect the differentiated characteristics of river spatial management, which not only achieves the river management objectives, but also reflects the intensive and economical use of land.

[0078] In another preferred embodiment, the step of determining the river cross-sectional shape according to the river grade, calculating the river drainage width under the drainage standard according to the river cross-sectional shape and the river discharge capacity, and generating the planned water area boundary of the river according to the river drainage width, the river centerline, and the river edge line specifically includes:

[0079] The river cross-sectional type is determined according to the river grade; wherein, the river cross-sectional type includes trapezoidal cross-section and rectangular cross-section;

[0080] Based on the river cross-sectional shape and the river discharge capacity, the river drainage width under the drainage standard is calculated by trial calculation.

[0081] A preliminary planned water area boundary for the river channel is generated by extending a second distance outward from both sides of the river channel centerline; wherein, the second distance is determined based on the drainage width of the river channel;

[0082] The preliminary planned water area boundary is superimposed on the river edge line, and the outer boundary line is taken as the final planned water area boundary.

[0083] Specifically, in this embodiment of the invention, the river cross-sectional shape is first determined according to the river's classification; wherein, the river cross-sectional shape includes trapezoidal cross-section and rectangular cross-section. For example, Class I and II rivers use trapezoidal cross-sections, while Class III rivers use rectangular cross-sections. Then, based on the river cross-sectional shape and the river's discharge capacity, the flow rate is calculated using the flow formula Q. I =A×v and flow velocity formula The river channel drainage width B (m) under the drainage standard was calculated using a trial calculation method. Where: Q I To determine the river channel discharge capacity (m³) under standard drainage conditions.3 / s), A is the cross-sectional area of ​​the river channel (m²) 2 Where v is the design flow velocity of the river (m / s), n is the river roughness coefficient, R is the hydraulic radius of the river cross-section (m), and J is the river slope (m / m). The calculation process is as follows:

[0084] 1) Set the initial river width and depth:

[0085] Assuming an initial channel width B0 and depth h0, we obtain the initial cross-sectional area of ​​the flow channel A0 = B0 × h0.

[0086] 2) Calculate the initial flow velocity:

[0087] Using the flow rate formula Calculate the initial flow velocity.

[0088] 3) Verify traffic:

[0089] Use traffic public QQ I =A×v, calculate the initial flow rate Q I,0 .

[0090] Compare Q I,0 With design drainage flow rate Q I .

[0091] 4) Adjust the width and depth of the river channel:

[0092] If Q I,0 I If so, you need to increase the bandwidth, which can be achieved by increasing the width B or the depth h (or both).

[0093] If Q I,0 Q I If so, you need to reduce the flow rate, which can be achieved by reducing the width B or the depth h (or both).

[0094] Repeat steps 2) and 3) until Q. I,0 Approximately equal to Q I .

[0095] 5) Determine the final river width:

[0096] Through trial and error, we found that Q satisfies I,0 ≈Q I The width B and depth h of the river channel.

[0097] Record the final river channel width B as the width required to meet drainage requirements.

[0098] ​It should be noted that during the trial calculation process, the channel width and depth may need to be adjusted multiple times to find the combination closest to the design flow rate. Considering the limitations and constraints in actual engineering (such as land availability, cost, environmental impact, etc.), the final channel width and depth may need to be appropriately adjusted while still meeting the design flow rate requirements. Furthermore, if manual trial calculations are too tedious, a loop can be written using a programming language (such as Python) to automatically adjust the width and depth and find the optimal combination that meets the conditions.

[0099] Please see Figure 2 , Figure 2 This is a schematic diagram illustrating the generation of the planned water area boundary in a method for delineating urban blue lines provided by this invention. In this embodiment, after calculating the drainage width B of the river under the drainage standard, a preliminary planned water area boundary is generated by extending a second distance outward from both sides of the river centerline. The second distance is determined based on the drainage width B. For example, a second distance of B / 2 is selected. Then, based on the consideration that the planned water area is not less than the existing water area, the preliminary planned water area boundary is superimposed on the existing water area boundary line, i.e., the river boundary line extracted from the remote sensing image, and the outer envelope is taken as the final planned water area boundary.

[0100] The embodiments of the present invention overlay the planned water area of ​​the river that meets the drainage requirements with the existing water area map, and take the outer envelope as the final boundary of the planned water area of ​​the river, which reflects the water area occupation and compensation balance strategy and ensures that the planned water area is not reduced compared with the existing water area.

[0101] In yet another preferred embodiment, the method further includes:

[0102] Overlay the river blue line with the existing control detailed plan to determine whether the land use within the river blue line area is entirely water area or green space.

[0103] If so, then there is no need to modify the aforementioned blue line of the river channel;

[0104] If not, the first distance is adjusted based on the width of the waterfront green space and the aforementioned waterlogging risk level to correct the blue line of the river channel.

[0105] Specifically, in this embodiment of the invention, the initially delineated river channel blue line is overlaid with the existing detailed control plan to determine whether the land use within the river channel blue line area is entirely water area or green space. If so, meaning all land use within the river channel blue line area is water area or green space, then no modification to the river channel blue line is required. If not, meaning the river channel blue line conflicts with public service land A, commercial land B, industrial land M, and residential land R, then the first distance of the extension is modified based on the width ΔB (m) of the waterfront green space and the level of urban flooding risk, thereby modifying the river channel blue line. For example, the modified extension distance is as follows:

[0106] 1) River channels that receive rainwater from high-risk catchment areas

[0107] Class I waterways: When the width of the waterfront green space ΔB < 10m, the outer extension distance is corrected by 10m; when 10 ≤ ΔB < 20, the outer extension distance is corrected by ΔB.

[0108] Class II waterways: When the width of the waterfront green space ΔB < 10m, the outer extension distance is corrected by 10m; when 10 ≤ ΔB < 15, the outer extension distance is corrected by ΔB.

[0109] Class III waterways: When the width of the waterfront green space ΔB < 5m, the outer extension distance is corrected by 5m; when 5 ≤ ΔB < 10m, the outer extension distance is corrected by ΔB.

[0110] 2) River channels that receive and discharge rainwater from low-risk catchment areas

[0111] Class I waterways: When the width of the waterfront green space ΔB < 5m, the outer extension distance is corrected by 5m; when 5 ≤ ΔB < 15, the outer extension distance is corrected by ΔB.

[0112] Class II waterways: When the width of the waterfront green space ΔB < 5m, the outer extension distance is corrected by 5m; when 5 ≤ ΔB < 10, the outer extension distance is corrected by ΔB.

[0113] Class III waterways: When the width of the waterfront green space ΔB < 5m, the outer extension distance shall be corrected according to ΔB.

[0114] The revised outer boundary line is the final river channel blue line. This river channel blue line can be incorporated into the national land space management platform as the basis for spatial control of river protection and administrative approval of river-related projects.

[0115] Accordingly, the present invention also provides an urban blue line delineation device, which can implement all the processes of the urban blue line delineation method in the above embodiments.

[0116] Please see Figure 3 , Figure 3 This is a schematic diagram of a preferred embodiment of an urban blue line delineation device provided by the present invention. The urban blue line delineation device includes:

[0117] Data acquisition module 301 is used to acquire remote sensing images and DEM data, and extract the river centerline and river edge line from the remote sensing images;

[0118] The classification module 302 is used to delineate the river catchment area based on the DEM data, the river centerline and the river edge line, and to determine the waterlogging risk level of the river catchment area.

[0119] The boundary delineation module 303 is used to classify the river level according to the river discharge under the self-drainage condition, determine the river cross-section type according to the river level, calculate the river drainage width under the drainage standard according to the river cross-section type and the river discharge, and generate the planned water area boundary of the river according to the river drainage width, the river centerline and the river edge line.

[0120] The blue line delineation module 304 is used to extend the boundary of the planned water area of ​​the river by a first distance based on the three zones and three lines of the national land space plan, the waterlogging risk level, and the river level, to generate the river blue line.

[0121] Preferably, the grade classification module 302 specifically includes:

[0122] A catchment area delineation unit is used to delineate the catchment area of ​​a river channel based on the DEM data.

[0123] The catchment area correction unit is used to correct the catchment area of ​​the river based on the river centerline and the river edge line, so that the river centerline and the catchment area do not overlap.

[0124] The waterlogging level determination unit is used to determine the waterlogging risk level of the river catchment area based on the water depth of historical waterlogging points; wherein, the waterlogging risk level includes high risk and low risk.

[0125] Preferably, the process of classifying river levels based on the river's discharge capacity under gravity drainage conditions specifically includes:

[0126] Based on the preset river hydrodynamic model, the river discharge capacity of each section of the river under the self-drainage condition is calculated.

[0127] The discharge capacity of each river segment is normalized, and the standard value of the discharge capacity is calculated.

[0128] Based on the standard flow rate and the preset flow rate range, the river class of each section of the river is determined.

[0129] Preferably, the step of determining the river cross-section type according to the river grade, calculating the river drainage width under the drainage standard according to the river cross-section type and the river discharge capacity, and generating the planned water area boundary of the river according to the river drainage width, the river centerline, and the river edge line specifically includes:

[0130] The river cross-sectional type is determined according to the river grade; wherein, the river cross-sectional type includes trapezoidal cross-section and rectangular cross-section;

[0131] Based on the river cross-sectional shape and the river discharge capacity, the river drainage width under the drainage standard is calculated by trial calculation.

[0132] A preliminary planned water area boundary for the river channel is generated by extending a second distance outward from both sides of the river channel centerline; wherein, the second distance is determined based on the drainage width of the river channel;

[0133] The preliminary planned water area boundary is superimposed on the river edge line, and the outer boundary line is taken as the final planned water area boundary.

[0134] Preferably, the blue line delineation module 304 is specifically used for:

[0135] If the river is located in the agricultural or ecological space of the national land space plan, then according to the river level, the boundary of the planned water area of ​​the river is extended by different first distances to generate the river blue line;

[0136] If the river is located in the urban space of the national land space plan, then according to the waterlogging risk level and the river level, the boundary of the planned water area of ​​the river will be extended by different first distances to generate the river blue line.

[0137] The first distance is directly proportional to the level of waterlogging risk.

[0138] Preferably, the device further includes a blue line correction module, used for:

[0139] Overlay the river blue line with the existing control detailed plan to determine whether the land use within the river blue line area is entirely water area or green space.

[0140] If so, then there is no need to modify the aforementioned blue line of the river channel;

[0141] If not, the first distance is adjusted based on the width of the waterfront green space and the aforementioned waterlogging risk level to correct the blue line of the river channel.

[0142] In specific implementation, the working principle, control process and technical effects of the urban blue line delineation device provided in this embodiment of the invention are the same as those of the urban blue line delineation method in the above embodiments, and will not be repeated here.

[0143] Please see Figure 4 , Figure 4 This is a schematic diagram of a preferred embodiment of a terminal device provided by the present invention. The terminal device includes a processor 401, a memory 402, and a computer program stored in the memory 402 and configured to be executed by the processor 401. When the processor 401 executes the computer program, it implements the urban blue line delineation method described in any of the above embodiments.

[0144] Preferably, the computer program can be divided into one or more modules / units (such as computer program 1, computer program 2, ...), and the one or more modules / units are stored in the memory 402 and executed by the processor 401 to complete the present invention. The one or more modules / units can be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used to describe the execution process of the computer program in the terminal device.

[0145] The processor 401 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor, or the processor 401 may be any conventional processor. The processor 401 is the control center of the terminal device, connecting various parts of the terminal device through various interfaces and lines.

[0146] The memory 402 mainly includes a program storage area and a data storage area. The program storage area can store the operating system, applications required for at least one function, etc., while the data storage area can store related data, etc. Furthermore, the memory 402 can be a high-speed random access memory, or a non-volatile memory, such as a plug-in hard disk, a smart media card (SMC), a secure digital card (SD), and a flash card, or it can be other volatile solid-state storage devices.

[0147] It should be noted that the aforementioned terminal devices may include, but are not limited to, processors and memory, as will be understood by those skilled in the art. Figure 4 The structural diagram is merely an example of the terminal device described above and does not constitute a limitation on the terminal device described above. It may include more or fewer components than shown in the diagram, or combine certain components, or use different components.

[0148] This invention also provides a computer-readable storage medium, which includes a stored computer program, wherein the computer program, when running, controls the device where the computer-readable storage medium is located to execute the urban blue line delineation method described in any of the above embodiments.

[0149] This invention also provides a computer program product, which includes a computer program or computer instructions. When the computer program or computer instructions are executed by a processor, they implement the urban blue line delineation method described in any of the above embodiments.

[0150] This invention provides a method, apparatus, equipment, medium, and computer program product for delineating urban blue lines. It acquires remote sensing images and DEM data, extracts the river centerline and river edge lines from the remote sensing images, delineates the river catchment area based on the DEM data, the river centerline, and the river edge lines, and determines the flood risk level of the river catchment area. It classifies the river according to the river's discharge capacity under self-drainage conditions, determines the river cross-sectional type based on the river level, calculates the river drainage width under the drainage standard based on the river cross-sectional type and the river's discharge capacity, and generates the planned water area boundary of the river based on the river drainage width, the river centerline, and the river edge lines. Finally, it extends the planned water area boundary of the river by a first distance based on the three zones and three lines of the national land spatial planning, the flood risk level, and the river level, generating the river blue line. The embodiments of the present invention fully consider the risk of urban flooding, connect the three zones and three lines of the national land space planning, reduce the planning conflicts between the river blue line and other land uses, are more conducive to promoting the integrated development of urban and water, and are more operable and feasible.

[0151] It should be noted that the system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the system embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0152] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for delineating urban blue lines, characterized in that, include: Acquire remote sensing images and digital elevation model (DEM) data, and extract the river centerline and river edge line from the remote sensing images; The catchment area of ​​the river is delineated based on the DEM data, the center line of the river channel, and the edge line of the river channel, and the waterlogging risk level of the catchment area is determined. Rivers are classified into different grades based on their discharge capacity under self-drainage conditions, and the cross-sectional shape of the river is determined based on the river grade. The drainage width of the river under the drainage standard is calculated based on the cross-sectional shape of the river and the discharge capacity of the river. The planned water area boundary of the river is generated based on the drainage width of the river, the center line of the river, and the edge line of the river. Based on the three zones and three lines of the national land space plan, the aforementioned urban flooding risk level, and the aforementioned river level, the river planning water area boundary is extended by a first distance to generate the river blue line; Specifically, the step of delineating the river catchment area based on the DEM data, the river centerline, and the river edge, and determining the flood risk level of the river catchment area, includes: The catchment area of ​​the river channel was delineated based on the DEM data; The catchment area of ​​the river is corrected based on the river centerline and the river edge line so that the river centerline and the river catchment area do not overlap. The flood risk level of the river catchment area is determined based on the water depth at historical flood points; wherein the flood risk level includes high risk and low risk. Specifically, the steps of determining the river cross-section type based on the river grade, calculating the river drainage width under the drainage standard based on the river cross-section type and the river discharge capacity, and generating the planned water area boundary of the river based on the river drainage width, the river centerline, and the river edge line include: The river cross-sectional type is determined according to the river grade; wherein, the river cross-sectional type includes trapezoidal cross-section and rectangular cross-section; Based on the river cross-sectional shape and the river discharge capacity, the river drainage width under the drainage standard is calculated by trial calculation. A preliminary planned water area boundary for the river channel is generated by extending a second distance outward from both sides of the river channel centerline; wherein, the second distance is determined based on the drainage width of the river channel; The preliminary planned water area boundary is superimposed on the river edge line, and the outer envelope is taken as the final planned water area boundary. Specifically, the step of extending the boundary of the planned water area of ​​the river by a first distance, based on the three zones and three lines of the national land spatial planning, the waterlogging risk level, and the river level, to generate the river blue line, includes: If the river is located in the agricultural or ecological space of the national land space plan, then according to the river level, the boundary of the planned water area of ​​the river is extended by different first distances to generate the river blue line; If the river is located in the urban space of the national land space plan, then according to the waterlogging risk level and the river level, the boundary of the planned water area of ​​the river will be extended by different first distances to generate the river blue line. The first distance is directly proportional to the level of waterlogging risk.

2. The method for delineating urban blue lines as described in claim 1, characterized in that, The classification of river levels based on the discharge capacity of the river under self-drainage conditions specifically includes: Based on the preset river hydrodynamic model, the river discharge capacity of each section of the river under the self-drainage condition is calculated. The discharge capacity of each river segment is normalized, and the standard value of the discharge capacity is calculated. Based on the standard flow rate and the preset flow rate range, the river class of each section of the river is determined.

3. The method for delineating urban blue lines as described in claim 2, characterized in that, The method further includes: Overlay the river blue line with the existing control detailed plan to determine whether the land use within the river blue line area is entirely water area or green space. If so, then there is no need to modify the aforementioned blue line of the river channel; If not, the first distance is adjusted based on the width of the waterfront green space and the aforementioned waterlogging risk level to correct the blue line of the river channel.

4. A device for delineating urban blue lines, characterized in that, include: The data acquisition module is used to acquire remote sensing images and DEM data, and extract the river centerline and river edge line from the remote sensing images. The grading module is used to delineate the river catchment area based on the DEM data, the river centerline, and the river edge line, and to determine the waterlogging risk level of the river catchment area. The boundary delineation module is used to classify river levels according to the river discharge capacity under the self-drainage condition, determine the river cross-sectional type according to the river level, calculate the river drainage width under the drainage standard according to the river cross-sectional type and the river discharge capacity, and generate the planned water area boundary of the river according to the river drainage width, the river centerline and the river edge line. The blue line delineation module is used to extend the boundary of the planned water area of ​​the river by a first distance based on the three zones and three lines of the national land space plan, the waterlogging risk level, and the river level, to generate the river blue line. The grade classification module specifically includes: A catchment area delineation unit is used to delineate the catchment area of ​​a river channel based on the DEM data. The catchment area correction unit is used to correct the catchment area of ​​the river based on the river centerline and the river edge line, so that the river centerline and the catchment area do not overlap. The waterlogging level determination unit is used to determine the waterlogging risk level of the river catchment area based on the water depth of historical waterlogging points; wherein, the waterlogging risk level includes high risk and low risk; Specifically, the steps of determining the river cross-section type based on the river grade, calculating the river drainage width under the drainage standard based on the river cross-section type and the river discharge capacity, and generating the planned water area boundary of the river based on the river drainage width, the river centerline, and the river edge line include: The river cross-sectional type is determined according to the river grade; wherein, the river cross-sectional type includes trapezoidal cross-section and rectangular cross-section; Based on the river cross-sectional shape and the river discharge capacity, the river drainage width under the drainage standard is calculated by trial calculation. A preliminary planned water area boundary for the river channel is generated by extending a second distance outward from both sides of the river channel centerline; wherein, the second distance is determined based on the drainage width of the river channel; The preliminary planned water area boundary is superimposed on the river edge line, and the outer envelope is taken as the final planned water area boundary. Specifically, the blue line delineation module is used for: If the river is located in the agricultural or ecological space of the national land space plan, then according to the river level, the boundary of the planned water area of ​​the river is extended by different first distances to generate the river blue line; If the river is located in the urban space of the national land space plan, then according to the waterlogging risk level and the river level, the boundary of the planned water area of ​​the river will be extended by different first distances to generate the river blue line. The first distance is directly proportional to the level of waterlogging risk.

5. A terminal device, characterized in that, It includes a processor and a memory, the memory storing a computer program configured to be executed by the processor, the processor executing the computer program to implement the urban blue line delineation method as described in any one of claims 1 to 4.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein when the device containing the computer-readable storage medium executes the computer program, it implements the urban blue line delineation method as described in any one of claims 1 to 4.

7. A computer program product, characterized in that, The computer program product includes a computer program or computer instructions, which, when executed by a processor, implement the urban blue line delineation method as described in any one of claims 1 to 4.

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