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

Abstract

The invention discloses an urban blue line delimiting method, device and equipment, a medium and a computer program product, and the method comprises the steps: obtaining a remote sensing image and DEM data, and extracting a river channel center line and a river channel side line from the remote sensing image; according to the DEM data, the riverway center line and the riverway sideline, a riverway water collection range and a corresponding waterlogging risk grade are delimited; dividing a river channel grade according to the river channel discharge bearing flow, determining a river channel section type according to the river channel grade, calculating a river channel drainage width under a drainage standard according to the river channel section type and the river channel discharge bearing flow, and generating a river channel planning water area boundary; and according to the territorial space planning three-area three-line, the waterlogging risk level and the river channel level, extending the boundary of the river channel planning water area by a first distance to generate a river channel blue line. According to the method, the waterlogging risk is fully considered, territorial space planning three areas and three lines are joined, planning conflicts between river blue lines and other lands are reduced, city-water fusion development can be promoted, and operability and feasibility are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of urban planning, and particularly to a method, device, equipment, medium and computer program product for demarcating urban blue lines. Background Art

[0002] The demarcation of river blue lines is an important measure to practice ecological civilization construction and is also one of the important contents of territorial space planning. Since the Ministry of Housing and Urban-Rural Development promulgated the "Measures for the Administration of Urban Blue Lines" in 2005, attempts have been made to demarcate river blue lines across the country. However, due to the lack of refined blue line demarcation methods, there are serious conflicts in the planning of river blue line demarcation results, and there are significant differences among relevant departments for water-related management, making it difficult to implement on the ground.

[0003] The current blue line demarcation method is mainly based on the single goal of river protection, and combines the river embankment type and the design flood level to demarcate the blue line. The current river blue line demarcation method belongs to a typical pre-control type of spatial control, demarcating a large and wide range to protect the river and prevent illegal construction. However, this demarcation method does not consider the waterlogging risk in the river's catchment area, nor does it connect with a series of territorial space plans. It only focuses on river protection and is not conducive to the intensive and economical use of land in territorial space, resulting in the inability to implement the river blue line demarcation results on the ground. 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 demarcating urban blue lines, which fully considers the waterlogging risk, connects with the three zones and three lines of territorial space planning, reduces the planning conflicts between river blue lines and other land uses, is more conducive to promoting the integrated development of cities and water, and is also more operable and implementable.

[0005] To achieve the above object, an embodiment of the present invention provides a method for demarcating urban blue lines, including:

[0006] Obtain remote sensing images and DEM data, and extract the river center line and river bank line from the remote sensing images;

[0007] Demarcate the river catchment area according to the DEM data, the river center line and the river bank line, and demarcate the waterlogging risk level of the river catchment area;

[0008] Divide the river grades according to the river conveyance flow under self-drainage conditions, determine the river cross-section type according to the river grades, calculate the river drainage width under the drainage standard according to the river cross-section type and the river conveyance flow, and generate the river planning water area boundary according to the river drainage width, the river center line and the river bank line;

[0009] According to the three zones and three boundaries of the territorial space plan, the urban waterlogging risk level, and the river channel level, extend the boundary of the planned water area of the river channel by a first distance to generate the blue line of the river channel.

[0010] As an improvement to the above solution, the method of delineating the river channel catchment area according to the DEM data, the river channel center line, and the river channel side line, and delineating the urban waterlogging risk level of the river channel catchment area specifically includes:

[0011] Delineate the river channel catchment area according to the DEM data;

[0012] Modify the river channel catchment area according to the river channel center line and the river channel side line so that there is no overlap between the river channel center line and the river channel catchment area;

[0013] Delineate the urban waterlogging risk level of the river channel catchment area according to the water accumulation depth of historical urban waterlogging points; wherein, the urban waterlogging risk level includes high risk and low risk.

[0014] As an improvement to the above solution, the method of dividing the river channel level according to the river channel's discharge capacity under self-drainage conditions specifically includes:

[0015] According to a preset river channel hydrodynamic model, calculate the river channel's discharge capacity for each section of the river channel under self-drainage conditions;

[0016] Normalize the river channel's discharge capacity for each section of the river channel and calculate the flow standard value;

[0017] Divide the river channel level of each section of the river channel according to the flow standard value and a preset flow interval.

[0018] As an improvement to the above solution, the method of determining the river channel cross-section type according to the river channel level, calculating the river channel drainage width under the drainage standard according to the river channel cross-section type and the river channel's discharge capacity, and generating the boundary of the planned water area of the river channel according to the river channel drainage width, the river channel center line, and the river channel side line specifically includes:

[0019] Determine the river channel cross-section type according to the river channel level; wherein, the river channel cross-section type includes trapezoidal cross-section and rectangular cross-section;

[0020] According to the river channel cross-section type and the river channel's discharge capacity, use the trial calculation method to calculate the river channel drainage width under the drainage standard;

[0021] Extend a second distance on both sides of the river channel center line to generate a preliminary boundary of the planned water area of the river channel; wherein, the second distance is determined according to the river channel drainage width;

[0022] Overlay the preliminary water area boundary of the river channel planning with the river channel side line, and take the outer envelope line as the final water area boundary of the river channel planning.

[0023] As an improvement to the above solution, according to the three zones and three lines of the territorial space planning, the waterlogging risk level, and the river channel level, extend the water area boundary of the river channel planning by a first distance to generate a blue line of the river channel, specifically including:

[0024] If the river channel is located in the agricultural space or ecological space in the territorial space planning, extend the water area boundary of the river channel planning by different first distances according to the river channel level to generate a blue line of the river channel;

[0025] If the river channel is located in the urban space in the territorial space planning, extend the water area boundary of the river channel planning by different first distances according to the waterlogging risk level and the river channel level to generate a blue line of the river channel;

[0026] Among them, the first distance is proportional to the waterlogging risk level.

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

[0028] Overlay the blue line of the river channel with the current regulatory detailed planning, and judge whether the land use nature within the blue line of the river channel is all water area or green space;

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

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

[0031] The embodiment of the present invention also provides an urban blue line demarcation device, including:

[0032] A data acquisition module for acquiring remote sensing images and DEM data, and extracting the river channel center line and river channel side line from the remote sensing images;

[0033] A level demarcation module for demarcating the river channel catchment area according to the DEM data, the river channel center line, and the river channel side line, and demarcating the waterlogging risk level of the river channel catchment area;

[0034] A boundary demarcation module for dividing the river channel level according to the river channel carrying capacity under the self-draining condition, determining the river channel cross-section type according to the river channel level, calculating the river channel drainage width under the drainage standard according to the river channel cross-section type and the river channel carrying capacity, and generating a water area boundary of the river channel planning according to the river channel drainage width, the river channel center line, and the river channel side line;

[0035] A blue line demarcation module, configured to extend the boundary of the planned water area of the river by a first distance according to the three zones and three lines of the national territorial space planning, the waterlogging risk level, and the river level, so as to generate a river blue line.

[0036] An embodiment of the present invention further 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. When the processor executes the computer program, the urban blue line demarcation method described in any one of the above is implemented.

[0037] An embodiment of the present invention further provides a computer-readable storage medium. The computer-readable storage medium includes a stored computer program. When the computer program runs, it controls the device where the computer-readable storage medium is located to execute the urban blue line demarcation method described in any one of the above.

[0038] An embodiment of the present invention further provides a computer program product. The computer program product includes a computer program or computer instructions. When the computer program or the computer instructions are executed by a processor, the urban blue line demarcation method described in any one of the above is implemented.

[0039] Compared with the prior art, the beneficial effects of an urban blue line demarcation method, device, equipment, medium, and computer program product provided by an embodiment of the present invention are as follows: By obtaining remote sensing images and DEM data, the river center line and river bank line are extracted from the remote sensing images; According to the DEM data, the river center line, and the river bank line, the river catchment area is demarcated, and the waterlogging risk level of the river catchment area is demarcated; The river level is divided according to the river conveyance flow under the self-drainage condition, and the river cross-section type is determined according to the river level. According to the river cross-section type and the river conveyance flow, the river drainage width under the drainage standard is calculated. According to the river drainage width, the river center line, and the river bank line, the boundary of the planned water area of the river is generated; According to the three zones and three lines of the national territorial space planning, the waterlogging risk level, and the river level, the boundary of the planned water area of the river is extended by a first distance to generate a river blue line. The embodiment of the present invention fully considers the waterlogging risk, connects with the three zones and three lines of the national territorial space planning, reduces the planning conflict between the river blue line and other land uses, is more conducive to promoting the integrated development of the city and water, and is also more operable and implementable. Description of the Drawings

[0040] Figure 1 It is a schematic flowchart of a preferred embodiment of an urban blue line demarcation method provided by the present invention;

[0041] Figure 2 It is a schematic diagram of the generation of the boundary of the planned water area of the river in an urban blue line demarcation method provided by the present invention;

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

[0043] Figure 4 It is a schematic structural diagram of a preferred embodiment of a terminal device provided by the present invention. Specific embodiments

[0044] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0045] Please refer to Figure 1 , Figure 1 It is a schematic flow diagram of a preferred embodiment of an urban blue line demarcation provided by the present invention. The urban blue line demarcation method includes:

[0046] S1, obtaining remote sensing images and DEM data, and extracting the center line and bank line of the river from the remote sensing images;

[0047] S2, demarcating the river catchment area according to the DEM data, the center line and the bank line of the river, and demarcating the waterlogging risk level of the river catchment area;

[0048] S3, dividing the river grades according to the river carrying discharge under the self-draining condition, determining the river cross-section type according to the river grades, calculating the river drainage width under the drainage standard according to the river cross-section type and the river carrying discharge, and generating the river planning water area boundary according to the river drainage width, the center line and the bank line of the river;

[0049] S4, extending the river planning water area boundary by a first distance according to the three zones and three lines of the national territorial space planning, the waterlogging risk level and the river grades to generate the river blue line.

[0050] Specifically, in the embodiments of the present invention, a basic database of river channel water systems within the research scope is first established by using remote sensing images and high-precision DEM data. The remote sensing images and DEM data are obtained, and the river channel centerlines and river channel side lines are extracted from the remote sensing images. Exemplarily, in the embodiments of the present invention, remote sensing images are used to extract river channel water system patches and form vector data in the Shapefile format. For example, the research scope is selected by using the full-functional version of the Bigmap large map software, a commonly used local coordinate system is selected, and the highest-level remote sensing image map and DEM data are downloaded; the image map is imported into the GIS software, various water body data in the image map are initially judged, various water bodies in the image are picked up and training sample points in their threshold intervals are generated; the training sample points are called, and the water bodies in the image map of the entire research scope are judged by the threshold method and raster data are generated; the water body raster data are converted into surface data in the GIS, the river channel water system surface data are screened out, the connecting lines upstream and downstream of the river channel surface data are identified and deleted, and the river channel vector surface data are converted into two independent boundary lines to form a vector database of the current river channel side lines. Then, the river channel centerlines are extracted by the line segment mean method, and a "river channel ID" field is added to the river channel centerlines and encoded. For example, the river channel bank line database is converted into a CAD file, and the PathAverage.lsp file is loaded in CAD; the pav command is input, the number of segmented line segments is defined, the current river channel side lines are selected, and vector data of the river channel centerlines are generated; the river channel centerlines are imported into the vector database of the current river channel side lines, a "river channel ID" field is added to the river channel centerlines, and encodings such as A, B, C,... are assigned in the order of the elements. Then, the river channel catchment areas are delimited according to the DEM data, the river channel centerlines and the river channel side lines, and the waterlogging risk levels of the river channel catchment areas are delimited. The river channel grades are divided according to the river channel discharge capacity under the self-draining condition, the river channel cross-section types are determined according to the river channel grades, the river channel drainage widths under the drainage standard are calculated according to the river channel cross-section types and the river channel discharge capacity, and the river channel planning water area boundaries are generated according to the river channel drainage widths, the river channel centerlines and the river channel side lines. Finally, according to the "Urban Blue Line Management Measures" promulgated by the Ministry of Housing and Urban-Rural Development, the blue line refers to the territorial boundary for the protection and control of urban surface water bodies such as rivers, lakes, reservoirs, canals and wetlands determined by urban planning, that is, the river channel blue line needs to extend a certain distance on the basis of the river channel planning water area boundary. Therefore, in the embodiments of the present invention, in combination with the three zones and three lines of the national territorial space planning, the waterlogging risk level and the river channel grade, the river channel planning water area boundary is extended by different first distances to generate the river channel blue line.

[0051] As a preferred solution, if the river channel is located in the agricultural space or ecological space in the national territorial space planning, the river channel planning water area boundary is extended by different first distances according to the river channel grade to generate the river channel blue line;

[0052] If the river channel is located in the urban space in the territorial spatial planning, according to the waterlogging risk level and the river channel level, extend the planned water area boundary of the river channel by different first distances to generate the river channel blue line;

[0053] Among them, the first distance is proportional to the waterlogging risk level.

[0054] For example:

[0055] (1) For the river channels located in the agricultural space and ecological space in the territorial spatial planning, the planned water area boundaries of Class I, Class II, and Class III river channels are extended by 20m, 15m, and 10m respectively as the preliminarily delimited river channel blue lines.

[0056] (2) For the river channels located in the urban space in the territorial spatial planning, delimit the river channel blue lines according to the following rules:

[0057] 1) For the river channels that convey rainwater from high-risk catchment areas, the planned water area boundaries of Class I, Class II, and Class III river channels are extended by 20m, 15m, and 10m respectively as the preliminarily delimited river channel blue lines.

[0058] 2) For the river channels that convey rainwater from low-risk catchment areas, the planned water area boundaries of Class I, Class II, and Class III river channels are extended by 15m, 10m, and 5m respectively as the preliminarily delimited river channel blue lines.

[0059] The embodiments of the present invention fully consider the waterlogging risk, connect the three zones and three lines of the territorial spatial planning, reduce the planning conflicts between the river channel blue line and other land uses, are more conducive to promoting the integrated development of the city and water, and are also more operable and implementable.

[0060] In another preferred embodiment, in S2, according to the DEM data, the river channel center line, and the river channel side line, delimit the river channel catchment area and delimit the waterlogging risk level of the river channel catchment area, specifically including:

[0061] S201, delimit the river channel catchment area according to the DEM data;

[0062] S202, correct the river channel catchment area according to the river channel center line and the river channel side line so that there is no overlap between the river channel center line and the river channel catchment area;

[0063] S203, delimit the waterlogging risk level of the river channel catchment area according to the accumulated water depth of historical waterlogging points; among them, the waterlogging risk level includes high risk and low risk.

[0064] Specifically, in the embodiments of the present invention, DEM data is imported into GIS software, and the catchment area of each river channel is generated through processes such as watershed basin determination - catchment outlet determination - catchment area segmentation in the GIS hydrological analysis module. Then, the centerline vector line of the river channel is overlaid with the topographic data and the image map, and the possible local overlapping situations between the centerline of the river channel and the catchment area line are adjusted to correct the catchment area of the river channel, ensuring that the centerline of each river channel independently falls within a single catchment area without overlapping. Finally, based on the ledger of historical waterlogging points within the research scope collected and established, the waterlogging risk level of the catchment area of the river channel is delimited according to the waterlogging depth of the historical waterlogging points. For example, the catchment area of the river channel containing waterlogging points with a waterlogging depth exceeding 0.2 m is defined as a high-risk catchment area, and the others are low-risk catchment areas. Among them, the waterlogging risk levels include high risk and low risk.

[0065] In yet another preferred embodiment, the division of river channel grades according to the river channel's discharge capacity under self-draining conditions specifically includes:

[0066] According to a preset river channel hydrodynamic model, calculate the river channel's discharge capacity for each section of the river channel under self-draining conditions;

[0067] Normalize the river channel's discharge capacity for each section of the river channel and calculate the flow standard value;

[0068] According to the flow standard value and a preset flow range, divide the river channel grades for each section of the river channel.

[0069] Specifically, in the embodiments of the present invention, first, according to the preset river channel hydrodynamic model Mike, calculate the river channel's discharge capacity Q I (m 3 / s) of each section of the river channel under self-draining conditions. It should be noted that the river channel water systems in the plain river network area are interconnected. Under the condition of the backwater effect of the high tide level of the outer river with a low probability, the flow direction and flow rate of the river channel water are greatly affected and not unique by the artificially operated hydraulic structures. However, under the self-draining condition with a high probability, the waterlogging discharge capacity of the river channel can more fully reflect the functional grade of the river channel for waterlogging drainage. Exemplarily, the specific operation steps for calculating the river channel's discharge capacity under self-draining conditions using the river channel hydrodynamic model Mike in the embodiments of the present invention are as follows:

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

[0071] 2) Treatment of the water volume flowing into the river: In the river channel catchment area, the water volume flowing into the river channel is treated as a lateral uniform inflow per unit width and enters the river network, that is, q = 0.278×F×H / L, where: 0.278 is the unit conversion coefficient, q is the inflow rate into the river per unit length of the river channel (m 3 / s·m), F is the river channel catchment area (km 2 ), H is the runoff depth during the inflow period in the river channel sub-region under the design waterlogging drainage standard (mm), and L is the length of the river channel (m).

[0072] 3) Setting of the self-drainage condition: The water level of the outer river tide is the same as the initial water level of the river channel, generally the average tide level of the outer river.

[0073] 4) Simulation calculation: Calculate the peak flow of each river channel section at a step of 5 minutes. The peak flow of the jth section of the river channel with ID I is denoted as Q I-j (m 3 / s).

[0074] 5) Select the section with the maximum peak flow as the discharge capacity of this section of the river channel, that is, Q I = max(Q I-1 , Q I-2 , …, Q I-j ). In the Shapefile file of the river channel center line, add the field attribute of "discharge capacity", and use the GIS spatial analysis function to associate and match the discharge capacity with the river channel center line.

[0075] Then, normalize the discharge capacity of each section of the river channel and calculate the flow standard value. According to this flow standard value and the preset flow interval, divide the river channel grade of each section of the river channel.

[0076] Exemplarily, extract the upper and lower limits of the discharge capacity of the river channels within the research scope, which are denoted as [Q min , Q max . Add the field of "flow normalization" to the river channel center line, and the field type is double precision. Assume that the specific flow value is Q i , and the corresponding flow standard value is q. Through the formula q = (Q i - Q min ) / (Q max - Q min)Calculate the standard value of the calculated field "flow normalization". Add a "flow level" field to the center line of the river channel. When the standard value q ∈ [0, 0.33), assign "Grade III river channel" to the "flow level" field (indicating that the river channel undertakes a small flood flow, has a weak function, and belongs to the micro river channel in the watershed partition); when the standard value q ∈ [0.33, 0.67], assign "Grade II river channel" to the "flow level" field (indicating that the river channel undertakes a moderate flood flow, has a strong function, and belongs to the medium and small river channels); when the standard value q ∈ (0.67, 1.0], assign "Grade I river channel" to the "flow level" field (indicating that the river channel undertakes a large flood flow, has a high functional positioning, and belongs to the large river channel).

[0077] In the embodiment of the present invention, the river channel grade is divided according to the flood discharge capacity of the river channel under the self-draining condition, which can fully reflect the drainage function level borne by the river channel. Designating the blue line according to the river channel grade reflects the differential characteristics of the river channel spatial control, which not only realizes the river channel control goal but also reflects the intensive and economical use of land for national use.

[0078] In another preferred embodiment, determining the river channel cross-section type according to the river channel grade, calculating the river channel drainage width under the drainage standard according to the river channel cross-section type and the flood discharge capacity of the river channel, and generating the river channel planned water area boundary according to the river channel drainage width, the center line of the river channel, and the bank line of the river channel specifically includes:

[0079] Determine the river channel cross-section type according to the river channel grade; wherein, the river channel cross-section type includes trapezoidal cross-section and rectangular cross-section;

[0080] Calculate the river channel drainage width under the drainage standard by means of trial calculation according to the river channel cross-section type and the flood discharge capacity of the river channel;

[0081] Extend a second distance on both sides of the center line of the river channel to generate a preliminary river channel planned water area boundary; wherein, the second distance is determined according to the river channel drainage width;

[0082] Overlay the preliminary river channel planned water area boundary with the bank line of the river channel, and take the envelope line as the final river channel planned water area boundary.

[0083] Specifically, in the embodiment of the present invention, first determine the river channel cross-section type according to the river channel grade; wherein, the river channel cross-section type includes trapezoidal cross-section and rectangular cross-section. Exemplarily, trapezoidal cross-sections are adopted for Grade I and Grade II river channels, and rectangular cross-sections are adopted for Grade III river channels. Then, according to the river channel cross-section type and the flood discharge capacity of the river channel, according to the flow formula Q I = A × v and the flow velocity formula Calculate the river channel drainage width B (m) under the drainage standard by means of trial calculation. Wherein: Q I is the flood discharge capacity (m of the river channel under the designed drainage standard condition3 / s), where A is the cross-sectional area of the river channel (m 2 ), v is the designed flow velocity of the river channel (m / s), n is the roughness coefficient of the river channel, R is the hydraulic radius of the cross-sectional area of the river channel (m), and J is the slope of the river channel (m / m). Exemplarily, the calculation process is as follows:

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

[0085] Assume an initial river channel width B0 and depth h0, so as to obtain the initial cross-sectional area A0 = B0 × h0.

[0086] 2) Calculate the initial flow velocity:

[0087] Use the flow velocity formula to calculate the initial flow velocity.

[0088] 3) Verify the flow rate:

[0089] Use the flow rate formula Q I = A × v to calculate the initial flow rate Q I,0 .

[0090] Compare Q I,0 with the designed drainage flow rate Q I .

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

[0092] If Q I,0 < Q I , then the flow rate needs to be increased, which can be achieved by increasing the width B or the depth h (or both).

[0093] If Q I,0 > Q I , then the flow rate needs to be decreased, which can be achieved by decreasing the width B or the depth h (or both).

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

[0095] 5) Determine the final river channel width:

[0096] Through trial calculation, find the river channel width B and depth h that satisfy Q I,0 ≈ Q I .

[0097] Record the final river channel width B as the width that meets the drainage requirements.

[0098] It should be noted that during the trial calculation process, it may be necessary to adjust the river width and depth multiple times to find the combination closest to the design flow. Considering the limitations and constraints in actual projects (such as land availability, cost, environmental impact, etc.), the final river width and depth may need to be appropriately adjusted on the basis of meeting the design flow. Additionally, if manual trial calculation is too cumbersome, 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 refer to Figure 2 , Figure 2 is a schematic diagram showing the generation of the boundary of the planned water area of the river in a method for demarcating the urban blue line provided by the present invention. After calculating the drainage width B of the river under the drainage standard in an embodiment of the present invention, a second distance is extended on both sides of the center line of the river to first generate a preliminary boundary of the planned water area of the river. Among them, the second distance is determined according to the drainage width B of the river. For example, the second distance is selected as B / 2. Then, based on the consideration that the planned water area is not less than the current water area, the preliminary boundary of the planned water area of the river is superimposed on the current water area boundary line, that is, the river boundary line extracted from the remote sensing image, and the outer envelope line is taken as the final boundary of the planned water area of the river.

[0100] In an embodiment of the present invention, the width of the planned water area of the river that meets the drainage requirements is superimposed on the current water area map patch, and the outer envelope line is taken 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 does not shrink compared with the current water area.

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

[0102] Superimpose the river blue line on the current regulatory detailed plan, and determine whether the land use nature within the river blue line is all water area or green space;

[0103] If so, there is no need to correct the river blue line;

[0104] If not, the first distance is corrected according to the width of the waterfront green space and the waterlogging risk level to correct the river blue line.

[0105] Specifically, in an embodiment of the present invention, the preliminarily demarcated river blue line is superimposed on the current regulatory detailed plan to determine whether the land use nature within the river blue line is all water area or green space. If so, that is, the land use nature within the river blue line is all water area or green space, there is no need to correct the river blue line. If not, that is, the river blue line conflicts with public service land A, commercial land B, industrial land M, residential land R, etc., the extended first distance is corrected according to the width of the waterfront green space ΔB(m) and the waterlogging risk level to correct the river blue line. Exemplarily, the corrected extended distance is as follows:

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

[0107] Grade I river channels: When the width of the waterfront green space ΔB < 10m, the extension distance is corrected according to 10m; when 10 ≤ ΔB < 20, the extension distance is corrected according to ΔB.

[0108] Grade II river channels: When the width of the waterfront green space ΔB < 10m, the extension distance is corrected according to 10m; when 10 ≤ ΔB < 15, the extension distance is corrected according to ΔB.

[0109] Grade III river channels: When the width of the waterfront green space ΔB < 5m, the extension distance is corrected according to 5m; when 5 ≤ ΔB < 10m, the extension distance is corrected according to ΔB.

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

[0111] Grade I river channels: When the width of the waterfront green space ΔB < 5m, the extension distance is corrected according to 5m; when 5 ≤ ΔB < 15, the extension distance is corrected according to ΔB.

[0112] Grade II river channels: When the width of the waterfront green space ΔB < 5m, the extension distance is corrected according to 5m; when 5 ≤ ΔB < 10, the extension distance is corrected according to ΔB.

[0113] Grade III river channels: When the width of the waterfront green space ΔB < 5m, the extension distance is corrected according to ΔB.

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

[0115] Correspondingly, the present invention also provides a device for demarcating urban blue lines, which can implement all the processes of the urban blue line demarcation method in the above embodiments.

[0116] Please refer to Figure 3 , Figure 3 , which is a schematic structural diagram of a preferred embodiment of a device for demarcating urban blue lines provided by the present invention. The device for demarcating urban blue lines includes:

[0117] A data acquisition module 301, configured to acquire remote sensing images and DEM data, and extract the river centerline and river bank line from the remote sensing images;

[0118] A grade demarcation module 302, configured to demarcate the river catchment area according to the DEM data, the river centerline, and the river bank line, and demarcate the waterlogging risk grade of the river catchment area;

[0119] A boundary demarcation module 303, configured to divide river channel grades according to the flood conveyance flow of the river channel under self-draining conditions, determine the river channel cross-section type according to the river channel grade, calculate the river channel drainage width under the drainage standard according to the river channel cross-section type and the flood conveyance flow of the river channel, and generate a boundary of the planned river channel water area according to the river channel drainage width, the river channel center line, and the river channel side line;

[0120] A blue line demarcation module 304, configured to extend the boundary of the planned river channel water area by a first distance according to the three zones and three lines of the territorial space planning, the waterlogging risk grade, and the river channel grade to generate a river channel blue line.

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

[0122] A catchment area demarcation unit, configured to demarcate the catchment area of the river channel according to the DEM data;

[0123] A catchment area correction unit, configured to correct the catchment area of the river channel according to the river channel center line and the river channel side line so that there is no overlap between the river channel center line and the catchment area of the river channel;

[0124] A waterlogging grade demarcation unit, configured to demarcate the waterlogging risk grade of the catchment area of the river channel according to the waterlogging depth of historical waterlogging points; wherein, the waterlogging risk grade includes high risk and low risk.

[0125] Preferably, the dividing the river channel grade according to the flood conveyance flow of the river channel under self-draining conditions specifically includes:

[0126] Calculating the flood conveyance flow of each section of the river channel under self-draining conditions according to a preset river channel hydrodynamic model;

[0127] Normalizing the flood conveyance flow of each section of the river channel and calculating the flow standard value;

[0128] Dividing the river channel grade of each section of the river channel according to the flow standard value and a preset flow interval.

[0129] Preferably, the determining the river channel cross-section type according to the river channel grade, calculating the river channel drainage width under the drainage standard according to the river channel cross-section type and the flood conveyance flow of the river channel, and generating a boundary of the planned river channel water area according to the river channel drainage width, the river channel center line, and the river channel side line specifically includes:

[0130] Determining the river channel cross-section type according to the river channel grade; wherein, the river channel cross-section type includes trapezoidal cross-section and rectangular cross-section;

[0131] Calculating the river channel drainage width under the drainage standard by means of trial calculation according to the river channel cross-section type and the flood conveyance flow of the river channel;

[0132] Extend a second distance on both sides of the center line of the river channel to generate a preliminary boundary of the planned water area of the river channel; wherein, the second distance is determined according to the drainage width of the river channel;

[0133] Overlay the preliminary boundary of the planned water area of the river channel with the side line of the river channel, and take the outer envelope line as the final boundary of the planned water area of the river channel.

[0134] Preferably, the blue line demarcation module 304 is specifically configured to:

[0135] If the river channel is located in the agricultural space or ecological space in the territorial space planning, extend different first distances from the boundary of the planned water area of the river channel according to the river channel grade to generate the river channel blue line;

[0136] If the river channel is located in the urban space in the territorial space planning, extend different first distances from the boundary of the planned water area of the river channel according to the waterlogging risk level and the river channel grade to generate the river channel blue line;

[0137] Wherein, the first distance is proportional to the waterlogging risk level.

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

[0139] Overlay the river channel blue line with the current regulatory detailed plan, and judge whether the land use nature within the range of the river channel blue line is all water area or green land;

[0140] If so, there is no need to correct the river channel blue line;

[0141] If not, correct the first distance according to the width of the waterfront green land and the waterlogging risk level to correct the river channel blue line.

[0142] In specific implementation, the working principle, control process and achieved technical effects of the urban blue line demarcation device provided in the embodiments of the present invention are correspondingly the same as those of the urban blue line demarcation method in the above embodiments, and will not be elaborated here.

[0143] Please refer to Figure 4 , Figure 4 is a schematic structural 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, the urban blue line demarcation method described in any of the above embodiments is implemented.

[0144] Preferably, the computer program may 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 implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing specific functions, and these 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 may also be 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 also be any conventional processor. The processor 401 is the control center of the terminal device, and connects various parts of the terminal device through various interfaces and circuits.

[0146] The memory 402 mainly includes a program storage area and a data storage area. Among them, the program storage area may store an operating system, application programs required for at least one function, etc., and the data storage area may store relevant data, etc. In addition, the memory 402 may be a high-speed random access memory, or may also be a non-volatile memory, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc., or the memory 402 may also be other volatile solid-state storage devices.

[0147] It should be noted that the above terminal device may include, but is not limited to, a processor and a memory. Those skilled in the art can understand that Figure 4 the structural schematic diagram is only an example of the above terminal device, and does not limit the above terminal device. It may include more or fewer components than shown in the figure, or combine certain components, or different components.

[0148] The embodiment of the present invention also provides a computer-readable storage medium. The computer-readable storage medium includes a stored computer program, and when the computer program runs, it controls the device where the computer-readable storage medium is located to execute the urban blue line demarcation method described in any one of the above embodiments.

[0149] An embodiment of the present invention also provides a computer program product, which includes a computer program or computer instructions. When the computer program or the computer instructions are executed by a processor, the urban blue line demarcation method described in any of the above embodiments is implemented.

[0150] An embodiment of the present invention provides an urban blue line demarcation method, device, equipment, medium and computer program product. By obtaining remote sensing images and DEM data, the center line and the side line of the river are extracted from the remote sensing images; according to the DEM data, the center line and the side line of the river, the river catchment area is demarcated, and the waterlogging risk level of the river catchment area is demarcated; according to the river discharge capacity under self-drainage conditions, the river grade is divided, and according to the river grade, the river cross-section type is determined. According to the river cross-section type and the river discharge capacity, the river drainage width under the drainage standard is calculated. According to the river drainage width, the center line and the side line of the river, the planned water area boundary of the river is generated; according to the three zones and three lines of the national territorial space planning, the waterlogging risk level and the river grade, the river planned water area boundary is extended by a first distance to generate the river blue line. The embodiment of the present invention fully considers the waterlogging risk, connects with the three zones and three lines of the national territorial space planning, reduces the planning conflict between the river blue line and other land uses, is more conducive to promoting the integrated development of the city and water, and is also more operable and implementable.

[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 separated. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. In addition, in the drawings of the system embodiments provided by the present invention, the connection relationship between the modules indicates that they have a communication connection, which can be specifically implemented as one or more communication buses or signal lines. Those of ordinary skill in the art can understand and implement without creative work.

[0152] The above is the preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A method for delineating an urban blue line, characterized in that: include: Acquire remote sensing images and digital elevation model (DEM) data, and extract the river centerline and river edgeline from the remote sensing images; Delineating a river catchment area according to the DEM data, the river centerline, and the river boundary, and determining a waterlogging risk level of the river catchment area; Divide the river channel into grades according to the discharge flow of the river channel under the self-drainage condition, determine the river channel cross-sectional type according to the river channel grade, calculate the river channel drainage width under the drainage standard according to the river channel cross-sectional type and the river channel discharge flow, and generate the river channel planning water area boundary according to the river channel drainage width, the river channel centerline and the river channel sideline; According to the three zones and three lines of the national land space planning, the waterlogging risk level and the river level, the boundary of the planned river water area is extended by a first distance to generate a river blue line.

2. The urban blue line delineation method according to claim 1, characterized in that: Delineating the river catchment area according to the DEM data, the river centerline and the river boundary, and determining the waterlogging risk level of the river catchment area, specifically includes: Delineate the river catchment area according to the DEM data; The water collection range of the river channel is modified according to the center line of the river channel and the edge line of the river channel so that there is no overlap between the center line of the river channel and the water collection range of the river channel; The waterlogging risk level of the river catchment area is determined based on the water accumulation depth at historical waterlogging points; wherein the waterlogging risk level includes high risk and low risk.

3. The urban blue line delineation method according to claim 2, characterized in that: The river level classification according to the river discharge capacity under the self-drainage condition specifically includes: According to the preset river hydrodynamic model, calculate the river discharge flow of each section of the river under the self-drainage condition; Normalize the discharge flow of each section of the river and calculate the standard value of the flow; The river grade of each river section is divided according to the flow standard value and the preset flow range.

4. The urban blue line delineation method according to claim 3, characterized in that: Determining the cross-sectional form of the river channel according to the river channel grade, calculating the drainage width of the river channel under the drainage standard according to the cross-sectional form of the river channel and the discharge flow of the river channel, and generating the planned water area boundary of the river channel according to the drainage width of the river channel, the center line of the river channel and the river channel sideline, specifically includes: Determining a river channel cross-section type according to the river channel grade; wherein the river channel cross-section type includes a trapezoidal cross-section and a rectangular cross-section; Calculate the drainage width of the river channel under the drainage standard by trial calculation according to the cross-sectional type of the river channel and the discharge capacity of the river channel; Extending a second distance on both sides of the centerline of the river channel to generate a preliminary planned water boundary of the river channel; wherein the second distance is determined according to the drainage width of the river channel; The preliminary river planning water area boundary is superimposed with the river edge line, and the outer envelope is taken as the final river planning water area boundary.

5. The urban blue line delineation method according to claim 4, characterized in that: According to the three zones and three lines of the national land space planning, the waterlogging risk level and the river level, the river planning water boundary is extended by a first distance to generate a river blue line, specifically including: If the river is located in the agricultural space or ecological space in the national land space planning, then according to the river level, the water boundary of the river planning is extended by different first distances to generate a river blue line; If the river is located in the urban space in the national land space planning, then according to the waterlogging risk level and the river level, the planned water boundary of the river is extended by different first distances to generate a river blue line; Among them, the first distance is proportional to the waterlogging risk level.

6. The urban blue line delineation method according to claim 5, characterized in that: The method further comprises: Superimpose the river blue line with the current regulatory detailed plan to determine whether all the land within the river blue line is water or green land; If so, there is no need to amend the blue line of the said river; If not, the first distance is corrected according to the width of the waterfront green space and the level of waterlogging risk to correct the blue line of the river.

7. A device for delineating urban blue lines, characterized in that: include: A data acquisition module is used to acquire remote sensing images and DEM data, and extract the river centerline and river edgeline from the remote sensing images; A level delineation module is used to delineate the river catchment range according to the DEM data, the river centerline and the river edge line, and to delineate the waterlogging risk level of the river catchment range; A boundary delineation module is used to classify the river channel according to the discharge flow of the river channel under the self-drainage condition, and determine the cross-sectional type of the river channel according to the river channel grade, calculate the drainage width of the river channel under the drainage standard according to the cross-sectional type of the river channel and the discharge flow of the river channel, and generate the boundary of the river channel planning water area according to the drainage width of the river channel, the center line of the river channel and the side line of the river channel; The blue line delineation module is used to extend the boundary of the river planning water area by a first distance to generate a river blue line according to the three zones and three lines in the national land space planning, the urban flood risk level and the river level.

8. A terminal device, characterized in that: It includes a processor and a memory, wherein a computer program is stored in the memory, and the computer program is configured to be executed by the processor, and when the processor executes the computer program, the urban blue line delineation method as described in any one of claims 1 to 6 is implemented.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, wherein when the device where the computer-readable storage medium is located executes the computer program, the urban blue line delineation method as described in any one of claims 1 to 6 is implemented.

10. A computer program product, characterized in that The computer program product includes a computer program or computer instructions, and when the computer program or the computer instructions are executed by a processor, the urban blue line delineation method as described in any one of claims 1 to 6 is implemented.

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