Subway rainstorm waterlogging risk expression method

Abstract

The invention discloses a subway rainstorm waterlogging risk expression method, and the method comprises the steps: screening and determining subway disaster-bearing bodies according to subway components, and dividing the subway disaster-bearing bodies into a point type and a linear type; according to actual spatial scale characteristics of a point-shaped disaster-bearing body and a linear disaster-bearing body, by establishing a vector point buffer area and segmenting a vector line, rainstorm ponding depth raster data information is assigned to disaster-bearing body vector points and disaster-bearing body vector lines, and then subway rainstorm waterlogging risk expression is achieved. Scientific support can be provided for urban subway operation decision making.

Description

Technical Field

[0001] The present invention belongs to the technical field of atmospheric and environmental sciences, and particularly relates to a method for expressing the risk of rainstorm waterlogging in urban subways. Background Art

[0002] Frequent extreme rainfall events caused by climate change have led to urban waterlogging, and urban subways are more vulnerable to the impact of rainstorm waterlogging disasters, resulting in the phenomenon of backflow of accumulated water at the entrances and exits. In urban rail transit, subways account for more than 75%. Therefore, evaluating the risk of rainstorm waterlogging in urban subways and effectively expressing risk information are of great significance for preventing rainstorm waterlogging accidents in urban subways, maintaining the safe operation of cities, and protecting people's lives and property.

[0003] Existing urban rainstorm waterlogging simulations are based on raster data for operations, and the generated waterlogging depths are also raster data. The subway disaster-bearing bodies are summarized by geographical information and can be expressed in two vector data forms: points and lines. The data structures of vector data and raster data are different, and their scales and geometric shapes are completely different. Vector data is a logical abstraction of geographical information, while raster data is based on pixels (rasters), and multiple rasters are connected into a complete plane. How to assign the rainstorm waterlogging depth information stored in raster data to subway disaster-bearing bodies (point and line vector elements) and effectively express risks according to different disaster-bearing bodies is an important link in the risk assessment of subway rainstorm waterlogging. Summary of the Invention

[0004] Object of the Invention: Aiming at the technical problems existing in the prior art, the present invention provides a method for expressing the risk of rainstorm waterlogging in subways, which assigns the raster data information of rainstorm waterlogging depth to the vector points and vector lines of subway disaster-bearing bodies, thereby realizing the risk expression of subway rainstorm waterlogging and providing scientific support for meteorological disaster prevention and mitigation and urban subway operation decision-making.

[0005] Technical Solution: To achieve the above object of the invention, the present invention adopts the following technical solutions: A method for expressing the risk of rainstorm waterlogging in subways, comprising the following steps: Step S1, determination of subway disaster-bearing bodies: Taking ground lines, underground stations, ground stations, above-ground vehicle bases, and tunnel entrances as subway disaster-bearing bodies, and dividing the five subway disaster-bearing bodies into point-shaped disaster-bearing bodies and line-shaped disaster-bearing bodies; the point-shaped disaster-bearing bodies include underground stations, ground stations, above-ground vehicle bases, and tunnel entrances, and the line-shaped disaster-bearing body is the ground line; Step S2, risk grading of the impact of rainstorm waterlogging on subway disaster-bearing bodies: For different types of subway disaster-bearing bodies, according to the impact of the waterlogging depth on the subway disaster-bearing bodies, determine the risk level W of the impact of rainstorm waterlogging depth on the subway disaster-bearing bodies; Step S3, determination of the waterlogging depth of subway disaster-bearing bodies: (1)For point disaster-bearing bodies, a buffer is established with the vector points of subway disaster-bearing bodies as the center; the buffer is used as a vector envelope to intercept the grid data of urban rainstorm waterlogging depth, and the grid data of waterlogging depth within the buffer range of the vector points of subway disaster-bearing bodies is constructed; the maximum value of the waterlogging depth of all grids within the buffer range of the vector points of subway disaster-bearing bodies is assigned to the vector points of the subway disaster-bearing bodies as the waterlogging depth of the vector points of the subway disaster-bearing bodies. (2)For linear disaster-bearing bodies, the vector lines of linear disaster-bearing bodies are evenly divided into multiple line segments; and a midpoint buffer is established with the midpoint of each line segment as the center; the midpoint buffer of each line segment is used as a vector envelope to intercept the grid data of urban rainstorm waterlogging depth, and the grid data of waterlogging depth within the midpoint buffer range of each line segment is constructed; the maximum value of the waterlogging depth of all grids within the midpoint buffer range is assigned to the corresponding line segment as the waterlogging depth of the line segment. Step S4, determination of the waterlogging risk level of the subway disaster-bearing body: For different disaster-bearing bodies, the rainstorm waterlogging depth is converted into a risk level. Step S5, production of the spatial distribution map of subway rainstorm waterlogging risk: Using a geographic information system, for subway disaster-bearing bodies, different colors are assigned according to their rainstorm waterlogging risk levels for information display, and the spatial distribution map of subway rainstorm waterlogging risk is produced to realize the expression of risk information.

[0006] Furthermore, in step S2, for underground stations and ground stations in subway disaster-bearing bodies, the risk level affected by rainstorm waterlogging depth is determined by the following formula. , In the formula, W a represents the risk level of the underground station or the ground station, d represents the waterlogging depth, and the risk levels 1, 2, 3, 4, and 5 correspond to low risk, relatively low risk, medium risk, relatively high risk, and high risk in sequence. For above-ground vehicle bases and ground lines in subway disaster-bearing bodies, the risk level affected by rainstorm waterlogging depth is determined by the following formula. , In the formula, W b represents the risk level of the above-ground vehicle base or the ground line, d represents the waterlogging depth, and the risk levels 1, 2, 3, 4, and 5 correspond to low risk, relatively low risk, medium risk, relatively high risk, and high risk in sequence. For tunnel entrances in subway disaster-bearing bodies, the risk level affected by rainstorm waterlogging depth is determined by the following formula. , In the formula, W c represents the risk level of the tunnel entrance, d represents the waterlogging depth, and the risk levels 1, 2, 3, 4, and 5 correspond to low risk, relatively low risk, medium risk, relatively high risk, and high risk in sequence.

[0007] Further, in step S3, for the point-like disaster-bearing bodies, the buffer zone radius for the buffer zone between the underground station and the ground station is 300 m, the buffer zone radius for the above-ground vehicle base is 500 m, and the buffer zone radius for the tunnel entrance is 100 m.

[0008] Further, in step S3, the vector line of the linear disaster-bearing body is evenly divided into multiple line segments, with the line segment length being 30 - 50 m; the buffer zone radius for the midpoint of each line segment is 50 m.

[0009] Beneficial effects: Compared with the prior art, the subway rainstorm waterlogging risk expression method proposed by the present invention classifies subway disaster-bearing bodies into two categories, point-like and linear, according to the subway component elements. Based on the actual spatial scale characteristics of the point-like disaster-bearing bodies and the linear disaster-bearing bodies, by establishing a vector point buffer zone and dividing the vector line, the rainstorm waterlogging depth raster data information is assigned to the disaster-bearing body vector points and the disaster-bearing body vector lines, thereby realizing the expression of the subway rainstorm waterlogging risk. The results can provide scientific support for urban subway operation decision-making. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic flow chart of the subway rainstorm waterlogging risk expression method described in the present invention.

[0011] Figure 2 It is a map of the waterlogging risk of Nanjing subway stations under the rainstorm scenario with a return period of 100 a in the embodiment of the present invention.

[0012] Figure 3 It is a map of the waterlogging risk of Nanjing subway vehicle bases under the rainstorm scenario with a return period of 50 a in the embodiment of the present invention.

[0013] Figure 4 It is a map of the waterlogging risk of Nanjing subway tunnel entrances under the rainstorm scenario with a return period of 3 a in the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] The following further clarifies the present invention in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. After reading the present invention, various equivalent modifications made by those skilled in the art to the present invention all fall within the scope defined by the appended claims of this application.

[0015] As Figure 1 shown, the technical idea and process of the subway rainstorm waterlogging risk expression method of the present invention are introduced in detail as follows: S1, Determination of subway disaster-bearing bodies The subway is split according to its constituent elements. Taking whether each element will be exposed to urban land surface water as the criterion, the subway disaster-bearing bodies are determined. The subway consists of 4 elements, namely: subway lines, subway stations, vehicle bases, and tunnel entrances. Subway lines include underground lines, surface lines, and elevated lines; subway stations include underground stations, surface stations, and elevated stations; vehicle bases include underground vehicle bases and above-ground vehicle bases; and tunnel entrances.

[0016] When urban land surface water accumulates due to heavy rain, there is no risk of waterlogging for the elevated lines and elevated stations of the subway. Without considering engineering water leakage, there is also no risk of waterlogging for underground lines and underground vehicle bases. Therefore, the subway disaster-bearing bodies are: surface lines, underground stations (with their entrances on the ground), surface stations, above-ground vehicle bases, and tunnel entrances, a total of 5 disaster-bearing bodies. These subway disaster-bearing bodies can be expressed in geographical information and can be expressed as two vector data forms: points and lines. Among them, underground stations, surface stations, above-ground vehicle bases, and tunnel entrances can be represented by point vectors and are called point disaster-bearing bodies (disaster-bearing body vector points); surface lines can be represented by line vectors and are called line disaster-bearing bodies (disaster-bearing body vector lines).

[0017] S2, Risk grading of the impact of rainstorm waterlogging on subway disaster-bearing bodies

[0018] For different subway disaster-bearing bodies, the construction specifications are different, and the tolerance to waterlogging is also different. Combining with the "Code for Design of Metro GB 50157 - 2013", the risk levels of the impact of rainstorm waterlogging on different subway disaster-bearing bodies are determined, as shown in Table 1: Table 1 Risk grading of the impact of rainstorm waterlogging on urban subway disaster-bearing bodies

[0019] S3, Determination of the waterlogging depth of point-shaped subway disaster-bearing bodies

[0020] (1) On the basis of comprehensively considering the actual spatial ranges of various point-shaped disaster-bearing bodies, buffer zones are established for the disaster-bearing body vector points according to a certain range radius. The buffer zone range radius is shown in Table 2: Table 2 Impact range of rainstorm waterlogging on point-shaped subway disaster-bearing bodies

[0021] (2) Taking the buffer zone of the disaster-bearing body vector points as a vector mask, the urban rainstorm waterlogging depth raster data is intercepted.

[0022] (3) Adhering to the principle of taking the higher risk for prevention, the highest value of the raster waterlogging depth within the buffer zone range of the disaster-bearing body vector points is assigned to the disaster-bearing body vector points as the waterlogging depth of the disaster-bearing body vector points.

[0023] S4, Determination of the waterlogging depth of line-shaped subway disaster-bearing bodies

[0024] (1) Uniformly divide the vector line of the disaster-bearing body into multiple line segments, that is: split a vector line feature into multiple vector line features, and the line segment length can be taken as 30 - 50m.

[0025] (2) Obtain the midpoint (vector point feature) of each line segment;

[0026] (3) Establish a buffer zone for the midpoint of each line segment (abbreviation: midpoint buffer zone) according to a certain range radius, and the buffer zone range radius is 50m.

[0027] (4) Use each line segment midpoint buffer zone as a vector mask to intercept the urban rainstorm waterlogging depth raster data, and construct the waterlogging depth raster data within the range of each line segment midpoint buffer zone.

[0028] (5) Adhering to the principle of taking the higher risk for prevention, assign the highest value of the waterlogging depth of all raster cells within the midpoint buffer zone to the corresponding line segment (vector line feature).

[0029] S5, Determination of the risk level of the subway disaster-bearing body's waterlogging: According to Table 1, convert the waterlogging depth of the subway disaster-bearing body into a risk level.

[0030] S6, Production of the subway rainstorm waterlogging risk spatial distribution map: Using a geographic information system, for the subway disaster-bearing body, according to its rainstorm waterlogging risk level, assign different colors for information display, produce the subway rainstorm waterlogging risk spatial distribution map, and realize the expression of risk information.

[0031] Note: Draw maps separately for different types of disaster-bearing bodies; in order to maintain the integrity and coherence of the map information, for the subway elevated lines, elevated stations, underground lines, and underground vehicle bases that are not disaster-bearing bodies, directly assign the lowest risk color scale.

[0032] Embodiment

[0033] Taking the Nanjing subway as an example, illustrate the implementation process of the present invention. The research area covers: the main city of Nanjing and some surrounding areas, specifically including parts of Xuanwu District, Gulou District, Qinhuai District, Jianye District, Yuhuatai District, Pukou District, Jiangning District, Qixia District, and Liuhe District. The main subway disaster-bearing bodies in this research area are: surface stations, underground stations, surface vehicle bases, and tunnel entrances. There are very few subway surface lines, mainly the parts connected to the above-ground vehicle bases, which are ignored.

[0034] According to the urban rainstorm waterlogging model, calculate and obtain the raster waterlogging depth with a resolution of 30m × 30m under different return period rainstorm scenarios in the research area. According to the implementation steps of the present invention, determine the waterlogging depth of the subway disaster-bearing body in the research area under different rainstorm scenarios, and then obtain the risk level of the subway disaster-bearing body under different return period rainstorm scenarios, and produce the Nanjing subway rainstorm waterlogging risk spatial distribution map. The sample map is shown in Figures 2 - 4 .

[0035] Inspired by the above ideal embodiments of the present invention, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A method for expressing subway rainstorm waterlogging risk, characterized in that The following steps are involved: S1, the subway disaster-bearing body is determined, and the ground line, underground station, ground station, ground vehicle base and tunnel entrance are taken as the subway disaster-bearing body, and the five types of subway disaster-bearing bodies are divided into point-shaped disaster-bearing bodies and linear disaster-bearing bodies; the point-shaped disaster-bearing bodies include underground stations, ground stations, ground vehicle bases and tunnel entrances, and the linear disaster-bearing body is the ground line; S2, risk grading of the impact of rainstorm waterlogging on subway disaster-bearing bodies. For different types of subway disaster-bearing bodies, the risk level W of the impact of rainstorm waterlogging depth on subway disaster-bearing bodies is determined according to the impact of waterlogging depth on subway disaster-bearing bodies; S3, the water depth of the subway disaster-bearing volume is determined, (1) For point-shaped disaster-prone bodies, a buffer zone is established with the subway disaster-prone body vector point as the center; the buffer zone is used as a vector mask to intercept the urban rainstorm water depth raster data and construct the water depth raster data within the subway disaster-prone body vector point buffer zone; the highest value of all raster water depth within the subway disaster-prone body vector point buffer zone is assigned to the subway disaster-prone body vector point as the water depth of the subway disaster-prone body vector point; (2) For linear disaster-prone bodies, the vector lines of the linear disaster-prone bodies are evenly divided into multiple line segments; and a midpoint buffer zone is established with the midpoint of each line segment as the center; the midpoint buffer zone of each line segment is used as a vector mask to intercept the urban rainstorm water depth raster data and construct the water depth raster data within the midpoint buffer zone of each line segment; the highest value of the water depth of all grids within the midpoint buffer zone is assigned to the corresponding line segment as the water depth of the line segment; S4. The waterlogging risk level of the subway disaster-bearing body is determined. For different disaster-bearing bodies, the depth of rainstorm water is converted into risk level.

2. The method for expressing subway rainstorm waterlogging risk according to claim 1, characterized in that: In step S2, For underground stations and ground stations in the subway disaster-bearing body, the risk level of the impact of rainstorm water depth is determined by the following formula: ， Where W a Indicates the risk level of underground stations or ground stations, d indicates the depth of water accumulation, and risk levels 1, 2, 3, 4, and 5 correspond to: low risk, lower risk, medium risk, higher risk, and high risk; For the ground vehicle base and ground lines in the subway disaster-bearing body, the risk level of the impact of rainstorm water depth is determined by the following formula: ， Where W b Indicates the risk level of the ground vehicle base or ground line, d indicates the depth of water accumulation, and risk levels 1, 2, 3, 4, and 5 correspond to: low risk, lower risk, medium risk, higher risk, and high risk; For the tunnel entrance in the subway disaster-bearing body, the risk level of the impact of the depth of rainstorm water accumulation is determined by the following formula: ， Where W c It indicates the risk level of the tunnel entrance, d indicates the depth of water accumulation, and the risk levels 1, 2, 3, 4, and 5 correspond to: low risk, lower risk, medium risk, higher risk, and high risk.

3. The method for expressing subway rainstorm waterlogging risk according to claim 1, characterized in that: In step S3, the buffer zone radius of the point-shaped disaster-bearing body is 300m for the underground station and the ground station, 500m for the ground vehicle base, and 100m for the tunnel entrance.

4. The method for expressing subway rainstorm waterlogging risk according to claim 1, characterized in that: In step S3, the linear disaster-bearing body vector line is evenly divided into multiple line segments with a line segment length of 30-50m; the buffer zone radius of the middle point of each line segment is 50m.

5. The method for expressing subway rainstorm waterlogging risk according to claim 1, characterized in that: The process also includes step S5, which uses the geographic information system to assign different colors to the subway disaster-prone bodies according to their rainstorm waterlogging risk levels for information display, and to produce a subway rainstorm waterlogging risk spatial distribution map to express risk information.

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