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CN-122021424-A - Urban bad ventilation area diagnosis method based on typhoon wind field-building group coupling effect

CN122021424ACN 122021424 ACN122021424 ACN 122021424ACN-122021424-A

Abstract

The invention relates to the technical field of urban planning and meteorological disaster prevention, and particularly discloses a method for diagnosing urban bad ventilation areas based on typhoon wind field-building group coupling effect. Firstly, accurately simulating a typhoon wind field based on a WRF mode and an optimal urban canopy model, and secondly, embedding an optimal Urban Canopy Model (UCM) scheme into the WRF to realize urban scale simulation under the driving of three-dimensional building parameters. Thirdly, constructing high-quality boundary conditions by combining classical wind profile functions, driving block scale CFD simulation, and quantitatively evaluating dynamic influence of building density, height and layout on a near-ground wind field. And finally, providing a city morphology grading optimization strategy based on the simulation result. The invention can diagnose the bad ventilation area in the city, obviously improve the safety of the local wind environment through the optimization strategy, improve the proportion of the static wind area by 2-13 percentage points, reduce the proportion of the strong wind area by 4-7 percentage points, and provide an effective tool for the typhoon-resistant design of coastal cities.

Inventors

  • ZHOU XIN
  • SHEN XIAOHAN
  • Lin boya

Assignees

  • 东南大学

Dates

Publication Date
20260512
Application Date
20260123

Claims (6)

  1. 1. A city bad ventilation area diagnosis method based on typhoon wind field-building group coupling effect is characterized by comprising the following steps: S1, constructing a high-precision city parameterized database; step S2, dynamically simulating a multi-scale typhoon wind field, namely driving a mesoscale meteorological model WRF-UCM and a computational fluid dynamics model CFD by using the database to realize the refined simulation of the typhoon wind field from the city scale to the neighborhood scale; s3, quantitatively diagnosing the poor ventilation area, quantifying wind environment evaluation indexes based on the block scale simulation result, and diagnosing the poor ventilation area with the coexistence of the static wind area and the strong wind area through correlation analysis And S4, urban morphology hierarchical optimization and effect verification, namely, based on the diagnosis result and the correlation analysis conclusion in the step S3, formulating a hierarchical optimization strategy for covering macro urban planning and micro neighborhood morphology.
  2. 2. The urban bad ventilation area diagnosis method based on typhoon-building group coupling effect is characterized by comprising the steps of s1 generating a local climate partition map based on remote sensing images and GIS data by adopting a random forest algorithm, verifying, dividing a research area into 100M x 100M regular grids, calculating multidimensional urban morphological parameters of each grid, including a primary index and a derivative index, and fusing a local climate area LCZ map with the multidimensional urban morphological parameters to construct an urban parameterized database with spatial resolution of not less than 100 meters for driving a meteorological model.
  3. 3. The method for diagnosing a poor urban ventilation area based on typhoon-building group coupling according to claim 1, wherein the step S2 comprises the following steps: S2.1, large-scale climate simulation, namely updating the underlying surface parameters of a WRF mode by using the database constructed in the step S1, adopting a multi-layer bidirectional nested grid, selecting a BL physical parameter scheme to solve an optimal model of atmospheric turbulence, and obtaining a typhoon atmospheric boundary; S2.2 medium-scale city simulation, namely selecting a resolution grid dx=1 km and dy=2 km as a WRF mode reference grid system, coupling a multi-layer city canopy model MLUCM scheme, and simulating the whole typhoon process to obtain high space-time resolution wind field data of a city scale; S2.3, small-scale block simulation, namely extracting the wind field data of a typical height reference system of a 10m low-rise building, a 40m middle-rise building and a 100m high-rise building obtained by the simulation in the step S2.1, and obtaining the atmospheric boundary layer friction speed of the key parameter of the atmospheric boundary layer by fitting a logarithmic wind speed profile formula, wherein the atmospheric boundary layer friction speed is used as an inlet boundary condition of a computational fluid dynamics model, and the formula is as follows: and wherein: Height coordinates (meters); Pneumatic rough length (meter); The value of von Kamen constant is 0.41 or 0.42; atmospheric boundary layer friction speed (m/s); In addition, turbulent kinetic energy profile ) And turbulent dissipation ratio profile ) The friction speed of the atmospheric boundary layer is calculated; ; Wherein, the method comprises the steps of, A zero static pressure condition is defined as an outflow boundary condition; the MLUCM m height simulation wind speed output is selected as a reference value for calculating the friction speed of the boundary layer, and the formula is as follows: Wherein: In order to achieve the atmospheric friction speed, For the reference altitude wind speed, For the reference height to be used, Is the surface roughness length.
  4. 4. Based on Jiangjiang area LCZ map drawn by the GIS platform in the step S1, calculating city form index parameters of various types of streets, wherein the city form index parameters comprise a first-layer building area SF, a building perimeter L, a building density lambada p, a street aspect ratio ZH, an average building height H and a sky-opening width SVF, city form derivative indexes comprise a windward area index lambada f (z) and an absolute fold rate Hm, 10 typical streets models reflecting city forms are constructed, CFD geometric models are constructed, grid division is carried out, CFD simulation is carried out, three-dimensional wind field distribution of streets is obtained, and dynamic influence of three-dimensional building form parameters on a near-ground wind field is quantized.
  5. 5. The urban bad ventilation area diagnosis method based on typhoon-building group coupling effect is characterized by comprising the steps of calculating wind environment evaluation indexes of different height layers based on block scale three-dimensional wind field data, including average wind speed, static wind area ratio, strong wind area ratio and wind speed dispersion, quantifying statistical relations between the wind environment evaluation indexes and multidimensional urban morphological parameters by adopting a correlation analysis method, diagnosing bad ventilation areas with the static wind area and the strong wind area coexisting and high wind speed dispersion according to the statistical relations, and obtaining urban scale wind field data under the influence of typhoons by means of a multi-scale typhoon wind field simulation step based on a mesoscale meteorological mode WRF coupling urban canopy model UCM.
  6. 6. The urban bad ventilation area diagnosis method based on typhoon wind field-building group coupling effect according to claim 1, wherein the step S4 is characterized in that the strategy is applied to the selected high-risk area, and the effectiveness of the optimization strategy is verified by repeating the steps S2 and S3 and comparing wind environment evaluation indexes before and after optimization.

Description

Urban bad ventilation area diagnosis method based on typhoon wind field-building group coupling effect Technical Field The invention belongs to the technical field of urban planning and typhoon weather disaster prevention, and particularly relates to a method for diagnosing urban bad ventilation areas based on typhoon wind field-building group coupling effect. Background Typhoons are major natural disasters facing coastal cities, and accurately simulate and evaluate the near-ground wind fields of the typhoons, so that the typhoons have important application values for urban disaster prevention and reduction, wind resource utilization and building structure safety. Therefore, the development of a high-precision typhoon near-ground wind field simulation method has urgent practical significance for improving the urban toughness. Currently, numerical simulation is a main technical means for researching typhoon wind farms. At the mesoscale level, weather research and forecasting modes and the like are widely applied to simulating typhoon paths and macroscopic wind field structures. At the block building scale, the computational fluid dynamics model is then used to resolve the fine flow fields around the building complex. In recent years, the idea of combining a mesoscale mode with a diagnostic mode or a CFD model to achieve both simulation range and accuracy has become an important research direction. For example, the WRF mode is coupled with the CALMET diagnostic mode in order to obtain a higher resolution wind field. However, the prior art solutions still have significant limitations. Firstly, the resolution ratio of the mesoscale mode is coarse, and a fine disturbance mechanism of three-dimensional city morphological parameters such as building density, street layout, sky opening width and the like on a wind field is difficult to accurately represent. Secondly, CFD simulation is often limited in computational efficiency when applied to urban scales, and the entrance boundary conditions of the CFD simulation often depend on idealized assumptions or sparse meteorological observation data, so that a dynamic wind field structure under extreme weather, such as typhoons, is difficult to truly reflect, and the reliability and the practicability of simulation results are limited. More importantly, the existing research focuses on wind field simulation per se or only performs isolated form-wind field correlation analysis, and fails to form complete technical closed loops from multi-scale fine simulation to quantitative diagnosis of poor ventilation areas and to targeted form optimization, so that accurate and quantifiable decision support cannot be provided for urban typhoon resistance planning and design. Disclosure of Invention In order to solve the problems, the invention discloses a method for diagnosing a poor ventilation area of a city based on typhoon wind field-building group coupling effect, which aims to solve the technical problems that the influence of three-dimensional city forms on the wind field near the ground of typhoon is difficult to finely quantify, and the poor ventilation area cannot be systematically diagnosed and optimized in the prior art. A method for diagnosing a poor urban ventilation area based on typhoon wind field-building group coupling effect, comprising the following steps: S1, constructing a high-precision urban parameterized database, namely constructing the urban parameterized database fusing local climate zones and multidimensional urban morphological parameters based on multi-source geospatial data; S2, a multi-scale typhoon wind field coupling simulation step, namely driving a mesoscale meteorological model WRF-UCM and a computational fluid dynamics model RFD by using the database to realize the refined simulation of the typhoon wind field from the city scale to the neighborhood scale; S3, quantitatively diagnosing the poor ventilation area, namely quantifying wind environment evaluation indexes based on a block scale simulation result, and diagnosing the poor ventilation area with the coexistence of the static wind area and the strong wind area through correlation analysis; And S4, a city morphology grading optimization step, namely, based on a diagnosis result, proposing and verifying a targeted city morphology grading optimization strategy. Optionally, in the step S1, the multi-source geospatial data includes Landsat-8 remote sensing images, FNL global weather re-analysis data, SRTM topographic data, and three-dimensional building vector data. The urban parameterized database is built by adopting WUDAPT-LCZ and GIS platform integrated drawing strategy and random forest algorithm to generate local climate zone map of the research area; defining a research area, namely accurately defining a square research area through the space positioning function of a Google Earth platform, and meeting the requirement of a mesoscale meteorological model on the space continuity of underlying