A numerical simulation prediction method, system, and medium for determining the reconstruction and maintenance duration of a double-wall structure affected by terrain interference.

Abstract

This invention discloses a numerical simulation prediction method, system, and medium for determining the re-establishment and duration of double-eyewall typhoon structures under terrain interference, relating to the field of fine-scale typhoon structural evolution characterization and numerical simulation technology. This invention identifies double-eyewall typhoons through multi-source data fusion and constructs a high-resolution numerical simulation system. Based on vertical wind shear phase bounded analysis, the typhoon structure is divided into four quadrants according to the wind shear direction for differentiated diagnosis. The distribution characteristics of rapidly vortex-filamentation regions are captured by calculating vortex filamentation time parameters. A trench downdraft airflow detection mechanism is established, and tangential wind budget analysis is used to quantitatively assess the contributions of radial advection, tangential advection, vertical advection, and friction terms to tangential wind evolution. The energy growth rate is calculated to predict the duration of the double-eyewall formation. This invention outputs the determination of outer eyewall re-formation, the predicted outer eyewall radius band and duration interval, and uncertainty, applicable to real-time operational and research applications.

Description

Technical Field

[0001] This invention belongs to the field of typhoon fine structure evolution characterization and numerical simulation technology, and involves typhoon concentric eyewall evolution diagnosis, quadranted energy-momentum analysis and multi-source data and model field fusion. Specifically, it is a numerical simulation prediction method, system and medium for determining the re-formation and duration of typhoon eyewall structure after terrain interference, which is used to determine the re-formation and duration of typhoon eyewall structure after terrain interference. Background Technology

[0002] Typhoons occur over tropical or subtropical oceans and have complex internal structures, typically consisting of a warm-core low-pressure vortex system composed of a vigorous convection core and an outer spiral rainband. The eyewall is the most important part of the typhoon's structure, with gales and torrential rain of force 12 or higher primarily occurring within its eyewall region. The double eyewall process of a typhoon refers to the formation and subsequent replacement of the typhoon's eyewall (main eyewall or inner eyewall) and secondary eyewall (or outer eyewall). This is a significant phenomenon in typhoon development, characterized by the formation of a nearly circular convective ring by the outer spiral rainband of a strong typhoon at a distance of 2-3 times its maximum wind speed radius. Simultaneously, a second maximum tangential wind speed is generated and intensified, forming a second maximum wind speed radius. As the outer eyewall forms, the inner eyewall gradually weakens and eventually disappears. The second maximum tangential wind speed radius and the outer eyewall gradually shrink and replace the original maximum tangential wind speed radius and inner eyewall, becoming the new main eyewall, thus completing the eyewall replacement process. This process typically leads to typhoon intensity experiencing a cycle of weakening and then strengthening, and significantly expands the storm's strong wind radius, directly impacting risk assessment and emergency response in maritime operations and coastal areas.

[0003] Although most typhoon eyewalls originate in relatively strong and symmetrical typhoons, and their formation is often related to the activity of spiral rainbands, the complexity of the eyewall process has led to a lack of consensus on its formation mechanism. Many studies have focused on the dynamic and thermodynamic processes of the vortex itself, as well as the small- and medium-scale convective systems within the typhoon vortex, proposing several hypotheses regarding the formation mechanism of the typhoon eyewall and its subsequent replacement process. These hypotheses encompass both axisymmetric and asymmetric processes, as well as equilibrium and non-equilibrium dynamic processes. The typhoon eyewall can be triggered by internal thermodynamic processes or by external forcing, such as topographic forcing, upper tropospheric eddy momentum forcing, the settling, dissolution, and evaporation of upper tropospheric outflow condensates outside the main eyewall to form cold pools and block boundary layer inflows into the main eyewall, and the corrosive effect of variations in the Coriolis parameter with latitude and vertical wind shear on the environment. Existing research has yielded many new insights into the formation mechanism of the outer eyewall, but most of these studies are based on idealized case studies. In reality, typhoon structures are complex and variable, and are often influenced by topographical and underlying surface factors. The axisymmetry process of the asymmetric outer spiral rainband is crucial for the formation of the outer eyewall, and related research mainly focuses on how the asymmetric rainband evolves into a quasi-symmetric convective ring—the outer eyewall. However, there is still a lack of understanding and reasonable analysis regarding the regeneration of the outer eyewall structure after being damaged by external environmental influences.

[0004] The development of typhoons with double eyewall structures is influenced not only by the typhoon itself but also by the external environment. Most studies on double eyewalls begin from scratch, neglecting to investigate how the outer eyewall reforms during the intermediate stages of double eyewall formation. The Northwest Pacific is the most typhoon-prone sea area globally, containing numerous important island formations. When typhoons with double eyewall structures encounter these formations while moving westward or northwestward, the double eyewall structure often undergoes significant deformation due to the obstruction, friction, and destructive effects of the terrain. Current typhoon numerical forecasting models have significant shortcomings in handling double eyewall processes. They lack systematic diagnostic methods and prediction techniques for the damage and reconstruction processes of double eyewall structures under the influence of terrain, particularly in quantitatively predicting the likelihood and duration of double eyewall re-establishment.

[0005] In summary, whether the double-wall structure of a typhoon can re-establish itself and for how long after terrain interference occurs are crucial issues affecting the accuracy of typhoon intensity prediction. Therefore, developing a numerical simulation prediction method that can consider the influence of terrain and accurately determine whether the double-wall structure of a typhoon can re-form and predict its duration is a pressing technical problem to be solved in current typhoon research. Summary of the Invention

[0006] (a) Purpose of the invention

[0007] To address the aforementioned deficiencies and shortcomings of existing technologies, this invention aims to provide a numerical simulation prediction method, system, and medium for determining the reconstruction probability and duration of typhoon double-wall structures under terrain interference. By establishing a typhoon structure diagnostic system based on vertical wind shear quadrant analysis, and combining path and terrain influence analysis, wind shear quadrant quadrant diagnosis, rapid vortex formation region identification, downdraft detection, tangential wind momentum budget analysis, and quadrant energy growth rate assessment, a multi-parameter comprehensive determination and duration prediction framework based on energy growth rate is constructed. This enables objective prediction of the reconstruction probability and quantitative estimation of the duration of typhoon double-wall structures under terrain interference, demonstrating significant application value and engineering promotion potential.

[0008] (II) Technical Solution

[0009] To achieve the objective of this invention and solve its technical problems, the present invention adopts the following technical solution:

[0010] The first objective of this invention is to provide a numerical simulation prediction method for determining the re-establishment and duration of the outer eyewall structure after a typhoon is disturbed by terrain. This method is used to objectively determine and quantitatively predict whether the outer eyewall will re-form and its duration after the inner and outer eyewalls merge to form a thick eyewall when the typhoon crosses island-like terrain. The method includes at least the following steps:

[0011] S100. Typhoon double-wall structure identification: Acquire and fuse multi-source observation and numerical model output field data, identify and determine whether the target typhoon has generated a double-wall structure on the ocean surface. When the radial wind speed profile and image features meet the double-wall discrimination criteria, the typhoon is confirmed to have a double-wall structure; otherwise, the subsequent process is terminated.

[0012] S200. Typhoon Path and Topographic Impact Assessment: Obtain forecast data of the movement path of typhoons with confirmed double-wall structures, analyze the spatial relationship between the typhoon center's movement trajectory and the island topography, determine whether the double-wall typhoon will pass through or has already passed through the island topographic impact area, and initiate the double-wall structure reconstruction prediction process when the typhoon path meets the island topographic interference conditions; otherwise, terminate the subsequent prediction process.

[0013] S300. Construction of high-resolution numerical simulation system: A high-resolution numerical simulation system with multiple nested grids is established for double-wall typhoons affected by island topography. The innermost grid has the highest resolution and covers the core area of ​​the typhoon and the surrounding preset range. A physical parameterization scheme suitable for typhoon fine structure simulation is configured, and the typhoon vortex structure is initialized with high-precision topographic data and sea surface temperature field to ensure accurate simulation of the interaction between the typhoon and the topography.

[0014] S400. Vertical wind shear phase boundary analysis: Based on the three-dimensional wind field data output by numerical simulation, the direction and intensity of the vertical wind shear vector in the typhoon environment are calculated. A relative coordinate system is established according to the direction of the vertical wind shear, and the typhoon structure is divided into the left quadrant of upwind shear, the right quadrant of upwind shear, the left quadrant of downwind shear, and the right quadrant of downwind shear. The differences in dynamic and thermodynamic characteristics in each quadrant are analyzed, and the dominant quadrant that is conducive to the reconstruction of the outer eyewall is identified.

[0015] S500. Rapid vortex formation region identification and localization: Calculate the vorticity field and strain rate tensor distribution at each height layer inside the typhoon, use the rapid vortex formation time discriminant formula to identify regions where the rapid vortex formation time is less than the adaptive threshold, locate potential outer eyewall formation advantage regions, analyze the spatial distribution characteristics and the correspondence between the vertical wind shear quadrants, and determine the candidate radius zone for outer eyewall reconstruction when the rapid vortex formation region is concentrated in the left quadrant of the downwind shear.

[0016] S600. Detection of downdraft in trench area between eyewalls: Based on vertical velocity field data from numerical simulation, the intensity, horizontal distribution range, and duration of downdraft are detected in the annular trench area between the inner and outer eyewalls of a typhoon. A threshold for downdraft intensity and a minimum duration threshold are set. The percentage of grid points that meet the threshold conditions in the total number of grid points in the trench area is counted and accumulated over time windows. When the coverage ratio and duration of downdraft reach the preset conditions at the same time, it is determined to be a dynamic condition conducive to the formation and maintenance of the trench area.

[0017] S700. Tangential wind budget diagnosis and structural transition identification: Within the annulus containing the radius of the trench and the candidate outer eyewall, the contribution of radial and vertical advection to the increase of tangential wind in the inner and outer eyewall regions is determined by the tangential wind diagnostic analysis equation; when radial or vertical advection is dominant in the left quadrant of the downwind shear, tangential advection is dominant in the left quadrant of the upwind shear, and tangential jets appear at the downwind end, resulting in a significant decrease or sign change in the radial velocity of the boundary layer inflow, it is determined that a structural transition from inner wall dominance to outer wall dominance has occurred;

[0018] S800. Energy Growth Rate Assessment and Duration Estimation: The Energy Growth Rate (EGR) is calculated for the candidate outer eyewall radius zone. EGR is defined as the difference between surface enthalpy flux energy production and frictional dissipation and is integrally performed in the circumferential direction. When EGR remains positive within a preset time window and matches the convection asymmetry, it is predicted that the double eyewall structure can be maintained. A duration estimation model is established based on the magnitude and trend of EGR, and the quantitative results of the outer eyewall duration are output.

[0019] S900. Multi-parameter integrated judgment and prediction result output: When the comprehensive conditions of the rapid vortex formation region being dominated by the left quadrant of the downwind shear, the trench subsidence environment being established, the momentum balance being a combination of the target quadrants and the occurrence of tangential jet triggering, and the candidate radius zone having a positive and continuous EGR are simultaneously met, the judgment result of the re-formation of the outer eyewall and the duration range of its maintenance are output.

[0020] The second objective of this invention is to provide a numerical simulation prediction system for determining and maintaining the reconstructed structure of a double-walled structure under terrain interference, comprising multiple modules for performing the aforementioned numerical simulation prediction method for determining and maintaining the reconstructed structure of a double-walled structure under terrain interference.

[0021] The third objective of this invention is to provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned numerical simulation prediction method for determining and maintaining the reconstructed double-wall structure under terrain interference.

[0022] (III) Technical Effects

[0023] Compared with the prior art, the numerical simulation prediction method, system and medium for determining the reconstruction and maintenance duration of a double-wall structure under terrain interference in this invention have the following beneficial and significant technical effects:

[0024] (1) This invention accurately captures the physical mechanism of outer eyewall reconstruction by fusing vertical wind shear phase boundary analysis and rapid vortex filamentation region identification. Verification cases show that this method can effectively identify the rapid vortex filamentation region establishment process in the left quadrant of the upper shear and the subsidence motion characteristics in the right quadrant of the upper shear, providing a reliable dynamic diagnostic basis for outer eyewall reformation and significantly improving the predictive ability of typhoon structure changes in complex terrain environments.

[0025] (2) This invention employs tangential wind budget diagnostic technology to accurately identify the transition process of the double eyewall structure. By quantitatively analyzing the contributions of radial advection, tangential advection, vertical advection, and friction, the critical transition moment from inner eyewall dominance to outer eyewall dominance is accurately determined. Verification results show that this method can effectively distinguish the differences in tangential wind enhancement mechanisms in different quadrants, especially the radial-vertical advection-dominated mode in the lower left quadrant of the shear and the tangential advection-dominated mode in the upper left quadrant of the shear, providing a reliable dynamic discrimination criterion for the evolution process of the double eyewall.

[0026] (3) The energy growth rate assessment model established in this invention enables quantitative prediction of the duration of the concentric eyewall structure. Based on the physical mechanism of the balance between surface enthalpy flux and frictional dissipation, the duration of the concentric eyewall structure is accurately estimated through spatiotemporal evolution analysis of multi-quadrant energy distribution. In the case of Typhoon Doksuri, the predicted duration was 36-42 hours, with the prediction error controlled within 6 hours, providing important support and technical guarantee for typhoon prediction and disaster prevention and mitigation. Attached Figure Description

[0027] Figure 1 The diagram shows a flowchart of the numerical simulation prediction method for determining and maintaining the reconstruction duration of a double-wall structure under terrain interference provided in an embodiment of the present invention.

[0028] Figure 2 The image shows the time evolution sequence of radar reflectivity simulated for Typhoon Doksuri, displaying the radar reflectivity distribution at an altitude of 3 km (shaded, unit: dBZ) at 3-hour intervals. (a) shows the reflectivity distribution after 3 hours of simulation; (b) shows the distribution after 6 hours of simulation, where convective activity mainly occurs on the windward slope of the terrain; (c) shows the distribution after 9 hours of simulation, where discrete convective cells gradually organize into a wavenumber-1 asymmetric rainband structure; and (d) shows the distribution after 12 hours of simulation, where the spiral rainband has occupied the high reflectivity regions of all three quadrants, transforming into an approximate outer eyewall structure.

[0029] Figure 3 This is a time-series diagram of simulated radar reflectivity evolution for Typhoon Doksuri, in the same format as... Figure 2 The same applies, where (e) to (h) represent the formation process of the standard concentric eyewall structure after 15-24 hours of simulation. The black arrows indicate the direction and magnitude of the wind shear vector at a height of 3km.

[0030] Figure 4 To simulate the vertical wind shear phase boundary analysis diagram after 3 hours, (a)-(d) represent the inertial stability (10) of the downshear right (DR), upshear right (UR), downshear left (DL), and upshear left (UL) quadrants, respectively. -4 s -1 (shading) and adiabatic heating (K h) -1 Distribution of contour lines.

[0031] Figure 5 To simulate the vertical wind shear phase limit analysis diagram after 3 hours, the format is the same as... Figure 4 The same applies, where (e) to (h) correspond to the radial inflow (ms) in each quadrant. -1 (shadow) and vertical velocity (ms) -1Distribution of contour lines.

[0032] Figure 6 To simulate the vertical wind shear phase limit analysis diagram after 9 hours, the format is the same as... Figure 4 The same, but the time advances to 9 hours. Among them, (a)~(d) show the evolution characteristics of inertial stability and adiabatic heating in each quadrant.

[0033] Figure 7 To simulate the vertical wind shear phase limit analysis diagram after 9 hours, the format is the same as... Figure 6 The same applies, where (e)-(h) show the distribution variations of radial inflow and vertical velocity.

[0034] Figure 8 The diagram shows the radius-height distribution of the average vortex filamentation time (minutes, shaded) in the downwind fan-shaped region at different times. (a) represents the simulation at 3 hours, when there is no obvious Rapid Filamentation Zone (RFZ); (b) represents the simulation at 6 hours, where vortex filamentation in the outer rainband region is relatively slow and mainly limited to the lower layers; (c) represents the simulation at 9 hours, where the RFZ region is established as the outer rainband develops downwind; and (d) represents the simulation at 12 hours, where the RFZ is fully developed and mainly distributed in the lower layers where inertial stability is highest.

[0035] Figure 9 The diagram shows the diagnostic analysis of the tangential wind budget in the lower shear left quadrant (DL), displaying the composite average tangential wind budget terms over a period of 6–9 hours. (a) represents the radial advection term; (b) the tangential advection term; (c) the vertical advection term; (d) the diffusion term (mainly surface friction); (e) the net tangential wind tendency (the sum of the terms on the right-hand side of the budget equation); and (f) the actual tangential wind tendency.

[0036] Figure 10 This is a diagnostic analysis chart of tangential wind budget in the left quadrant (UL) of the upper shear line, formatted similarly to... Figure 9 Same, but applies to the UL quadrant. Detailed Implementation

[0037] This invention aims to provide a numerical simulation prediction method, system, and medium for determining the re-establishment and duration of the outer eyewall structure after a typhoon's passage through island-like terrain, which causes the inner and outer eyewalls to merge and form a thick eyewall. This method objectively determines and quantitatively predicts whether the outer eyewall will re-form and its duration after such a typhoon causes disturbance by crossing island-like terrain. To make the objectives and advantages of this invention clearer, the technical solutions in the embodiments will be described in more detail below with reference to the accompanying drawings. The described embodiments are some, but not all, of the embodiments of this invention, and are exemplary and intended to explain the invention, not to limit it.

[0038] Example 1: Determination of Reconstruction of Double-wall Structure in Typhoon

[0039] like Figure 1 As shown in the embodiment of the present invention, the numerical simulation prediction method for determining the reconstruction and maintenance duration of a double-wall structure under terrain interference provided by the present invention mainly includes the following steps in its implementation:

[0040] S100. Typhoon double-wall structure identification:

[0041] Acquire and fuse multi-source observation and numerical model output field data, identify and determine whether the target typhoon has generated a double-wall structure over the ocean. When the radial wind speed profile and image features meet the double-wall discrimination criteria, the typhoon is confirmed to have a double-wall structure and the subsequent steps are continued; otherwise, the subsequent process is terminated.

[0042] As a preferred approach, multi-source observation data includes radar observation data, satellite observation data, radiosonde data, and / or ground meteorological station observation data. The numerical model output data field includes historical simulation or real-time forecast data from global or regional meteorological models. Data fusion integrates data from different sources and at different resolutions onto a unified spatiotemporal grid. Objective analysis methods or variational assimilation methods are used to perform quality control and error correction on the fused data, eliminating data redundancy and inconsistency, and establishing a dataset covering the entire life cycle of a typhoon. This allows for more accurate identification and judgment of whether a target typhoon has formed a double-wall structure over the ocean.

[0043] Furthermore, when identifying and determining whether a target typhoon has formed a double-wall structure over the ocean, only during the period and region when the typhoon center is completely over the ocean, the presence of two distinct extreme wind speed regions is analyzed in the typhoon's radial wind speed profile. The inner eyewall corresponds to the maximum wind speed radius, and the outer eyewall is located 2 to 3 times the maximum wind speed radius outside the inner eyewall. Simultaneously, radar reflectivity factor or satellite cloud image analysis is used to detect whether two clear ring-shaped eyewall structures appear, with a relatively weak reflectivity or cloud cover region between the inner and outer eyewalls. When both the radial wind speed profile and image features meet the double-wall discrimination criteria, the typhoon is confirmed to have a double-wall structure.

[0044] S200. Typhoon Path and Topographic Impact Assessment:

[0045] Obtain forecast data of the movement path of typhoons with confirmed double-wall structures, analyze the spatial relationship between the typhoon center's movement trajectory and the island topography, and determine whether the double-wall typhoon will pass through or has already passed through the island topography's influence area. When the typhoon path meets the island topography interference conditions, initiate the double-wall structure reconstruction prediction process; otherwise, terminate the subsequent prediction process.

[0046] As a preferred approach, when assessing the impact of typhoon paths and topography, the first step is to obtain forecast data on the movement paths of typhoons with confirmed double-wall structures, analyze the spatial relationship between the typhoon center's movement trajectory and the island's topography, calculate the minimum distance between the typhoon center and the island's topography, and determine that the double-wall typhoon will be or has already been significantly affected by the island's topography when the predicted distance between the typhoon center and the island's coastline is less than 200 kilometers or when the outer wind circle of the typhoon will cover the island's topography.

[0047] Construction of the S300 high-resolution numerical simulation system:

[0048] A high-resolution, multi-nested grid numerical simulation system was established for double-wall typhoons affected by island topography. The innermost grid has the highest resolution and covers the typhoon core area and the surrounding preset range. A physical parameterization scheme suitable for typhoon fine structure simulation was configured, and the typhoon vortex structure was initialized with high-precision topographic data and sea surface temperature field to ensure accurate simulation of the interaction between typhoon and topography.

[0049] As a preferred approach, a high-resolution triple-nested grid numerical simulation system is established for double-walled typhoons affected by island topography. The resolution of the innermost grid is set to no more than 2km, the middle grid resolution to 6km, and the outermost grid resolution to 18km. The innermost grid covers the core area of ​​the typhoon and a surrounding range of 300km. Physical parameterization schemes suitable for typhoon fine structure simulation are configured, including microphysics schemes, cumulus convection schemes, and boundary layer schemes. High-precision topographic data and sea surface temperature field are used to initialize the typhoon vortex structure to ensure accurate simulation of the interaction between the typhoon and the topography.

[0050] Furthermore, when constructing the numerical simulation system, variational data assimilation techniques are used to fuse multi-source observation data. By optimizing the background error covariance matrix, incremental observation information is incorporated into the model's initial field. At the same time, a dynamic grid adaptive adjustment mechanism is established to automatically adjust the grid resolution and coverage based on changes in the typhoon's movement speed and intensity. When the typhoon's movement speed exceeds 15 m / s, the grid coverage is expanded by 20%. When the typhoon's intensity reaches the super typhoon level, the resolution of the innermost grid is increased to 1 km, ensuring a high-precision numerical simulation capability for the typhoon's fine structure.

[0051] S400. Vertical wind shear phase limit analysis:

[0052] Based on the three-dimensional wind field data output by numerical simulation, the direction and intensity of the vertical wind shear vector in the typhoon environment are calculated. A relative coordinate system is established according to the direction of the vertical wind shear, and the typhoon structure is divided into the left quadrant of upwind shear, the right quadrant of upwind shear, the left quadrant of downwind shear, and the right quadrant of downwind shear. The differences in dynamic and thermodynamic characteristics within each quadrant are analyzed, and the dominant quadrant that is conducive to the reconstruction of the outer eyewall is identified.

[0053] As a preferred approach, based on the wind field data output from numerical simulation, the direction and intensity of the vertical wind shear vector in the typhoon environment between 200 hPa and 850 hPa are calculated. A relative coordinate system is established with the vertical wind shear direction as the reference, and the 360° range around the typhoon is divided into four relative quadrants: the lower shear left quadrant, the lower shear right quadrant, the upper shear left quadrant, and the upper shear right quadrant. The differences in dynamic and thermodynamic characteristics within each quadrant are analyzed, including vorticity, divergence, vertical velocity, and temperature field, to identify the dominant quadrants that are conducive to the reconstruction of the outer eyewall.

[0054] Furthermore, when conducting vertical wind shear phase boundary analysis, a time-series-based vertical wind shear evolution monitoring system is established. The directional change rate and intensity change rate of the vertical wind shear vector over the past 24 hours are calculated. When the directional change rate is less than 30° / 12h and the intensity change rate is less than 2m / s / 12h, it is determined to be a stable vertical wind shear environment. Differentiated physical diagnostic indicators are established for different quadrants. The left quadrant of downwind shear focuses on monitoring low-level convergence and mid-level upward motion, while the left quadrant of upwind shear focuses on monitoring high-level divergence and convective instability energy. Through the synergistic analysis of multi-level physical quantities, the quadrant combination pattern and optimal timing window most conducive to external eyewall reconstruction are identified.

[0055] S500. Rapid identification and localization of vortex-like regions:

[0056] The vorticity field and strain rate tensor distribution at various heights within the typhoon are calculated. The rapid vortex filamentation time discriminant formula is used to identify regions where the rapid vortex filamentation time is less than the adaptive threshold. Potential areas with dominant outer eyewall formation are located, and the spatial distribution characteristics and their correspondence with the vertical wind shear quadrants are analyzed. When the rapid vortex filamentation regions are concentrated in the left quadrant of the downwind shear, the candidate radius zone for outer eyewall reconstruction is determined.

[0057] As a preferred approach, the vorticity field and strain rate tensor distribution at various altitude levels within the typhoon are calculated, and the following rapid vortex filamentation time discrimination formula is used for quantitative evaluation:

[0058]

[0059] in, τ fil To accelerate the vortexing time, S 1 and S 2 represents two eigenvalues ​​of the strain rate tensor. ζ As the vertical component of relative vorticity, areas with rapid vortex formation time less than a preset threshold of three hours are identified to locate potential areas with an advantage in outer eyewall formation. The spatial distribution characteristics and their correspondence with the vertical wind shear quadrants are analyzed. When the rapid vortex formation area is concentrated in the left quadrant of the lower shear, it indicates a high probability of outer eyewall reconstruction and is identified as a candidate radius zone for outer eyewall reconstruction.

[0060] Furthermore, a multi-scale vortex filamentation assessment system was established for rapid vortex filamentation region identification. Vortex filamentation times were calculated at spatial scales of 1 km, 3 km, and 5 km in the horizontal direction, and the vertical distribution of vortex filamentation characteristics from the boundary layer to the tropopause was analyzed in the vertical direction. A vortex filamentation efficiency index, EFI, was introduced. τ fil -1 × ζ ,in τ fil To accelerate the vortexing time, ζ The vertical component of relative vorticity is given when EFI exceeds 0.1s. -2 Furthermore, the continuous distribution area within the left quadrant of the downwind shear exceeds 500 km². 2 At that time, it was identified as an area with advantages in efficient vortex formation; combined with helicity analysis, when the relative helicity is greater than 0.8 and the overlap with the high EFI area exceeds 70%, it is predicted that the area has a strong potential for three-dimensional vortex development.

[0061] S600. Detection of subsidence airflow in the trench area between eyewalls:

[0062] Based on vertical velocity field data from numerical simulation, the intensity, horizontal distribution range, and duration of downdrafts are detected within the annular trench area between the inner and outer eyewalls of a typhoon. Downdraft intensity thresholds and minimum duration thresholds are set, and the percentage of grid points meeting the threshold conditions is counted among the total grid points in the trench area, with time windows accumulated. When the downdraft coverage ratio and duration simultaneously reach the preset conditions, it is determined to be a dynamic condition conducive to the formation and maintenance of the trench area.

[0063] As a preferred method, based on the vertical velocity field data from numerical simulation, the intensity, horizontal distribution range, and duration of the downdraft are detected in the annular trench area between the inner and outer eyewalls of the typhoon. The downdraft intensity threshold is set to -2 m / s, and the percentage of grid points that meet the threshold condition is counted out of the total number of grid points in the trench area. When the downdraft coverage ratio continuously exceeds 60% and the duration is greater than 6 hours, it is determined that the dynamic conditions conducive to the formation and maintenance of the trench area are met.

[0064] S700. Tangential wind budget diagnosis and structural transition identification:

[0065] Within the annulus containing the radius of the trench and the candidate outer eyewall, the contribution of radial and vertical advection to the increase of tangential wind in the inner and outer eyewall regions is determined by the tangential wind diagnostic analysis equation. When it is detected that the left quadrant of the downwind shear is dominated by radial / vertical advection, the left quadrant of the upwind shear is dominated by tangential advection, and a tangential jet appears at the downwind end, resulting in a significant reduction or change in the radial velocity of the boundary layer inflow, it is determined that a structural transition from inner wall dominance to outer wall dominance has occurred.

[0066] As a preferred approach, within the annular zone encompassing the radius of the trench and the candidate outer eyewall, the contributions of the radial advection term, vertical advection term, Coriolis force term, and frictional force term to the tangential wind variation in the inner and outer eyewall regions are calculated using the tangential wind diagnostic analysis equation:

[0067]

[0068] in, u , v , w These are the radial wind speed component, the tangential wind speed component, and the vertical velocity component, respectively. f Coriolis parameters; This represents the vertical component of the relative vorticity. ρ air density, t For time, p For pressure; F λ This represents the vertical diffusion term of tangential wind, which includes surface friction. x , y z represents the coordinates in the east-west, north-south, and height directions in a rectangular coordinate system, respectively; r , λ These represent the horizontal distance from the typhoon center and the angular position relative to the typhoon center, respectively.

[0069] The magnitudes of each diagnostic term are calculated using the numerical difference method. The radial advection term uses the central difference scheme to calculate the radial tangential wind gradient, the vertical advection term uses the forward difference scheme to calculate the vertical tangential wind gradient, the Coriolis force term is directly calculated based on the local latitude and radial wind speed, and the friction force term is obtained through the boundary layer parameterization scheme.

[0070] In the inner eyewall region with a radius of 15-25 km and the candidate outer eyewall region with a radius of 40-80 km, the circumferential average value and temporal evolution characteristics of each diagnostic item were statistically analyzed. When the radial advection term in the outer eyewall region is continuously positive and its contribution rate exceeds 50% of the total tangential wind tendency, while the vertical advection term contributes more than 20%, and the Coriolis force term has the same sign as the radial advection term and its contribution rate is greater than 15%, the outer eyewall region is determined to have the dynamic conditions for continuous enhancement.

[0071] When it is detected that the left quadrant of the downwind shear is dominated by radial / vertical advection, the left quadrant of the upwind shear is dominated by tangential advection, and a tangential jet stream appears at the downwind end, resulting in a significant decrease in the radial velocity of the boundary layer inflow, it is determined that a structural transition from inner wall dominance to outer wall dominance has occurred.

[0072] Furthermore, step S700 also includes the analysis of the spiral rainband axisymmetric transformation process. Based on the numerical simulation output of the radar reflectivity factor, the three-dimensional structural features of the outer spiral rainband of the typhoon are extracted, the asymmetric parameters and axisymmetric index of the rainband structure are calculated, the wavenumber characteristics of the rainband are analyzed using the Fourier decomposition method, and the spatiotemporal evolution process of the spiral rainband transforming into an axisymmetric ring structure is monitored. When the contribution rate of the 0 wavenumber component increases from 40% of the initial value to more than 70%, it is determined that the spiral rainband has completed the transformation into an axisymmetric structure. This process is an important precursor signal for the formation of the outer eyewall.

[0073] S800. Energy growth rate assessment and duration estimation:

[0074] The energy growth rate (EGR) of the candidate outer eyewall radius zone is calculated. The EGR is defined as the difference between surface enthalpy flux energy production and frictional dissipation and is integrated in the circumferential direction. When the EGR remains positive within a preset time window and matches the convection asymmetry, it is predicted that the double eyewall structure can be maintained. Based on the magnitude and trend of the EGR, a maintenance duration estimation model is established, and the quantitative results of the outer eyewall maintenance duration are output.

[0075] As a preferred approach, the EGR is calculated for the candidate outer eyewall radius zone, and an energy balance diagnosis system based on the balance between surface enthalpy flux and frictional dissipation is established:

[0076]

[0077] in, r i and r o These are the inner and outer boundary radii of the candidate outer eyewall radius zone, respectively. ρ air density, ε It is the ratio of the molecular weight of water vapor to the molecular weight of dry air. Near-surface wind speed, C k The enthalpy exchange coefficient, C D This is the drag coefficient. The specific humidity is saturated at sea surface. κ a The boundary layer air is humid. r The radius is denoted by ; the first integral term represents the sea surface enthalpy flux energy term, and the second integral term represents the friction dissipation term;

[0078] The EGR distribution characteristics in the four different quadrants of the candidate outer eyewall radius zone were calculated, and time smoothing and persistence statistics were performed within a preset time window. When the quadranted EGR of the candidate outer eyewall radius zone showed a positive and persistent value that matched the convection asymmetry, and its duration and amplitude both exceeded the threshold set based on the near-term quantile, it was determined that the quadrant had energy support for the maintenance of the outer eyewall.

[0079] The duration and mean amplitude of positive EGR, the ratio of trench width to outer eyewall width within the radius band, and the phase consistency between quadrants are jointly input into the maintenance duration estimation model, and the outer eyewall maintenance duration range and confidence level are output. To ensure engineering consistency, the EGR numerical integration is implemented using a finite volume consistent with the model mesh, and energy budget residual constraints are set for quality control.

[0080] S900. Multi-parameter integrated judgment and prediction result output:

[0081] When the following comprehensive conditions are met simultaneously: the rapid vortex formation region is dominated by the left quadrant of the downwind shear, the trench subsidence environment is established, the momentum balance is a combination of the target quadrants and tangential jet flow is triggered, and the candidate radius zone has a positive and continuous EGR, the result of the outer eyewall re-formation and the duration range are output.

[0082] As a preferred approach, the multi-parameter integrated judgment and prediction adopts a rule-based weighted fusion framework, which normalizes and scores the rapid vortex filamentation indicator, trench subsidence environment, tangential wind momentum budget and EGR and performs time series consistency tests to form a reconstruction confidence score. When the evidence is consistent but some indicators are missing, a near-term interpolation and confidence reduction mechanism is activated. The output includes structured results such as whether the outer eyewall has re-formed, the predicted outer eyewall radius band, the duration interval and its uncertainty quantification and quality labeling.

[0083] It is important to emphasize that Example 1 establishes a systematic prediction method for the reconstruction of the outer eyewall structure under terrain interference. It proposes a physical diagnostic method based on vertical wind shear phase limits to accurately identify the dominant quadrant for outer eyewall reconstruction; establishes a quantitative method for rapid identification of vortex filamentation regions to achieve precise positioning of candidate areas for outer eyewall reconstruction; employs tangential wind budget diagnostic technology to accurately identify structural turning points; establishes an energy growth rate assessment model to achieve quantitative prediction of duration; and adopts a multi-parameter comprehensive judgment fusion framework to significantly improve prediction reliability. Through the above-mentioned collaborative mechanisms, this invention achieves accurate prediction of the double eyewall reconstruction process, providing important technical support for typhoon operational forecasting.

[0084] Example 2: Application Case

[0085] Based on Example 1 above, Example 2 combines the actual prediction application of Typhoon Doksuri (2023) to verify the effectiveness and accuracy of the present invention. Doksuri was the strongest typhoon to make landfall in southern Fujian since 2017, and it experienced two consecutive outer eyewall formation processes during its life cycle.

[0086] like Figure 2 , Figure 3 As shown, by fusing multi-source observation data with WRF high-resolution numerical simulation output, the first double-eyewall structure formed by Typhoon Doksuri east of Luzon Island, Philippines, at 1600 UTC on July 24, 2023, was successfully identified. As the typhoon slowly passed through the northern part of the island, the eastern regions of the inner and outer eyewalls merged due to topographic interference, forming a broad and thick eyewall structure, verifying the accuracy of the topographic impact assessment in step S200 of this invention. As Doksuri gradually moved away from the Philippine topography, the spiral rainbands re-encircled the vortex center, marking the initiation of the outer eyewall re-formation process.

[0087] A numerical simulation system with a triple-nested grid was established for Typhoon Doksuri, which was affected by island topography. The innermost grid had a resolution of 2 km, the middle layer 6 km, and the outermost layer 18 km, with a simulation duration of 72 hours. A dynamic initialization method was used to ensure that the initial field closely matched the actual vortex structure. The simulation results show that, under moderate to strong vertical wind shear (approximately 10 m / s), the complete process of the spiral rainband transforming into the outer eyewall was successfully reproduced.

[0088] like Figures 4 to 7 As shown, based on the simulated three-dimensional wind field data, the typhoon structure was divided into four quadrants according to the vertical wind shear direction for analysis. In the lower shear right quadrant (DR), a positive diabetic heating region exists in the upwind part of the outer rainband, corresponding to the development of discrete convective cells; in the lower shear left quadrant (DL), the inner eyewall heating and the outer rainband heating are almost connected in the boundary layer; in the upper shear left quadrant (UL), the rainband and the inner eyewall are almost merged, showing two peaks only above 5 km; in the upper shear right quadrant (UR), only a single eyewall structure exists. The results of this quadrant analysis accurately identified the dominant quadrant combinations that are conducive to outer eyewall reconstruction.

[0089] like Figure 8 As shown, the rapid vortexing time is calculated. τ filThe study identified a rapid vortex filamentation time of less than 30 minutes between the eyewall and a 60km radius, confirming the existence of the Rapid Filamentation Zone (RFZ). In the initial 3 hours of the simulation, no obvious RFZ region had formed; after 6 hours, vortex filamentation in the outer rainband region was relatively slow, mainly confined to the lower layers; as the leeward side of the outer rainband developed, the RFZ region gradually established and was mainly distributed in the lower layers where inertial stability was highest. When the leeward part of the rainband approached the core, high-wavenumber asymmetric vortices became axisymmetric at the outer edge of the RFZ, leading to acceleration of the low-level tangential winds.

[0090] Based on vertical velocity field data, a clear descending airflow channel exists in the right quadrant (UR) of the upper shear. Air moves downwards and radially inwards from the upper outer layer to the eyewall, satisfying the dynamic conditions for trench formation. Tangential wind budget analysis, such as... Figure 9 and Figure 10 As shown, in the lower left quadrant of the shear (DL), the increase in tangential wind in the eyewall and rainband regions mainly comes from radial and vertical advection contributions above the boundary layer; in the upper left quadrant of the shear (UL), the increase in tangential wind in the eyewall region mainly originates from the inward movement of the leeward end of the outer rainband through the tangential advection term. This diagnostic result verifies the differences in the tangential wind enhancement mechanisms across different quadrants and accurately identifies the structural transition from inner wall dominance to outer wall dominance.

[0091] Based on the energy budget diagnosis using the balance between surface enthalpy flux and frictional dissipation, the energy growth rate (EGR) distribution characteristics in different quadrants were calculated. The results show that in the outer DL quadrant, the EGR value is relatively low because convective activity mainly occurs over land; however, in the outer rainband region, the EGR increases significantly over time, indicating significant development of convective activity. After 9 hours of simulation, the peak EGR in the DL quadrant occurs at a radius of approximately 110 km, while the maximum EGR in the UL quadrant is located at a radius of approximately 70 km, indicating that the outer rainband spirals from the DL quadrant and continues to move radially inward in the UL quadrant. By utilizing the sustained positive EGR value and its matching with the convective asymmetry phase, the outer eyewall structure was successfully predicted to persist for more than 36 hours until typhoon landfall.

[0092] By considering multiple criteria, including the dominant distribution of the rapid vortex formation region in the left quadrant of the lower shear zone, the establishment of the subsidence environment in the trench area, the target combination of tangential wind budget in different quadrants, and the continuous positive EGR of the candidate radius zone, an accurate prediction of the re-formation of the outer eyewall of Dusurui was successfully generated. The predicted duration of the outer eyewall was 36-42 hours, which highly matches the actual observed duration, verifying the prediction accuracy and practical value of the technical solution of this invention.

[0093] This embodiment 2, through the case study of Typhoon Doksuri, demonstrates the significant advantages of the technical solution of this invention in predicting the reconstruction of double-walled structures after terrain interference: the prediction accuracy reaches over 85%, and the prediction error for the duration of damage is controlled within 6 hours, improving the prediction accuracy by approximately 30% compared to traditional empirical forecasting methods. Particularly in complex terrain environments, the diagnostic method of this invention exhibits significant technical advantages, providing crucial scientific support for refined typhoon forecasting and disaster prevention and mitigation.

[0094] The objectives of this invention have been fully and effectively achieved through the above embodiments. Those skilled in the art will understand that this invention includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments described above. Although the invention has been described with reference to what is currently considered the most practical and preferred embodiments, it should be understood that the invention is not limited to the disclosed embodiments, and any modifications that do not depart from the functional and structural principles of the invention will be included within the scope of the claims.

Claims

1. A numerical simulation prediction method for determining the reconstruction and maintenance duration of a double-wall structure affected by terrain disturbance, characterized in that, It should include at least the following steps: S100. Acquire and fuse multi-source observation and numerical model output field data, identify and determine whether the target typhoon has generated a double-wall structure on the ocean surface; if so, proceed with the next steps. S200. Obtain typhoon path forecast data, determine whether the double-walled typhoon will pass through or has already passed through the island terrain-affected area, and if so, proceed with the following steps; S300. A numerical simulation system was established for double-wall typhoons affected by island topography, a physical parameterization scheme was configured, and the typhoon vortex structure was initialized using high-precision topographic data and sea surface temperature field. S400. Based on numerical simulation results, calculate the direction and intensity of the vertical wind shear vector in the typhoon environment, divide the typhoon structure into four wind shear quadrants, and identify the dominant quadrant that is conducive to the reconstruction of the outer eyewall. S500. Identify regions where the rapid vortex formation time is less than the adaptive threshold, locate potential areas where the outer eyewall forms a dominant shape, and determine the candidate radius band for outer eyewall reconstruction when rapid vortex formation is concentrated in the left quadrant of the downwind shear. S600. Detect the intensity, horizontal distribution range and duration of the descending airflow in the trench area between the inner and outer eyewalls. When the coverage ratio and duration of the descending airflow reach the preset conditions, it is determined to be a dynamic condition conducive to the formation and maintenance of the trench area. S700. Determine the contribution of radial and vertical advection to the increase in tangential wind in the inner and outer eyewall regions. When it is detected that radial or vertical advection is the dominant force in the left quadrant of the downwind shear, tangential advection is the dominant force in the left quadrant of the upwind shear, and tangential jets appear at the downwind end, resulting in a significant reduction in the radial velocity of the boundary layer inflow, it is determined that a structural transition from inner wall dominance to outer wall dominance has occurred. S800. Calculate the energy growth rate (EGR) for the candidate outer eyewall radius zone. When the EGR remains positive within a preset time window and matches the convection asymmetry, predict that the double eyewall structure can be maintained. Establish a maintenance duration estimation model based on the magnitude and trend of the EGR. S900. When the following conditions are met simultaneously: the rapid vortex formation region is dominated by the left quadrant of the downwind shear, the trench subsidence environment is established, the momentum balance is in the target quadrant combination and tangential jet flow is triggered, and the candidate radius zone EGR is positive and continuous, the result of the outer eyewall re-formation and the duration range are output.

2. The numerical simulation prediction method for determining the reconstruction and maintenance duration of a double-wall structure affected by terrain interference as described in claim 1, is characterized in that... In step S100, the multi-source observation data includes radar observation data, satellite observation data, radiosonde data, and / or ground meteorological station observation data. The numerical model output data field includes historical simulation or real-time forecast data from global or regional meteorological models. Data fusion integrates data from different sources and at different resolutions onto a unified spatiotemporal grid. Objective analysis methods or variational assimilation methods are used to perform quality control and error correction on the fused data to eliminate data redundancy and inconsistency, and to establish a dataset covering the entire life cycle of a typhoon.

3. The numerical simulation prediction method for determining the reconstruction and maintenance duration of a double-wall structure affected by terrain interference according to claim 1 or 2, characterized in that, In step S100, when identifying and determining whether a target typhoon has formed a double-wall structure over the ocean, the following steps are taken: Only during the period and region when the typhoon center is completely over the ocean surface, the radial wind speed profile of the typhoon is analyzed to determine if there are two distinct extreme wind speed regions. The inner eyewall corresponds to the maximum wind speed radius, and the outer eyewall is located 2-3 times the maximum wind speed radius outside the inner eyewall. Simultaneously, radar reflectivity factor or satellite cloud image analysis is used to detect whether two clear ring-shaped eyewall structures appear, with a relatively weak reflectivity or cloud cover region between the inner and outer eyewalls. When both the radial wind speed profile and image features meet the double-wall discrimination criteria, the typhoon is confirmed to have a double-wall structure.

4. The numerical simulation prediction method for determining the reconstruction and maintenance duration of a double-wall structure affected by terrain interference as described in claim 1, characterized in that, In step S200, when assessing the impact of typhoon path and topography, the forecast data of the movement path of typhoons with confirmed double-wall structures are first obtained. The spatial relationship between the movement trajectory of the typhoon center and the island topography is analyzed. The minimum distance between the typhoon center and the island topography is calculated. When the predicted distance between the typhoon center and the island coastline is less than 200 kilometers or the outer wind circle of the typhoon will cover the island topography, it is determined that the double-wall typhoon will be or has already been significantly affected by the island topography in the future.

5. The numerical simulation prediction method for determining the reconstruction and maintenance duration of a double-wall structure affected by terrain interference as described in claim 1, characterized in that, In step S300, for double-wall typhoons affected by island topography, a high-resolution triple-nested grid numerical simulation system is established. The resolution of the innermost grid is set to no more than 2km, the resolution of the middle grid is 6km, and the resolution of the outermost grid is 18km. The innermost grid covers the core area of ​​the typhoon and a surrounding range of 300km. A physical parameterization scheme suitable for typhoon fine structure simulation is configured, including a microphysics scheme, a cumulus convection scheme, and a boundary layer scheme. High-precision topographic data and sea surface temperature field are used to initialize the typhoon vortex structure to ensure accurate simulation of the interaction between the typhoon and the topography.

6. The numerical simulation prediction method for determining the reconstruction and maintenance duration of a double-wall structure affected by terrain interference as described in claim 1, characterized in that, In step S400, based on the three-dimensional wind field data output by numerical simulation, the direction and intensity of the vertical wind shear vector in the typhoon environment between 200 hPa and 850 hPa are calculated. A relative coordinate system is established with the vertical wind shear direction as the reference, and the 360° range around the typhoon is divided into four relative quadrants, namely the lower shear left quadrant, the lower shear right quadrant, the upper shear left quadrant, and the upper shear right quadrant. The differences in dynamic and thermodynamic characteristics in each quadrant are analyzed, including at least vorticity, divergence, vertical velocity, and temperature field, and the dominant quadrants that are conducive to the reconstruction of the outer eyewall are identified.

7. The numerical simulation prediction method for determining the reconstruction and maintenance duration of a double-wall structure affected by terrain interference as described in claim 1, characterized in that, In step S500, the vorticity field and strain rate tensor distribution at each altitude level within the typhoon are calculated, and the following rapid vortex filamentation time discrimination formula is used for quantitative evaluation: in, τ fil To accelerate the vortexing time, S 1 and S 2 represents two eigenvalues ​​of the strain rate tensor. ζ As the vertical component of relative vorticity, areas with rapid vortex formation time less than a preset threshold of three hours are identified to locate potential areas with an advantage in outer eyewall formation. The spatial distribution characteristics and their correspondence with the vertical wind shear quadrants are analyzed. When the rapid vortex formation area is concentrated in the left quadrant of the lower shear, it indicates a high probability of outer eyewall reconstruction and is identified as a candidate radius zone for outer eyewall reconstruction.

8. The numerical simulation prediction method for determining the reconstruction and maintenance duration of a double-wall structure affected by terrain interference as described in claim 1, characterized in that, In step S600, based on the vertical velocity field data from numerical simulation, the intensity, horizontal distribution range, and duration of the downdraft are detected in the annular trench area between the inner and outer eyewalls of the typhoon. The downdraft intensity threshold is set to -2 m / s. The percentage of grid points that meet the threshold condition is counted among the total grid points in the trench area. When the downdraft coverage ratio continuously exceeds 60% and the duration is greater than 6 hours, it is determined that the dynamic conditions conducive to the formation and maintenance of the trench area are met.

9. The numerical simulation prediction method for determining the reconstruction and maintenance duration of a double-wall structure affected by terrain interference as described in claim 1, characterized in that, In step S700, within the annular zone encompassing the trench and the candidate outer eyewall radius, the contributions of the radial advection term, vertical advection term, Coriolis force term, and frictional force term to the tangential wind variation in the inner and outer eyewall regions are calculated using the tangential wind diagnostic analysis equation: in, u , v , w These are the radial wind speed component, the tangential wind speed component, and the vertical velocity component, respectively. f Coriolis parameters; This represents the vertical component of the relative vorticity. ρ air density, t For time, p For pressure; F λ This represents the vertical diffusion term of tangential wind, which includes surface friction. x , y z represents the coordinates in the east-west, north-south, and height directions in a rectangular coordinate system, respectively; r , λ These represent the horizontal distance from the typhoon center and the angular position relative to the typhoon center, respectively. The magnitudes of each diagnostic term are calculated using the numerical difference method. The radial advection term uses the central difference scheme to calculate the radial tangential wind gradient, the vertical advection term uses the forward difference scheme to calculate the vertical tangential wind gradient, the Coriolis force term is directly calculated based on the local latitude and radial wind speed, and the friction force term is obtained through the boundary layer parameterization scheme. In the inner eyewall region with a radius of 15-25 km and the candidate outer eyewall region with a radius of 40-80 km, the circumferential average value and temporal evolution characteristics of each diagnostic item were statistically analyzed. When the radial advection term in the outer eyewall region is continuously positive and its contribution rate exceeds 50% of the total tangential wind tendency, while the vertical advection term contributes more than 20%, and the Coriolis force term has the same sign as the radial advection term and its contribution rate is greater than 15%, the outer eyewall region is determined to have the dynamic conditions for continuous enhancement. When it is detected that the left quadrant of the downwind shear is dominated by radial or vertical advection, the left quadrant of the upwind shear is dominated by tangential advection, and a tangential jet stream appears at the downwind end, resulting in a significant decrease in the radial velocity of the boundary layer inflow, it is determined that a structural transition from inner wall dominance to outer wall dominance has occurred.

10. The numerical simulation prediction method for determining the reconstruction and maintenance duration of a double-wall structure affected by terrain interference as described in claim 1, characterized in that, In step S800, the EGR is calculated for the candidate outer eyewall radius zone, and an energy balance diagnosis system based on the balance between surface enthalpy flux and frictional dissipation is established: in, r i and r o These are the inner and outer boundary radii of the candidate outer eyewall radius zone, respectively. ρ air density, ε It is the ratio of the molecular weight of water vapor to the molecular weight of dry air. Near-surface wind speed, C k The enthalpy exchange coefficient, C D This is the drag coefficient. The specific humidity is saturated at sea surface. κ a The boundary layer air is humid. r The radius is denoted by ; the first integral term represents the sea surface enthalpy flux energy term, and the second integral term represents the friction dissipation term; The EGR distribution characteristics in the four different quadrants of the candidate outer eyewall radius zone were calculated, and time smoothing and persistence statistics were performed within a preset time window. When the quadranted EGR of the candidate outer eyewall radius zone showed a positive and persistent value that matched the convection asymmetry, and its duration and amplitude both exceeded the threshold set based on the near-term quantile, it was determined that the quadrant had energy support for the maintenance of the outer eyewall. The duration and mean amplitude of positive EGR, the ratio of trench width to outer eyewall width within the radius band, and the phase consistency between quadrants are jointly input into the maintenance duration estimation model, and the outer eyewall maintenance duration range and confidence level are output. To ensure engineering consistency, the EGR numerical integration is implemented using a finite volume consistent with the model mesh, and energy budget residual constraints are set for quality control.

11. A numerical simulation prediction system for determining the reconstruction and maintenance duration of a double-wall structure affected by terrain interference, characterized in that, It includes multiple modules for executing the numerical simulation prediction method for determining the reconstruction and maintenance duration of a double-wall structure under terrain interference as described in any one of claims 1 to 10.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the numerical simulation prediction method for determining the reconstruction and maintenance duration of a double-wall structure under terrain interference as described in any one of claims 1 to 10.

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