Litchi forest damage assessment method under strong wind

Abstract

The invention relates to the technical field of loss assessment, in particular to a litchi forest damage assessment method under strong wind, which comprises the following steps of: based on litchi garden information, extracting coordinates and elevation information of a tree from map data by adopting a coordinate extraction technology, measuring the height of the tree, and integrating the data into a ground projection and a vertical density matrix of the litchi tree to obtain a litchi forest damage assessment result. And obtaining an initialized data set. According to the method, the potential wind influence intensity is distributed to each tree, the processing meticulous degree is increased, the evaluation scientificity is improved, the actual windward area of each tree is considered, adjustment is carried out in combination with the terrain influence, the accuracy of wind loss estimation under different terrains is ensured, damage evaluation is closer to the actual situation, and the evaluation accuracy is improved. Through mechanical analysis and statistical evaluation, a seriously damaged area can be identified, more specific and operable data support is provided, the accuracy and practicability of wind loss data are remarkably improved, and agricultural management and formulation of an insurance compensation strategy are greatly assisted.

Description

Technical Field

[0001] The invention relates to the technical field of loss assessment, and in particular to a method for assessing damage to a litchi forest under strong winds. Background Art

[0002] The field of loss assessment technology involves estimating or quantifying the loss of crops, buildings, or other property due to external factors such as natural disasters, diseases, pest infestations, etc. This field generally includes direct visual assessment of damage, remote monitoring using sensor technology, and image processing and data analysis techniques to assess the extent of damage. Technology can help governments, agricultural operators, insurance companies, and other stakeholders develop appropriate compensation strategies, recovery plans, and disaster prevention measures.

[0003] Among them, the litchi forest damage assessment method under strong winds is a technology specifically designed to systematically assess the damage to litchi forests after being hit by strong winds. The main purpose is to accurately quantify the extent of damage to litchi forests, thereby providing data support for farm managers to help them make more effective management decisions. This method collects geographical and meteorological data of litchi forests, combines tree damage, and assesses the potential economic losses caused by damage, providing a basis for insurance compensation and post-disaster reconstruction.

[0004] Traditional assessment methods mainly rely on intuitive loss assessment, such as visual inspection or basic remote sensing technology, which has obvious deficiencies in accuracy and efficiency. For example, visual assessment is limited by the observer's perspective and experience, is prone to errors, and cannot cover a large area, which is obviously insufficient to meet the needs in large-scale agricultural applications. In addition, although basic remote sensing technology can provide certain remote monitoring capabilities, the accuracy and reliability of its data are still limited under complex terrain and climatic conditions. The limitations of these technologies have resulted in farmers and insurance companies being unable to obtain accurate and comprehensive loss data in the case of severe wind damage, which has affected the fairness and efficiency of loss compensation, increased conflicts between farmers and insurance companies, and caused additional time and economic losses in post-disaster recovery and claims. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a method for assessing damage to a litchi forest under strong winds.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme: a method for assessing damage to a litchi forest under strong winds, comprising the following steps:

[0007] S1: Based on the information of litchi orchard, coordinate extraction technology is used to extract the coordinates and elevation information of trees from map data, measure the tree height, and integrate the data into the ground projection and vertical density matrix of litchi trees to obtain the initialization data set;

[0008] S2: Based on the initialization data set, by analyzing the data of boundary factors and wind direction factors, combined with the distribution of litchi trees in the litchi orchard, the potential intensity of wind impact on each tree is allocated to obtain a wind impact weight matrix;

[0009] S3: Based on the wind impact weight matrix, combined with the wind direction factor and the vertical density matrix, the density in each direction is analyzed item by item, the actual windward area of ​​the litchi tree is calculated and updated, and the adjusted windward area matrix information is obtained;

[0010] S4: Based on the adjusted windward area matrix information, according to the terrain influence of the litchi orchard, using the terrain attenuation factor, correcting each item in the adjusted windward area matrix, calculating the terrain adjusted windward area of ​​each tree, and obtaining the terrain adjusted windward area information;

[0011] S5: Based on the terrain-adjusted windward area information, combined with air density, air resistance coefficient and wind speed, a mechanical analysis is performed on the terrain-adjusted windward area of ​​each tree, the wind force borne by each tree is calculated, and a wind force influence matrix is ​​obtained;

[0012] S6: Based on the wind impact matrix, identify severely damaged areas and trees through numerical comparison, evaluate the degree of wind impact on differentiated areas, and obtain litchi forest damage assessment results.

[0013] As a further solution of the present invention, the initialization data set includes the location coordinates of the trees, the elevation information of each tree, the tree height data, the ground projection area and the vertical density information; the wind impact weight matrix includes the boundary impact information of each tree, the wind direction impact score and the dynamic weight of the wind direction and boundary adjustment; the adjusted windward area matrix information includes the windward area of ​​each tree adjusted for density and the windward area adjustment value of the wind direction change; the terrain adjusted windward area information includes the windward area of ​​each tree adjusted based on its elevation and tree height and the windward area after the influence of terrain attenuation; the wind force impact matrix includes the predicted wind force value of each tree under the set wind speed conditions and the wind force impact scores in multiple directions; the litchi forest damage assessment results include the location of the severely wind-affected areas, the list of damaged trees and the classification of the degree of damage.

[0014] As a further solution of the present invention, based on the litchi orchard information, coordinate extraction technology is used to extract the coordinates and elevation information of the trees from the map data, measure the tree height, and integrate the data into the ground projection and vertical density matrix of the litchi tree. The steps of obtaining the initialization data set are specifically as follows:

[0015] S101: Based on the litchi orchard information, the geographical coordinates of each tree are located by GPS positioning, the geographical coordinates of the tree are input, the X and Y coordinate positions of each tree are obtained, and a coordinate data set is obtained;

[0016] S102: Based on the coordinate data set, using a laser measurement device, measure the elevation and tree height of each tree one by one, record the relative ground height and absolute tree height of each tree, and obtain an elevation and tree height data set;

[0017] S103: Based on the coordinate data set and the elevation and tree height data sets, the data sets are integrated into the ground projection and vertical density matrix of the litchi tree to obtain an initialization data set.

[0018] As a further solution of the present invention, based on the initialization data set, by analyzing the data of the boundary factor and the wind direction factor, combined with the distribution of litchi trees in the litchi orchard, the potential intensity of wind impact on each tree is allocated, and the steps of obtaining the wind impact weight matrix are specifically as follows:

[0019] S201: Based on the initialization data set, using the tree location information and combining the GIS data of the park boundary, the relative position of each tree to the park boundary is calculated, a decreasing function is applied to simulate the boundary factor, and the boundary influence coefficient of each tree is set to obtain a boundary factor data set;

[0020] S202: Based on the boundary factor data set, the dominant wind direction information is obtained from the meteorological station, and the influence of the wind direction on each tree is calculated according to the relative angle between the position of each tree and the wind direction, and the potential intensity of each tree being affected by the wind is evaluated to obtain a wind direction influence data set;

[0021] S203: Based on the wind direction impact data set and the boundary factor data set, the potential intensity of wind impact on each tree is evaluated to obtain a wind impact weight matrix.

[0022] As a further solution of the present invention, based on the wind impact weight matrix, combined with the wind direction factor and the vertical density matrix, the actual windward area of ​​the litchi tree is calculated and updated by comparing and analyzing the density in each direction item by item, and the steps of adjusting the windward area matrix information are specifically as follows:

[0023] S301: Based on the wind impact weight matrix, data of the windward area of ​​each litchi tree is collected one by one, and compared and analyzed with the multi-directional density values ​​recorded in the vertical density matrix, and the windward area adjustment values ​​of each tree in multiple directions are evaluated to obtain windward area comparison data;

[0024] S302: extracting the windward area adjustment value of each tree based on the windward area comparison data, updating the actual windward area of ​​the litchi tree, arranging the new windward area data into a table, re-evaluating the total windward area for each tree, and obtaining updated windward area data;

[0025] S303: Based on the updated windward area data, data aggregation is performed to construct a litchi orchard windward area matrix to obtain adjusted windward area matrix information.

[0026] As a further solution of the present invention, based on the adjusted windward area matrix information, according to the terrain influence of the litchi orchard, each item in the adjusted windward area matrix is ​​corrected by using the terrain attenuation factor, and the terrain adjusted windward area of ​​each tree is calculated. The steps of obtaining the terrain adjusted windward area information are specifically as follows:

[0027] S401: Based on the adjusted windward area matrix information, using the terrain data of the litchi orchard, including the elevation and tree height information of each tree, calculating the impact of the terrain on the windward area, evaluating the attenuation effect of the terrain factor, setting a matching terrain attenuation factor for each tree, and obtaining a terrain attenuation factor data set;

[0028] S402: Based on the terrain attenuation factor data set, the windward area of ​​each tree in the adjusted windward area matrix is ​​corrected, and the windward area of ​​each tree is updated by the adopted terrain factor to obtain corrected windward area data;

[0029] S403: Based on the corrected windward area data, collect and sort out the corrected windward areas of all trees, summarize the data, sort out the terrain-adjusted windward area of ​​each tree in the entire litchi orchard, and obtain terrain-adjusted windward area information.

[0030] As a further solution of the present invention, based on the terrain-adjusted windward area information, combined with air density, air resistance coefficient and wind speed, a mechanical analysis is performed on the terrain-adjusted windward area of ​​each tree, and the wind force borne by each tree is calculated. The steps of obtaining a wind force influence matrix are specifically as follows:

[0031] S501: adjusting the windward area information based on the terrain and combining it with the current air density parameter, collecting air density, air resistance coefficient and wind speed data, setting initial variables for wind force calculation, and obtaining wind force analysis preparation data;

[0032] S502: Based on the wind force analysis preparation data, evaluate the wind force borne by the trees to obtain a wind force impact evaluation result of each tree;

[0033] S503: Based on the wind impact assessment results of each tree, data is summarized to construct a wind impact matrix for the entire park, showing the wind force that each tree is subjected to, and obtaining a wind impact matrix.

[0034] As a further solution of the present invention, based on the terrain-adjusted windward area information, combined with air density, air resistance coefficient and wind speed, a mechanical analysis is performed on the terrain-adjusted windward area of ​​each tree, and the wind force borne by each tree is calculated. The steps of obtaining a wind force influence matrix are specifically as follows:

[0035] S501: adjusting the windward area information based on the terrain and combining it with the current air density parameter, collecting air density, air resistance coefficient and wind speed data, setting initial variables for wind force calculation, and obtaining wind force analysis preparation data;

[0036] S502: Based on the wind force analysis preparation data, evaluate the wind force borne by the trees to obtain a wind force impact evaluation result of each tree;

[0037] S503: Based on the wind impact assessment results of each tree, data is summarized to construct a wind impact matrix for the entire park, showing the wind force that each tree is subjected to, and obtaining a wind impact matrix.

[0038] As a further solution of the present invention, based on the wind impact matrix, the steps of identifying severely damaged areas and trees through numerical comparison, evaluating the degree of wind impact on differentiated areas, and obtaining the litchi forest damage assessment result are specifically as follows:

[0039] S601: Based on the wind force impact matrix, the wind force data of trees in each area are sorted by a numerical method to identify the area with the largest wind force and obtain the identification data of the high wind force area;

[0040] S602: Based on the high wind area identification data, a wind difference analysis is performed on each area in the high wind area identification data, and by comparing the wind data, trees that are severely affected by the wind in each area are identified to obtain regional wind difference analysis results;

[0041] S603: Based on the regional wind force difference analysis result, a damage assessment index is calculated, and the damage situation of the entire litchi orchard is assessed to obtain a litchi orchard damage assessment result.

[0042] As a further solution of the present invention, the formula for calculating the damage assessment index is:

[0043]

[0044] Among them, R is the damage assessment index, F ij represents the wind force on the tree in row i and column j, Z ij represents the relative area of ​​the tree in the i-th row and j-th column in the litchi forest, X ij is the distance from the tree to the center of the litchi forest, and e is the base of the natural logarithm.

[0045] Compared with the prior art, the advantages and positive effects of the present invention are:

[0046] In the present invention, by extracting the coordinates and elevation information of the trees from the map data and combining with the laser ranging technology, the tree position and height information of the litchi orchard are made more accurate. By dynamically calculating the wind direction and position weight of the trees, the potential wind impact intensity is allocated to each tree, which increases the meticulousness of the processing and improves the scientific nature of the assessment. By considering the actual windward area of ​​each tree and adjusting it in combination with the influence of the terrain, the accuracy of wind damage estimation under different terrains is ensured, making the damage assessment closer to the actual situation. Through mechanical analysis and statistical evaluation, severely damaged areas can be identified, providing more specific and operational data support, and the accuracy and practicality of wind damage data are significantly improved, which greatly helps agricultural management and the formulation of insurance compensation strategies. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of the main steps of the present invention;

[0048] Figure 2 It is a schematic diagram of the refinement of S1 of the present invention;

[0049] Figure 3 It is a schematic diagram of the refinement of S2 of the present invention;

[0050] Figure 4 It is a schematic diagram of the refinement of S3 of the present invention;

[0051] Figure 5 It is a schematic diagram of the refinement of S4 of the present invention;

[0052] Figure 6 It is a detailed schematic diagram of S5 of the present invention;

[0053] Figure 7 It is a detailed schematic diagram of S6 of the present invention. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0055] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, in the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0056] See also Figure 1 The present invention provides a technical solution: a method for assessing damage to a litchi forest under strong winds, comprising the following steps:

[0057] S1: Based on the information of litchi orchards, coordinate extraction technology is used to extract the coordinates and elevation information of trees from map data, and the tree height is measured by laser ranging. The data is integrated into the ground projection and vertical density matrix of litchi trees to obtain the initialization data set;

[0058] S2: Based on the initialization data set, by analyzing the data of boundary factors and wind direction factors, combined with the distribution of litchi trees in the litchi orchard, the dynamic weight of wind direction and position of each tree is calculated. Through numerical methods, the potential intensity of wind impact on each tree is assigned to obtain the wind impact weight matrix;

[0059] S3: Based on the wind impact weight matrix, combined with the wind direction factor and the vertical density matrix, the density in each direction is compared and analyzed item by item, the actual windward area of ​​the litchi tree is calculated and updated to obtain the adjusted windward area matrix information;

[0060] S4: Based on the adjusted windward area matrix information, according to the terrain influence of the litchi orchard, each item in the adjusted windward area matrix is ​​corrected using the terrain attenuation factor, and the correction factor is applied to the elevation and tree height data of each tree to calculate the terrain adjusted windward area of ​​each tree, thereby obtaining the terrain adjusted windward area information;

[0061] S5: Based on the terrain-adjusted windward area information, combined with air density, air resistance coefficient and wind speed, a mechanical analysis is performed on the terrain-adjusted windward area of ​​each tree, the wind force borne by each tree is calculated, and a wind force influence matrix is ​​obtained;

[0062] S6: Based on the wind impact matrix, identify the severely damaged areas and trees through numerical comparison, integrate the data, and evaluate the degree of wind impact in differentiated areas through statistical analysis to obtain the litchi forest damage assessment results.

[0063] The initialization data set includes the location coordinates of the trees, the elevation information of each tree, the tree height data, the ground projection area and the vertical density information. The wind impact weight matrix includes the boundary impact information of each tree, the wind direction impact score and the dynamic weights of the wind direction and boundary adjustment. The adjusted windward area matrix information includes the windward area of ​​each tree after density adjustment and the windward area adjustment value of the wind direction change. The terrain adjusted windward area information includes the windward area of ​​each tree adjusted based on its elevation and tree height and the windward area after terrain attenuation. The wind force impact matrix includes the predicted wind force value of each tree under the set wind speed conditions and the wind force impact score in multiple directions. The litchi forest damage assessment results include the location of the severely wind-affected areas, the list of damaged trees and the classification of the degree of damage.

[0064] See also Figure 2 ,Based on the information of litchi orchard, the coordinate extraction technology is used to extract the coordinates and elevation information of the trees from the map data, and the tree height is measured by laser ranging, and the data is integrated into the ground projection and vertical density matrix of the litchi tree. The initialization data set includes the following steps:

[0065] S101: Based on the litchi orchard information, the geographical coordinates of each tree are located by GPS positioning, the geographical coordinates of the tree are input, the X and Y coordinate positions of each tree are obtained, and a coordinate data set is obtained;

[0066] Based on the information of the litchi orchard, GPS receiving equipment is configured to ensure the accurate acquisition of the geographic location of each litchi tree. The equipment continuously tracks the location data of the trees through satellite signals, and records the longitude and latitude information of the trees in real time. Through software processing, this geographic information is converted into a specific X and Y coordinate system. The data correction function supported by GIS software is used to ensure the accuracy of the coordinates and filter out unstable data points with weak GPS signals or interference. After data cleaning and verification, a complete coordinate data set is formed. The coordinate data is stored in the central database for further analysis and use to obtain an initialized coordinate data set.

[0067] S102: Based on the coordinate data set, using a laser measurement device, measure the elevation and tree height of each tree one by one, record the relative ground height and absolute tree height of each tree, and obtain an elevation and tree height data set;

[0068] Based on the coordinate data set, laser measurement equipment is used to measure the elevation and tree height of each tree. By configuring the laser rangefinder to aim at the highest point and root position of each tree, the instrument emits a laser beam and receives the reflected signal to calculate the tree height and the height relative to the ground. Before each measurement, the instrument is calibrated to ensure the accuracy and repeatability of the measurement data. Multi-point sampling technology is used in the laser measurement process to increase the data collection points to improve the accuracy of the results. The measured height data is optimized by algorithm to eliminate possible errors, forming a detailed elevation and tree height data set, which is recorded in a dedicated data management system to obtain the elevation and tree height data set.

[0069] S103: Based on the coordinate dataset and the elevation and tree height datasets, the datasets are integrated into the ground projection and vertical density matrix of the litchi tree to obtain an initialization dataset;

[0070] Based on the coordinate dataset and the elevation and tree height dataset, they are integrated into the ground projection and vertical density matrix of the litchi trees. Through the data integration software, the coordinate data are correlated with the elevation and tree height data to construct a three-dimensional model of each tree, and the ground projection area and vertical spatial distribution of the tree are calculated. The process includes comprehensive sorting and classification of the data of each tree, and the use of statistical methods to analyze the dataset to ensure the accuracy and comprehensiveness of the data integration, and generate an initialization dataset containing the ground projection and vertical density distribution of all trees.

[0071] See also Figure 3 ,Based on the initialization data set, by analyzing the data of boundary factors and wind direction factors,combining the distribution of litchi trees in the litchi orchard,the dynamic weight of wind direction and position is calculated for each tree,and the potential intensity of wind impact is assigned to each tree through numerical methods,and the wind impact weight matrix is ​​obtained,including the following steps:

[0072] S201: Based on the initialization data set, using the tree location information and combining the GIS data of the park boundary, the relative position of each tree to the park boundary is calculated, the decreasing function is applied to simulate the boundary factor, the boundary influence coefficient of each tree is set, and the boundary factor data set is obtained;

[0073] Based on the initialization data set, the calculation was performed in combination with the GIS data of the park boundary. The boundary of the litchi orchard was imported into the GIS system. By comparing it with the geographic coordinate data of the trees, the geographic information system was used to calculate the straight-line distance from each tree to the nearest park boundary. The distance was automatically completed through the distance calculation function of the GIS software. In order to simulate the actual impact of the boundary, a decreasing function was used to express the relationship between distance and impact intensity. This decreasing function was preset based on field measurement data and vegetation distribution. The function was applied to each tree to calculate their respective boundary influence coefficients. The coefficients reflected the specific impact of the park boundary on the tree growth environment, and the boundary factor data set of all trees was obtained. The data set recorded the location of each tree and the boundary influence coefficient.

[0074] S202: Based on the boundary factor data set, the dominant wind direction information is obtained from the meteorological station, and the influence of the wind direction on each tree is calculated according to the relative angle between the position of each tree and the wind direction, and the potential intensity of each tree being affected by the wind is evaluated to obtain the wind direction influence data set;

[0075] Based on the boundary factor data set, the current wind direction data is obtained from the nearest meteorological station. The data includes wind direction and wind speed. This information is automatically updated through the interface. GIS and data processing software are used to calculate the angle between the geographical location of each tree and the wind direction. This includes converting the wind direction into a relative angle with the north direction of the map, and then calculating the angle between the wind direction and the position of each tree. Through the preset wind impact model, the angle is converted into a quantitative indicator of the degree of impact of the wind on each tree. The shielding effect of wind speed and tree height is taken into account, and the potential intensity of the wind on each tree is evaluated to form a detailed wind direction impact data set.

[0076] S203: Based on the wind direction impact data set and the boundary factor data set, the potential intensity of wind impact on each tree is evaluated to obtain a wind impact weight matrix;

[0077] Based on the wind direction impact dataset and the boundary factor dataset, the potential intensity of wind impact on each tree was evaluated. The two datasets were imported into a unified analysis platform, and the wind direction impact data and boundary factor data were integrated through data fusion technology. The data fusion algorithm used in the process was optimized specifically for the impact of environmental factors, taking into account the temporal and spatial distribution characteristics of the data to ensure the accuracy of the evaluation. The wind impact weight of each tree was obtained by calculation. The weight was calculated based on the combined impact of wind direction and boundary factors. The weight matrix showed the potential intensity of wind impact on each tree in the park, providing a basis for wind damage prevention measures.

[0078] See also Figure 4 Based on the wind impact weight matrix, combined with the wind direction factor and the vertical density matrix, the actual windward area of ​​the litchi tree is calculated and updated by comparing and analyzing the density in each direction item by item, and the adjusted windward area matrix information is obtained, including the following steps:

[0079] S301: Based on the wind impact weight matrix, data on the windward area of ​​each litchi tree is collected one by one, and compared with the multi-directional density values ​​recorded in the vertical density matrix, and the windward area adjustment values ​​of each tree in multiple directions are evaluated to obtain windward area comparison data;

[0080] Based on the wind impact weight matrix, data is collected on the windward area of ​​each litchi tree, and collection equipment is configured to conduct actual measurements in the windward direction of each tree, including using anemometers and angle sensors to record wind direction and speed, as well as the area in direct contact with the trees. High-resolution cameras are used to capture the shape of the trees from multiple angles. The data is analyzed by a real-time data processing system and compared with the existing vertical density matrix. An algorithm is used to compare the windward area of ​​each tree with the multi-directional density values ​​recorded in the vertical density matrix, and each data point is adjusted to accurately match the actual situation. The comparison and analysis process is performed with professional software to ensure the accuracy and consistency of each data, and generate comparison data containing all adjusted windward area values.

[0081] S302: based on the windward area comparison data, extract the windward area adjustment value of each tree, update the actual windward area of ​​the litchi tree, organize the new windward area data into a table, re-evaluate the total windward area for each tree, and obtain updated windward area data;

[0082] Based on the windward area comparison data, the windward area adjustment value of each tree was extracted, the actual windward area of ​​the litchi tree was updated, the windward area adjustment value in the comparison data set was exported, and the value was updated to the record of each tree through data processing software. The updated data included the windward area of ​​each tree and its change value. This information was reorganized into a table format for further analysis and archiving. The table included the tree identification number, original windward area, adjusted windward area and adjustment range. In the process, a database management system was used to process large amounts of data to ensure accurate entry and timely updating of information. The total windward area was re-evaluated for each tree to form an updated windward area data set, which will be used for subsequent environmental impact assessments.

[0083] S303: Based on the updated windward area data, data aggregation is performed to construct a litchi orchard windward area matrix, and adjusted windward area matrix information is obtained.

[0084] Based on the updated windward area data, data aggregation is performed and the windward area matrix of the litchi orchard is constructed. The windward area data of each tree is aggregated using data integration tools, which involves the import, processing and aggregation of data. The windward area data of each tree is aggregated into a unified matrix. The matrix reflects the distribution and size of the windward area of ​​all trees in the orchard. During the data aggregation process, statistical software is used for data verification and analysis to ensure the correctness of each value and the accuracy of the entire matrix. After the integration is completed, the adjusted windward area matrix information is generated, providing basic data for analysis and planning.

[0085] See also Figure 5 Based on the adjusted windward area matrix information, according to the terrain influence of the litchi orchard, each item in the adjusted windward area matrix is ​​corrected using the terrain attenuation factor, and the correction factor is applied to the elevation and tree height data of each tree to calculate the terrain adjusted windward area of ​​each tree. Obtaining the terrain adjusted windward area information includes the following steps:

[0086] S401: Based on the adjusted windward area matrix information, using the terrain data of the litchi orchard, including the elevation and tree height information of each tree, calculating the impact of the terrain on the windward area, evaluating the attenuation effect of the terrain factor, setting a matching terrain attenuation factor for each tree, and obtaining a terrain attenuation factor data set;

[0087] Based on the adjustment of the windward area matrix information, the terrain data of the litchi orchard, including the elevation and tree height information of each tree, was used for calculation. The elevation data and tree height data of each tree were extracted from the GIS system. The data were obtained through previous laser measurement and terrain mapping. The terrain analysis software was used to calculate the direct and indirect effects of the terrain on the windward area according to the slope, orientation and specific location of each tree. In the process, the digital elevation model was used for detailed terrain analysis. By setting model parameters, such as the slope influence coefficient and the orientation adjustment coefficient, the attenuation effect of the terrain was simulated, and a matching terrain attenuation factor was set for each tree. The factor was calculated based on the impact of the terrain on the wind flow pattern, ensuring that each factor reflects the impact of the actual terrain on the windward area of ​​the tree, and obtaining a data set containing the terrain attenuation factors of all trees.

[0088] S402: Based on the terrain attenuation factor data set, the windward area of ​​each tree in the adjusted windward area matrix is ​​corrected, and the windward area of ​​each tree is updated by the adopted terrain factor to obtain corrected windward area data;

[0089] Based on the terrain attenuation factor dataset, the windward area of ​​each tree in the adjusted windward area matrix is ​​corrected. By adopting the influence of terrain factors, the terrain attenuation factor is integrated with the windward area data of each tree in the windward area matrix. These factors are applied using data processing software for automatic correction, including adjusting the windward area of ​​each tree according to its terrain attenuation factor to ensure that the corrected windward area can reflect the actual terrain influence. The correction process considers the nonlinear influence of the factors and the interaction of multiple variables, updates the windward area of ​​each tree, and obtains the corrected windward area data, which reflects the actual wind impedance characteristics of the trees.

[0090] S403: Based on the corrected windward area data, collect and sort out the corrected windward areas of all trees, summarize the data, sort out the terrain-adjusted windward area of ​​each tree in the entire litchi orchard, and obtain terrain-adjusted windward area information;

[0091] Based on the corrected windward area data, the corrected windward areas of all trees were collected and sorted, the data were summarized, and all the corrected windward area data were imported into the data summary system. The data were sorted and analyzed through statistical analysis software. During the sorting process, the data of each tree were recorded in detail, including its geographical location, original and corrected windward area, and the application results of the terrain attenuation factor. Through the summary of the data, a detailed matrix containing the terrain-adjusted windward area of ​​each tree in the entire litchi orchard was constructed.

[0092] See also Figure 6 Based on the terrain-adjusted windward area information, combined with air density, air resistance coefficient and wind speed, the terrain-adjusted windward area of ​​each tree is mechanically analyzed, the wind force borne by each tree is calculated, and the wind force influence matrix is ​​obtained, which includes the following steps:

[0093] S501: adjusting the windward area information based on the terrain, combining it with the current air density parameter, collecting air density, air resistance coefficient and wind speed data, setting the initial variables for wind force calculation, and obtaining wind force analysis preparation data;

[0094] The windward area information is adjusted based on the terrain and combined with the current air density parameters. The air density parameters in the current environment are collected, including obtaining the air density value from the recent meteorological data. The air resistance coefficient and wind speed are recorded at the same time. The data is provided by the automatic weather station, updated in real time and transmitted to the central database through the data interface. The initial variables for wind calculation are set to include wind speed, air density and resistance coefficient. The obtained wind analysis preparation data provides the necessary input for subsequent steps to ensure the accuracy and real-time nature of wind assessment.

[0095] S502: Based on the wind force analysis preparation data, the wind force to which the trees are subjected is evaluated to obtain the wind force impact evaluation result of each tree;

[0096] The calculation formula for assessing the wind force to which a tree is subjected is:

[0097] F ij =∑0.5×ρ×Cd×σ h ×D ij ×W ij ×M ij ×H σij ×v 2

[0098] Among them, F ij represents the wind force on the tree in the i-th row and j-th column, ρ is the air density, Cd is the air resistance coefficient, σ h is the vertical density of litchi, D ij is the ground projection of the litchi tree, W ij is the wind direction factor, M ij is the boundary factor, H σij is the terrain attenuation factor, and v is the wind speed.

[0099] formula:

[0100] F ij =∑0.5×ρ×Cd×σ h ×D ij ×W ij ×M ij ×H σij ×v 2

[0101] Parameter details and how to obtain them:

[0102] Air density ρ: Air density is the mass of air per unit volume. At standard atmospheric pressure and temperature (0°C, 101.325kPa), the air density is approximately 1.225kg / m3. In practical applications, this value can be obtained from meteorological data or estimated by standard atmospheric conditions.

[0103] Air resistance coefficient Cd: It is a dimensionless coefficient used to describe the magnitude of the resistance encountered by an object when it moves in a fluid. For trees, this value generally depends on the shape and size of the tree, and is generally between 0.1 and 0.3. The specific value can be obtained through wind tunnel experiments or related literature.

[0104] Vertical density σ h : Indicates the density of branches and leaves of litchi trees in different directions. The closer the value is to 1, the more luxuriant the tree is in that direction. It is usually evaluated through field measurements or remote sensing technology.

[0105] The ground projection of the litchi tree D ij: Represents the projected area of ​​the tree on the ground, which can be estimated by measuring the maximum diameter of the crown, usually assuming that the crown is circular.

[0106] Wind direction factor W ij : This factor adjusts the effect of wind according to the direction of the wind, with the weight of direct wind being 1, the weight of crosswind decreasing, and the weight of opposite wind being 0. This can be determined by the actual wind direction and the relationship between the tree orientation, with the weight of direct wind being 1, the weight of crosswind decreasing, and the weight of opposite wind being 0.

[0107] Boundary factor M ij : Border trees have different exposure levels due to windbreaks, and this factor is used to adjust for this border effect. It is generally determined by the relative position of the tree to the forest boundary, with the edge tree being 1 and decreasing inwards.

[0108] Terrain attenuation factor H σij :The terrain effect is reflected by adjusting the weight of tree height and relative elevation. This factor is obtained by measuring the elevation and tree height on the spot, and is calculated by the formula H σij =A+2×B, where A and B are the conversion values ​​of relative elevation and tree height respectively, the range of A is [0, 1], and the range of B is [0.5, 1].

[0109] Wind speed v: Wind speed is the key parameter affecting wind force and can be directly obtained from the nearest weather station data.

[0110] Calculation example:

[0111] Set the parameters as follows:

[0112] ρ=1.225kg / m 3 (standard air density), Cd = 0.25 (commonly used tree air resistance coefficient), σ h = 0.9 (assuming that trees are very dense in a particular direction), D ij =10m 2 (crown projected area), W ij =0.8 (considering a larger side wind effect), M ij = 0.75 (trees not on the border but close to the edge), H σij =1.5 (elevation and tree height adjustment factor), v=10m / s (general wind speed).

[0113] Substituting into the formula:

[0114] F ij =∑0.5×1.225×0.25×0.9×10×0.8×0.75×1.5×10 2

[0115] =0.5×1.225×0.25×0.9×10×0.8×0.75×1.5×100

[0116] =247.03125 Newtons

[0117] It shows that under the given conditions, each tree is subjected to a wind force of approximately 247.03 Newtons. This calculation result can be used to assess the extent of damage to the litchi forest under this wind speed.

[0118] S503: Based on the wind impact assessment results of each tree, data is summarized to construct a wind impact matrix for the entire park, showing the wind force that each tree is subjected to, and obtaining a wind impact matrix;

[0119] Based on the wind impact assessment results of each tree, data is summarized and a wind impact matrix for the entire orchard is constructed. All assessment result data is imported into a unified data processing platform. Through data summary tools, the wind data of each tree in the entire litchi orchard is aggregated. The constructed wind impact matrix includes the location, wind size and direction of each tree. The matrix is ​​displayed through a graphical interface, which is convenient for managers to view and analyze the wind force borne by each tree in the park. The entire data summary process ensures the integrity of the data and the convenience of analysis. The resulting wind impact matrix provides an important basis for park risk management and disaster prevention planning.

[0120] See also Figure 7 ,Based on the wind impact matrix, through numerical comparison, we identify the severely damaged areas and trees, integrate the data, and through statistical analysis, evaluate the degree of wind impact in differentiated areas.,The damage assessment results of litchi forests include the following steps:

[0121] S601: Based on the wind force impact matrix, the wind force data of trees in each area are sorted by numerical method, the area with the largest wind force is identified, and the identification data of the high wind force area is obtained;

[0122] Based on the wind impact matrix, the wind data of trees in each area were sorted by numerical methods. The wind impact matrix was imported using data analysis software. The matrix contained the wind data of each tree in the litchi orchard. The software sorted the data according to the wind size through a sorting algorithm. The process included data cleaning to eliminate any outliers and duplicate records. The trees with the strongest wind in each area were screened out by setting parameters. Automated scripts were used to optimize calculation efficiency and accuracy. The high wind area identification data obtained included the trees with the strongest wind in each area, their specific locations and wind values.

[0123] S602: Based on the high wind area identification data, a wind difference analysis is performed on each area in the high wind area identification data, and by comparing the wind data, trees that are severely affected by the wind in each area are identified to obtain regional wind difference analysis results;

[0124] Based on the high wind area identification data, a wind difference analysis is performed on each area in the high wind area identification data, and the data of the high wind area is imported into a dedicated statistical analysis software. The software uses comparative analysis tools to analyze the wind data of all trees in each area, especially the wind difference with the trees with the strongest wind. The analysis helps identify the trees that are severely affected by the wind in each area. The analysis results not only include wind differences, but also evaluate the possible contribution of wind direction and terrain factors to wind impacts, and obtain regional wind difference analysis results. The results list in detail the trees most affected by wind in each area and their related wind data.

[0125] S603: Based on the regional wind force difference analysis results, a damage assessment index is calculated, and the damage of the entire litchi orchard is assessed to obtain a litchi orchard damage assessment result;

[0126] The formula for calculating the damage assessment index is:

[0127]

[0128] Among them, R is the damage assessment index, F ij represents the wind force on the tree in row i and column j, Z ij represents the relative area of ​​the tree in the i-th row and j-th column in the litchi forest, X ij is the distance from the tree to the center of the litchi forest, and e is the base of the natural logarithm.

[0129] formula:

[0130]

[0131] Parameter details and how to obtain them:

[0132] F ij : Represents the wind force received by the tree in the i-th row and j-th column.

[0133] Z ij : represents the relative area of ​​the tree in row i and column j in the litchi forest. This is usually estimated from tree canopy cover obtained through ground measurements or from GIS data.

[0134] X ij : is the distance from the tree to the center of the litchi forest. The distance can be accurately measured by GPS positioning and GIS technology, usually in meters.

[0135] Calculation example:

[0136] Set the following parameter values: F ij = 200N (the wind force on a tree in a strong wind), Z ij =50m 2 (ground coverage of trees), X ij = 150m (the distance from the tree to the center of the litchi forest), e -Xij / 100 ≈e -1.5 ≈0.22313 (distance attenuation effect).

[0137] Substituting these values ​​into the formula:

[0138]

[0139] Suppose there are 10 trees in the litchi forest, and the Z of all trees ij Total is 500m 2 , and the conditions for all trees are similar, we can calculate:

[0140]

[0141] R represents the average damage assessment index of the entire litchi forest, with a value of 44.626, indicating the average degree of wind impact on the entire litchi forest under given wind force and tree location conditions. The value can be used to assess the possible degree of damage to the litchi forest and formulate corresponding management or restoration measures accordingly.

[0142] The above are only preferred embodiments of the present invention and are not intended to limit the present invention in other forms. Any technician familiar with the profession may use the technical contents disclosed above to change or modify them into equivalent embodiments with equivalent changes and apply them to other fields. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for assessing damage to litchi forests under strong winds, characterized in that: The following steps are involved: Based on the information of litchi orchards, coordinate extraction technology is used to extract the coordinates and elevation information of trees from map data, measure the tree height, and integrate the data into the ground projection and vertical density matrix of litchi trees to obtain the initialization data set. Based on the initialization data set, by analyzing the data of boundary factors and wind direction factors, combined with the distribution of litchi trees in the litchi orchard, the potential intensity of wind impact on each tree is allocated to obtain a wind impact weight matrix; Based on the wind impact weight matrix, combined with the wind direction factor and the vertical density matrix, the actual windward area of ​​the litchi tree is calculated and updated by comparing and analyzing the density in each direction item by item, so as to obtain the adjusted windward area matrix information; Based on the adjusted windward area matrix information, according to the terrain influence of the litchi orchard, each item in the adjusted windward area matrix is ​​corrected using the terrain attenuation factor, the terrain adjusted windward area of ​​each tree is calculated, and the terrain adjusted windward area information is obtained; Based on the terrain-adjusted windward area information, combined with air density, air resistance coefficient and wind speed, a mechanical analysis is performed on the terrain-adjusted windward area of ​​each tree, the wind force borne by each tree is calculated, and a wind force influence matrix is ​​obtained; Based on the wind impact matrix, the severely damaged areas and trees are identified through numerical comparison, the degree of wind impact on differentiated areas is evaluated, and the damage assessment results of the litchi forest are obtained.

2. The method for assessing damage to litchi forests under strong winds according to claim 1, characterized in that: The initialization data set includes the location coordinates of the trees, the elevation information of each tree, the tree height data, the ground projection area and the vertical density information; the wind impact weight matrix includes the boundary impact information of each tree, the wind direction impact score and the dynamic weight of the wind direction and boundary adjustment; the adjusted windward area matrix information includes the windward area of ​​each tree adjusted for density and the windward area adjustment value of the wind direction change; the terrain adjusted windward area information includes the windward area of ​​each tree adjusted based on its elevation and tree height and the windward area after the terrain attenuation effect; the wind force impact matrix includes the predicted wind force value of each tree under the set wind speed conditions and the wind force impact scores in multiple directions; the litchi forest damage assessment results include the location of the severely wind-affected areas, the list of damaged trees and the classification of the degree of damage.

3. The method for assessing damage to litchi forests under strong winds according to claim 1, characterized in that: Based on the information of the litchi orchard, the coordinate extraction technology is used to extract the coordinates and elevation information of the trees from the map data, measure the tree height, and integrate the data into the ground projection and vertical density matrix of the litchi tree. The specific steps to obtain the initialization data set are as follows: Based on the litchi orchard information, the geographical coordinates of each tree are located through GPS positioning, and the geographical coordinates of the tree are entered to obtain the X and Y coordinate positions of each tree to obtain a coordinate data set; Based on the coordinate data set, using a laser measurement device, the elevation and tree height of each tree are measured one by one, and the relative ground height and absolute tree height of each tree are recorded to obtain an elevation and tree height data set; Based on the coordinate data set and the elevation and tree height data sets, they are integrated into the ground projection and vertical density matrix of the litchi tree to obtain an initialization data set.

4. The method for assessing damage to litchi forests under strong winds according to claim 1, characterized in that: Based on the initialization data set, by analyzing the data of boundary factors and wind direction factors, combined with the distribution of litchi trees in the litchi orchard, the potential intensity of wind impact on each tree is allocated, and the steps of obtaining the wind impact weight matrix are specifically as follows: Based on the initialization data set, using the tree location information and combining with the GIS data of the park boundary, the relative position of each tree to the park boundary is calculated, a decreasing function is applied to simulate the boundary factor, and the boundary influence coefficient of each tree is set to obtain the boundary factor data set; Based on the boundary factor data set, the dominant wind direction information is obtained from the meteorological station, and the influence of the wind direction on each tree is calculated according to the relative angle between the position of each tree and the wind direction, and the potential intensity of each tree being affected by the wind is evaluated to obtain the wind direction influence data set; Based on the wind direction impact data set and the boundary factor data set, the potential intensity of wind impact on each tree is evaluated to obtain a wind impact weight matrix.

5. The method for assessing damage to litchi forests under strong winds according to claim 1, characterized in that: Based on the wind impact weight matrix, combined with the wind direction factor and the vertical density matrix, the actual windward area of ​​the litchi tree is calculated and updated by comparing and analyzing the density in each direction item by item, and the steps of adjusting the windward area matrix information are as follows: Based on the wind impact weight matrix, data on the windward area of ​​each litchi tree is collected one by one, and compared with the multi-directional density values ​​recorded in the vertical density matrix, and the windward area adjustment values ​​of each tree in multiple directions are evaluated to obtain windward area comparison data; Based on the windward area comparison data, extract the windward area adjustment value of each tree, update the actual windward area of ​​the litchi tree, organize the new windward area data into a table, re-evaluate the total windward area for each tree, and obtain updated windward area data; Based on the updated windward area data, data aggregation is performed to construct a litchi orchard windward area matrix to obtain adjusted windward area matrix information.

6. The method for assessing damage to litchi forests under strong winds according to claim 1, characterized in that: Based on the adjusted windward area matrix information, according to the terrain influence of the litchi orchard, each item in the adjusted windward area matrix is ​​corrected by using the terrain attenuation factor, and the terrain adjusted windward area of ​​each tree is calculated. The steps of obtaining the terrain adjusted windward area information are specifically as follows: Based on the adjusted windward area matrix information, using the terrain data of the litchi orchard, including the elevation and tree height information of each tree, the influence of the terrain on the windward area is calculated, the attenuation effect of the terrain factor is evaluated, and a matching terrain attenuation factor is set for each tree to obtain a terrain attenuation factor data set; Based on the terrain attenuation factor data set, the windward area of ​​each tree in the adjusted windward area matrix is ​​corrected, and the windward area of ​​each tree is updated by the adopted terrain factor to obtain corrected windward area data; Based on the corrected windward area data, the corrected windward areas of all trees are collected and sorted, the data are summarized, and the terrain-adjusted windward area of ​​each tree in the entire litchi orchard is sorted to obtain terrain-adjusted windward area information.

7. The method for assessing damage to litchi forests under strong winds according to claim 1, characterized in that: Based on the terrain-adjusted windward area information, combined with air density, air resistance coefficient and wind speed, a mechanical analysis is performed on the terrain-adjusted windward area of ​​each tree, and the wind force borne by each tree is calculated. The steps of obtaining the wind force influence matrix are as follows: Adjusting the windward area information based on the terrain and combining it with the current air density parameters, collecting air density, air resistance coefficient and wind speed data, setting initial variables for wind force calculation, and obtaining wind force analysis preparation data; Based on the wind force analysis preparation data, the wind force to which the trees are subjected is evaluated to obtain a wind force impact evaluation result for each tree; Based on the wind impact assessment results of each tree, data are summarized to construct a wind impact matrix for the entire park, showing the wind force that each tree is subjected to, and obtaining a wind impact matrix.

8. The method for assessing damage to litchi forests under strong winds according to claim 7, characterized in that: The calculation formula for evaluating the wind force that trees bear is: F ij =∑0.5×ρ×Cd×σ h ×D ij ×W ij ×M ij ×H σij ×v 2 Among them, F ij represents the wind force on the tree in the i-th row and j-th column, ρ is the air density, Cd is the air resistance coefficient, σ h is the vertical density of litchi, D ij is the ground projection of the litchi tree, W ij is the wind direction factor, M ij is the boundary factor, H σij is the terrain attenuation factor, and v is the wind speed.

9. The method for assessing damage to litchi forests under strong winds according to claim 1, characterized in that: Based on the wind impact matrix, the steps of identifying severely damaged areas and trees through numerical comparison, evaluating the degree of wind impact on differentiated areas, and obtaining the litchi forest damage assessment results are as follows: Based on the wind force impact matrix, the wind force data of trees in each area are sorted by numerical method, the area with the largest wind force is identified, and the identification data of the high wind force area is obtained; Based on the high wind area identification data, a wind difference analysis is performed on each area in the high wind area identification data, and by comparing the wind data, trees that are severely affected by the wind in each area are identified to obtain regional wind difference analysis results; Based on the analysis results of the regional wind force differences, a damage assessment index is calculated, the damage situation of the entire litchi orchard is assessed, and the litchi orchard damage assessment results are obtained.

10. The method for assessing damage to litchi forests under strong winds according to claim 9, characterized in that: The formula for calculating the damage assessment index is: Among them, R is the damage assessment index, F ij represents the wind force on the tree in row i and column j, Z ij represents the relative area of ​​the tree in the i-th row and j-th column in the litchi forest, X ij is the distance from the tree to the center of the litchi forest, and e is the base of the natural logarithm.

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