A method for investigating lithofacies intertidal sessile organisms based on visual modeling

Abstract

The application discloses a facies intertidal zone sessile organism investigation method based on visual modeling, first, the low tide period of spring tide day is determined in combination with the data of the tidal station, the orthographic image and three-dimensional model of the investigation area are acquired by using the RTK unmanned aerial vehicle, the accurate investigation range is demarcated and the entry and exit paths are planned through the geographic information system processing. The slope parameters are calculated by using the digital land surface model and the personnel equipment configuration is optimized, the ground control points are laid on the site, and the geodetic coordinate system reference is established. The double route oblique photography mode is adopted, the image shooting sampling is carried out at a 45-degree visual angle, a 0.4m object distance and a 70% image overlap rate, the high-precision three-dimensional ecological model is generated through the point cloud reconstruction in combination with the morphological identification result of the species, and the parameters such as the habitat density, interspecific competition and light adaptability of the sessile organism are efficiently investigated.

Description

Technical Field

[0001] This invention relates to the fields of remote sensing information technology and biological survey and assessment, and more specifically, to a method for surveying lithological intertidal fixed organisms based on visual modeling. Background Technology

[0002] The intertidal zone refers to the area covered by seawater between the mean high and low tides. As a relatively narrow area where land and sea meet, the intertidal zone is home to a diverse array of biological groups and is a typical two-facies zone. Different parts of the lithofacies intertidal zone are exposed to varying degrees of environmental stress. The sessile biological communities inhabiting this zone (such as snails and barnacles) are significantly affected by waves, tides, salinity, light, and human disturbance due to their conservative activity range, forming a unique biological zone with highly representative ecological types. Research on the distribution patterns and driving factors of sessile organisms in the lithofacies intertidal zone is crucial for a comprehensive understanding of the distribution patterns of marine biodiversity and its response to complex ecological factors. Current research on these organisms primarily employs field surveys, involving the destructive collection of biological samples through transects or quadrats, and the on-site measurement of intertidal environmental factors (elevation, slope, aspect, light intensity, tidal height, salinity, and human disturbance). The collected samples are then analyzed for species composition, abundance variations, community structure, and influencing factors. Because the intertidal zone is only exposed for a short period (approximately 2 hours in the subtidal zone), completing the sampling and measurement work within this narrow time window severely limits the biological sampling area and the types and density of environmental factor data collected. Only localized measurements of a small number of biological samples and a few environmental factors can be obtained, significantly restricting the accuracy and depth of analysis on the distribution patterns and environmental response mechanisms of these organisms. Furthermore, multiple investigators operating together with numerous instruments and equipment in a confined space under strict time constraints pose significant safety hazards.

[0003] Therefore, it is necessary to invent a method for surveying sessile organisms in the intertidal zone based on oblique photogrammetry modeling technology to address the above problems. This method can obtain the species and quantity of all sessile organisms within the survey area, as well as the measurements of multiple environmental factors at each individual's location. This will improve the completeness and resolution of data collection, significantly reduce workload and operation time, and enhance the safety of field surveys. It can provide a solid scientific basis for assessing intertidal biodiversity, ecological function, and ecological value. Summary of the Invention

[0004] This invention overcomes the shortcomings of existing technologies and proposes a method for investigating sessile organisms in the intertidal zone of lithofacies based on visual modeling.

[0005] The first aspect of this invention provides a method for investigating sessile organisms in the intertidal zone based on visual modeling, comprising:

[0006] S1: Define the investigation area of ​​the intertidal zone of lithofacies, obtain the tide forecast information released by the latest tide gauge station, and extend the working time by 1 hour before and after the lowest tide time.

[0007] S2: Based on the high-resolution satellite map of the survey area, determine the preliminary survey range, set the flight path of the mapping drone according to the preliminary survey range, the mapping drone includes an RTK function module and a flight camera, and start the mapping drone at the lowest tide on the day of spring tide to obtain orthophotos.

[0008] S3: Preprocess the orthophotos, align the aerial images and generate point cloud data. Based on the point cloud data, create an orthophoto map and digital surface model of the aerial survey area, and build a 3D model. Load the orthophoto map into the geographic information system (GIS) software, delineate the precise survey area based on image features, calculate the area of ​​the survey area and export it in CAD format. Load the 3D model into the GIS software, determine the entry points, entry methods, exit points and exit methods for survey personnel and equipment based on the terrain distribution characteristics of the survey area. Load the digital surface model into the GIS software, calculate the average slope of the survey area, and determine the equipment type requirements and the number of personnel based on the average slope.

[0009] S4: Based on the tide forecast, set the second spring tide day, enter the survey site at the beginning of the working period, import the CAD file of the precise survey range into the RTK measuring instrument, carry out the layout, determine the actual location of the boundary of the survey area, and then lay red cables along the boundary.

[0010] S5: Search for and collect various types of sessile biological samples within the survey area. The number of individuals collected for each species shall be ≤3. After collection, the samples shall be immediately placed in a 4℃ refrigerator for preservation. The collected biological samples shall be morphologically identified to obtain the species identification results.

[0011] S6: Set up ≥10 ground control points within the survey area, place circular metal signs with the center point marked at the ground control point locations, and use an RTK measuring instrument to determine the geographic coordinates and elevation of the center point of the sign. The coordinate system adopted is the 2000 National Geodetic Coordinate System, and the projection method is selected as Gauss-Kruger projection.

[0012] S7: Camera parameters are preset as follows: center-weighted average metering, autofocus, auto white balance, aperture priority, and aperture value set to ƒ / 8; if a camera device that cannot adjust the aperture is selected, the camera's native aperture value will be used and auto ISO will be set; hold the camera and take pictures in sequence along two paths, one horizontal and one vertical, based on an "S" shaped route.

[0013] S8: When taking photos, the photographer stands still, holds the camera, and makes the lens at an angle of about 45° to the rock surface. The lens is about 0.4m away from the subject. Take 3 photos at each shooting point, and make the center points of the 3 photos follow the same straight line. The overlap rate between the photos is ≥70%. Then the photographer moves 0.7m along the shooting line and continues to take photos in the above manner. Repeat the shooting until the entire line is walked and the overlap rate between all adjacent photos is ≥70%. Then leave the survey area.

[0014] S9: Import the oblique photographs from S8 into the data processing software, align the photographs, mark the coordinates of ground control points, optimize the photograph alignment parameters, generate a second point cloud, establish an orthophoto map and digital surface model of the survey area based on the second point cloud, and establish a three-dimensional model. Combined with the species identification results, conduct an ecological survey of sessile organisms and generate the habitat density, spatial competition relationship, and light adaptability of each sessile organism.

[0015] In this solution, S2 specifically refers to:

[0016] The requirements for UAV flight path parameters are as follows: the main flight path should be parallel to the shoreline; the flight altitude relative to the ground should be ≤30 m; the lateral overlap rate of aerial photographs should be ≥70%; the forward overlap rate should be ≥80%; the flight start point should be set to the point closest to the waterline; the surveying UAV should be launched at the lowest tide level on a spring tide day; the surveying UAV should be equipped with an RTK function module, have image control-free surveying function; the flight camera should have a pixel count ≥20 million; the lens equivalent focal length should be 24~60 cm; the flight speed along the flight path should be ≥5 m / s; and the UAV should collect orthophotos along the set flight path.

[0017] In this scheme, in S3, the ground resolution of the orthophoto map is ≤1cm / pixel, the ground resolution of the digital surface model is ≤1cm / pixel, and the three-dimensional model is an OSGB format model.

[0018] In this scheme, the formula for calculating the total photo-taking time in S7 is: (total length of the two routes / 0.7 m) × 0.2 min; if the total photo-taking time is ≥ 30 min, then the number of photographers and camera positions will be increased.

[0019] In this scheme, in S9, the ground resolution of the orthophoto map is ≤0.25mm / pixel, the ground resolution of the digital surface model is ≤0.25 mm / pixel, and the three-dimensional model is an OSGB format model.

[0020] In this solution, S9 includes:

[0021] The 3D model established by S9 was imported into the geographic information system software. Based on the species identification results, the sessile organisms in the model were identified and classified using visual or human-computer interaction methods. A point marker was added to the center point of each individual, and the point markers of different species were distinguished by different attribute values. Each individual was briefly marked with a polygon to form an individual outline. The polygons of different species were distinguished by different attribute values. Based on the above point markers, the total number of species and the number of individuals of each species within the survey area were counted, and the habitat density of each organism was calculated.

[0022] In this solution, S9 includes:

[0023] The digital surface model established in step 9 is imported into the geographic information system (GIS) software to generate slope and aspect raster maps of the survey area, with a ground resolution ≤ 0.25 mm / pixel. Then, the point markers of sessile organisms are imported into the GIS software to extract the elevation, slope, and aspect values ​​of each individual's location. Frequency distribution analysis is used to analyze the range and degree of each species' preference for habitat elevation, slope, and aspect, thus obtaining the spatial niche characteristics of each sessile species. Kernel density analysis is performed based on individual point markers to obtain the distribution map of dense areas of various sessile organisms. The spatial competition relationship of various organisms for habitat is analyzed by the degree of overlap of dense areas of various organisms.

[0024] In this solution, S9 includes:

[0025] The polygonal outlines of sessile organisms are imported into a geographic information system software. The habitat area occupied by each organism is counted, and light analysis is performed. The statistical period is set to one natural year. The total solar radiation projected onto each individual is counted, and the light adaptability of each species is analyzed.

[0026] A second aspect of the present invention also provides a visual modeling-based system for surveying lithological intertidal zone sessile organisms. The system includes a memory and a processor. The memory includes a visual modeling-based program for surveying lithological intertidal zone sessile organisms. When executed by the processor, the visual modeling-based program performs the following steps:

[0027] S1: Define the investigation area of ​​the intertidal zone of lithofacies, obtain the tide forecast information released by the latest tide gauge station, and extend the working time by 1 hour before and after the lowest tide time.

[0028] S2: Based on the high-resolution satellite map of the survey area, determine the preliminary survey range, set the flight path of the mapping drone according to the preliminary survey range, the mapping drone includes an RTK function module and a flight camera, and start the mapping drone at the lowest tide on the day of spring tide to obtain orthophotos.

[0029] S3: Preprocess the orthophotos, align the aerial images and generate point cloud data. Based on the point cloud data, create an orthophoto map and digital surface model of the aerial survey area, and build a 3D model. Load the orthophoto map into the geographic information system (GIS) software, delineate the precise survey area based on image features, calculate the area of ​​the survey area and export it in CAD format. Load the 3D model into the GIS software, determine the entry points, entry methods, exit points and exit methods for survey personnel and equipment based on the terrain distribution characteristics of the survey area. Load the digital surface model into the GIS software, calculate the average slope of the survey area, and determine the equipment type requirements and the number of personnel based on the average slope.

[0030] S4: Based on the tide forecast, set the second spring tide day, enter the survey site at the beginning of the working period, import the CAD file of the precise survey range into the RTK measuring instrument, carry out the layout, determine the actual location of the boundary of the survey area, and then lay red cables along the boundary.

[0031] S5: Search for and collect various types of sessile biological samples within the survey area. The number of individuals collected for each species shall be ≤3. After collection, the samples shall be immediately placed in a 4℃ refrigerator for preservation. The collected biological samples shall be morphologically identified to obtain the species identification results.

[0032] S6: Set up ≥10 ground control points within the survey area, place circular metal signs with the center point marked at the ground control point locations, and use an RTK measuring instrument to determine the geographic coordinates and elevation of the center point of the sign. The coordinate system adopted is the 2000 National Geodetic Coordinate System, and the projection method is selected as Gauss-Kruger projection.

[0033] S7: Camera parameters are preset as follows: center-weighted average metering, autofocus, auto white balance, aperture priority, and aperture value set to ƒ / 8; if a camera device that cannot adjust the aperture is selected, the camera's native aperture value will be used and auto ISO will be set; hold the camera and take pictures in sequence along two paths, one horizontal and one vertical, based on an "S" shaped route.

[0034] S8: When taking photos, the photographer stands still, holds the camera, and makes the lens at an angle of about 45° to the rock surface. The lens is about 0.4m away from the subject. Take 3 photos at each shooting point, and make the center points of the 3 photos follow the same straight line. The overlap rate between the photos is ≥70%. Then the photographer moves 0.7m along the shooting line and continues to take photos in the above manner. Repeat the shooting until the entire line is walked and the overlap rate between all adjacent photos is ≥70%. Then leave the survey area.

[0035] S9: Import the oblique photographs from S8 into the data processing software, align the photographs, mark the coordinates of ground control points, optimize the photograph alignment parameters, generate a second point cloud, establish an orthophoto map and digital surface model of the survey area based on the second point cloud, and establish a three-dimensional model. Combined with the species identification results, conduct an ecological survey of sessile organisms and generate the habitat density, spatial competition relationship, and light adaptability of each sessile organism.

[0036] A third aspect of the present invention also provides a computer-readable storage medium comprising a visual modeling-based lithofacies intertidal zone sessile organism survey program, wherein when the visual modeling-based lithofacies intertidal zone sessile organism survey program is executed by a processor, it implements the steps of the visual modeling-based lithofacies intertidal zone sessile organism survey method as described in any of the preceding claims.

[0037] This invention discloses a visual modeling-based method for surveying sessile organisms in the intertidal zone of lithofacies. First, by combining data from tide gauge stations to determine the low tide period on spring tide days, orthophotos and 3D models of the survey area are acquired using an RTK drone. Geographic Information System (GIS) processing is then used to delineate the precise survey area and plan entry and exit routes. Slope parameters are calculated using a digital surface model to optimize personnel and equipment configuration. Ground control points are established on-site, and a geodetic coordinate system benchmark is created. A dual-route oblique photography method is employed, with image sampling at a 45° angle, 0.4m object distance, and 70% image overlap. Combined with species morphological identification results, a high-precision 3D ecological model is generated through point cloud reconstruction, efficiently investigating parameters such as habitat density, interspecific competition, and light adaptability of sessile organisms. Attached Figure Description

[0038] Figure 1 A flowchart of a method for investigating lithological intertidal bound organisms based on visual modeling according to the present invention is shown;

[0039] Figure 2 A reference diagram of the control points of the present invention is shown;

[0040] Figure 3 This diagram illustrates the first photographing action line of the present invention.

[0041] Figure 4 A schematic diagram of the second photographing action line of the present invention is shown;

[0042] Figure 5 A schematic diagram of the photographing process of this invention is shown;

[0043] Figure 6 A block diagram of a lithofacies intertidal zone sessile organism survey system based on visual modeling of the present invention is shown. Detailed Implementation

[0044] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0045] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0046] Figure 1 The flowchart of a method for investigating sessile organisms in the intertidal zone based on visual modeling according to the present invention is shown.

[0047] like Figure 1 As shown, the first aspect of the present invention provides a method for investigating sessile organisms in the intertidal zone based on visual modeling, comprising:

[0048] S1: Define the investigation area of ​​the intertidal zone of lithofacies, obtain the tide forecast information released by the latest tide gauge station, and extend the working time by 1 hour before and after the lowest tide time.

[0049] S2: Based on the high-resolution satellite map of the survey area, determine the preliminary survey range, set the flight path of the mapping drone according to the preliminary survey range, the mapping drone includes an RTK function module and a flight camera, and start the mapping drone at the lowest tide on the day of spring tide to obtain orthophotos.

[0050] S3: Preprocess the orthophotos, align the aerial images and generate point cloud data. Based on the point cloud data, create an orthophoto map and digital surface model of the aerial survey area, and build a 3D model. Load the orthophoto map into the geographic information system (GIS) software, delineate the precise survey area based on image features, calculate the area of ​​the survey area and export it in CAD format. Load the 3D model into the GIS software, determine the entry points, entry methods, exit points and exit methods for survey personnel and equipment based on the terrain distribution characteristics of the survey area. Load the digital surface model into the GIS software, calculate the average slope of the survey area, and determine the equipment type requirements and the number of personnel based on the average slope.

[0051] The requirements for equipment type and number of staff are determined based on the average slope, as shown in the table below:

[0052]

[0053] S4: Based on the tide forecast, set the second spring tide day, enter the survey site at the beginning of the working period, import the CAD file of the precise survey range into the RTK measuring instrument, carry out the layout, determine the actual location of the boundary of the survey area, and then lay red cables along the boundary.

[0054] S5: Search for and collect various types of sessile biological samples within the survey area. The number of individuals collected for each species shall be ≤3. After collection, the samples shall be immediately placed in a 4℃ refrigerator for preservation. The collected biological samples shall be morphologically identified to obtain the species identification results.

[0055] S6: Set up ≥10 ground control points within the survey area, place circular metal signs with the center point marked at the ground control point locations, and use an RTK measuring instrument to determine the geographic coordinates and elevation of the center point of the sign. The coordinate system adopted is the 2000 National Geodetic Coordinate System, and the projection method is selected as Gauss-Kruger projection.

[0056] Figure 2 A reference diagram of the control points of the present invention is shown;

[0057] Control Point Reference Figure 2 Deployment;

[0058] S7: Camera parameters are preset as follows: center-weighted average metering, autofocus, auto white balance, aperture priority, and aperture value set to ƒ / 8; if a camera device that cannot adjust the aperture is selected, the camera's native aperture value will be used and auto ISO will be set; hold the camera and take pictures in sequence along two paths, one horizontal and one vertical, based on an "S" shaped route.

[0059] Figure 3 This diagram illustrates the first photographing action line of the present invention.

[0060] Figure 4 A schematic diagram of the second photographing action line of the present invention is shown;

[0061] Figure 5 A schematic diagram of the photographing process of this invention is shown;

[0062] The first photo-taking route is as follows: Figure 3 ;

[0063] The second photo-taking route is as follows: Figure 4 ;

[0064] S8: When taking photos, the photographer stands still, holding the camera with the lens at approximately a 45° angle to the rock surface and about 0.4m from the subject. Take three consecutive photos at each shooting point, ensuring the center points of the three photos are aligned in a straight line and the overlap between photos is ≥70%. Then, the photographer moves 0.7m along the shooting route and continues taking photos in the same manner, repeating the process until the entire route is completed and the overlap between all adjacent photos is ≥70%. Afterwards, leave the survey area.

[0065] Photo format such as Figure 5 ;

[0066] S9: Import the oblique photographs from S8 into the data processing software, align the photographs, mark the coordinates of ground control points, optimize the photograph alignment parameters, generate a second point cloud, establish an orthophoto map and digital surface model of the survey area based on the second point cloud, and establish a three-dimensional model. Combined with the species identification results, conduct an ecological survey of sessile organisms and generate the habitat density, spatial competition relationship, and light adaptability of each sessile organism.

[0067] It should be noted that multiple working periods can be set during the survey period to ensure that the survey needs are met.

[0068] The present invention sets up model data, including orthophoto maps, digital surface models, and three-dimensional models of the survey area (range) and orthophoto maps, digital surface models, and three-dimensional models of the aerial survey area.

[0069] According to an embodiment of the present invention, S2 specifically includes:

[0070] The requirements for UAV flight path parameters are as follows: the main flight path should be parallel to the shoreline; the flight altitude relative to the ground should be ≤30 m; the lateral overlap rate of aerial photographs should be ≥70%; the forward overlap rate should be ≥80%; the flight start point should be set to the point closest to the waterline; the surveying UAV should be launched at the lowest tide level on a spring tide day; the surveying UAV should be equipped with an RTK function module, have image control-free surveying function; the flight camera should have a pixel count ≥20 million; the lens equivalent focal length should be 24~60 cm; the flight speed along the flight path should be ≥5 m / s; and the UAV should collect orthophotos along the set flight path.

[0071] It should be noted that route planning can be performed using flight route planning software.

[0072] In S3, preprocessing is based on aerial survey post-processing software for data processing and point cloud data generation. CAD format files are used, such as .dwg files. Based on the terrain characteristics of the precise survey area, equipment entry and exit points are determined, generally preferably in flat, open locations. Entry and exit methods include land or water transport. After defining the precise survey area, subsequent steps are conducted within that area. The preliminary survey area is used to determine the flight path of the surveying UAV.

[0073] In S4, red cables are laid to provide guidance for subsequent operations. The ground control points are based on the CGCS2000 national geodetic coordinate system, with the Gauss-Kruger projection (3° zoning) selected.

[0074] In the S7, camera devices that cannot adjust the aperture can include mobile devices such as smartphones and portable video recording devices.

[0075] According to an embodiment of the present invention, in step S3, the ground resolution of the orthophoto map is ≤1cm / pixel, the ground resolution of the digital surface model is ≤1cm / pixel, and the three-dimensional model is an OSGB format model.

[0076] According to an embodiment of the present invention, in step S7, the formula for calculating the total time for taking photos is: (total length of the two routes / 0.7 m) × 0.2 min; if the total time for taking photos is ≥ 30 min, then the number of photographers and camera positions will be increased.

[0077] It should be noted that the increase in the number of filming personnel and camera positions was to reduce labor intensity and ensure that the filming work was completed before the evacuation time.

[0078] According to an embodiment of the present invention, in step S9, the ground resolution of the orthophoto map is ≤0.25 mm / pixel, the ground resolution of the digital surface model is ≤0.25 mm / pixel, and the three-dimensional model is an OSGB format model.

[0079] According to an embodiment of the present invention, S9 includes:

[0080] The 3D model established by S9 was imported into the geographic information system software. Based on the species identification results, the sessile organisms in the model were identified and classified using visual or human-computer interaction methods. A point marker was added to the center point of each individual, and the point markers of different species were distinguished by different attribute values. Each individual was briefly marked with a polygon to form an individual outline. The polygons of different species were distinguished by different attribute values. Based on the above point markers, the total number of species and the number of individuals of each species within the survey area were counted, and the habitat density of each organism was calculated.

[0081] It should be noted that the habitat density of each organism is the overall habitat density, i.e., the distribution data.

[0082] According to an embodiment of the present invention, S9 includes:

[0083] The digital surface model established in step 9 is imported into the geographic information system (GIS) software to generate slope and aspect raster maps of the survey area, with a ground resolution ≤ 0.25 mm / pixel. Then, the point markers of sessile organisms are imported into the GIS software to extract the elevation, slope, and aspect values ​​of each individual's location. Frequency distribution analysis is used to analyze the range and degree of each species' preference for habitat elevation, slope, and aspect, thus obtaining the spatial niche characteristics of each sessile species. Kernel density analysis is performed based on individual point markers to obtain the distribution map of dense areas of various sessile organisms. The spatial competition relationship of various organisms for habitat is analyzed by the degree of overlap of dense areas of various organisms.

[0084] According to an embodiment of the present invention, S9 includes:

[0085] The polygonal outlines of sessile organisms are imported into a geographic information system software. The habitat area occupied by each organism is counted, and light analysis is performed. The statistical period is set to one natural year. The total solar radiation projected onto each individual is counted, and the light adaptability of each species is analyzed.

[0086] It should be noted that in this invention, "individual" and "species" specifically refer to the sessile organisms being investigated and studied.

[0087] According to an embodiment of the present invention, it further includes:

[0088] Within the survey area, a unit area is formed based on each shooting point, and the survey area is further divided into multiple unit areas;

[0089] A sessile organism was selected for analysis. Based on habitat density, spatial competition, and light adaptability within the survey area, a habitat density value, competition level value, and light intensity were assigned to each unit area.

[0090] For each unit area, an environmental characteristic is defined based on habitat density, competition level, and light intensity.

[0091] The number of clusters K is determined based on the number of sessile species within the survey area;

[0092] Using the K-means clustering algorithm, environmental features are used as clustering input. K initial cluster centers are set, and the distance between the clustering input and the cluster centers is calculated iteratively and the cluster centers are updated until the center points no longer move, thus obtaining the clustering results.

[0093] Based on the clustering results, the unit area is divided into K region groups. The regions are sorted in ascending order based on the number of unit areas in each region group, and the monitoring priority is dynamically set for the region groups in sequence.

[0094] It should be noted that habitat density values ​​vary across multiple unit areas. Environmental characteristics can be represented as vectors, with dimensions corresponding to habitat density, competition level, and light intensity. Competition level is set based on the overlap of various biologically dense areas, and distance is calculated using standard Euclidean distance. K equals the number of sessile species within the survey area multiplied by a preset coefficient (range 0.5~2.5). This means that in this invention, based on a survey period, environmental characteristics of a unit area are defined using biological survey data obtained from a precise survey area. These environmental characteristics represent the relationship between sessile organisms in the intertidal zone and the intertidal environment using multi-dimensional information. Clustering is used to fuse similar range characteristics within unit areas. Furthermore, region groups are generated based on the clustering results. Region groups with fewer regions have significantly different ecological characteristics from the overall picture, indicating greater monitoring needs. Therefore, monitoring priorities are set based on the ranked region groups, with higher-ranked regions having higher priority. Monitoring plans are dynamically adjusted in the next survey cycle to dynamically adjust monitoring resources and efficiency, thereby improving the accuracy of biological surveys.

[0095] Figure 6 A block diagram of a lithofacies intertidal zone sessile organism survey system based on visual modeling of the present invention is shown.

[0096] A second aspect of the present invention also provides a visual modeling-based intertidal zone sessile organism survey system 6, which includes a memory 61 and a processor 62. The memory 61 includes a visual modeling-based intertidal zone sessile organism survey program. When the visual modeling-based intertidal zone sessile organism survey program is executed by the processor 62, it performs the following steps:

[0097] S1: Define the investigation area of ​​the intertidal zone of lithofacies, obtain the tide forecast information released by the latest tide gauge station, and extend the working time by 1 hour before and after the lowest tide time.

[0098] S2: Based on the high-resolution satellite map of the survey area, determine the preliminary survey range, set the flight path of the mapping drone according to the preliminary survey range, the mapping drone includes an RTK function module and a flight camera, and start the mapping drone at the lowest tide on the day of spring tide to obtain orthophotos.

[0099] S3: Preprocess the orthophotos, align the aerial images and generate point cloud data. Based on the point cloud data, create an orthophoto map and digital surface model of the aerial survey area, and build a 3D model. Load the orthophoto map into the geographic information system (GIS) software, delineate the precise survey area based on image features, calculate the area of ​​the survey area and export it in CAD format. Load the 3D model into the GIS software, determine the entry points, entry methods, exit points and exit methods for survey personnel and equipment based on the terrain distribution characteristics of the survey area. Load the digital surface model into the GIS software, calculate the average slope of the survey area, and determine the equipment type requirements and the number of personnel based on the average slope.

[0100] S4: Based on the tide forecast, set the second spring tide day, enter the survey site at the beginning of the working period, import the CAD file of the precise survey range into the RTK measuring instrument, carry out the layout, determine the actual location of the boundary of the survey area, and then lay red cables along the boundary.

[0101] S5: Search for and collect various types of sessile biological samples within the survey area. The number of individuals collected for each species shall be ≤3. After collection, the samples shall be immediately placed in a 4℃ refrigerator for preservation. The collected biological samples shall be morphologically identified to obtain the species identification results.

[0102] S6: Set up ≥10 ground control points within the survey area, place circular metal signs with the center point marked at the ground control point locations, and use an RTK measuring instrument to determine the geographic coordinates and elevation of the center point of the sign. The coordinate system adopted is the 2000 National Geodetic Coordinate System, and the projection method is selected as Gauss-Kruger projection.

[0103] S7: Camera parameters are preset as follows: center-weighted average metering, autofocus, auto white balance, aperture priority, and aperture value set to ƒ / 8; if a camera device that cannot adjust the aperture is selected, the camera's native aperture value will be used and auto ISO will be set; hold the camera and take pictures in sequence along two paths, one horizontal and one vertical, based on an "S" shaped route.

[0104] S8: When taking photos, the photographer stands still, holds the camera, and makes the lens at an angle of about 45° to the rock surface. The lens is about 0.4m away from the subject. Take 3 photos at each shooting point, and make the center points of the 3 photos follow the same straight line. The overlap rate between the photos is ≥70%. Then the photographer moves 0.7m along the shooting line and continues to take photos in the above manner. Repeat the shooting until the entire line is walked and the overlap rate between all adjacent photos is ≥70%. Then leave the survey area.

[0105] S9: Import the oblique photographs from S8 into the data processing software, align the photographs, mark the coordinates of ground control points, optimize the photograph alignment parameters, generate a second point cloud, establish an orthophoto map and digital surface model of the survey area based on the second point cloud, and establish a three-dimensional model. Combined with the species identification results, conduct an ecological survey of sessile organisms and generate the habitat density, spatial competition relationship, and light adaptability of each sessile organism.

[0106] Based on the system operation and analysis requirements, the system of this invention can realize all the steps of the above-mentioned visual modeling-based method for investigating sessile organisms in the intertidal zone of lithofacies.

[0107] A third aspect of the present invention also provides a computer-readable storage medium comprising a visual modeling-based lithofacies intertidal zone sessile organism survey program, wherein when the visual modeling-based lithofacies intertidal zone sessile organism survey program is executed by a processor, it implements the steps of the visual modeling-based lithofacies intertidal zone sessile organism survey method as described in any of the preceding claims.

[0108] This invention discloses a visual modeling-based method for surveying sessile organisms in the intertidal zone of lithofacies. First, by combining data from tide gauge stations to determine the low tide period on spring tide days, orthophotos and 3D models of the survey area are acquired using an RTK drone. Geographic Information System (GIS) processing is then used to delineate the precise survey area and plan entry and exit routes. Slope parameters are calculated using a digital surface model to optimize personnel and equipment configuration. Ground control points are established on-site, and a geodetic coordinate system benchmark is created. A dual-route oblique photography method is employed, with image sampling at a 45° angle, 0.4m object distance, and 70% image overlap. Combined with species morphological identification results, a high-precision 3D ecological model is generated through point cloud reconstruction, efficiently investigating parameters such as habitat density, interspecific competition, and light adaptability of sessile organisms.

[0109] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0110] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0111] In addition, in the various embodiments of the present invention, each functional unit can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0112] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0113] Alternatively, if the integrated units of this invention are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this invention, or the parts that contribute to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROM, RAM, magnetic disks, or optical disks.

[0114] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for investigating sessile organisms in the intertidal zone of lithofacies based on visual modeling, characterized in that, include: S1: Define the investigation area of ​​the intertidal zone of lithofacies, obtain the tide forecast information released by the latest tide gauge station, and extend the working time by 1 hour before and after the lowest tide time. S2: Based on the high-resolution satellite map of the survey area, determine the preliminary survey range, set the flight path of the mapping drone according to the preliminary survey range, the mapping drone includes an RTK function module and a flight camera, and start the mapping drone at the lowest tide on the day of spring tide to obtain orthophotos. S3: Preprocess the orthophotos, align the aerial images and generate point cloud data. Based on the point cloud data, establish an orthophoto map and digital surface model of the aerial survey area, and build a 3D model. The orthophoto map is loaded into the geographic information system software. Based on the image features, the precise survey area is delineated, and the area of ​​the survey area is calculated and exported in CAD format. The 3D model is loaded into the geographic information system software, and the entry points, entry methods, exit points, and exit methods of the survey personnel and equipment are determined based on the terrain distribution characteristics of the survey area. The digital surface model is loaded into the geographic information system software, the average slope of the survey area is calculated, and the equipment type requirements and the number of personnel are determined based on the average slope. S4: Based on the tide forecast, set the second spring tide day, enter the survey site at the beginning of the working period, import the CAD file of the precise survey range into the RTK measuring instrument, carry out the layout, determine the actual location of the boundary of the survey area, and then lay red cables along the boundary. S5: Search for and collect various types of sessile biological samples within the survey area. The number of individuals collected for each species shall be ≤3. After collection, the samples shall be immediately placed in a 4℃ refrigerator for preservation. The collected biological samples shall be morphologically identified to obtain the species identification results. S6: Set up ≥10 ground control points within the survey area, place circular metal signs with the center point marked at the ground control point locations, and use an RTK measuring instrument to determine the geographic coordinates and elevation of the center point of the sign. The coordinate system adopted is the 2000 National Geodetic Coordinate System, and the projection method is selected as Gauss-Kruger projection. S7: Camera parameters are preset as follows: center-weighted average metering, autofocus, auto white balance, aperture priority, and aperture value set to ƒ / 8; if a camera device that cannot adjust the aperture is selected, the camera's native aperture value will be used and auto ISO will be set; handheld camera, based on an "S" shaped route, take photos in sequence along two routes set horizontally and vertically. S8: When taking photos, the photographer stands still, holds the camera, and makes the lens at an angle of about 45° to the rock surface. The lens is about 0.4 m away from the subject. Take 3 photos at each shooting point, and make the center points of the 3 photos follow the same straight line. The overlap rate between the photos is ≥70%. Then the photographer moves 0.7 m along the shooting line and continues to take photos in the above manner. Repeat the shooting until the entire shooting line is completed and the overlap rate between all adjacent photos is ≥70%. Then leave the survey area. S9: Import the oblique photographs from S8 into the data processing software, align the photographs, mark the coordinates of ground control points, optimize the photograph alignment parameters, generate a second point cloud, establish an orthophoto map and digital surface model of the survey area based on the second point cloud, and establish a three-dimensional model. Combined with the species identification results, conduct an ecological survey of sessile organisms and generate the habitat density, spatial competition relationship, and light adaptability of each sessile organism. Wherein, S9 includes: The 3D model established by S9 was imported into the geographic information system software. Based on the species identification results, the sessile organisms in the model were identified and classified using visual or human-computer interaction methods. A point marker was added to the center point of each individual, and the point markers of different species were distinguished by different attribute values. Each individual was briefly marked with polygons to form the individual outline. The polygons of different species were distinguished by different attribute values. Based on the above point markers, the total number of species and the number of individuals of each species within the survey area were counted, and the habitat density of each organism was calculated. S9 also includes: The digital surface model established in step 9 is imported into the geographic information system (GIS) software to generate slope and aspect raster maps of the survey area, with a ground resolution ≤ 0.25 mm / pixel. Then, the point markers of sessile organisms are imported into the GIS software to extract the elevation, slope, and aspect values ​​of each individual's location. Frequency distribution analysis is used to analyze the range and degree of each species' preference for habitat elevation, slope, and aspect, thus obtaining the spatial niche characteristics of each sessile species. Kernel density analysis is performed based on individual point markers to obtain the distribution map of dense areas of various sessile organisms. The spatial competition relationship of various organisms for habitat is analyzed by the degree of overlap of dense areas of various organisms. S9 also includes: The polygonal outlines of sessile organisms are imported into a geographic information system software. The habitat area occupied by each organism is counted, and light analysis is performed. The statistical period is set to one natural year. The total solar radiation projected onto each individual is counted, and the light adaptability of each species is analyzed.

2. The method for investigating sessile organisms in the intertidal zone based on visual modeling according to claim 1, characterized in that, Specifically, in S2: The requirements for UAV flight path parameters are as follows: the main flight path should be parallel to the shoreline; the flight altitude relative to the ground should be ≤30 m; the lateral overlap rate of aerial photographs should be ≥70%; the forward overlap rate should be ≥80%; the flight start point should be set to the point closest to the waterline; the surveying UAV should be launched at the lowest tide level on a spring tide day; the surveying UAV should be equipped with an RTK function module, have image control-free surveying function; the flight camera should have a pixel count ≥20 million; the lens equivalent focal length should be 24~60 cm; the flight speed along the flight path should be ≥5 m / s; and the UAV should collect orthophotos along the set flight path.

3. The method for investigating sessile organisms in the intertidal zone based on visual modeling according to claim 1, characterized in that, In S3, the ground resolution of the orthophoto map is ≤1cm / pixel, the ground resolution of the digital surface model is ≤1cm / pixel, and the three-dimensional model is an OSGB format model.

4. The method for investigating sessile organisms in the intertidal zone based on visual modeling according to claim 1, characterized in that, In S7, the formula for calculating the total photo-taking time is: (total length of the two routes / 0.7 m) × 0.2 min; if the total photo-taking time is ≥ 30 min, then the number of photographers and camera positions will be increased.

5. The method for investigating sessile organisms in the intertidal zone based on visual modeling according to claim 1, characterized in that, In S9, the ground resolution of the orthophoto map is ≤0.25 mm / pixel, the ground resolution of the digital surface model is ≤0.25 mm / pixel, and the three-dimensional model is an OSGB format model.

6. A visual modeling-based system for surveying lithological intertidal sessile organisms, characterized in that, The system includes a memory and a processor. The memory includes a visual modeling-based program for surveying lithological intertidal sessile organisms. When the processor executes the visual modeling-based program for surveying lithological intertidal sessile organisms, it implements the steps of the visual modeling-based method for surveying lithological intertidal sessile organisms as described in claim 1.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a visual modeling-based program for surveying lithological intertidal sessile organisms, which, when executed by a processor, implements the steps of the visual modeling-based method for surveying lithological intertidal sessile organisms as described in any one of claims 1 to 5.

Images