System and method for constructing a three-dimensional monitoring network of coastal birds under the influence of a wading bridge and assessing ecological impact

Abstract

The present application relates to the technical field of ecological system, and specifically discloses a system for constructing a three-dimensional monitoring network and evaluating ecological influence of coastal birds under the influence of a water-crossing bridge, comprising a three-dimensional monitoring network module, a data processing module and an ecological influence evaluation module; the three-dimensional monitoring network module is used for monitoring bird activities in a coastal nearshore area; the data processing module is used for calculating bird density and identifying bird spatial density mutation points based on data collected by the three-dimensional monitoring network module; and the ecological influence evaluation module is used for evaluating the ecological influence of the water-crossing bridge on birds based on bird density changes and mutation point migration. The shore-based, ship-based and bridge-based multi-dimensional monitoring nodes are cooperatively arranged, the shore-based fixed points cover the nearshore intertidal zone and land area, the ship-based mobile scanning supplements the far beach and channel blind area, and the bridge-based attachment points focus on the key areas around the bridge, thereby forming a three-dimensional network combining points, lines and surfaces, and solving the monitoring missing problem in the construction sensitive area and far shore area.

Description

Technical Field

[0001] This invention relates to the field of ecosystem technology, specifically to a system and method for constructing a three-dimensional monitoring network for coastal birds under the influence of water-crossing bridges and for assessing their ecological impact. Background Technology

[0002] Coastal wetlands and nearshore waters are important habitats, foraging grounds, and migration routes for birds, and the integrity of their ecosystems is crucial for maintaining bird diversity. In recent years, with the rapid development of infrastructure construction in coastal areas, the construction and operation of water-related bridges (such as cross-bay bridges and pier-style port terminals) have significantly disturbed surrounding bird habitats, including habitat fragmentation, destruction of foraging environments, and behavioral disturbances. Therefore, accurately monitoring changes in bird activity and quantitatively assessing the ecological impact of engineering projects on birds have become core requirements for the coordinated development of ecological protection and engineering construction.

[0003] Existing bird monitoring technologies have the following limitations:

[0004] Significant monitoring blind spots: Traditional methods rely on fixed monitoring points or manual surveys, which are difficult to cover construction-sensitive areas such as bridge pier cofferdams and waterway dredging areas. They cannot continuously capture the real-time disturbance of the project to birds' habitat and foraging behavior, making it difficult to quantify the intensity of the disturbance.

[0005] Influencing factors are difficult to distinguish: Bird activity is affected by natural factors such as tides and seasons, as well as human disturbances such as bridge construction and port expansion. Existing technologies lack spatiotemporal density comparison models, making it difficult to separate the independent effects of natural changes and engineering disturbances, resulting in insufficient accuracy of assessment results.

[0006] High cost and fragmented data: Existing solutions mostly rely on building new monitoring towers or deploying equipment at high density, resulting in high hardware and maintenance costs; at the same time, the monitoring data formats of different areas (such as intertidal zones, waterways, and areas around bridges) are not uniform and the standards are inconsistent, making it difficult to achieve continuous spatiotemporal scale bird density analysis and fusion applications.

[0007] Insufficient accuracy in identifying behavioral hotspots: Birds’ micro-behaviors, such as foraging, take-off and landing, in micro-topographic areas like tidal channels, breakwaters and shoals, are highly sensitive to habitat quality. However, current technologies lack the ability to accurately locate bird activities at this scale and cannot capture the dynamic changes of key behavioral hotspots.

[0008] The lack of data support for ecological compensation makes it difficult to accurately track bird habitat loss and hotspot migration routes (such as the shift from natural tidal channels to artificial breakwaters) caused by engineering projects. This makes ecological restoration plans (such as the selection of artificial habitat sites and the delineation of compensation areas) lack specificity, and quantitative assessment of ecological losses is out of the question. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a system for constructing a three-dimensional monitoring network for coastal birds under the influence of water-crossing bridges and an ecological impact assessment system. This system can cover the entire region, distinguish influencing factors, reduce costs, accurately identify behavioral hotspots, and support ecological compensation, thereby overcoming the deficiencies of existing technologies.

[0010] To achieve the above objectives, this invention provides the following technical solution: a system for constructing a three-dimensional monitoring network for coastal birds under the influence of water-crossing bridges and for assessing their ecological impact, comprising:

[0011] A three-dimensional monitoring network module is used to monitor bird activity in coastal and nearshore areas;

[0012] The data processing module is used to calculate bird density and identify abrupt changes in bird spatial density based on the data collected by the three-dimensional monitoring network module.

[0013] The ecological impact assessment module is used to assess the ecological impact of water-crossing bridges on birds based on changes in bird density and migration of mutation points.

[0014] The three-dimensional monitoring network module includes a shore-based monitoring submodule, a ship-based monitoring submodule, and a bridge-based monitoring submodule.

[0015] The shore-based monitoring submodule includes fixed monitoring nodes for the nearshore intertidal zone, port / hard shoreline buffer zone, mid-to-low altitude migration channel, and nearshore land low-altitude zone. Each node is equipped with optical equipment, acoustic equipment, or radar equipment, and the node spacing is matched with the equipment parameters to cover the target area.

[0016] The ship-based monitoring submodule includes mobile monitoring nodes in the open intertidal zone, main channel and extended area, and estuary / river mouth fan area. It cruises along a preset track and is equipped with radar, optical equipment and positioning equipment. The track spacing is matched with the equipment coverage width.

[0017] The bridge foundation monitoring submodule includes attached monitoring nodes in the conventional pier area, the bridge-bank intersection area, and the top of the bridge tower / cable tower. These nodes are equipped with optical equipment, acoustic equipment, or sensors, and their positions and heights meet the coverage requirements of the bridge openings, transition areas, and high-altitude areas.

[0018] Preferably, the data processing module uses the following method to calculate bird density:

[0019] (1) Calculate the effective monitoring volume of each monitoring device:

[0020] (2) Calculate intertidal bird density by integrating shore-based and ship-based data:

[0021] (3) Calculate bird density in the waterway crossing area by integrating bridge foundation and ship foundation data:

[0022] Effective monitoring volume of a single point on an optical device: ,in For horizontal field of view, The effective detection distance of the optical device, expressed in meters (m). This is the optical correction factor, and it is ≤1;

[0023] Effective monitoring volume of a single point on radar equipment: ,in, This is the radar's horizontal detection radius, in meters (m). To effectively detect height layers, the unit is meters (m). The radar attenuation coefficient is calculated from the rainfall: , Rainfall amount, in mm / h;

[0024] Effective monitoring volume of a single point on an acoustic device: ,in For horizontal beamwidth, The effective acoustic detection distance, measured in meters (m). This is the acoustic correction factor, and it is ≤1;

[0025] Total number of birds observed in the intertidal zone: ;

[0026] in, , , These are respectively shore-based optics, radar, and acoustics. The number of birds identified by each node. , These are ship-based optics and radar. The number of birds identified by each node. The number of birds repeatedly observed in overlapping intertidal zones;

[0027] Total effective observation volume of the intertidal zone:

[0028] ;

[0029] in, , , These are respectively shore-based optics, radar, and acoustics. The effective observation volume of each node , They are ship-based optics and radar. The effective observation volume of each node The effective observation volume of the intertidal overlapping area;

[0030] Intertidal bird density: ;

[0031] Total number of birds observed in the waterway crossing area:

[0032] ;

[0033] in, They are respectively bridge-based optics and acoustics. The number of birds identified by each node. , They are ship-based optics and radar. The number of birds identified by each node. The number of birds repeatedly observed in overlapping areas of the waterway crossing zone;

[0034] Total effective observation volume of the channel crossing area:

[0035] ;

[0036] in, , They are respectively bridge-based optics and acoustics. The effective observation volume of each node , They are ship-based optics and radar. The effective observation volume of each node The effective observation volume of the overlapping area of ​​the channel crossing zone;

[0037] Bird density in the waterway crossing area: .

[0038] Preferably, the data processing module uses the following method to identify abrupt changes in bird spatial density:

[0039] (1) Calculate the rate of change of spatial density of birds: ,in For bird spatial density, intertidal zone The waterway crosses the area. The partial derivatives are calculated using the central difference approximation formula. , respectively representing the density at , , Rate of change on the axis:

[0040] , The coordinates of the grid center are, This refers to the grid spacing;

[0041] (2) Calculate the second spatial derivative of density: The density difference between the current position and its six neighboring grids is solved by grid difference calculation;

[0042] (3) Identify mutation points: Calculate the mutation points in the monitoring space Standard deviation and average , will satisfy point These are identified as mutation points, forming a mutation point set CP.

[0043] Preferably, the ecological impact assessment module, when assessing ecological impacts, includes:

[0044] (1) Calculate the density change rate of the zones before and after the project:

[0045] (2) Calculate the migration rate of the mutation point before and after the project: ,in The average migration distance for all mutation points:

[0046] ;

[0047] in, These are the locations of the abrupt change points before and after construction. To monitor the maximum coverage radius of the network , , , These refer to the maximum detection range for shore-based, ship-based, and bridge-based equipment, respectively. , , These are the center-to-center straight-line distances between monitoring points on the shore base and ship base, the shore base and bridge base, and the ship base and bridge base, respectively.

[0048] (3) Assess the impact level based on density change rate and migration rate: when If the situation is deemed a significant ecological disturbance, the construction schedule needs to be adjusted and an ecological compensation plan needs to be developed.

[0049] Intertidal density change rate: ,in , These are the intertidal bird densities before and after construction.

[0050] Density change rate in the channel crossing area: ,in , These are the bird densities in the waterway crossing area before and after construction.

[0051] Preferably, the nearshore intertidal zone nodes of the shore-based monitoring submodule are arranged along the mean high tide line with an axial spacing of 1-1.2km and a longitudinal spacing of 1.5-2km. The core equipment consists of a wide-angle thermal imager, a visible light camera, and a ≥4-channel directional microphone array. The spacing between the nodes at the estuary and tidal channel confluence is reduced to 400-500m.

[0052] Preferably, the ship-based monitoring submodule cruises along equidistant tracks parallel to the shoreline in the open intertidal zone at a speed of 5-8 knots and a track spacing of 800-1000m. The core equipment includes a Ku-band scanning radar, a dual-spectrum gimbal camera, and a high-precision GPS / RTK.

[0053] Preferably, the conventional pier area nodes of the bridge foundation monitoring submodule are deployed on the bridge deck light poles or the top of the piers, with the equipment having a 30° downward angle to cover the bridge opening and the water areas extending on both sides. The core equipment is a wide-angle or medium-focus thermal imager.

[0054] A method for three-dimensional monitoring and ecological impact assessment of coastal birds includes the following steps:

[0055] S1. Construct a three-dimensional monitoring network: Deploy shore-based, ship-based, and bridge-based monitoring nodes to cover areas such as the nearshore intertidal zone, waterways, and the area surrounding bridges, and equip them with optical, acoustic, and radar equipment;

[0056] S2. Collect bird activity data: Obtain data on the number, location, and behavior of birds through various monitoring nodes;

[0057] S3. Calculate bird density: Calculate the bird density in the intertidal zone and the area traversed by the waterway;

[0058] S4. Identify density mutation points: Identify spatial density mutation points in birds;

[0059] S5. Assess ecological impacts: Calculate density change rate and mutation point migration rate, determine the impact level, and formulate response measures.

[0060] Preferably, in step S1, the arrangement of the shore-based, ship-based, and bridge-based monitoring nodes meets the principle of hierarchical monitoring, reuses existing infrastructure to reduce costs, and verifies the data of each node to eliminate monitoring blind spots.

[0061] Preferably, in step S5, the countermeasures include: when the impact level is low, and When the level is medium, routine tracking and monitoring should be carried out. When the level is high, closely monitor and supplement habitats; when the level is high, adjust the construction schedule and develop an ecological compensation plan.

[0062] This invention provides a system for constructing a three-dimensional monitoring network for coastal birds and assessing its ecological impact under the influence of water-crossing bridges, which has the following beneficial effects:

[0063] 1. Eliminate monitoring blind spots and achieve full coverage: The system adopts a multi-dimensional monitoring node layout that combines shore-based, ship-based, and bridge-based monitoring. The fixed shore-based points cover the nearshore intertidal zone and land area, the ship-based mobile scanning supplements the blind spots in the distant beach and waterway, and the bridge-based attachment points focus on key areas around the bridge, forming a three-dimensional network that combines "point-line-surface". This solves the problem of monitoring gaps in construction-sensitive areas and distant shore areas, and enables continuous and comprehensive capture of bird activities.

[0064] 2. Distinguish between natural and human-induced impacts to improve assessment accuracy: By using a spatiotemporal density comparison model and multi-source data fusion technology, natural factors such as tides and seasons are incorporated into the benchmark reference system. This allows for the quantification and separation of the independent impact of engineering disturbances (such as bridge construction noise and lighting) on ​​bird activity, clarifying the contribution rate of engineering disturbances and providing a scientific basis for accurate assessment.

[0065] 3. Reduce costs and achieve data fusion: Fully reuse existing infrastructure (such as lighthouses, fixed-route ships, and bridge structures) to deploy monitoring equipment, reducing investment in new hardware; at the same time, through unified data format and spatiotemporal calibration algorithm, achieve seamless fusion of shore-based, ship-based, and bridge-based data, support bird density analysis at continuous spatiotemporal scales, and solve the problem of data fragmentation.

[0066] 4. Improve the accuracy of behavioral hotspot identification: By combining optical (thermal infrared + visible light), acoustic (directional microphone array), and radar (air / sea) multimodal technologies, the system can accurately locate bird foraging, take-off, landing, and roosting behaviors at the micro-topographic scale of tidal channels, breakwaters, etc., with identification accuracy reaching the meter level, providing detailed evidence for the protection of key habitat areas.

[0067] 5. Supporting Scientific Ecological Compensation and Restoration: By capturing bird migration hotspots (such as habitat relocation caused by engineering projects) and quantifying ecological losses, data support is provided for ecological restoration measures such as the selection of artificial habitats and the delineation of compensation areas. This ensures the relevance and effectiveness of compensation plans and promotes the coordinated development of engineering construction and ecological protection. Attached Figure Description

[0068] Figure 1 This is a schematic diagram of the principle of the three-dimensional monitoring network for coastal birds under the influence of water-crossing bridges described in this invention, and the ecological impact assessment system.

[0069] Figure 2 This is a flowchart illustrating a method for three-dimensional monitoring and ecological impact assessment of coastal birds as described in this invention. Detailed Implementation

[0070] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0071] like Figure 1 As shown, this invention provides a technical solution: a system for constructing a three-dimensional monitoring network for coastal birds and assessing their ecological impact under the influence of water-crossing bridges, comprising: a three-dimensional monitoring network module, a data processing module, and an ecological impact assessment module; the three-dimensional monitoring network module is used to monitor bird activities in nearshore coastal areas; the data processing module is used to calculate bird density and identify spatial density mutation points based on the data collected by the three-dimensional monitoring network module; the ecological impact assessment module is used to assess the ecological impact of water-crossing bridges on birds based on changes in bird density and the migration of mutation points.

[0072] The three-dimensional monitoring network module includes a shore-based monitoring submodule, a ship-based monitoring submodule, and a bridge-based monitoring submodule. The shore-based monitoring submodule includes fixed monitoring nodes in the nearshore intertidal zone, port / hard shoreline buffer zone, mid-to-low altitude migration channel, and nearshore land low-altitude zone. Each node is equipped with optical, acoustic, or radar equipment, and the node spacing is matched with the equipment parameters to cover the target area. The ship-based monitoring submodule includes mobile monitoring nodes in the open intertidal zone, main channel and extension zone, and estuary / river mouth fan-shaped zone. These nodes cruise along a preset track and are equipped with radar, optical, and positioning equipment. The track spacing is matched with the equipment coverage width. The bridge-based monitoring submodule includes attached monitoring nodes in the conventional bridge pier area, bridge-shore intersection area, and bridge tower / cable tower top. These nodes are equipped with optical, acoustic, or sensor equipment, and the node positions and heights meet the coverage requirements of bridge openings, transition zones, and high-altitude areas.

[0073] More specifically, the data processing module uses the following method to calculate bird density:

[0074] (1) Calculate the effective monitoring volume of each monitoring device:

[0075] (2) Calculate intertidal bird density by integrating shore-based and ship-based data:

[0076] (3) Calculate bird density in the waterway crossing area by integrating bridge foundation and ship foundation data:

[0077] Effective monitoring volume of a single point on an optical device: ,in The horizontal field of view (unit: radians; determined by equipment parameters, such as wide-angle thermal imagers with a field of view ≥120°, which need to be converted to radians for calculation). The effective detection distance of optical equipment, measured in meters (i.e., the maximum distance at which the equipment can clearly identify birds). This is the optical correction factor, and it is ≤1 (used to correct for the reduction in detection efficiency caused by environmental factors such as lighting and haze; for example, a value of 0.8 can be used on cloudy days).

[0078] Effective monitoring volume of a single point on radar equipment: ,in, This is the radar's horizontal detection radius, measured in meters (i.e., the radar's effective coverage area in the horizontal direction). To effectively detect different height levels, the unit is meters (i.e., the radar's monitoring range in the vertical direction, such as 0-50m). The radar attenuation coefficient is calculated from the rainfall: , This refers to rainfall, expressed in mm / h; it's used to correct for the absorption and attenuation of radar waves by rainfall. For example, when the rainfall is 5 mm / h, ;

[0079] Effective monitoring volume of a single point on an acoustic device: ,in Horizontal beamwidth (unit: radians; determined by the directivity parameters of the microphone array). The acoustically effective detection distance (i.e., the maximum distance at which the device can detect bird calls), is measured in meters (m). It is the acoustic correction factor, and ≤1 (used to correct the decrease in detection efficiency caused by background noise (such as ocean waves) (a value of 0.7 can be taken in noisy nearshore environments)).

[0080] Total number of birds observed in the intertidal zone: ;

[0081] in, , , These are respectively shore-based optics, radar, and acoustics. The number of birds identified by each node. , They are ship-based optics and radar. The number of birds identified by each node. The number of birds repeatedly observed in overlapping intertidal zones (such as 1-3 km from the shore) (removed by spatiotemporal coordinate matching, for example, if the same flock of birds is recorded simultaneously by shore-based radar and ship-based optical equipment, it is counted only once).

[0082] Total effective observation volume of the intertidal zone:

[0083] ;

[0084] in, , , These are respectively shore-based optics, radar, and acoustics. The effective observation volume of each node , They are ship-based optics and radar. The effective observation volume of each node The effective observation volume of the intertidal overlapping area;

[0085] Intertidal bird density: ;

[0086] Total number of birds observed in the waterway crossing area:

[0087] ;

[0088] in, They are respectively bridge-based optics and acoustics. The number of birds identified by each node. , They are ship-based optics and radar. The number of birds identified by each node. The number of birds repeatedly observed in overlapping areas of the waterway crossing zone;

[0089] Total effective observation volume of the channel crossing area:

[0090] ;

[0091] in, , They are respectively bridge-based optics and acoustics. The effective observation volume of each node , They are ship-based optics and radar. The effective observation volume of each node The effective observation volume of the overlapping area of ​​the channel crossing zone;

[0092] Bird density in the waterway crossing area: .

[0093] The data processing module achieves accurate quantification of bird density in the intertidal zone and waterway crossing area through a three-stage process of "effective monitoring volume calculation - zoned data fusion - density solution". The core lies in combining the characteristics of different monitoring devices and eliminating monitoring blind spots and duplicate counts through multi-source data fusion.

[0094] Bird density calculation takes "the number of birds observed per unit volume" as the core indicator. It is necessary to first determine the effective monitoring range (volume) of each monitoring device, and then, based on the combination of monitoring sub-modules (shore-based + ship-based / bridge-based + ship-based) of the target area (intertidal zone / channel crossing area), integrate multi-source data and deduct interference from overlapping areas to finally solve for the density value.

[0095] The effective monitoring volume calculation for each device utilizes different formulas based on the physical characteristics of optical, radar, and acoustic equipment: Optical equipment is calculated using a conical volume model based on the horizontal field of view and detection distance, with an optical correction coefficient (≤1) to compensate for environmental interference; radar equipment is calculated using a cylindrical volume model based on the horizontal detection radius and height layer, with signal loss corrected using an attenuation coefficient related to rainfall; acoustic equipment is calculated using a conical volume model based on the horizontal beamwidth and detection distance, with an acoustic correction coefficient (≤1) to compensate for background noise. These volume calculations directly determine the accuracy of subsequent density measurements and require strict matching of equipment parameters with the monitoring scenario (e.g., nearshore / farshore, calm water / waterway).

[0096] Partition data fusion rules:

[0097] Intertidal zone: Integrating shore-based (fixed node) and ship-based (mobile node) data, summarizing the number of birds identified and the monitored volume by optical, radar, and acoustic equipment, and eliminating data redundancy by deducting duplicate counts and volumes in overlapping areas;

[0098] Waterway crossing area: Integrate bridge foundation (attached node) and ship foundation (moving node) data, summarize the number of birds identified and the monitoring volume from optical and acoustic (bridge foundation) and optical and radar (ship foundation) data, and also deduct interference from overlapping areas to focus on bird activities around the bridge.

[0099] In the above formula, the equipment parameters (such as...) Calibration is required based on the actual monitoring scenario (e.g., shore-based optical equipment). (500m was taken in the nearshore intertidal zone, and 1000m in the offshore open area); the identification of overlapping areas relied on spatial matching of GPS / RTK positioning data and the device's coverage area to ensure data uniqueness; calculation results This provides a basic quantitative indicator for subsequent identification of abrupt changes in bird spatial density and assessment of the ecological impact of bridges across water.

[0100] More specifically, the data processing module uses the following method to identify abrupt changes in the spatial density of birds:

[0101] (1) Calculate the rate of change of spatial density of birds (spatial gradient vector): ,in For bird spatial density, intertidal zone The waterway crosses the area. The central difference approximation formula is used for calculation: , The coordinates of the grid center are, This refers to the grid spacing;

[0102] (2) Calculate the second spatial derivative of density (Laplace operator): The density difference between the current position and its six neighboring grids is solved by grid difference calculation;

[0103] (3) Identify mutation points: Calculate the mutation points in the monitoring space Standard deviation and average , will satisfy point These are identified as mutation points, forming a mutation point set CP.

[0104] The data processing module identifies abrupt changes in bird spatial density through a third-order mathematical analysis process. This involves first calculating the density change rate (spatial gradient), then solving for the second derivative of density (Laplace operator), and finally filtering abrupt change points based on statistical thresholds. This enables precise location of bird activity hotspot boundaries, habitat transition zones, or boundaries affected by disturbances, as detailed below:

[0105] The spatial density change rate of birds is calculated using the spatial gradient vector, which quantifies the intensity and direction of the change in bird density in three-dimensional space. The calculation formula is as follows:

[0106] ;

[0107] in: For bird spatial density, values ​​are taken for different regions: intertidal zone bird density is taken. Bird density in the waterway crossing area The calculation method is described above; partial derivatives Let x represent the rate of change of density along the x (coastal direction), y (seaward direction), and z (vertical height) axes, respectively, and calculate using the central difference approximation formula:

[0108] ;

[0109] ;

[0110] ;

[0111] In the formula, The center coordinates of the three-dimensional monitoring grid (the grid is a spatial discretization unit of the monitoring area). The grid spacing in the x, y, and z directions are respectively (set according to the monitoring accuracy requirements, for example, in the intertidal zone). ).

[0112] The second spatial derivative of the density is calculated using the Laplace operator, which describes the local curvature of the density field and reflects the "acceleration rate" of density changes. The formula is as follows:

[0113] ;

[0114] The second-order partial derivatives are obtained through grid difference:

[0115] Each second-order partial derivative (e.g.) ) is calculated from the density difference between the current grid and the adjacent grids along the positive and negative directions of that axis (e.g., );

[0116] The overall result is the sum of the second-order partial derivatives of the three axes, which quantifies the degree of density difference between the current grid and its six neighboring grids (one each along the positive and negative directions of the x, y, and z axes).

[0117] Identifying abrupt change points and screening for density abrupt change points based on the statistical properties of the Laplace operator involves the following steps:

[0118] Calculate the values ​​of all grids within the monitoring space. Find the value and obtain its probability distribution; calculate the standard deviation of this distribution. and average (The average value is usually close to 0 because the positive and negative curvature regions in the density field are symmetrically distributed.)

[0119] Set threshold conditions: to meet grid center point Identified as a mutation point, among which (Corresponding to a 95%~99.7% confidence interval in statistics, ensuring that the selected mutation points are statistically significant);

[0120] All points that meet the criteria constitute the mutation point set CP, which corresponds to areas of drastic changes in bird density (such as the edge of bird gathering areas, the boundary between habitat and non-habitat areas, the boundary affected by bridge construction disturbances, etc.).

[0121] In this embodiment, the grid spacing The grid spacing must match the spatial resolution of the monitoring equipment (e.g., when the monitoring accuracy of the optical equipment is 10m, the grid spacing should not be greater than 10m); threshold coefficient The monitoring area can be dynamically adjusted based on the intensity of bird activity: areas with even bird distribution are selected. (Strict screening) Areas with frequent activity are selected. (To avoid missing detections); the mutation point set CP provides core spatial coordinates for subsequent analysis of bird habitat migration and assessment of bridge disturbance range.

[0122] More specifically, when assessing ecological impacts, the ecological impact assessment module includes:

[0123] (1) Calculate the density change rate of the zones before and after the project:

[0124] (2) Calculate the migration rate of the mutation point before and after the project: ,in The average migration distance for all mutation points:

[0125] ;

[0126] in, These are the locations of the abrupt change points before and after construction. To monitor the maximum coverage radius of the network , , , These refer to the maximum detection range for shore-based, ship-based, and bridge-based equipment, respectively. , , These are the center-to-center straight-line distances between monitoring points on the shore base and ship base, the shore base and bridge base, and the ship base and bridge base, respectively.

[0127] (3) Assess the impact level based on density change rate and migration rate: when If the situation is deemed a significant ecological disturbance, the construction schedule needs to be adjusted and an ecological compensation plan needs to be developed.

[0128] Intertidal density change rate: ,in , These are the intertidal bird densities before and after construction.

[0129] Density change rate in the channel crossing area: ,in , These are the bird densities in the waterway crossing area before and after construction.

[0130] The ecological impact assessment module quantifies changes in bird density and mutation point migration characteristics before and after engineering projects to achieve a graded assessment of the ecological impact of water-related bridges, providing a basis for project optimization and ecological compensation. The assessment process includes three core steps: calculating the zonal density change rate, calculating the mutation point migration rate, and determining the impact level based on two indicators, as detailed below:

[0131] The density change rate before and after the project was calculated. This rate quantifies the impact of the bridge construction on bird populations in different key areas, and is calculated separately for the intertidal zone and the waterway crossing area.

[0132] The intertidal density change rate is calculated using the following formula:

[0133] ;

[0134] in: The density of intertidal birds before construction (unit: birds / cubic meter). The density of intertidal birds after construction was calculated using the data processing module (see the "Bird Density Calculation" section for details).

[0135] The results are percentage values: positive values ​​indicate increased density, and negative values ​​indicate decreased density (the larger the absolute value of the negative value, the more significant the reduction in birds caused by the project).

[0136] The density change rate of the channel crossing area is given by the following formula:

[0137] ;

[0138] in: The bird density in the waterway crossing area before construction. The bird density in the channel crossing area after construction was also calculated by the data processing module; the meaning of the result is consistent with that of the intertidal zone, mainly reflecting the impact of bridge construction on bird migration routes.

[0139] The migration rate of mutation points before and after the project is calculated. The mutation point migration rate is used to measure the degree of spatial migration of bird density mutation points (such as habitat boundaries and the edge of the bird flock core area) before and after the project. The calculation formula is as follows:

[0140] ;

[0141] The average migration distance refers to the average displacement of all abrupt change points before and after the project. The formula is:

[0142] ;

[0143] in: The total number of mutation points (from the set of mutation points CP identified by the data processing module); For the first time before construction The three-dimensional coordinates (latitude, longitude and altitude) of each mutation point; For the first time after construction The three-dimensional coordinates of each mutation point; the square root represents the Euclidean distance formula, which quantifies the migration distance of a single mutation point, and the average value reflects the overall migration trend.

[0144] The maximum coverage radius of the monitoring network, used as a benchmark for mobility calculation, represents the effective coverage area of ​​the entire monitoring system. The formula is:

[0145] ;

[0146] in: These are the maximum detection ranges for shore-based, ship-based, and bridge-based equipment, respectively (determined by equipment parameters, such as a shore-based radar with a maximum detection range of 5km). These represent the center-to-center straight-line distances between monitoring points on shore and ship, shore and bridge, and ship and bridge (calculated using GPS positioning data). The formula calculates the maximum radius (in meters) that the monitoring network can actually cover by overlaying the maximum detection distance of the equipment and subtracting the overlapping distance between monitoring points.

[0147] The migration rate is expressed as a percentage, reflecting the proportion of the average migration distance of mutation points to the maximum coverage radius of the monitoring network (the higher the proportion, the more significant the shift in bird activity area caused by the project).

[0148] Impact levels are assessed based on density change rate and migration rate. Combining these two indicators, ecological impacts are classified into three levels, each corresponding to a different response measure:

[0149] Significant ecological disturbance (high level), criteria for determination: ;

[0150] Meaning: A decrease in bird density of more than 10% in at least one area of ​​the intertidal zone and the area traversed by the waterway, and an overall migration distance of the mutation point exceeding 10% of the maximum coverage radius of the monitoring network, indicates that the project has caused significant disturbance to bird habitats;

[0151] Countermeasures: The construction schedule needs to be adjusted (e.g., avoiding peak bird migration periods) and an ecological compensation plan needs to be developed (e.g., constructing new artificial wetlands and designating no-navigation zones).

[0152] Moderate ecological disturbance (medium level), criteria for determination: ;

[0153] Meaning: The decline in bird density is moderate, the migration range of the mutation point is limited, and the impact of the project is within a controllable range;

[0154] Response measures: Closely monitor changes in data and supplement habitats (such as planting submerged plants in the intertidal zone) to mitigate disturbances.

[0155] Minor ecological disturbance (low level), criteria for judgment: ;

[0156] Meaning: Bird density and mutation point location are basically stable, and the project has no significant impact on bird activity;

[0157] Response: Conduct routine monitoring; no additional intervention is required.

[0158] In this embodiment, the density change rate and migration rate need to be calculated synchronously with the project cycle (e.g., assessed once each one year before construction, during construction, and one year after completion) to ensure the capture of long-term impact trends; monitor the maximum coverage radius of the network. Regular calibration is required (e.g., updating the maximum detection distance and monitoring point location of the equipment every quarter) to avoid baseline deviations due to equipment aging or location changes; the specific implementation of countermeasures needs to be further refined in combination with local bird species (e.g., migratory / resident birds) and habitat types (e.g., mudflats / rocky coastlines) to ensure targeting and effectiveness.

[0159] More specifically, the nearshore intertidal zone (0-2km) nodes of the shore-based monitoring submodule are arranged along the mean high tide line, with an axial (alongshore) spacing of 1-1.2km and a longitudinal (seaward) spacing of 1.5-2km. The core equipment consists of a wide-angle thermal imager (field of view ≥120°), a visible light camera, and a ≥4-channel directional microphone array. The spacing between nodes at the estuary and tidal channel confluence is reduced to 400-500m.

[0160] The shore-based monitoring submodule focuses on key nearshore areas, forming a monitoring baseline with fixed nodes, and mainly covers the intertidal zone and terrestrial transition zone where birds forage and rest. The deployment plan is as follows: nearshore intertidal zone (0-2km).

[0161] Node layout: The nodes are distributed in a grid pattern along the average high tide line, with an axial (parallel to the coastline) node spacing of 1-1.2 km and a longitudinal (perpendicular to the coastline, towards the sea) node spacing of 1.5-2 km. For areas with high bird activity, such as estuaries and tidal channel inlets, the node spacing is reduced to 400-500 m to improve local monitoring accuracy.

[0162] Core equipment: A wide-angle thermal imager with a field of view ≥120°, supporting bird identification in nighttime and low-light environments, with an effective detection distance ≥500m; a visible light camera with a resolution ≥20 megapixels, working with a telephoto lens to capture detailed bird features; and a ≥4-channel directional microphone array with a horizontal beamwidth ≤30°, capable of locating bird call sources, with an effective detection distance ≥300m. This system monitors the feeding, flocking, and short-distance movement of intertidal birds, covering the entire process of bird migration towards the shore during high tide and dispersal into the mudflats during low tide.

[0163] Other monitoring areas: In addition to the nearshore intertidal zone, the shore-based monitoring submodule also includes fixed nodes in the port / hard shoreline buffer zone, the mid-to-low altitude migration channel, and the nearshore land low-altitude zone. The equipment configuration and spacing are adjusted according to the regional characteristics (such as adding radar equipment to the port buffer zone to penetrate complex backgrounds), but the core deployment logic is the same as that of the intertidal zone, that is, to achieve blind-spot-free coverage by matching the node density and equipment parameters.

[0164] More specifically, the ship-based monitoring submodule cruises along equidistant tracks parallel to the shoreline in the open intertidal zone (3-10km from the shore) at a speed of 5-8 knots and a track spacing of 800-1000m. The core equipment includes a Ku-band scanning radar, a dual-spectrum gimbal camera, and a high-precision GPS / RTK.

[0165] The ship-based monitoring submodule supplements the monitoring of the far-shore area by mobile patrol, focusing on the open intertidal zone and waterway, filling the coverage blind spots of shore-based equipment. The deployment plan is as follows: open intertidal zone (3-10km from the shore).

[0166] Cruise path: Cruise along an equidistant track parallel to the coastline, with a track spacing of 800-1000m (matching the coverage width of the radar equipment), and control the speed at 5-8 knots to ensure that the equipment has enough time to complete data acquisition and storage.

[0167] Core equipment: Ku-band scanning radar with a horizontal detection radius ≥2km, effective detection altitude 0-100m, capable of identifying the spatial distribution of flocks of birds; dual-spectrum gimbal camera integrating visible light and thermal infrared channels, capable of remote zoom (optical zoom ≥30x), working with radar guidance to achieve precise image capture of target birds; high-precision GPS / RTK positioning error ≤5cm, used to record track coordinates and spatiotemporal markers for monitoring data. Monitors bird activity in offshore tidal flats and shallow sea areas, especially open waters difficult to cover by shore-based equipment, supplementing bird density data across the entire intertidal zone.

[0168] Other monitoring areas: The cruise paths of the main channel and its extension area, and the estuary / river mouth fan area are dynamically adjusted according to the tidal flow direction and bird migration routes. The track spacing and equipment parameters are kept consistent with the open intertidal zone to ensure data format uniformity and the feasibility of fusion analysis.

[0169] More specifically, the conventional pier area nodes of the bridge foundation monitoring submodule are deployed on the bridge deck light poles or the top of the piers (height ≥6-8m), with the equipment at a 30° downward angle covering the bridge opening and the water areas extending on both sides (≥500m). The core equipment is a wide-angle or medium-focus thermal imager (FOV 60°-90°, IP68 protection level).

[0170] The bridge foundation monitoring submodule relies on the bridge structure to deploy attached nodes, focusing on bird activities around the bridge, especially migration routes crossing the bridge openings. The deployment plan is as follows: conventional bridge pier area;

[0171] Node location: Deployed on the top of the bridge deck light pole or pier, with an installation height of ≥6-8m, ensuring that the equipment can cover the bridge opening and the water area extending ≥500m on both sides when the downward angle is 30°.

[0172] Core equipment: Wide-angle or medium-range thermal imager with a field of view (FOV) of 60°-90°, IP68 protection rating (suitable for high humidity and salt spray environments), and an effective detection distance ≥800m; auxiliary sensors integrate temperature, humidity, wind speed, and wind direction sensors to correct for the impact of environmental factors on monitoring data. Monitors bird crossing behavior in and around the bridge, recording bird avoidance or utilization patterns of the bridge structure (e.g., perching along bridge piers).

[0173] Other monitoring areas: The bridge-shore junction node focuses on monitoring the transitional activities of birds from land to water. The nodes at the top of the bridge tower / cable tower are equipped with omnidirectional radar to cover high-altitude migration channels. The equipment selection is compatible with the conventional bridge pier area to ensure that the data can be integrated across regions.

[0174] like Figure 2 As shown, a method for three-dimensional monitoring and ecological impact assessment of coastal birds includes the following steps:

[0175] S1. Construct a three-dimensional monitoring network: Deploy shore-based, ship-based, and bridge-based monitoring nodes to cover areas such as the nearshore intertidal zone, waterways, and the area surrounding bridges, and equip them with optical, acoustic, and radar equipment;

[0176] S2. Collect bird activity data: Obtain data on the number, location, and behavior of birds through various monitoring nodes;

[0177] S3. Calculate bird density: Calculate the bird density in the intertidal zone and the area traversed by the waterway;

[0178] S4. Identify density mutation points: Identify spatial density mutation points in birds;

[0179] S5. Assess ecological impacts: Calculate density change rate and mutation point migration rate, determine impact level, and formulate response measures.

[0180] More specifically, in step S1, the arrangement of the shore-based, ship-based, and bridge-based monitoring nodes meets the principle of hierarchical monitoring, reusing existing infrastructure (lighthouses, fixed-route vessels, bridges) to reduce costs, and cross-verifying data from each node to eliminate monitoring blind spots. In step S5, the countermeasures include: when the impact level is low, and When the level is medium, routine tracking and monitoring should be carried out. When the level is high, closely monitor and supplement habitats; when the level is high, adjust the construction schedule and develop an ecological compensation plan.

[0181] The monitoring point deployment plan is as follows:

[0182] Table 1. Shore-based monitoring point layout scheme (fixed point network);

[0183] Target partition Bird activity characteristics and monitoring targets Deployment strategy Typical node spacing / density Core equipment combination and functional requirements Encryption of key nodes and special requirements ① Nearshore intertidal zone (0-2km) Low-altitude intensive foraging, takeoff and landing, short-distance movement (0-30m) Core objectives: Locating foraging sites and takeoff / landing points High tide line: Deployed in a safe position above the mean high tide line (with stable dikes / rock foundations), the camera looks down at the low tide mudflats, tracks landing / takeoff behavior, and covers distant mudflats. Axial (coastal): 1-1.2km; Longitudinal (seaward): 1.5-2km Optics: Wide-angle thermal imager (field of view >= 120°, resolution sufficient for detecting medium-sized birds within 300m) + visible light camera (for auxiliary identification and recording). Acoustics: Multi-channel directional microphone array (>= 4 channels, wind noise reduction design, with sound source localization (DOA) capability). Power supply / communication: Mains power / 4G / fiber optic. River estuaries, major tidal channel inlets, and known hotspots: spacing reduced to 400-500m. ② Port / hard shoreline buffer zone (0-1km) Nocturnal activity is significant, attracted by lights. Takeoffs and landings are concentrated at breakwaters, breakwaters, and pier edges. Core objectives: Monitoring nocturnal activity, human-bird conflict points, and avoidance behavior. Single-line loop chain + key point coverage: Prioritize the use of existing light poles, tower crane platforms (>=8m high), and warehouse rooftops. Nodes are deployed on the seaward side of the facility, with cameras / microphones providing horizontal or slightly overhead coverage of nearshore waters, wharf edges, and breakwaters. Prioritize placement at breakwater ends, harbor basin corners, and breakwater heads. Along the wharf / shoreline: 500-1000m breakwater / wave-dissipating breakwater: installed at the ends Optical: Dual-spectrum camera with pan-tilt unit (thermal imaging + visible light dual spectrum; pan-tilt unit can be preset to cruise position; infrared resolution meets 150m detection requirements at night). Acoustic: Directional microphone array (pointed to key activity areas). Priority should be given to the deployment of breakwaters at both ends of the harbor basin and the center point of the approach channel entrance. ③ Low-to-medium altitude migration corridors (0-5km behind the shoreline, altitude 30-300m) Birds pass through rapidly during the migratory season (30-300m). Core objectives: Monitor migration flow, altitude, and direction, and provide early warning of flocking activities. Utilize high-point network: prioritize existing lighthouses, signal towers, communication towers, and high mountain peaks with a height of ≥20m. Station spacing should be designed based on an actual detection radius of 3km. Adjacent radar detection ranges should have ≥30% overlap. Inter-station spacing: 3-5km (depending on radar performance; typically, the detection radius for small birds is 3-5km). Core equipment: Dedicated bird monitoring radar (X or Ku band, with Automatic Target Detection and Tracking (ATD) function). Power supply / communication: Mains power / fiber optic / 4G. High-power solar panels + batteries are used where mains power is unavailable. Main river estuaries, above main channels, and sandbar gaps: Auxiliary optical equipment (gimbal camera) can be installed for target verification. ④ Low-altitude zone near the coast (0-1km behind the shoreline) Daily activities at altitudes below 30m (traveling between mudflats and habitats). Core objective: To supplement monitoring of the mudflat-land transition zone and track birds moving inland. Deploy cameras along the landside: utilize dike tops, streetlights, and low-rise buildings (≥4m). Position the camera horizontally or slightly downwards, pointing towards the mudflats, ensuring no vegetation / building obstructions. Focus deployment on the landside of the estuary, forest edges, and grassland-mudflat interfaces. Along the landside: 1-1.2km Optical: Static wide-angle thermal imager. Acoustic: Directional microphone (pointed towards mudflats or activity channels). Power / Communication: 4G / Solar. Known habitat entrances and important tidal channel landside ends: densified to 400-500m.

[0184] Table 2. Ship-based monitoring point layout scheme (moving scan line);

[0185] Target partition Bird activity characteristics and monitoring targets Navigation and Deployment Strategies Typical track spacing / pattern Core equipment combination and functional requirements ① Open intertidal zone (3-10km from the shore) It migrates at low altitudes (<50m) in a straight line at high speed. Its core objectives are: to cover distant beaches, monitor migrating flocks, and supplement blind spots in shore-based monitoring. Parallel shoreline cruise: Design an equidistant scanning track parallel to the shoreline. Maintain a stable low speed (5-8 knots) to facilitate stable equipment scanning and data acquisition. Track spacing: 800m-1000m (depending on equipment coverage width) Radar: Ship-mounted Ku-band or higher scanning radar (detection altitude 50-200m, with bird target detection capability). Optics: Single dual-spectrum gimbal camera, medium-to-long telephoto zoom (with image stabilization). Positioning: High-precision GPS / RTK. Data: Local storage + 4G backhaul of critical data. ② Main channel and extended area (±2.5km) Birds are lifted across the waterway (20-100m). Core objective: To monitor the height, density, and avoidance behavior of bird flocks crossing the waterway and to assess the risk of collision. Parallel navigation along the channel centerline or edge markings. Maintain standard cruising speed (to avoid impacting shipping). Monitor the airspace above the channel closely. Track spacing: According to waterway rules, it is usually a single line coverage. Radar: Top-mounted radar (core component, monitoring the height, speed, and trajectory of bird flocks above the waterway). Optics: Gimbal camera assists in observation and verification. ③ Estuary / Sea estuary sector Birds disperse in a fan shape from the river channel to the mudflats to forage, with significant variations in altitude. Core objective: To cover the estuary diffusion area and monitor the dynamics of foraging flocks. The ship cruises in a radial pattern, maintaining a stable low speed (5-8 knots). Scan line spacing: 500m-1000m Optics: Single zoom pan-tilt camera with adaptive zoom.

[0186] Table 3. Bridge foundation monitoring point layout scheme (attachment points of water-related structures);

[0187] Target partition Bird activity characteristics and monitoring targets Deployment strategy Typical node spacing / location Core equipment combination and functional requirements ① Conventional bridge pier area (0-3km offshore) Flying close to the water surface (<10m) through bridge openings. Core objective: To monitor bridge crossing frequency and behavior, and to detect commonly used bridge openings. Prioritize the deployment of bridge deck light poles, with a height of 4-6m (for wave protection and collision avoidance), and a 30° downward angle to cover the attachment points of the bridge openings and piers. Install monitoring equipment on the top of the piers or on the outer protective columns, at a height of >= 6-8m (for wave protection). The equipment should be horizontal or slightly tilted downwards, covering the water area below the bridge openings and extending to both sides (>= 500m). Spacing should be based on the width of the bridge openings and coverage requirements. Prioritize deployment in key areas (main navigation passages, large / irregular piers, known bird passageways). Optical: Wide-angle or medium-range thermal imager (FOV 60°-90°) + waterproof and salt spray resistant (IP68). ②Bridge-shore junction area (approach bridge) This area is a densely populated zone for bird take-off and landing, and habitat transition, connecting terrestrial habitats with aquatic foraging areas. Core objective: To monitor activity in the bridge-land transition zone and connect with shore-based network data. Approach bridge light pole / structure attachment: Deploy low-level nodes (4-8m high) using light poles on both sides of the approach bridge or the outer platform of the guardrail. Cover the mudflats, water area and adjacent land below the approach bridge (radius >= 500m). The distance from the nearest shore-based grid node should be <= 1000m. Prioritize deployment in key areas (main navigation passages, large / irregular piers, known bird passageways). Optical: Wide-angle thermal imager (static). Acoustic: Directional microphone (covering the area under the bridge and the mudflats). Illumination: Illuminance sensor (quantifying the impact of light pollution). ③Top of bridge tower / cable tower High-altitude (>80m) migration routes may be affected by tower lights. Core objective: To monitor high-altitude migration flows and assess the potential attraction / distraction of tower lights to birds. Tower top view of nodes: A monitoring platform is set up at the top of the main tower / cable tower of the key passage, and the equipment overlooks the surrounding airspace. Prioritize deployment in key areas (main navigation passages, large / irregular piers, known bird passageways). Optics: High-resolution thermal imager with wide-angle coverage. Light intensity: Spectrometer / light intensity sensor (monitoring tower light intensity and spectrum).

[0188] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A system for constructing a three-dimensional monitoring network of coastal birds under the influence of a wading bridge and evaluating the ecological impact, characterized in that, The system comprises: a stereoscopic monitoring network module for monitoring bird activities in a coastal nearshore area; a data processing module for calculating bird density and identifying bird spatial density mutation points based on data collected by the stereoscopic monitoring network module; an ecological impact assessment module for assessing the ecological impact of a wading bridge on birds based on bird density changes and mutation point migration; wherein the stereoscopic monitoring network module comprises a shore-based monitoring sub-module, a ship-based monitoring sub-module, and a bridge-based monitoring sub-module; the shore-based monitoring sub-module comprises fixed monitoring nodes in the nearshore intertidal zone, port / hard shoreline buffer zone, medium-low altitude migration channel, and nearshore land low-altitude zone, each node is equipped with optical, acoustic, or radar equipment, and the node spacing and equipment parameters are matched to cover the target area; the ship-based monitoring sub-module comprises mobile monitoring nodes in the open intertidal zone, main channel and extended area, and river mouth / sea inlet fan-shaped area, cruising along the preset track, equipped with radar, optical equipment, and positioning equipment, the track spacing is matched with the equipment coverage width; the bridge-based monitoring sub-module comprises attached monitoring nodes in the regular pier area, bridge-shore intersection area, and bridge tower / cable tower top, equipped with optical, acoustic, or sensor equipment, the node position and height meet the coverage requirements of the bridge hole, transition area, and high-altitude area; when calculating bird density, the data processing module uses the following methods: (1) calculating the effective monitoring volume of each monitoring device: (2) fusing shore-based and ship-based data to calculate intertidal zone bird density: (3) fusing bridge-based and ship-based data to calculate channel crossing area bird density: Optical device single point effective monitoring volume: wherein is a horizontal field of view, is an optical device effective detection distance in m, is an optical correction coefficient, and ≤ 1; Radar device single point effective monitoring volume: wherein, is the radar horizontal detection radius in m, is the effective detection height layer in m, is the radar attenuation coefficient, calculated from the rainfall: , is the rainfall in mm / h; Acoustic device single point effective monitoring volume: wherein is the horizontal beam width, is the acoustic effective detection distance in m, is the acoustic correction factor and ≤ 1; Total observed bird number in the intertidal zone: ； in, , , These are respectively shore-based optics, radar, and acoustics. The number of birds identified by each node. , They are ship-based optics and radar. The number of birds identified by each node. The number of birds repeatedly observed in overlapping intertidal zones; Total effective observation volume in the intertidal zone: ； wherein, , , are the effective observation volumes of the shore-based optical, radar, acoustic 1st , are the effective observation volumes of the ship-based optical, radar 1st is the effective observation volume of the intertidal overlap region;​​ Intertidal bird density: ; Total observed bird number in the channel crossing area: ； wherein, the number of birds identified by the bridge-based optical and acoustic , the number of birds identified by the ship-based optical and radar the number of birds observed repeatedly in the overlapping areas of the channel crossing zones;​​ Total effective observation volume in the channel crossing area: ； wherein, , are the effective observation volumes of the bridge-based optical, acoustic 1st nodes, respectively, , are the effective observation volumes of the ship-based optical, radar 1st nodes, respectively, is the effective observation volume of the overlap area of the channel crossing areas. Bird density in the channel crossing area: . 2.The system according to claim 1, wherein, When identifying bird spatial density mutation points, the data processing module uses the following methods: (1) Calculate the rate of change of spatial density of birds: ,in For bird spatial density, intertidal zone The waterway crosses the area. The partial derivatives are calculated using the central difference approximation formula. , respectively representing the density at , , Rate of change on the axis: , is the grid center coordinate, is the grid spacing; (2) Calculate the second-order spatial derivative of density: Solve the density difference between the current position and the 6 neighboring grids by grid difference; (3) Identify mutation points: Calculate the mutation points in the monitoring space. Standard deviation and average , will satisfy point These are identified as mutation points, forming a mutation point set CP. 3.The system according to claim 2, wherein, When assessing ecological impact, the ecological impact assessment module includes: (1) calculating the partition density change rate before and after the project: (2) Calculate the mobility shift of the mutation points before and after the engineering: wherein is the average migration distance of all mutation points: ； Wherein, Respectively, the position of the mutation point before and after the construction, The maximum coverage radius of the monitoring network , , , Respectively, the maximum detection distance of the shore-based, ship-based and bridge-based equipment, , , Respectively, the center straight line distance of the monitoring points of the shore-based and ship-based, shore-based and bridge-based, and ship-based and bridge-based. (3) Based on the density change rate and migration rate to evaluate the impact level: when , it is determined as significant ecological disturbance, and the construction schedule needs to be adjusted and an ecological compensation scheme needs to be built. Rate of change of density in intertidal zone: where , are the bird densities in the intertidal zone before and after construction, respectively; Density change rate of channel crossing area: Wherein , Density of birds in channel crossing area before and after construction, respectively.

4. The system according to claim 3, wherein, The shore-based monitoring sub-module nodes in the nearshore intertidal zone are arranged along the mean high tide line, with an axial spacing of 1-1.2 km and a longitudinal spacing of 1.5-2 km, the core equipment is a wide-angle thermal imager, a visible light camera, and a ≥4-channel directional microphone array, the river mouth and tidal creek inlet node spacing is reduced to 400-500 m. 5.The system for constructing a stereoscopic monitoring network of coastal birds under the influence of a wading bridge and evaluating ecological impact according to claim 4, wherein, The ship-based monitoring sub-module's open intertidal zone cruises along equidistant tracks parallel to the shoreline at a speed of 5-8 knots, with a track spacing of 800-1000 m, the core equipment is a Ku-band scanning radar, a dual-spectrum pan-tilt camera, and a high-precision GPS / RTK. 6.The system for constructing a stereoscopic monitoring network of coastal birds under the influence of a wading bridge and evaluating ecological impact according to claim 5, wherein, The bridge-based monitoring sub-module's regular pier area nodes are deployed on the bridge deck light poles or pier tops, with a device depression angle of 30° to cover the bridge hole and the extended water area on both sides, the core equipment is a wide-angle or medium focal length thermal imager.

7. A method for three-dimensional monitoring of coastal birds and ecological impact assessment, which is applied to the three-dimensional monitoring network construction and ecological impact assessment system of coastal birds under the influence of the wading bridge according to claim 6, characterized in that, The system comprises the following steps: S1. Construct a stereoscopic monitoring network: deploy shore-based, ship-based, and bridge-based monitoring nodes to cover the nearshore intertidal zone, channel, and bridge surrounding area, respectively, and configure optical, acoustic, and radar equipment; S2. Collect bird activity data: obtain bird number, location, and behavior data through each monitoring node; S3. Calculate bird density: calculate the bird density in the intertidal zone and channel crossing area; S4. Identify density mutation point: identify the mutation point of bird spatial density; S5. Evaluate ecological impact: calculate the density change rate and mutation point migration rate, determine the impact level and develop countermeasures.

8. A method of monitoring and assessing ecological impact of coastal birds in three dimensions according to claim 7, characterized in that, In step S1, the arrangement of the shore-based, ship-based and bridge-based monitoring nodes meets the principle of hierarchical monitoring, reuses existing infrastructure to reduce costs, and each node data is verified with each other to eliminate monitoring blind spots.

9. A method of monitoring and assessing ecological impact of coastal birds in three dimensions according to claim 8, characterized in that, In step S5, the countermeasures include: when the impact level is low, and When the level is medium, routine tracking and monitoring should be carried out. When the level is high, closely monitor and supplement habitats; when the level is high, adjust the construction sequence and develop an ecological compensation plan.

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