A salt marsh target elevation calculation method and system based on tidal level time series data

Abstract

The application discloses a salt marsh target elevation calculation method and system based on tidal level time series data, and belongs to the technical field of computer data processing, which comprises the following steps: acquiring target salt marsh region terrain elevation data, water power measuring point position and tidal level time series data, and generating measuring point tidal level elevation correlation data; generating measuring point submergence-exposure state sequence according to sampling time, and counting measuring point daily average submergence time length data; performing Kriging spatial interpolation based on the measuring point position, generating regional daily average submergence time length spatial distribution and contour map; determining a salt marsh suitable submergence region according to the suitable daily average submergence time length of target salt marsh vegetation, and generating salt marsh target elevation data in space correspondence with the terrain elevation data. Through the continuous data chain of measuring point level time series submergence statistics, spatial continuous and elevation back reading, the application reduces the target elevation deviation caused by discrete measuring points and single tidal level representation.

Description

Technical Field

[0001] This invention relates to the field of computer data processing technology, and in particular to a method and system for calculating the target elevation of salt marshes based on tidal time series data. Background Technology

[0002] Coastal salt marshes are located in areas of interaction between land and sea, and the establishment and growth of salt marsh vegetation are jointly influenced by tidal flooding processes, beach elevation, substrate, and salinity conditions. Tidal levels change periodically over time, and different beach elevations correspond to varying durations of flooding within one or more tidal cycles. Simultaneously, silt-forming mudflats are affected by sediment deposition and tidal erosion, resulting in significant spatial variations in topographic elevation. Therefore, in the ecological restoration of salt marshes, it is necessary to determine the target restoration elevation that matches the hydrological habitat of the target salt marsh vegetation based on actual tidal level changes and beach topographic conditions, providing an executable elevation control basis for beach topographic modification.

[0003] Current methods for analyzing suitable elevations for vegetation in salt marshes or coastal wetlands typically compare tidal time series with candidate elevations, calculate the cumulative flooding time when the tide level is above the corresponding elevation, and determine the suitable elevation based on the appropriate flooding time for the target vegetation. Some schemes further combine digital elevation models to create a raster of daily average flooding durations corresponding to different elevations, or calculate flooding duration and frequency based on whether the hourly water depth is greater than zero, and then divide the vegetation remediation area. For the continuous processing of discrete spatial data, Kriging interpolation, rasterization, and contour line generation are also commonly used methods in geospatial data processing. Search results show that there are already corresponding technical foundations for determining suitable vegetation elevations based on tidal time series, spatial representation of DEM and daily average flooding duration, and interpolation and contour line processing.

[0004] However, in actual tidal flats to be restored, different hydrodynamic measuring points have their own spatial locations, elevations, and tidal level changes. If the flooding time is directly calculated based on a preset elevation, or if suitability zones are formed solely based on a grid model or data from a single tide gauge station, the correspondence between the actual tidal level response at the measuring point level and the local tidal surface elevation is difficult to continuously transfer to the target elevation calculation results. Furthermore, if the submerged-exposed state of measuring points, average daily flooding duration, spatial continuity results between discrete measuring points, suitable flooding areas, and actual topographic elevations are processed separately, a clear data continuity relationship is easily lacking between the processing stages. Therefore, it is necessary to organize the correlation of tidal levels and elevations of multiple hydrodynamic measuring points, flooding event statistics, spatial interpolation of average daily flooding duration, determination of suitable flooding areas, and topographic elevation back-reading into a continuous data processing process to reduce the spatial correspondence bias generated during the conversion of discrete observation information to the target elevation for restoration. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a method and system for calculating the target elevation of salt marshes based on tidal time-series data. By using a continuous data chain of time-series flooding statistics at measurement points, spatial continuity, and elevation backreading, the deviation in target elevation caused by discrete measurement points and single tidal level representation is reduced.

[0006] The above objectives can be achieved through the following approach: A method for calculating the target elevation of a salt marsh based on tidal time-series data includes: acquiring topographic elevation data of the target salt marsh area and the locations of multiple hydrodynamic measuring points; collecting tidal time-series data corresponding to each hydrodynamic measuring point within a preset observation period, wherein the preset observation period includes at least one complete tidal cycle; extracting the measuring point elevation from the topographic elevation data based on the measuring point location; unifying the tidal time-series data and the measuring point elevation to the same elevation datum and associating them according to the hydrodynamic measuring points to generate measuring point tidal elevation association data; based on the measuring point tidal elevation association data, comparing the tidal level value and the measuring point elevation of each hydrodynamic measuring point according to the sampling time, marking the tidal submersion state, tidal exposure state, and tidal arrival state to generate a measuring point submersion-exposure state sequence; determining the submersion duration period for each hydrodynamic measuring point based on the measuring point submersion-exposure state sequence, accumulating the submersion duration periods within the preset observation period, and calculating according to the observation period corresponding to the preset observation period. The duration is converted to a daily scale to generate daily average flood duration data for the measuring points. Based on the location of the measuring points and the daily average flood duration data, a spatial sample of daily average flood duration is constructed. Kriging spatial interpolation is performed on the spatial locations within the target salt marsh area where the hydrodynamic measuring points are not located to generate a spatial distribution of the regional daily average flood duration. Based on the spatial distribution of the regional daily average flood duration, spatial isopleths corresponding to different daily average flood durations are extracted to generate a daily average flood duration isopleth map. Suitable daily average flood duration parameters for the target salt marsh vegetation are obtained. Based on the suitable daily average flood duration parameters, corresponding spatial locations are selected from the regional daily average flood duration spatial distribution and the daily average flood duration isopleth map to generate a suitable salt marsh flood area. The suitable salt marsh flood area is spatially correlated with the topographic elevation data. The topographic elevation corresponding to the suitable salt marsh flood area is read to generate target elevation data for the salt marsh. The target elevation data for the salt marsh is used as the elevation control data for the transformation of the beach topography in the target salt marsh area.

[0007] Based on the same inventive concept, this invention also provides a system for calculating the target elevation of a salt marsh based on tidal time series data. The system includes: a data acquisition and association module, used to acquire topographic elevation data of a target salt marsh area and the locations of multiple hydrodynamic measuring points; collect tidal time series data corresponding to each hydrodynamic measuring point within a preset observation period, the preset observation period including at least one complete tidal cycle; extract the measuring point elevation from the topographic elevation data based on the measuring point location; unify the tidal time series data and the measuring point elevation to the same elevation datum and associate them according to the hydrodynamic measuring points to generate measuring point tidal elevation association data; a state sequence generation module, used to compare the tidal value of each hydrodynamic measuring point with the measuring point elevation according to the sampling time based on the measuring point tidal elevation association data, mark the tidal submersion state, tidal exposure state, and tidal arrival state, and generate a measuring point submersion-exposure state sequence; and a flood duration statistics module, used to determine the submersion duration for each hydrodynamic measuring point based on the measuring point submersion-exposure state sequence, accumulate the submersion duration within the preset observation period, and calculate the submersion duration according to the preset observation period. The observation duration corresponding to the measurement cycle is converted to a daily scale to generate daily average flood duration data for the measurement points; the spatial interpolation module is used to construct a spatial sample of daily average flood duration based on the location of the measurement points and the daily average flood duration data of the measurement points, and to perform Kriging spatial interpolation on the spatial locations in the target salt marsh area where the hydrodynamic measurement points are not set up to generate the spatial distribution of the daily average flood duration of the region; the contour line generation module is used to extract the spatial isomorphic locations corresponding to different daily average flood durations based on the spatial distribution of the daily average flood duration of the region, and generate a daily average flood duration contour map; the suitable area determination module... The system is used to obtain the suitable daily average flooding duration parameter for the target salt marsh vegetation, and to filter the corresponding spatial location from the spatial distribution of the daily average flooding duration and the contour map of the daily average flooding duration based on the suitable daily average flooding duration parameter to generate a suitable flooding area for the salt marsh; the target elevation output module is used to spatially correspond the suitable flooding area of ​​the salt marsh with the topographic elevation data, read the topographic elevation corresponding to the suitable flooding area of ​​the salt marsh, generate target elevation data for the salt marsh, and use the target elevation data of the salt marsh as the elevation control data for the transformation of the beach topography of the target salt marsh area.

[0008] Compared with the prior art, the present invention has the following advantages: This invention establishes a correspondence between the location and elevation of hydrodynamic measuring points and the time-series data of tide levels. Under a unified elevation benchmark, it compares the tide level with the elevation of the measuring points at the sampling time to generate a sequence of submerged and exposed states of the measuring points and data on the average daily flood duration of the measuring points. This allows the spatial location, elevation conditions, and actual tide level changes of each hydrodynamic measuring point to be continuously connected in the same data chain, avoiding the state correspondence deviation caused by separating the tide level information of different spatial locations from the beach elevation.

[0009] This invention constructs a spatial sample of daily average flood duration using the location of hydrodynamic measuring points and the daily average flood duration data of the measuring points. Kriging spatial interpolation is then performed within the target salt marsh area to generate a spatial distribution map of the daily average flood duration and a contour map of the daily average flood duration. This transforms the time-scale flood information obtained from discrete measuring points into continuous spatial information covering the area to be restored. This provides a spatial basis for determining suitable flood areas for vegetation in the target salt marsh that is consistent with the actual measuring point observation results, reducing the lack of spatial representativeness caused by determining the restoration area based solely on a single measuring point or local location.

[0010] This invention determines suitable flooding areas of salt marshes from the spatial distribution of regional average daily flooding duration based on the suitable daily flooding duration parameters of the target salt marsh vegetation. It then spatially correlates these suitable flooding areas with topographic elevation data to generate target elevation data for salt marshes with spatial location relationships. This target elevation data is used for elevation control in beach topography modification, creating a continuous connection between tidal level timing observation, vegetation hydrological habitat requirements, and actual topographic modification. In the ecological restoration scenario of Suaeda salsa in saline-alkali land, by identifying flooding conditions that meet the target growth requirements and reading the corresponding spatial elevation information, it can provide a target elevation basis for subsequent beach habitat creation. Attached Figure Description

[0011] Figure 1 This is a schematic flowchart of a method for calculating the target elevation of a salt marsh based on tidal time series data, according to an embodiment of the present invention.

[0012] Figure 2 is a schematic diagram of the generation of tide level elevation correlation data at measuring points according to an embodiment of the present invention.

[0013] Figure 3 This is a schematic diagram illustrating the determination of tide level and submersion status at measuring points according to an embodiment of the present invention.

[0014] Figure 4 This is a schematic diagram of the process for generating the flooding state sequence and calculating the average daily flooding duration according to an embodiment of the present invention.

[0015] Figure 5 This is a schematic diagram of Kriging space interpolation of the average daily flooding duration in a region according to an embodiment of the present invention.

[0016] Figure 6 This is a schematic diagram illustrating the daily average flood duration contour lines and the determination of suitable flood areas in salt marshes, according to an embodiment of the present invention.

[0017] Figure 7 This is a schematic diagram illustrating the spatial correspondence between suitable flooded areas of salt marshes and topographic elevation, and the generation of target elevations, according to an embodiment of the present invention.

[0018] Figure 8 This is a schematic diagram of a salt marsh target elevation calculation system based on tidal time series data, according to an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0020] Reference Figure 1 One embodiment of the present invention proposes a method for calculating the target elevation of salt marshes based on tidal time series data. By using a continuous data chain of time series flooding statistics at measuring points, spatial continuity, and elevation back reading, the deviation of the target elevation caused by discrete measuring points and single tidal level characterization is reduced.

[0021] The method described in this embodiment specifically includes: S1. Obtain topographic elevation data of the target salt marsh area and the location of multiple hydrodynamic measuring points. Collect tidal time series data corresponding to each hydrodynamic measuring point within a preset observation period. The preset observation period includes at least one complete tidal cycle. Extract the measuring point elevation from the topographic elevation data based on the measuring point location. Unify the tidal time series data and the measuring point elevation to the same elevation datum and associate them according to the hydrodynamic measuring points to generate measuring point tidal elevation association data. In one embodiment of the present invention, step S1 includes the following steps: Obtain information on substrate type, total water-soluble salt content, and historical native vegetation distribution in candidate tidal flat areas; The suitability of the candidate tidal flat area for ecological restoration of Suaeda salsa is determined based on the substrate type, the total amount of water-soluble salt, and the historical local vegetation distribution information. When the substrate type is mainly clayey silt, the total amount of water-soluble salt is between 5g / kg and 25g / kg, and the historical local vegetation distribution information indicates the presence of historical Suaeda salsa distribution, the corresponding candidate tidal flat area is determined as the target salt marsh area. A topographic survey was conducted on the target salt marsh area to obtain the topographic elevation data; Multiple hydrodynamic measuring points are set up in the target salt marsh area, the location of each hydrodynamic measuring point is recorded, and the tidal time series data of each hydrodynamic measuring point are collected in chronological order within the preset observation period. Based on the location of the measuring point, the elevation of the corresponding spatial location in the topographic elevation data is read to determine the measuring point elevation of each of the hydrodynamic measuring points; The tide level values ​​in the tide time series data and the elevation of the measuring point are converted to the same elevation datum, and the correspondence between the measuring point location, the measuring point elevation and the tide time series data is established according to the hydrodynamic measuring point identifier, so as to generate the measuring point tide level elevation association data.

[0022] Specifically, such as Figure 2 As shown, the target salt marsh region is defined by a two-dimensional spatial boundary. The topographic elevation data originates from topographic surveys of the target salt marsh area. It can be generated through RTK surveying, UAV topographic surveying, or by verifying existing digital elevation data on-site. The data is then organized into a spatial elevation dataset according to a unified plane coordinate system. ; In the formula, Indicates the first The planar coordinates of a terrain location, in meters; This indicates the topographic elevation of the corresponding terrain location under a unified elevation datum, in meters. This indicates the total number of terrain elevation locations.

[0023] Within the target salt marsh area, settings were established according to the tidal flat elevation gradient and spatial distribution. There are 1 hydrodynamic measuring points, and the set of measuring points is represented as follows: ; No. The location of each hydrodynamic measuring point is represented as follows: ; in accordance with Spatial sampling is performed on the terrain elevation data to obtain the elevation of the measurement points. Each measuring point follows a uniform sampling interval. Record the tide levels to form tide level time series data: ; In the formula, Indicates the first Each sampling time; Indicates the first Each hydrodynamic measuring point is located at The tide level at any given time; This indicates the total number of sampling times within the preset observation period.

[0024] When the tide level acquisition equipment and topographic surveying use different elevation zero points, the elevation datum correction is obtained through on-site leveling. The tide level elevation and the measuring point elevation are converted using the following formulas: ; ; In the formula, This indicates the original tide level recorded by the tide level acquisition equipment; Indicates the first Correction amount of each hydrodynamic measuring point tidal level device relative to a unified elevation benchmark; This indicates the original elevation of the measuring point obtained from the topographic survey; This represents the elevation correction corresponding to the topographic survey benchmark. and All values ​​were obtained through on-site leveling or measurement datum conversion parameters, without using manually set values.

[0025] After unifying the elevation datum, establish a tidal level-elevation correlation record for each hydrodynamic measuring point: ; All measurement point records constitute the tide level elevation correlation data for each measurement point: ; The tide level elevation correlation data at the measuring points ensures that each tide level sample value can be mapped to a specific spatial coordinate and measuring point elevation, and serves as the input for hourly state comparison in step S2.

[0026] For example, in a pre-remediation survey of Suaeda salsa in a silty mudflat, the surface sediment of the candidate area was mainly clayey silt. The total water-soluble salt content of three representative surface sediment samples was 12.6 g / kg, 13.2 g / kg, and 14.1 g / kg, respectively, all within the range of 5 g / kg to 25 g / kg. Historical vegetation survey data recorded the distribution of Suaeda salsa. Therefore, an area of ​​approximately The candidate area was identified as the target salt marsh area. A topographic elevation grid was established with a topographic sampling interval of 10m. The direction forms 21 sampling positions. The direction forms 17 sampling positions, and a total of These are the elevation locations of various terrain features. For example, some terrain locations are as follows: , , , and The corresponding terrain elevations are 1.58m, 1.59m, 1.60m, 1.83m, and 2.06m, respectively. The remaining terrain locations are arranged consecutively at 10m intervals, thus forming terrain elevation data containing 357 spatial elevation elements. Five representative hydrodynamic measuring points were deployed within the target salt marsh area, therefore The hydrodynamic measurement point set is backfilled as follows: The spatial locations of the five hydrodynamic measuring points are as follows: Spatial readings are performed on the terrain elevation data based on the spatial location of each measuring point, for example... lie in The corresponding unified benchmark terrain elevation is 1.83m, therefore: Similarly, the data can be read... to The elevations of the measuring points are 1.62m, 1.74m, 1.90m, and 2.04m, respectively. The preset observation period is 48 consecutive hours, and the tide level sampling interval is 30 minutes. A total of [data missing] data are generated, including the start and end times. Each sampling time was used to generate tidal time series data for each measuring point at the same sampling time. For example, the complete tide time series contains 97 records, of which the unified reference tide levels corresponding to 05:00, 05:30, 06:00, 06:30, and 07:00 are 1.76m, 1.83m, 1.91m, 1.83m, and 1.78m, respectively. Therefore, it can be backfilled according to the established structure as follows: The omitted positions correspond to other consecutive sampling records within the same 48-hour observation period. It actually includes all 97 tide level records. The tide level data was obtained using an independent zero-point measurement device, connected to on-site leveling measurements. Corresponding tide level correction For example, if the original tide levels recorded at 05:30, 06:00, and 06:30 are 0.63m, 0.71m, and 0.63m respectively, then the tide level conversion processes are as follows: ; ; The topographic survey data uses a different original zero point than the tidal level equipment, and the topographic elevation correction is obtained by on-site leveling. .For example Corresponding to the original terrain elevation ,but: After the elevation datum is unified, The backfilled records of tide level correlation at the measuring points are as follows: Similarly, to Formed separately , , and Finally, we obtained the correlation data of tidal level and elevation of all 5 hydrodynamic measuring points, including their spatial locations, elevations, and 97 tidal level records: ; S2. Based on the tide level-elevation correlation data of the measuring points, compare the tide level value of each hydrodynamic measuring point with the elevation of the measuring point according to the sampling time, mark the tide submerged state, the tide exposed state and the tide level arrival state, and generate a measuring point submerged-exposed state sequence. In one embodiment of the present invention, step S2 includes the following steps: According to the sampling time, the tide level value and the elevation of each hydrodynamic measuring point are read from the tide level-elevation correlation data of the measuring points. When the tide level is higher than the elevation of the measuring point, it is marked as the state of being submerged by the tide; when the tide level is lower than the elevation of the measuring point, it is marked as the state of being exposed by the tide; when the tide level is equal to the elevation of the measuring point, it is marked as the state of being reached by the tide, and measuring point status marking data is generated. The state marker data of the measuring points are connected in chronological order of the sampling times to generate the submerged-exposed state sequence of the measuring points.

[0027] Specifically, such as Figure 3 As shown, the correlation data between the tide level and elevation at the measuring point... According to the hydrodynamic measuring point marking and sampling time Reading tide level and the elevation of the measuring points Define state flags : ; In the formula, express The tide submerged the first One hydrodynamic measuring point; express Time of the first One hydrodynamic measuring point was exposed; This indicates that the tide level has just reached the elevation of the measuring point. In actual digital calculations, the elevation comparison accuracy is kept consistent with the effective resolution of the tide level equipment and topographic survey to avoid repeated state switching caused by decimal differences exceeding the measurement accuracy of the equipment.

[0028] No. The sequence of submerged-exposed states of a hydrodynamic measuring point during the entire preset observation period is represented as follows:

[0029] The state sequence of all hydrodynamic measuring points is as follows:

[0030] The state sequence preserves the continuous transition relationship between tidal exposure, tidal level arrival, and tidal submersion according to the time axis, so that step S3 can identify the start and end times of each complete submersion process.

[0031] For example, continue to use Corresponding tide level elevation records at the corresponding measuring points Perform state identification, the elevation of the measuring point is The tide levels at five consecutive sampling times—05:00, 05:30, 06:00, 06:30, and 07:00—were 1.76m, 1.83m, 1.91m, 1.83m, and 1.78m, respectively. At 05:00... The status is marked as 05:30 The status is marked as 06:00 The status is marked as 06:30 The status is marked as 07:00 The status is marked as The corresponding state determinations are as follows: ; ; Therefore, the period from 05:00 to 07:00 is formed. The state change corresponds to a complete state transition process from tide emergence, tide arrival, tide submersion, tide arrival again, and then tide emergence again. Continue to process according to the same rules. All within 48 hours At each sampling time, a complete submersion-exposure state sequence of the measuring points is obtained: The omitted positions correspond to State markers at other consecutive sampling times Actually includes from to All 97 time-state records were processed according to the same tide level comparison rules. , , and The 97 sampling times yielded , , and This ultimately forms the submerged-exposed state sequence for all five hydrodynamic measuring points: ; S3. Determine the inundation duration of each hydrodynamic measuring point according to the inundation-exposure state sequence of the measuring point, accumulate the inundation duration within the preset observation period and convert it to the daily scale according to the observation duration corresponding to the preset observation period, and generate the daily average inundation duration data of the measuring point. In one embodiment of the present invention, step S3 includes the following steps: The flooding-exposure state sequence of the hydrodynamic measuring points is read respectively. The flooding start time and flooding end time are determined according to the state transition between the tidal exposure state, the tidal level arrival state and the tidal flooding state, and the flooding duration period is generated. The inundation duration is accumulated for all the inundation periods within the preset observation period for the same hydrodynamic measuring point to generate the cumulative inundation duration. Based on the cumulative inundation duration and the observation duration corresponding to the preset observation period, a daily-scale conversion is performed to generate the average daily inundation duration data for each hydrodynamic measuring point.

[0032] Specifically, such as Figure 4 As shown, for the measurement point state sequence When the state is in accordance with When the state changes, the moment corresponding to state 0 is determined as the inundation start moment of a flooding process. When the state is in accordance with When the state changes, the time corresponding to state 0 is determined as the end time of the corresponding flooding process. When the discrete sampling time does not directly occur At that time, linear time interpolation is performed between two adjacent tide level sampling points on different sides to determine the tide arrival time:

[0033] In the formula, This indicates the estimated time when the tide level crosses the elevation of the measuring point; and These represent two consecutive tidal levels before and after crossing the elevation of the measuring point.

[0034] No. Composition of the total submersion duration of each hydrodynamic measuring point:

[0035] In the formula, Indicates the first observation within the preset observation period The number of complete flooding periods observed at each hydrodynamic measuring point.

[0036] Total duration of flooding Accumulate items according to each inundation period:

[0037] When the total observation duration corresponding to the preset observation period is The cumulative flooding duration will be converted to a 24-hour daily scale.

[0038] In the formula, Indicates the first The average daily flooding duration for each hydrodynamic monitoring point is expressed in hours per day. The average daily flooding duration for all monitoring points is organized according to the monitoring point identification as follows:

[0039] Average daily flood duration data at monitoring points The measurement point positions in step S1 are kept in a one-to-one correspondence and are used as the attribute value input for spatial interpolation in step S4.

[0040] For example, Four representative complete flooding periods were identified during the continuous 48-hour observation period: 05:30 to 06:30 on the first day, 17:50 to 18:50 on the first day, 06:05 to 07:05 on the second day, and 18:25 to 19:25 on the second day. Each period lasted for 1 hour, thus forming: The total submersion time is: Observation duration The daily-scale conversion result is as follows: Using the same processing procedure, to The corresponding cumulative flooding durations within 48 hours are 15.0h, 11.6h, 6.2h, and 2.4h, respectively. Therefore: The final data on the average daily flood duration at the monitoring points is generated. The average daily flood duration is uniformly measured in hours per day.

[0041] S4. Based on the location of the measuring point and the daily average flooding duration data of the measuring point, construct a spatial sample of the daily average flooding duration. Perform Kriging spatial interpolation on the spatial locations in the target salt marsh area where the hydrodynamic measuring point is not set up to generate the spatial distribution of the daily average flooding duration in the region. In one embodiment of the present invention, step S4 includes the following steps: Based on the hydrodynamic measuring points, the locations of the measuring points are associated one by one with the daily average flood duration data of the measuring points to generate the daily average flood duration spatial sample. Using the location of the measuring point as spatial coordinates and the average daily flooding duration data of the measuring point as spatial interpolation attribute value, Kriging spatial interpolation is performed on the spatial location of the target salt marsh area where the hydrodynamic measuring point is not set to generate an estimated value of the average daily flooding duration. The daily average flood duration data and the estimated daily average flood duration of the measuring points are organized according to their corresponding spatial locations, and the spatial range is limited to the target salt marsh area to generate the spatial distribution of the daily average flood duration of the area.

[0042] Specifically, such as Figure 5 As shown, the coordinates of the measuring points determined in step S1 are... Compared with the average daily flood duration obtained in step S3 One-to-one pairing was performed to construct a spatial sample of the average daily flood duration: ; In the target salt marsh area A spatial interpolation grid is established within the data. The grid resolution is determined jointly based on the topographic measurement resolution, the average spacing of hydrodynamic measurement points, and the final accuracy of beach elevation control, ensuring that the interpolation grid does not exceed the spatial resolution actually supported by the original topographic data.

[0043] For any position to be estimated The weights of each spatial sample are determined using the ordinary kriging method. The spatial semivariogram obtained by fitting with the empirical semivariogram. The Kriging weights describe the spatial correlation of daily average flood duration among different measuring points, satisfying the following: ; And it satisfies the unbiased constraint: ; In the formula, Represents the Lagrange multipliers; Indicates the first The spatial sample and the first The semivariogram values ​​among spatial samples; This represents the semivariogram value between the spatial sample and the location to be estimated. The nugget value, sill value, and range of the semivariogram are obtained by fitting the spatial sample of the average daily flooding duration of the current target salt marsh area, without being pre-assigned fixed empirical values.

[0044] The estimated daily flood duration for the location to be estimated is calculated as follows: ; The interpolation grid locations within the target salt marsh area were repeatedly calculated, and the measured daily average flooding duration at the measuring points and the estimated daily average flooding duration at non-measuring points were uniformly organized to obtain the spatial distribution of the regional daily average flooding duration: ; In the formula, This represents the total number of grid locations participating in the spatial representation within the target salt marsh region; at the hydrodynamic measurement point location... The average daily flooding duration at the corresponding measuring points was used. .

[0045] For example, a spatial sample is constructed using the five hydrodynamic monitoring points obtained in step S3 and their average daily flood duration. The five monitoring points are as follows: , , , and The corresponding daily average flooding durations are 7.5 h / d, 5.8 h / d, 3.1 h / d, 1.2 h / d, and 2.0 h / d, respectively. Therefore, the complete backfill of the spatial sample of daily average flooding duration is as follows: The spatial coordinates are in meters, and the average daily flooding duration is in hours per day. The estimated location within the target salt marsh region... For example, according to The spatial distances between five measuring points and the average daily flood duration were sampled and fitted with semivariograms. Kriging equations were then established to obtain the values ​​of the five spatial samples for... The weights are respectively , , , and ,satisfy: The weights are calculated by weighting each weight with the average daily flooding duration at the corresponding monitoring point: Kriging spatial interpolation was performed on the spatial locations of the remaining un-established hydrodynamic measuring points within the target salt marsh area using the same method. The planar extent of the target salt marsh area was taken as... When using 10m as the spatial interval, The direction forms 21 grid positions. The direction forms 17 grid positions, forming a total of The spatial location is determined by the following steps. For grid locations coinciding with hydrodynamic measurement points, the measured daily average flood duration obtained in step S3 is directly retained. For other grid locations, the estimated daily average flood duration obtained through Kriging interpolation is recorded. For example, the calculated... , , as well as And hydrodynamic measuring points Directly retain Therefore, 357 grid locations and their average daily flood durations were organized according to spatial location. The spatial distribution of the average daily flood duration in the region was backfilled as follows:

[0046] ;in, to The average daily flood duration corresponds to 357 spatial locations; the locations of hydrodynamic measuring points use measured values, while the remaining spatial locations use Kriging spatial interpolation results. Maintain a continuous spatial location-average daily flood duration correspondence within the target salt marsh area, and use this as direct input for step S5 to extract locations with equivalent daily flood durations of 1h / d, 2h / d, 3h / d, and others.

[0047] S5. Based on the spatial distribution of the average daily flooding duration in the area, extract the spatial isopleths corresponding to different average daily flooding durations and generate an isopleth map of the average daily flooding duration. In one embodiment of the present invention, step S5 includes the following steps: Extract spatial locations with the same daily average flood duration from the spatial distribution of the average daily flood duration in the region, and generate multiple sets of locations with equal flood duration. Connect the spatial locations in each set of locations with equal flood duration to generate flood duration contour lines corresponding to different daily average flood durations; The range of the flood duration contour lines is defined according to the spatial boundary of the target salt marsh area, and the daily average flood duration corresponding to each of the flood duration contour lines is marked to generate the daily average flood duration contour map.

[0048] Specifically, such as Figure 6 As shown, the spatial distribution of the average daily flood duration in the region. Set contour levels , No. The set of locations with equal flood duration is defined as: ; When contour lines pass through two adjacent spatial grid nodes and And the average daily flooding duration corresponding to the two nodes and Located at the contour level When on both sides, perform linear position interpolation along the grid edges: ; In the formula, This represents the intersection point of the contour line with the current grid edge. The contour intersection points within the same grid cell are calculated sequentially, and adjacent intersection points are connected. Then, the line segments within each grid cell are connected sequentially according to spatial adjacency to form a continuous contour line corresponding to the daily average flood duration.

[0049] The intervals for contour lines are set based on the range of average daily flood duration in the region and the suitable average daily flood duration parameters for the target vegetation. The range of contour line levels is determined by the maximum and minimum values ​​of average daily flood duration in the spatial distribution of average daily flood duration in the region, while the contour intervals are determined based on the spatial interpolation resolution and the data accuracy of habitat flood duration information. When generating the average daily flood duration contour map, each flood duration contour line retains its corresponding average daily flood duration attribute, enabling the subsequent extraction of matching flood duration contour lines based on the suitable average daily flood duration parameters for the target salt marsh vegetation.

[0050] All contour lines pass through the boundary of the target salt marsh region. After cutting, a contour map of the average daily flood duration is generated:

[0051] In the formula, This represents the total number of daily average flood duration levels extracted.

[0052] For example, the spatial distribution of the average daily flood duration in the region formed in step S4. Based on this, the contour levels are set to 1h / d, 2h / d, 3h / d, 4h / d, 5h / d, 6h / d, and 7h / d. ,correspond , , , , , and All units are hours per day. According to each value level... Extract spatial locations and form them respectively. to .by For example, the set of locations corresponding to the equivalent duration of flooding is as follows: Select a 10m×10m grid cell through which the 2h / d contour line passes, with the two endpoints of the grid edge being... and The corresponding average daily flooding durations are as follows: and .because For grid edges located between 2.3h / d and 1.9h / d, perform linear position interpolation: The two endpoints of the other edge of the same grid cell are respectively and The corresponding average daily flooding durations are 2.1 h / d and 1.7 h / d, respectively. Therefore: The calculation results show that, and ,therefore and All belong to Continue performing the same interpolation on the remaining grid cells traversed by the 2h / d isovalue level to obtain the remaining isovalue locations. Therefore, the specific location set of 2h / d flood duration equivalents is backfilled as follows: In the formula, This indicates the total number of isopleths contained within the 2h / d contour lines. They are connected sequentially according to their spatial adjacency. The spatial locations within the data are used to form continuous isolines of flood duration for 2 hours per day. Using the same method, spatial locations are extracted and connected for 1 hour per day, 3 hours per day, 4 hours per day, 5 hours per day, 6 hours per day, and 7 hours per day, respectively, to obtain... , , , , and Therefore, the set of locations with equal flood durations in this embodiment satisfies: Each contour line is aligned with the spatial boundary of the target salt marsh region. The data is cropped while retaining the corresponding daily average flood duration markers, ultimately forming a daily average flood duration contour map: in, In , The spatial location can be directly transmitted to step S6, which is used to determine the suitable flooding area of ​​the salt marsh according to the parameter of suitable daily flooding duration of Suaeda salsa var. ...

[0053] S6. Obtain the suitable daily flooding duration parameters of the target salt marsh vegetation, and select the corresponding spatial location from the spatial distribution of the daily flooding duration of the region and the contour map of the daily flooding duration based on the suitable daily flooding duration parameters to generate a suitable flooding area for the salt marsh. In one embodiment of the present invention, step S6 includes the following steps: Obtain habitat flooding duration information corresponding to the target salt marsh vegetation, and determine the suitable daily average flooding duration parameter based on the habitat flooding duration information; Extract spatial locations that match the suitable daily average flood duration parameter from the spatial distribution of the average daily flood duration in the region, and generate a set of suitable flood spatial locations. Based on the suitable daily average flood duration parameter, the corresponding flood duration contour lines are extracted from the daily average flood duration contour map, and the flood duration contour lines are used to spatially define the suitable flood spatial location set to generate the suitable flood area of ​​the salt marsh.

[0054] Specifically, habitat flooding duration information is used to characterize the flooding duration conditions of the target salt marsh vegetation in its natural distribution area, historically stable habitat, or ecological restoration experimental area. Data sources include historical vegetation survey data of the target salt marsh area, monitoring data of adjacent stable salt marsh communities, ecological restoration experimental records, or existing habitat survey data. Habitat flooding duration information should at least include the target salt marsh vegetation type, flooding duration statistical scale, suitable flooding duration value or suitable flooding duration range, and the corresponding data source. Based on the habitat flooding duration information, a daily-scale control value for current beach topography modification is extracted, and this daily-scale control value is determined as the suitable daily average flooding duration parameter. The unit is hours per day. When the habitat flooding duration information directly provides the representative daily average flooding duration, the representative daily average flooding duration will be used as... When the habitat flooding duration information provides a suitable flooding duration range, the appropriate range should be determined based on the habitat control values ​​adopted in the current ecological restoration design. The habitat control values ​​are derived from the statistical results of the historical stable habitats of the target vegetation or the results of restoration experiments.

[0055] Spatial distribution of average daily flood duration in the region Read spatial positions one by one Corresponding average daily flood duration The parameters were matched according to an appropriate daily average flood duration. Considering the accuracy of tide level sampling, Kriging space interpolation error, and the data accuracy of the habitat flood duration information itself, a flood duration matching tolerance was set. The matching tolerance is determined based on the accuracy of the current observation equipment, spatial interpolation verification error, and the temporal resolution of the habitat survey data; a specific value is not fixed in advance. The set of suitable flooding locations is defined as: ; In the formula, This represents a set of suitable locations for flooding. This indicates the flood duration matching tolerance, in hours per day.

[0056] according to From the isopleth map of average daily flood duration Extracting the daily average flood duration attribute and Consistent isopleths of flood duration are denoted as : ; use As a continuous spatial reference, for Limit the space and retain with Matching grid positions that intersect, are adjacent, or are continuously distributed along contour lines are selected, excluding isolated matching positions that are spatially discontinuous with the corresponding contour lines due to local interpolation fluctuations. This process ultimately forms a suitable flooding area for the salt marsh. Spatial coordinates of suitable flooded areas in the salt marshland are retained, using the same spatial reference as the topographic elevation data generated in step S1, for use in step S7 for topographic elevation rereading.

[0057] For example, in this embodiment, *Suaeda salsa* is selected as the target salt marsh vegetation. Based on a historical distribution survey of *Suaeda salsa* in the target salt marsh area and flooding monitoring records of adjacent stable *Suaeda salsa* communities, the habitat flooding duration information indicates a representative daily average flooding duration of 2.0 h / d. Therefore: The tidal level sampling, spatial interpolation, and habitat data accuracy in this embodiment can support a matching scale of 0.1 h / d, therefore, [the appropriate scale is adopted]. The spatial distribution of the average daily flooding duration in the region, as determined in step S4, shows that... correspond , and The corresponding interpolated average daily flooding duration is 2.0 h / d. Furthermore, the average daily flooding durations for some adjacent grid locations are 1.94 h / d, 2.06 h / d, and 2.08 h / d, respectively, all satisfying a difference of no more than 0.1 h / d from 2.0 h / d. Therefore, the suitable set of flooded spatial locations for backfilling is: ;in, , and These represent the matching spatial locations corresponding to 1.94 h / d, 2.06 h / d, and 2.08 h / d, respectively. The daily average flood duration contour map generated in step S5 contains a flood duration contour line for 2.0 h / d; therefore: ;use right Limit the space and preserve the area along Continuous distribution and its adjacent matching grid positions, excluding those far away. The isolated matching locations eventually form suitable flooding areas in the salt marsh. Therefore, 2.0 h / d is only a specific parameter determined in this embodiment based on the flooding duration information of the Suaeda salsa habitat, and is not a fixed limitation on the suitable daily flooding duration parameter for the target salt marsh vegetation.

[0058] S7. Spatial correspondence is established between the suitable flooding area of ​​the salt marshland and the terrain elevation data. The terrain elevation corresponding to the suitable flooding area of ​​the salt marshland is read, and the target elevation data of the salt marshland is generated. The target elevation data of the salt marshland is used as the elevation control data for the transformation of the beach terrain of the target salt marshland area. In one embodiment of the present invention, step S7 includes the following steps: Based on the spatial location of each area in the suitable flooding zone of the salt marsh, the corresponding topographic location is determined from the topographic elevation data; Read the terrain elevation values ​​of each corresponding terrain location, and retain the spatial distribution relationship of the terrain elevation values ​​according to the spatial location to generate the target elevation data of the salt marsh. The target elevation data of the salt marsh is output to the beach terrain modification stage of the target salt marsh area, so that the beach terrain of the target salt marsh area is controlled according to the target elevation data of the salt marsh.

[0059] Specifically, such as Figure 7 As shown, the salt marshland suitable for flooding is formed in step S6. Spatial position As a spatial index, the terrain elevation data formed in step S1 This determines the terrain location corresponding to the same spatial location. When terrain elevation data is stored using a regular grid and... When it coincides with a terrain grid node, the terrain elevation of the corresponding node is read directly; when When located between adjacent terrain grid nodes, the elevation value of the corresponding position is read according to the original spatial interpolation rules of the terrain elevation data, so that the reading result continues to maintain the unified elevation benchmark adopted in step S1.

[0060] No. The target elevation corresponding to a suitable flood-prone spatial location is represented as follows: ; In the formula, Indicates the first The target elevation of the salt marsh corresponding to a suitable flooding location; Represents the spatial location of terrain elevation data The topographic elevation of the location.

[0061] right Perform the same spatial mapping and elevation reading on all spatial locations within the data to form the target elevation data for the salt marsh: ; In the formula, This indicates the number of spatial locations within the suitable flooding area of ​​the salt marsh used for elevation control. The target elevation data of the salt marsh is output to the beach topography modification stage according to a one-to-one correspondence between spatial coordinates and target elevations, so that different spatial locations can be controlled for construction using target elevations corresponding to their suitable flooding conditions.

[0062] For example, the suitable flooding area of ​​the salt marsh determined in step S6 based on the flooding duration information of the Suaeda salsa habitat is continued to be used. It includes , and Based on the topographic elevation data obtained in step S1, the elevations at the three locations are 1.83m, 1.84m, and 1.82m, respectively. Therefore: ; ; Similarly, for The terrain elevations of the remaining spatial locations were read one by one, yielding target elevations of 1.80m, 1.85m, and 1.86m for some locations. The target elevation data for the salt marshland was then backfilled as follows:

[0063] When modifying the beach topography, according to The spatial location and target elevation correspondence are controlled, for example, the location Elevation control was established at 1.83m, location Elevation control was established at 1.84m, location Elevation control was established at 1.82m. Therefore, step S7 itself does not depend on the specific type of target salt marsh vegetation or a fixed daily average flood duration. When step S6 uses other target salt marsh vegetation and determines different... Time will only change The corresponding spatial location is not changed, and the process of spatial back-reading of terrain elevation and generation of salt marsh target elevation data is not altered.

[0064] Based on the same inventive concept, such as Figure 8 As shown, the present invention also provides a system for calculating the elevation of a salt marsh target based on tidal time series data, the system comprising: The data acquisition and association module is used to acquire topographic elevation data of the target salt marsh area and the location of multiple hydrodynamic measuring points, collect tidal time series data corresponding to each hydrodynamic measuring point within a preset observation period, the preset observation period including at least one complete tidal cycle, extract the measuring point elevation from the topographic elevation data according to the measuring point location, unify the tidal time series data and the measuring point elevation to the same elevation datum and associate them according to the hydrodynamic measuring points to generate measuring point tidal elevation association data; The state sequence generation module is used to compare the tide level value of each hydrodynamic measuring point with the measuring point elevation according to the tide level elevation association data of the measuring point at the sampling time, mark the tide submerged state, the tide exposed state and the tide level arrival state, and generate a measuring point submerged-exposed state sequence. The flood duration statistics module is used to determine the flood duration of each hydrodynamic measuring point based on the flood-exposure state sequence of the measuring point, accumulate the flood duration within the preset observation period and convert it to the daily scale according to the observation duration corresponding to the preset observation period, and generate the average daily flood duration data of the measuring point. The spatial interpolation module is used to construct a spatial sample of the average daily flooding duration based on the location of the measuring point and the average daily flooding duration data of the measuring point, and to perform Kriging spatial interpolation on the spatial location of the target salt marsh area where the hydrodynamic measuring point is not set, so as to generate the spatial distribution of the average daily flooding duration of the region. The contour line generation module is used to extract the spatial isomorphic locations corresponding to different daily average flood durations based on the spatial distribution of the daily average flood duration in the region, and generate a daily average flood duration contour map. The suitable area determination module is used to obtain the suitable daily flooding duration parameters of the target salt marsh vegetation, and to filter the corresponding spatial locations from the spatial distribution of the daily flooding duration of the area and the contour map of the daily flooding duration based on the suitable daily flooding duration parameters, thereby generating a suitable flooding area for the salt marsh. The target elevation output module is used to spatially correspond the suitable flooding area of ​​the salt marsh with the topographic elevation data, read the topographic elevation corresponding to the suitable flooding area of ​​the salt marsh, generate target elevation data of the salt marsh, and use the target elevation data of the salt marsh as the elevation control data for the transformation of the beach topography of the target salt marsh area.

[0065] All equivalent changes and modifications made in accordance with the teachings of this invention are still within the scope of this invention. Those skilled in the art will readily conceive of other embodiments of this invention upon considering the specification and the disclosure of practical truth. This application is intended to cover any variations, uses, or adaptations of this invention that follow the general principles of this invention and include common knowledge or conventional techniques in the art not described herein.

Claims

1. A method for calculating the target elevation of a salt marsh based on tidal time-series data, characterized in that, The method includes: The topographic elevation data and the locations of multiple hydrodynamic measuring points of the target salt marsh area are obtained. The tidal time series data corresponding to each of the hydrodynamic measuring points are collected within a preset observation period, which includes at least one complete tidal cycle. The measuring point elevation is extracted from the topographic elevation data based on the measuring point location. The tidal time series data and the measuring point elevation are unified to the same elevation datum and associated with the hydrodynamic measuring points to generate measuring point tidal elevation association data. Based on the tide level-elevation correlation data of the measuring points, the tide level value of each hydrodynamic measuring point is compared with the elevation of the measuring point according to the sampling time, and the tide submerged state, tide exposed state and tide level arrival state are marked to generate a measuring point submerged-exposed state sequence. Based on the submersion-exposure state sequence of the measuring points, the submersion duration of each hydrodynamic measuring point is determined. The submersion duration within the preset observation period is accumulated and converted to the daily scale according to the observation duration corresponding to the preset observation period to generate the average daily submersion duration data of the measuring points. Based on the location of the measuring point and the daily average flood duration data of the measuring point, a spatial sample of the daily average flood duration is constructed. Kriging spatial interpolation is performed on the spatial locations in the target salt marsh area where the hydrodynamic measuring point is not set up to generate the spatial distribution of the daily average flood duration in the region. Based on the spatial distribution of the average daily flood duration in the region, spatial isomorphic locations corresponding to different average daily flood durations are extracted, and an isomorphic map of the average daily flood duration is generated. Obtain the suitable daily flood duration parameters for the target salt marsh vegetation, and based on the suitable daily flood duration parameters, select the corresponding spatial locations from the spatial distribution of the daily flood duration in the region and the contour map of the daily flood duration to generate a suitable flood area for the salt marsh. Spatially map the suitable flooding area of ​​the salt marshland to the topographic elevation data, read the topographic elevation corresponding to the suitable flooding area of ​​the salt marshland, generate target elevation data of the salt marshland, and use the target elevation data of the salt marshland as the elevation control data for the transformation of the beach topography of the target salt marshland area.

2. The method for calculating the target elevation of a salt marsh based on tidal time series data according to claim 1, characterized in that, The determination of the target salt marsh area includes: Obtain information on substrate type, total water-soluble salt content, and historical native vegetation distribution in candidate tidal flat areas; The suitability of the candidate tidal flat area for ecological restoration of Suaeda salsa is determined based on the substrate type, the total amount of water-soluble salts, and the historical local vegetation distribution information, and a suitability determination result is generated. When the substrate type is mainly clayey silt, the total amount of water-soluble salt is between 5g / kg and 25g / kg, and the historical local vegetation distribution information indicates the historical distribution of Suaeda salsa, the corresponding candidate tidal flat area is determined as the target salt marsh area.

3. The method for calculating the target elevation of a salt marsh based on tidal time series data according to claim 1, characterized in that, The process involves acquiring topographic elevation data of the target salt marsh area and the locations of multiple hydrodynamic measuring points, collecting tidal time-series data corresponding to each hydrodynamic measuring point within a preset observation period (including at least one complete tidal cycle), extracting the measuring point elevation from the topographic elevation data based on the measuring point location, unifying the tidal time-series data and the measuring point elevation to the same elevation datum, and associating them according to the hydrodynamic measuring points to generate measuring point tidal elevation association data, including: A topographic survey was conducted on the target salt marsh area to obtain the topographic elevation data; Multiple hydrodynamic measuring points are set up in the target salt marsh area, the position of each hydrodynamic measuring point is recorded, and the tidal time series data of each hydrodynamic measuring point are collected in chronological order within the preset observation period. Based on the location of the measuring point, the elevation of the corresponding spatial location in the topographic elevation data is read to determine the measuring point elevation of each of the hydrodynamic measuring points; The tide level values ​​in the tide time series data and the elevation of the measuring point are converted to the same elevation datum, and the correspondence between the measuring point location, the measuring point elevation and the tide time series data is established according to the hydrodynamic measuring point identifier, so as to generate the measuring point tide level elevation association data.

4. The method for calculating the target elevation of a salt marsh based on tidal time series data according to claim 3, characterized in that, The process involves comparing the tide level and elevation of each hydrodynamic measuring point with the measuring point elevation at the sampling time, marking the submerged state, exposed state, and tide arrival state, and generating a measuring point submerged-exposed state sequence, including: According to the sampling time, the tide level value and the elevation of each hydrodynamic measuring point are read from the tide level-elevation correlation data of the measuring points. When the tide level is higher than the elevation of the measuring point, it is marked as the state of being submerged by the tide; when the tide level is lower than the elevation of the measuring point, it is marked as the state of being exposed by the tide; when the tide level is equal to the elevation of the measuring point, it is marked as the state of being reached by the tide, and measuring point status marking data is generated. The state marker data of the measuring points are connected in chronological order of the sampling times to generate the submerged-exposed state sequence of the measuring points.

5. The method for calculating the target elevation of a salt marsh based on tidal time series data according to claim 4, characterized in that, The process of determining the inundation duration for each hydrodynamic measuring point based on the inundation-exposure state sequence, accumulating the inundation duration within the preset observation period, and converting it to a daily scale according to the observation duration corresponding to the preset observation period, generates daily average inundation duration data for the measuring points, including: The flooding-exposure state sequence of the hydrodynamic measuring points is read respectively. The flooding start time and flooding end time are determined according to the state transition between the tidal exposure state, the tidal level arrival state and the tidal flooding state, and the flooding duration period is generated. The inundation duration is accumulated for all the inundation periods within the preset observation period for the same hydrodynamic measuring point to generate the cumulative inundation duration. Based on the cumulative inundation duration and the observation duration corresponding to the preset observation period, a daily-scale conversion is performed to generate the average daily inundation duration data for each hydrodynamic measuring point.

6. The method for calculating the target elevation of a salt marsh based on tidal time series data according to claim 5, characterized in that, The process involves constructing a spatial sample of daily average flood duration based on the location of the measuring points and the daily average flood duration data of the measuring points. Kriging spatial interpolation is then performed on spatial locations within the target salt marsh area where the hydrodynamic measuring points are not located to generate a spatial distribution of the regional daily average flood duration, including: Based on the hydrodynamic measuring points, the locations of the measuring points are associated one by one with the daily average flood duration data of the measuring points to generate the daily average flood duration spatial sample. Using the location of the measuring point as spatial coordinates and the average daily flooding duration data of the measuring point as spatial interpolation attribute value, Kriging spatial interpolation is performed on the spatial location of the target salt marsh area where the hydrodynamic measuring point is not set to generate an estimated value of the average daily flooding duration. The daily average flood duration data and the estimated daily average flood duration of the measuring points are organized according to their corresponding spatial locations, and the spatial range is limited to the target salt marsh area to generate the spatial distribution of the daily average flood duration of the area.

7. The method for calculating the target elevation of a salt marsh based on tidal time series data according to claim 6, characterized in that, The step of extracting spatial isopleths corresponding to different daily average flood durations based on the spatial distribution of the daily average flood duration in the region, and generating a daily average flood duration isopleth map, includes: Extract spatial locations with the same daily average flood duration from the spatial distribution of the average daily flood duration in the region, and generate multiple sets of locations with equal flood duration. Connect the spatial locations in each set of locations with equal flood duration to generate flood duration contour lines corresponding to different daily average flood durations; The range of the flood duration contour lines is defined according to the spatial boundary of the target salt marsh area, and the daily average flood duration corresponding to each of the flood duration contour lines is marked to generate the daily average flood duration contour map.

8. The method for calculating the target elevation of a salt marsh based on tidal time series data according to claim 7, characterized in that, The process of obtaining suitable daily flooding duration parameters for the target salt marsh vegetation, and then selecting corresponding spatial locations from the spatial distribution of daily flooding duration and the daily flooding duration contour map based on these parameters to generate suitable flooding areas for the salt marsh, includes: Obtain habitat flooding duration information corresponding to the target salt marsh vegetation, and determine the suitable daily average flooding duration parameter based on the habitat flooding duration information; Extract spatial locations that match the suitable daily average flood duration parameter from the spatial distribution of the average daily flood duration in the region, and generate a set of suitable flood spatial locations. Based on the suitable daily average flood duration parameter, the corresponding flood duration contour lines are extracted from the daily average flood duration contour map, and the flood duration contour lines are used to spatially define the suitable flood spatial location set to generate the suitable flood area of ​​the salt marsh.

9. The method for calculating the target elevation of a salt marsh based on tidal time series data according to claim 8, characterized in that, The step of spatially mapping the suitable flooding area of ​​the salt marsh to the topographic elevation data, reading the topographic elevation corresponding to the suitable flooding area of ​​the salt marsh, generating target elevation data for the salt marsh, and using the target elevation data for the salt marsh as elevation control data for the transformation of the beach topography in the target salt marsh area includes: Based on the spatial location of each area in the suitable flooding zone of the salt marsh, the corresponding topographic location is determined from the topographic elevation data; Read the terrain elevation values ​​of each corresponding terrain location, and retain the spatial distribution relationship of the terrain elevation values ​​according to the spatial location to generate the target elevation data of the salt marsh. The target elevation data of the salt marsh is output to the beach terrain modification stage of the target salt marsh area, so that the beach terrain of the target salt marsh area is controlled according to the target elevation data of the salt marsh.

10. A system for calculating the target elevation of a salt marsh based on tidal time-series data, applied to the method for calculating the target elevation of a salt marsh based on tidal time-series data as described in any one of claims 1-9, characterized in that, The system includes: The data acquisition and association module is used to acquire topographic elevation data of the target salt marsh area and the location of multiple hydrodynamic measuring points, collect tidal time series data corresponding to each hydrodynamic measuring point within a preset observation period, the preset observation period including at least one complete tidal cycle, extract the measuring point elevation from the topographic elevation data according to the measuring point location, unify the tidal time series data and the measuring point elevation to the same elevation datum and associate them according to the hydrodynamic measuring points to generate measuring point tidal elevation association data; The state sequence generation module is used to compare the tide level value of each hydrodynamic measuring point with the measuring point elevation according to the tide level elevation association data of the measuring point at the sampling time, mark the tide submerged state, the tide exposed state and the tide level arrival state, and generate a measuring point submerged-exposed state sequence. The flood duration statistics module is used to determine the flood duration of each hydrodynamic measuring point based on the flood-exposure state sequence of the measuring point, accumulate the flood duration within the preset observation period and convert it to the daily scale according to the observation duration corresponding to the preset observation period, and generate the average daily flood duration data of the measuring point. The spatial interpolation module is used to construct a spatial sample of the average daily flooding duration based on the location of the measuring point and the average daily flooding duration data of the measuring point, and to perform Kriging spatial interpolation on the spatial location of the target salt marsh area where the hydrodynamic measuring point is not set, so as to generate the spatial distribution of the average daily flooding duration of the region. The contour line generation module is used to extract the spatial isomorphic locations corresponding to different daily average flood durations based on the spatial distribution of the daily average flood duration in the region, and generate a daily average flood duration contour map. The suitable area determination module is used to obtain the suitable daily flooding duration parameters of the target salt marsh vegetation, and to filter the corresponding spatial locations from the spatial distribution of the daily flooding duration of the area and the contour map of the daily flooding duration based on the suitable daily flooding duration parameters, thereby generating a suitable flooding area for the salt marsh. The target elevation output module is used to spatially correspond the suitable flooding area of ​​the salt marsh with the topographic elevation data, read the topographic elevation corresponding to the suitable flooding area of ​​the salt marsh, generate target elevation data of the salt marsh, and use the target elevation data of the salt marsh as the elevation control data for the transformation of the beach topography of the target salt marsh area.

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