A method and system for evaluating the restoration efficiency of a coastal salt marsh ecosystem
By applying mechanical impact force to salt marsh plants and collecting vibration signals, combined with damping attenuation ratio and mass loss, the limitations of traditional assessment methods are overcome, and a multi-dimensional, non-destructive, and dynamic assessment of the restoration effectiveness of coastal salt marsh ecosystems is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NORTH CHINA SEA ENVIRONMENTAL MONITORING CENT OF STATE OCEANIC ADMINISTATION
- Filing Date
- 2026-04-24
- Publication Date
- 2026-07-14
Smart Images
Figure CN122385752A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of materials measurement and testing technology, and relates to a method and system for evaluating the restoration effectiveness of coastal salt marsh ecosystems. Background Technology
[0002] Coastal salt marsh ecosystems are important ecological transition zones between land and sea, and their health is crucial for maintaining coastline stability, purifying water bodies, and protecting biodiversity. Assessing the effectiveness of ecosystem restoration is essentially a scientific measure of the degree to which the structure and function of the restored ecosystem have recovered. This typically involves investigating and analyzing the physical, chemical, and biological characteristics of key components within the system and their interactions.
[0003] Existing technologies for assessing the restoration effectiveness of coastal salt marsh ecosystems mainly include remote sensing image analysis, quadrat surveys, and laboratory analysis. Remote sensing image analysis obtains macroscopic information such as vegetation cover and distribution patterns by interpreting satellite or UAV images. Quadrat surveys involve setting up quadrats on-site to statistically analyze plant species, density, height, and biomass. Laboratory analysis typically involves collecting soil or plant samples and measuring their physicochemical properties, such as soil organic matter content, porosity, or plant root biomass.
[0004] However, the aforementioned existing technologies have some inherent limitations in assessing ecosystem function. Remote sensing and quadrat surveys primarily focus on the macroscopic morphology and biomass of vegetation, making it difficult to directly quantify the core ecological functions of vegetation, such as soil stabilization, wave protection, and facilitating hydrological exchange. Laboratory analysis methods based on sampling are not only cumbersome and time-consuming, but their destructive sampling methods also prevent continuous dynamic monitoring of the same area. Furthermore, these methods often isolate plants from the soil environment, lacking direct measurement of the dynamic interactions between the two, leading to biased assessment results that fail to comprehensively reflect the functional recovery level of the ecosystem as a whole. Summary of the Invention
[0005] In view of this, in order to solve the problems mentioned in the background technology, a method and system for evaluating the restoration effectiveness of coastal salt marsh ecosystems are proposed.
[0006] The objective of this invention can be achieved through the following technical solution: The first aspect of this invention provides a method for evaluating the restoration effectiveness of a coastal salt marsh ecosystem, comprising: S1, applying a transverse mechanical transient impact force to the base of the stem of the salt marsh plant to be evaluated for in-situ excitation, collecting the plant vibration signal after excitation, and generating free mechanical vibration waveform data.
[0007] S2. Extract the vibration attenuation characteristics from the free mechanical vibration waveform data, and calculate the physical damping attenuation ratio based on the vibration attenuation characteristics.
[0008] S3. Obtain the initial and final weight data of the physical dissolution block in the microhabitat of the salt marsh plant to be evaluated before and after the hydrological cycle, calculate the difference between the initial and final weight data, and generate the physical mass loss.
[0009] S4. By integrating the physical damping attenuation ratio and physical mass loss, an effectiveness mapping is performed to generate a comprehensive evaluation index for the restoration effectiveness of coastal salt marsh ecosystems.
[0010] The second aspect of the present invention provides a coastal salt marsh ecosystem restoration efficiency assessment system, comprising: a free mechanical vibration waveform data generation module, which applies a transverse mechanical transient impact force to the base of the stem of the salt marsh plant to be assessed for in-situ excitation, collects the plant vibration signal after excitation, and generates free mechanical vibration waveform data.
[0011] The physical damping attenuation ratio calculation module extracts the vibration attenuation characteristics from the free mechanical vibration waveform data and calculates the physical damping attenuation ratio based on the vibration attenuation characteristics.
[0012] The physical mass loss calculation module obtains the initial and final weight data of the physically dissolved block in the microhabitat of the salt marsh plant to be evaluated before and after the hydrological cycle, calculates the difference between the initial and final weight data, and generates the physical mass loss.
[0013] The comprehensive evaluation index generation module integrates the physical damping attenuation ratio and physical mass loss to perform performance mapping and generate a comprehensive evaluation index for the restoration performance of coastal salt marsh ecosystems.
[0014] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects: (1) The method and system provided by the present invention realize a multi-dimensional comprehensive assessment of the restoration efficiency of coastal salt marsh ecosystems by integrating in-situ measurement methods of mechanics and hydrology. This method combines the dynamic vibration response of plants with the hydrological connectivity of the root zone soil, and quantifies it from the two core functional dimensions of root soil stabilization and wave prevention and improvement of groundwater hydrological environment. It overcomes the limitations of traditional assessment methods that only focus on single static indicators such as vegetation coverage or biomass, so that the assessment results can more comprehensively and profoundly reflect the degree of restoration of ecosystem functions.
[0015] (2) The evaluation method used in this invention is characterized by being in-situ, non-destructive, and highly repeatable. By applying transient impacts to plant stems and analyzing their vibration attenuation, the mechanical coupling information between the plant and the soil can be obtained without damaging the vegetation. At the same time, groundwater tracing is carried out using standardized physical dissolution blocks, avoiding large-scale excavation or destructive sampling. The entire testing process is highly standardized, the data collection is objective, and the interference of human factors is reduced, ensuring the reliability of the evaluation results and the comparability at different temporal and spatial scales.
[0016] (3) The assessment model established in this invention has good environmental adaptability and practicality. By introducing environmental influencing factors such as soil type and tidal dynamics, different performance indicators are dynamically weighted, so that the final comprehensive assessment index can be adaptively adjusted according to the environmental stress conditions of the specific site. This design makes the assessment results not only reflect the condition of the vegetation itself, but also reflect its functional performance under specific environmental conditions, thereby providing more targeted performance evaluation and decision support for salt marsh remediation projects in different regions. Attached Figure Description
[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of the method steps of the present invention.
[0019] Figure 2 This is a schematic diagram of the system structure connection of the present invention. Detailed Implementation
[0020] 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.
[0021] Please see Figure 1 The first aspect of the present invention provides a method for evaluating the restoration effectiveness of coastal salt marsh ecosystems, comprising: S1, applying a transverse mechanical transient impact force to the base of the stem of the salt marsh plant to be evaluated for in-situ excitation, collecting the plant vibration signal after excitation, and generating free mechanical vibration waveform data.
[0022] In a specific embodiment of the present invention, a transverse mechanical transient impact force is applied to the base of the stem of the salt marsh plant to be evaluated for in-situ excitation, and the vibration signal of the plant after excitation is collected to generate free mechanical vibration waveform data, including: clamping a piezoelectric vibration sensor to the base of the stem of the salt marsh plant to be evaluated and establishing a vibration monitoring link.
[0023] A constant-force physical impact hammer is used to apply a transverse mechanical transient impact force to the base of the stem through a vibration monitoring link, triggering free mechanical vibration of the plant.
[0024] Mechanical vibration signals during free mechanical vibration are recorded using piezoelectric vibration sensors to generate free mechanical vibration waveform data.
[0025] Specifically, to obtain raw data reflecting the mechanical properties of the interaction between the salt marsh plant and the soil to be evaluated, it is first necessary to subject the plant to non-destructive excitation in the field and record its response process. The core of this step lies in applying a standardized external energy input to excite the plant to produce vibrational behavior that can be accurately measured, thereby generating the basic data required for subsequent analysis.
[0026] The process begins with establishing a vibration monitoring link at the base of the stem of the salt marsh plant to be evaluated. The stem base refers to the part of the plant exposed above the mud surface and closest to the root system; vibration at this location best reflects the overall dynamic response of the root-soil system. The vibration monitoring link is a complete signal acquisition and transmission path, consisting of a piezoelectric vibration sensor, signal transmission cables, and data acquisition equipment. A piezoelectric vibration sensor is a device that converts mechanical vibration into a voltage signal. Its working principle is based on the piezoelectric effect of a specific crystalline material; when the crystal is deformed under stress, its surface generates an electric charge. The selection of a piezoelectric vibration sensor with extremely small weight and size aims to minimize the impact of its added mass on the plant's dynamic characteristics. The sensor is secured to the stem base using a specially designed clamp to ensure it vibrates synchronously with the plant. In addition, due to the high salinity and high humidity of coastal salt marsh habitats, in order to prevent short circuits or interference from salt mist in the high impedance weak voltage signal output by the piezoelectric sensor, the piezoelectric vibration sensor and its connection interface need to be physically isolated by a flexible silicone insulating waterproof coating to ensure the high signal-to-noise ratio and electrical reliability of the vibration monitoring link in the field environment.
[0027] In one specific embodiment of the invention, the mechanical structure and parameter boundaries of the specially designed clamp are as follows: To avoid the additional mechanical mass of the clamp altering the intrinsic dynamic stiffness matrix of the plant system, the total mass of the clamp and sensor should not exceed 5% of the estimated fresh weight of the aboveground part of the plant under test; simultaneously, considering that the epidermis of the stems of salt marsh herbaceous plants contains vascular bundles and is relatively fragile, an adaptive contoured rubber pad needs to be attached to the inner contact surface of the clamp. This pad provides sufficient static friction to ensure high-fidelity transmission of vibration signals across the entire frequency band, while dispersing clamping stress through surface contact to prevent structural damage caused by localized crushing of the internal tissues of the stem.
[0028] After the link is established, a transverse mechanical transient impact force is applied to the base of the stem using a constant-force physical impact hammer. A constant-force physical impact hammer is a tool that can release a preset and constant impact energy. It usually has a built-in spring and release mechanism to ensure that the force and duration of each strike are highly consistent, which is the key to ensuring the repeatability of the measurement.
[0029] In one specific embodiment of the present invention, the tail of the constant force physical hammer is provided with a pre-compressed adjustable spring, and the firing end is provided with a striking head with a buffer rubber pad. During operation, by pressing the release button, the spring releases potential energy to drive the striking head to overcome the damping and rush out. After the striking head releases a constant impulse upon contact with the stem, it automatically rebounds and retracts into the tube cover, thereby avoiding secondary multiple collisions and force fluctuations caused by direct hand strikes.
[0030] Transverse mechanical transient impact refers to a force that acts perpendicular to the natural growth direction of the plant stem and has an extremely short duration. This force can be ideally described as an impulse function, the purpose of which is to provide the system with initial excitation energy without causing structural damage to the plant, thereby triggering the plant's free mechanical vibration. Free mechanical vibration refers to the reciprocating motion of the plant after the transient impact has disappeared, relying solely on its own restoring force and system damping. Specifically, free mechanical vibration refers to the unforced vibration stage of the system after the external transient impulse has completely disappeared, dominated solely by the bending stiffness of the plant stem and the frictional damping of the root-soil system, excluding the response during the continuous work phase of wind load.
[0031] Impact The application process can be described by the following formula:
[0032]
[0033] In the formula, Represents the passage of time Changing lateral mechanical transient impact force; It is the peak value of the impact force, which is set according to the general biomechanical strength of the salt marsh plants to be evaluated. For example, based on a preliminary experiment on 200 groups of common coastal salt marsh plants, it is set to 5 Newtons to ensure effective excitation without causing damage. It is the duration of the impact force, usually in the millisecond range, and is set to 10 milliseconds to meet the definition of transient impact.
[0034] After the impact force triggers free mechanical vibration, the piezoelectric vibration sensor fixed to the base of the stem begins to operate. It captures the acceleration changes during the vibration process in real time and converts them into a continuous analog voltage signal, i.e., a mechanical vibration signal. acceleration at the base of the stem There is a linear relationship between them:
[0035]
[0036] In the formula, It is the sensor in time The output mechanical vibration signal voltage value; This is the sensitivity coefficient of the piezoelectric vibration sensor. It's a parameter provided and calibrated by the sensor manufacturer, typically measured in millivolts per second of gravitational acceleration. For example, if a sensitivity of [value missing] is selected... Sensors; It is the base of the stem in time Instantaneous acceleration.
[0037] In a specific embodiment of the present invention, the sensitivity coefficient of the piezoelectric vibration sensor... The typical value range of is preferably defined as The typical values selected in this paper are as follows: The absolute accuracy of this sensitivity is fundamental to the entire mechanical analysis; therefore, it is not a theoretical estimate but rather the result of rigorous calibration using the industry-standard "back-to-back comparison calibration method." The specific calibration procedure is as follows: the miniature sensor is rigidly connected in series with a national benchmark-level reference accelerometer sensor of known sensitivity on the same standard electrically driven vibration stage; the vibration stage is started and steady-state sinusoidal excitation is applied at the standard reference frequency; the data acquisition instrument simultaneously reads the output AC voltage amplitudes of both sensors; the absolute reference acceleration of the vibration stage is calculated by using the voltage value of the reference sensor; and then, by dividing the output voltage of this miniature sensor by this reference acceleration, its true sensitivity coefficient can be accurately calibrated. This rigorous process of tracing and calibrating physical quantities ensures that the collected mechanical vibration signals objectively reflect the true dynamic characteristics of the living plant.
[0038] Finally, the data acquisition equipment performs high-speed sampling and analog-to-digital conversion on the continuous mechanical vibration signals from the sensors to generate free mechanical vibration waveform data. This is discrete time-series data, recording the vibration amplitude at a series of time points during free mechanical vibration. Sampling frequency. The sampling frequency setting is crucial and must satisfy the Nyquist sampling theorem, which states that the sampling frequency must be at least twice the highest frequency component of the plant's vibration signal to avoid signal distortion. Based on studies of the vibration characteristics of salt marsh plants, their dominant frequency is typically below 50 Hz; therefore, setting the sampling frequency... A frequency of 1000 Hz is used to ensure complete capture of vibration details. This generates free mechanical vibration waveform data. It can be represented as:
[0039]
[0040] In the formula, It is the first The digital amplitude of each sampling point; It is the integer index of the sampling point; It is the sampling period, and its value is the sampling frequency. The reciprocal of the value. This series of discrete data points forms the basis for subsequent analysis of the plant's dynamic response characteristics.
[0041] For example, taking the evaluation of a salt marsh plant to be evaluated as an example, the implementation process of step S1 is described in detail.
[0042] First, select a Spartina alterniflora stem with a diameter of 8 mm and fix a piezoelectric vibration sensor 2 cm above the mud surface using a lightweight clamp. The sensitivity coefficient of this sensor is... Based on its calibration certificate, it is determined to be... The sensor is connected to a portable data acquisition unit via a shielded cable. The sampling frequency of the data acquisition unit... Set to 1000 Hz. The vibration monitoring link is now complete.
[0043] The operator then held a constant-force physical impact hammer and aimed its impact head at the stem near the sensor clamp. The peak impact force of the impact hammer... Pre-calibrated to 5 Newtons, impact duration The time is 10 milliseconds. When the operator presses the trigger button, the impact head of the hammer pops out, applying a precise lateral mechanical transient impact force to the stem, which then triggers the free mechanical vibration of the Spartina alterniflora plant.
[0044] The data acquisition device begins recording immediately after the impact and for a period of time thereafter, such as 5 seconds. The piezoelectric vibration sensor generates a changing voltage signal, i.e., a mechanical vibration signal, as the stem swings back and forth. For example, in... At 1 second, the sensor measured the acceleration at the base of the stem. If the weight is 0.5g, then the mechanical vibration signal voltage value output by the sensor at this time is... for The data acquisition instrument samples this continuous voltage signal at a frequency of 1000 Hz. At 1 second, the number of samples collected was 1. Each data point has a value. This corresponds to the digital value of 50 millivolts. During the 5-second sampling period, a total of [data missing] were collected. These 5000 data points, arranged in chronological order, together constitute the free mechanical vibration waveform data used for subsequent analysis.
[0045] S2. Extract the vibration attenuation characteristics from the free mechanical vibration waveform data, and calculate the physical damping attenuation ratio based on the vibration attenuation characteristics.
[0046] In a specific embodiment of the present invention, vibration attenuation characteristics are extracted from free mechanical vibration waveform data, and physical damping attenuation ratio is calculated based on the vibration attenuation characteristics, including: identifying the peak amplitude sequence and trough amplitude sequence in the free mechanical vibration waveform data, and generating envelope data.
[0047] In a specific embodiment of the present invention, identifying the peak amplitude sequence and trough amplitude sequence in the free mechanical vibration waveform data and generating envelope data includes: filtering high-frequency interference signals caused by environmental wind load in the free mechanical vibration waveform data and generating smooth vibration waveform data.
[0048] Extract the extreme points from the smooth vibration waveform data to construct the peak amplitude sequence and the trough amplitude sequence.
[0049] By combining the peak amplitude sequence and the trough amplitude sequence, the logarithmic decay rate of adjacent amplitudes is calculated to generate envelope data.
[0050] Specifically, in typical open microhabitats like coastal salt marshes, the free mechanical vibrations of plants are inevitably superimposed with random, low-amplitude, broadband interference caused by gusts. To accurately extract the envelope representing the intrinsic characteristics of plant-soil damping, high-precision digital signal processing techniques must be employed to extract the true amplitude attenuation trajectory from the aliased signal. This step aims to filter meteorological interference using algorithms and accurately pinpoint the true amplitude based on mathematical extremum theory, thereby constructing quantified envelope data.
[0051] First, high-frequency interference signals caused by environmental wind loads are filtered out from the free mechanical vibration waveform data. This step is achieved using a digital low-pass filter, which is an algorithm that can identify and attenuate components in the signal with frequencies above a certain threshold, while retaining the low-frequency main vibration information, thereby generating smooth vibration waveform data.
[0052] In a specific embodiment of the present invention, the typical range of the specific threshold is defined as 20 Hz to 80 Hz, and the typical value in this paper is set to 80 Hz. The core physical and biomechanical basis for setting the specific threshold lies in the "frequency band isolation principle": the stem-root physical system of coastal salt marsh plants is mechanically equivalent to a flexible damped cantilever beam planted in soft silt. Its first and lower-order natural frequencies are extremely low. The energy of the real macroscopic skeleton free vibration induced by mechanical impact is mostly concentrated in the low-frequency subband below 50 Hz. On the contrary, the micro-amplitude random flutter caused by the continuous sea breeze blowing on the leaves, the physical airflow friction, and the mechanical vibration of the sensor cables usually manifest as high-frequency "burr" noise with a frequency much higher than 100 Hz. Therefore, setting the filtering threshold precisely within the "spectral isolation band" between the upper limit of the intrinsic plant vibration and the lower limit of wind-induced interference can ensure that the low-frequency main flexible vibration signal passes through the passband without distortion and with high fidelity, while effectively filtering out high-frequency meteorological interference that masks the true amplitude in the stopband, thus providing pure waveform data with a high signal-to-noise ratio for the subsequent accurate extraction of the intrinsic envelope of the system.
[0053] The filtering process can be represented by the following formula:
[0054]
[0055] In the formula, It is the first The amplitude of the smoothed vibration waveform data at each sampling point; The original free mechanical vibration waveform data is in the first... The amplitude of each sampling point; These are the coefficients of the low-pass filter, which determine the filter's frequency response characteristics. This refers to the filter order, typically set between 31 and 51 to balance real-time performance and roll-off slope. The filter cutoff frequency is set based on the natural vibration frequency range of the salt marsh plants. For example, based on statistical analysis of vibration tests on various salt marsh plants, their dominant frequency is below 50 Hz, while wind-induced noise frequencies are usually above 100 Hz. Therefore, the cutoff frequency is set to 80 Hz to effectively separate the signal from the noise.
[0056] In a specific embodiment of the present invention, the coefficient It is not a single, fixed, simple constant, but a set of constants based on the system sampling frequency (e.g., ...). Hertz), and a specific cutoff frequency (such as) The one-dimensional discrete impulse response sequence is rigorously calculated using standard digital signal processing design methods, taking into account both the real-time performance of the edge computing device and the steepness of the band roll-off. In a typical embodiment of coastal salt marsh vibration testing, to balance the real-time performance of the edge computing device with the steepness of the band roll-off, the filter order is typically... The order is set between 31 and 51. At this point, the calculated... It exhibits a centrally symmetric sequence of decimal values, with the largest value in the middle and the smallest values on either side. Typical coefficient values range from -0.15 to 0.5. The core mechanism by which this set of coefficients determines the filter's frequency response characteristics lies in time-frequency mapping: in the time domain, this sequence of discrete coefficient values is weighted by a sliding window convolution with the noisy original plant vibration signal using the aforementioned formula; simultaneously, the discrete-time Fourier transform of this coefficient sequence in the frequency domain directly maps the filter's amplitude-frequency response curve. By precisely configuring this set of coefficients... The values and distribution of these values objectively "carve" an ideal isolation boundary in the frequency domain—that is, forming a flat region with a gain of approximately 1 in the low-frequency "passband" below 80 Hz, ensuring that the low-frequency vibration amplitude of the plant body can be effectively transmitted; while in the "stopband" above 80 Hz, the gain is forced to drop sharply to close to 0, and the wind-borne high-frequency interference level in the frequency domain is suppressed and filtered out through mathematical weighting.
[0057] After obtaining the smoothed vibration waveform data, the next step is to extract the extreme points. Extreme points refer to the local maximum values (peaks) and local minimum values (troughs) in the vibration waveform. This is done by traversing the smoothed vibration waveform data to find the points that satisfy these extreme values. and The point is taken as the peak, satisfying and The points are taken as troughs. All the identified peak amplitudes are arranged in chronological order to form a peak amplitude sequence, and similarly, a trough amplitude sequence is formed.
[0058] Subsequently, the logarithmic decay rate of adjacent amplitudes is calculated by combining the peak amplitude sequence and the trough amplitude sequence. For consistent processing, the absolute values of the trough amplitudes are taken and combined with the peak amplitudes to form a temporally ordered amplitude sequence. The logarithmic decay rate of adjacent amplitudes is an indicator of the degree of decay of vibrational energy within a single half-cycle, obtained by calculating the natural logarithm of the ratio of two amplitudes in adjacent half-cycles. Logarithmic decay rate The calculation formula is:
[0059]
[0060] In the formula, and These are two consecutive amplitude values in the amplitude sequence. By calculating the logarithmic decay rate of all adjacent amplitude pairs, a set of values can be obtained, which constitutes the envelope data.
[0061] Logarithmic decay features are extracted from the envelope data and fitted to generate vibration decay features.
[0062] Calculate the system energy dissipation rate corresponding to the vibration attenuation characteristics, and convert the system energy dissipation rate into the physical damping attenuation ratio.
[0063] Specifically, after obtaining the free mechanical vibration waveform data, it is necessary to extract key information that can quantify the energy dissipation rate of the plant-soil system. The purpose of this step is to transform the raw, time-varying vibration signal into a stable parameter with clear physical meaning: the physical damping attenuation ratio. The physical damping attenuation ratio directly reflects the rate at which energy is absorbed and dissipated when the plant's roots interact with the surrounding soil during vibration, and is an important basis for assessing the root system's ability to stabilize the soil.
[0064] Ideally, all The values should be equal, but fluctuations occur in actual measurements. Therefore, it is necessary to extract the logarithmic decay characteristics from the envelope data for fitting to obtain a stable and reliable representative value. The fitting here uses the method of calculating the arithmetic mean, applying this to all logarithmic decay rates. The summation is then divided by the total number to generate the vibration attenuation characteristics. .
[0065]
[0066] In the formula, It is a vibration decay characteristic, which represents the average half-cycle logarithmic decay rate of the entire vibration process; It is an amplitude sequence The total number of elements in the middle. This vibrational decay characteristic. It is a dimensionless pure number.
[0067] The final step is to calculate the system energy dissipation rate corresponding to the vibration attenuation characteristics and convert it into the physical damping attenuation ratio. Physical damping attenuation ratio It is a standardized dimensionless parameter used in structural dynamics to describe the magnitude of system damping. It is related to vibration damping characteristics. There exists a definite mathematical relationship between them. Since the extracted feature is a half-cycle decay characteristic, based on the theoretical mechanical damping derivation transformation, this relationship transforms the logarithmic decay description into a measure of linear energy dissipation rate. The theoretical calculation formula is as follows:
[0068]
[0069] In the formula, This is the final calculated physical damping attenuation ratio; It is the half-cycle vibration decay characteristic calculated in the previous step; It is pi. Because and All are dimensionless numbers, therefore the calculated physical damping attenuation ratio It is also dimensionless, while the formula has the same dimensions. The higher the value, the faster the plant's vibrational energy is dissipated, and the stronger the anchoring effect between the roots and the soil.
[0070] For example, the free mechanical vibration waveform data obtained in step S1 is a sequence containing 5000 sampling points.
[0071] First, a digital low-pass filter with a cutoff frequency of 80 Hz is applied to this set of free mechanical vibration waveform data to filter out high-frequency noise and generate smooth vibration waveform data.
[0072] Then, extreme points are extracted from this smoothed vibration waveform data. Assume the amplitudes (in millivolts) of the first few identified extreme points are: first peak 45.1, first trough -42.0, second peak 35.8, second trough -33.5, and third peak 28.5. This constructs the peak amplitude sequence {45.1, 35.8, 28.5, ...} and the trough amplitude sequence {-42.0, -33.5, ...}.
[0073] Next, by combining these two sequences, taking their absolute values and arranging them in chronological order, we obtain the amplitude sequence. ={45.1,42.0,35.8,33.5,28.5,...}. This sequence is used to calculate the logarithmic decay rate of adjacent amplitudes, generating envelope data.
[0074] First logarithmic decay rate .
[0075] Second logarithmic decay rate .
[0076] The third logarithmic decay rate .
[0077] The fourth logarithmic decay rate .
[0078] Assume that a total of 20 logarithmic decay rate values are calculated for the entire decay process, forming the envelope data.
[0079] Subsequently, the logarithmic decay feature was extracted from the envelope data and fitted. The arithmetic mean of these 20 logarithmic decay rate values was calculated. Assuming the average of these 20 values is 0.145, the generated vibration decay feature... That is, 0.145.
[0080] Finally, based on vibration attenuation characteristics Calculate the physical damping attenuation ratio .
[0081]
[0082] The calculation results show that the physical damping attenuation ratio of the salt marsh plant to be evaluated is 0.0461. This value will be used in subsequent steps to evaluate the effectiveness of its root system in stabilizing soil and preventing waves.
[0083] S3. Obtain the initial and final weight data of the physical dissolution block in the microhabitat of the salt marsh plant to be evaluated before and after the hydrological cycle, calculate the difference between the initial and final weight data, and generate the physical mass loss.
[0084] In a specific embodiment of the present invention, the initial weight data and final weight data of the physically dissolved block in the microhabitat of the salt marsh plant to be evaluated before and after experiencing a hydrological cycle are obtained, the difference between the initial weight data and the final weight data is calculated, and the physical mass loss is generated. This includes: pressing a test entity with a preset geometric surface area using a salt material with known physical density and water solubility, and measuring the weight of the test entity to generate initial weight data.
[0085] In a specific embodiment of the present invention, a test entity with a preset geometric surface area is pressed using a salt material with known physical density and water solubility, and the weight of the test entity is measured to generate initial weight data, including: obtaining hemihydrate calcium sulfate powder with a specific water-cement ratio, mixing and stirring it with water to generate hemihydrate calcium sulfate slurry.
[0086] The hemihydrate calcium sulfate slurry is injected into a mold with a preset geometric surface area and pressed to form the initial test object.
[0087] The initial test specimen is dried until its mass is constant, and the test specimen is generated and the initial weight data is measured.
[0088] Specifically, this step aims to fabricate a physical tracer sensor—the "test entity"—for detecting underground micro-hydrological connectivity through standardized material preparation and molding processes. In the complex underground environment of coastal salt marshes, hydrological scouring forces and flow velocities are difficult to measure directly using conventional electronic instruments. This approach utilizes the physicochemical principle that the mass loss of solid matter dissolved under the shearing action of water flow is positively correlated with hydrodynamic intensity. By preparing a dissolved block with high physical consistency, complex fluid dynamic parameters are transformed into mass scalars that can be obtained through high-precision weighing, thereby achieving repeatable in-situ measurements based on these mass scalars.
[0089] The process begins with the fabrication of standardized test specimens. These specimens are pressed from salt-based materials with known physical densities and water solubility to ensure repeatability and comparability of measurements. Specifically, calcium sulfate hemihydrate powder is selected as the raw material; this is a material that undergoes a hydration reaction and solidifies upon contact with water. First, calcium sulfate hemihydrate powder with a specific water-cement ratio is mixed with water and stirred to generate a homogeneous calcium sulfate hemihydrate slurry. The water-cement ratio is a key parameter controlling the final physical properties of the test specimen; it directly affects the density, porosity, and mechanical strength after solidification, and consequently, its dissolution rate in water. Water-cement ratio The definition of is:
[0090]
[0091] In the formula, It's the quality of the water. This refers to the mass of calcium sulfate hemihydrate powder. Based on laboratory calibration experiments of the solubility characteristics of the tested substances under different ratios, the water-cement ratio was selected. With a ratio of 0.6, the test specimens generated at this ratio exhibit a moderate dissolution rate and sufficient structural strength to withstand field operations.
[0092] Next, the prepared calcium sulfate hemihydrate slurry is injected into a mold with a predetermined geometric surface area for pressing and molding, generating the initial test specimens. The shape and size of the mold are strictly limited to ensure that all test specimens have the same initial surface area, as the dissolution rate is directly related to the surface area exposed in water. A cylindrical mold is used here, with a diameter of [missing information]. It is 20 mm high. The initial test specimen is 30 mm thick. After molding, the initial test specimen is dried until its mass is constant, thus generating the final test specimen. The standardized drying process is carried out in an oven at a constant temperature of 60 degrees Celsius for 24 hours to completely remove free water from the slurry that has not participated in the hydration reaction. After drying, the weight of the test specimen is measured using an electronic balance with an accuracy of 0.01 grams to generate initial weight data. .
[0093] In one specific embodiment of this invention, the parameter setting of a constant temperature of 60 degrees Celsius is explained in detail below based on thermodynamic principles: Traditional soil moisture testing drying standards typically use 105 degrees Celsius. However, the calcium sulfate dihydrate crystals generated after hydration of the tracer material used in this system will experience chemical bond breakage and dehydration when the temperature exceeds 80 degrees Celsius, leading to loss of mechanical strength and pulverization degradation of the test object. Therefore, setting 60 degrees Celsius as the critical drying temperature threshold condition of this method aims to completely evaporate the liquid free water in the capillary pores using only gentle thermal motion, while ensuring that the crystal water bound within the calcium sulfate dihydrate solid framework is not lost. This ensures that the material benchmark for assessing water erosion based on mass loss remains constant.
[0094] The test object is fixed in a metal probe with a water-passing grid hole in the pipe wall and inserted into the lateral silt where the roots of the salt marsh plants to be evaluated reside, so that the test object experiences the hydrological cycle in a natural environment.
[0095] In a specific embodiment of the present invention, the test entity is fixed in a metal probe with a water-passing grid hole in the pipe wall and inserted into the lateral silt where the roots of the salt marsh plant to be evaluated reside, so that the test entity experiences a hydrological cycle in a natural environment, including: identifying the lateral silt area where the roots of the salt marsh plant to be evaluated reside, and determining the micropore development area as the target detection point.
[0096] Insert a metal probe containing the test object to the target detection point, align the water-passing grid holes with the micropore development zone, and establish a hydrophysical scouring channel for the underground microhabitat.
[0097] The monitoring of underground microhabitat hydrophysical scouring channels shows that they experience a complete tidal cycle, thus completing the hydrological cycle.
[0098] Specifically, this step aims to precisely deploy prefabricated physical test entities into the "core working area" of groundwater hydrological activity in the salt marsh ecosystem and utilize natural tidal dynamics to complete tracer testing. The primary way salt marsh plants improve microhabitat function is through their extensive root systems penetrating, decaying, and secreting organic matter in the laterally deep sediment, thereby creating or dissolving a complex network of microporous pores within the highly cohesive sediment matrix. Accurately locating and monitoring the actual water flow erosion within this microporous region is crucial for assessing the effectiveness of hydrological connectivity restoration. Simultaneously, due to the high viscosity and friction of salt marsh sediment, a clever hardware structure is required to ensure the test entities are implanted without damage and fully contact with water flow during testing.
[0099] In one specific embodiment of the present invention, to further prevent highly viscous silt from being squeezed through the water-permeable grid holes and clogging or enveloping the test object during the insertion of the probe into the silt, a removable rigid thin-walled sheath is coaxially fitted around the metal probe. During insertion, this rigid thin-walled sheath is closed, completely blocking and sealing the water-permeable grid holes, ensuring that the internal test chamber remains clean and mud-free during the probe's penetration of the silt. Once the water-permeable grid holes of the probe reach the micropore development zone at a predetermined depth, the metal probe body is kept stationary, and the rigid thin-walled sheath is vertically pulled upwards above the ground surface, completely exposing the water-permeable grid holes in the micropore development zone.
[0100] Meanwhile, a 200-mesh nylon microporous filter screen is attached to the inner side of the water-passing grid holes. This filter screen allows pore water containing dissolved salts to freely permeate and exchange, but effectively prevents large particles of sediment from entering the chamber and eroding the test object. Through the above-mentioned anti-clogging and filtration mechanisms, it is ensured that the test object is only subjected to hydrological erosion, thus guaranteeing the accuracy of the measurement of physical mass loss.
[0101] The prepared test specimens are deployed into the rhizosphere microhabitat of the salt marsh plants to be evaluated. To protect the test specimens from damage during insertion into the soil and to ensure full contact with the surrounding soil and water, they are secured to a metal probe with perforated drainage holes in its wall.
[0102] In one specific embodiment of the present invention, the structural features and size limitations of the water-permeable grid holes are as follows: If the size of the water-permeable grid holes is too large, the test object will easily fall out of the grid holes after its volume shrinks due to prolonged hydrological immersion, rendering the logic of using the final weight to characterize "dissolution and scour loss" completely ineffective; if the structure's porosity is too small, it will easily be blocked by sticky silt, preventing internal water flow. Therefore, the single aperture width of the water-permeable grid holes must be strictly smaller than the estimated minimum residual diameter of the test object after a maximum hydrological cycle, and the grid hole side area ratio of the probe test chamber section must reach a moderate value of 50% to 60%, thereby ensuring accurate feedback of the underground pore water flow velocity in the surrounding soil while preventing the leakage of test object fragments.
[0103] The selection of deployment location is crucial. It is necessary to identify the lateral silt areas where the roots of the salt marsh plants to be evaluated reside, and to determine the microporosity development zones within these areas as target probe points. Microporosity development zones are areas rich in pores and fissures formed in the soil during plant root penetration, organic matter secretion, and growth and death processes; these are the most active areas for groundwater exchange. A metal probe equipped with the test specimen is vertically inserted into the target probe point, aligning the perforated holes on the probe with the microporosity development zone. This establishes a hydrophysical scouring channel for the subsurface microhabitat, allowing natural tidal groundwater to flow through the test specimen.
[0104] The test specimen needs to undergo a complete hydrological cycle underground, that is, a complete tidal cycle. The completion of the hydrological cycle signifies that the test specimen has fully experienced the hydrological scouring of its microhabitat within a typical tidal dynamic cycle. According to the local tide table, a complete semi-diurnal tidal cycle is approximately 12.4 hours.
[0105] In a specific embodiment of the present invention, the hydrological cycle refers not only to the time span but also emphasizes the integrity of the hydrodynamic phase. To ensure that the test entity can fully capture the process from zero flow velocity to maximum flow velocity, the specific requirements for "monitoring the complete rise and fall of tides through the hydrophysical scour channel of the subsurface microhabitat" are as follows: the deployment of the test entity must be completed during the local slack tide or relatively low tide period, when the subsurface microhabitat water flow is relatively still or slowly flowing out. Subsequently, it must sequentially experience the upward infiltration and scour of seawater during the high tide period and the backflow and scour of subsurface pore water during the low tide period. Finally, it must be removed when the system returns to the low tide phase of the next cycle, thereby ensuring the bidirectional integrity of the test entity in the shear direction.
[0106] The test object after undergoing the hydrological cycle is taken out, dried in a standardized manner, and weighed to obtain the final weight data. The physical mass loss is generated by subtracting the final weight data from the initial weight data.
[0107] Specifically, to assess the restoration effectiveness of salt marsh ecosystems from another dimension—namely, the hydrological connectivity of the subsurface microenvironment—this step employs an in-situ tracing method to quantify the infiltration and scour characteristics of the soil surrounding the roots of the salt marsh plants being evaluated. The core idea is to utilize a standardized, soluble physical probe, i.e., the test entity, to indirectly measure the soil pore water exchange capacity improved by plant root activity, ultimately generating a quantified physical mass loss.
[0108] After the hydrological cycle is completed, the metal probe is carefully removed from the silt, and the test specimen, having undergone the hydrological cycle, is taken out. At this point, the test specimen's surface is covered with silt and its interior is filled with moisture. After surface cleaning, it undergoes standardized drying under the exact same conditions as the initial drying, i.e., drying in a constant-temperature oven at 60 degrees Celsius until the mass is constant. The specimen is then weighed again using the same electronic balance to obtain the final weight data. Finally, the physical mass loss is generated by calculating the difference between the initial and final weight data. .
[0109]
[0110] In the formula, It is the amount of physical mass loss, measured in grams; This is the initial weight data, in grams; This is the final weight data, in grams. All physical quantities in this formula are of mass, ensuring consistent dimensions. A greater loss of physical mass indicates more active groundwater exchange at that location, and a greater contribution of the root system to improving soil permeability.
[0111] For example, the implementation process of step S3 is illustrated by taking the microhabitat of the same Spartina alterniflora plant in steps S1 and S2 as an example.
[0112] First, prepare the test sample. Weigh 100.00 grams of calcium sulfate hemihydrate powder and 60.00 grams of water, mix and stir to form a calcium sulfate hemihydrate slurry. At this point, the water-cement ratio is... The slurry was poured into a cylindrical mold with an inner diameter of 20 mm and a height of 30 mm to create the initial test specimen. After drying in a 60°C oven for 24 hours, the specimen was weighed and recorded as 115.23 grams. After drying for another 4 hours, it was weighed again, and the weight remained 115.23 grams, confirming that the mass had stabilized. Therefore, the initial weight data... It weighs 115.23 grams.
[0113] Then, next to the roots of the salt marsh plants to be evaluated, a small resistance probe was used to detect a low-resistance area at a depth of 20 cm underground. This area was identified as a microporosity development zone and designated as the target detection point. The test object was then inserted into a metal probe with a water-permeable grid in its wall, and the probe was inserted into the target detection point, aligning the water-permeable grid with the 20 cm depth to establish a hydrophysical scouring channel for the underground microhabitat. Based on local tidal forecasts, deployment was completed at 10:00 AM on the same day, at high tide, and the probe was left in the silt for 13 hours to ensure it experienced a complete tidal cycle and completed the hydrological cycle.
[0114] The following morning, the metal probe and the test object inside were removed. After rinsing off the mud from the surface of the test object with clean water, it was placed in a 60°C oven for standardized drying. After 24 hours, it weighed 109.45 grams, and after another 4 hours, it weighed 109.44 grams, confirming a constant mass. The final weight data was obtained. It weighs 109.44 grams.
[0115] Finally, calculate the physical mass loss. : gram
[0116] The resulting physical mass loss was 5.79 grams. This value reflects the groundwater connectivity of the root zone microhabitat of the salt marsh plant under evaluation.
[0117] S4. By integrating the physical damping attenuation ratio and physical mass loss, an effectiveness mapping is performed to generate a comprehensive evaluation index for the restoration effectiveness of coastal salt marsh ecosystems.
[0118] In a specific embodiment of the present invention, the physical damping attenuation ratio and physical mass loss are integrated for performance mapping to generate a comprehensive evaluation index of the restoration performance of coastal salt marsh ecosystems. This includes: establishing a first mapping relationship between the physical damping attenuation ratio and the root anchoring performance, and converting the physical damping attenuation ratio into a root soil stabilization and wave protection performance index.
[0119] A second mapping relationship is established between physical mass loss and micro-hydrological connectivity effectiveness, transforming physical mass loss into an indicator of micro-hydrological connectivity restoration effectiveness.
[0120] Specifically, after obtaining the physical damping attenuation ratio, which characterizes the mechanical anchoring properties of the plant-soil system, and the physical mass loss, which characterizes the hydrological connectivity properties of the root zone soil, this step aims to integrate and map these two quantities measured from different physical dimensions to ultimately generate a single value that can comprehensively and holistically reflect the restoration effectiveness of the coastal salt marsh ecosystem, namely the comprehensive evaluation index of the restoration effectiveness of the coastal salt marsh ecosystem.
[0121] The process first requires converting the raw physical measurements into standardized performance indicators. The first step is to establish a primary mapping relationship between the physical damping attenuation ratio and the root anchoring effectiveness, transforming the physical damping attenuation ratio into a root-based soil stabilization and wave-breaking performance indicator. Physical damping attenuation ratio It is a direct physical quantity, while the root system's soil stabilization and wave protection effectiveness index It is a dimensionless fraction between 0 and 100, easy to understand and compare. This transformation is achieved through a nonlinear function that reflects the saturation effect of performance change with the physical damping attenuation ratio; that is, when the damping ratio reaches a certain level, its effect on improving performance weakens. This mapping relationship is constructed using a logistic function:
[0122]
[0123] In the formula, It is an indicator of the effectiveness of root system in soil stabilization and wave prevention; It is the physical damping attenuation ratio; It is the base of the natural logarithm; and These are the parameters of the mapping function. It is the gain coefficient, which determines the steepness of the curve. Its value is obtained by correlating and fitting a large amount of plant pulling experiment data with vibration data, and is set to 200. This is the center point parameter, representing the physical damping attenuation ratio corresponding to 50% effectiveness. Based on statistics of healthy salt marsh plant communities, it is set to 0.020. All variables in this formula are dimensionless and have consistent dimensions.
[0124] Concurrently, a second mapping relationship is established between physical mass loss and micro-hydrological connectivity effectiveness, transforming physical mass loss into an indicator of micro-hydrological connectivity restoration effectiveness. Physical mass loss The absolute value is influenced by various factors and needs to be standardized. Micro-hydrological connectivity restoration effectiveness index It is also a score between 0 and 100. This mapping is established by linear normalization and setting an upper limit:
[0125]
[0126] In the formula, It is an indicator of the effectiveness of micro-hydrological connectivity restoration; It is the amount of physical mass loss; This is a reference physical mass loss, representing the maximum loss level achievable in an ideal microporous development zone under the same testing conditions. This value was obtained through a control experiment on a pure, highly permeable sandy substrate and was set at 8.00 grams. The function takes the smaller of the two values within the parentheses, ensuring the index does not exceed 100. Because... and The units are the same (grams), and their ratio is dimensionless, therefore the formulas have consistent dimensions.
[0127] By integrating the root system soil stabilization and wave protection effectiveness indicators and the micro-hydrological connectivity restoration effectiveness indicators, a comprehensive evaluation index for the restoration effectiveness of coastal salt marsh ecosystems is generated.
[0128] In a specific embodiment of the present invention, the root system soil stabilization and wave protection efficiency index and the micro-hydrological connectivity restoration efficiency index are integrated and weighted to generate a comprehensive evaluation index of the restoration efficiency of the coastal salt marsh ecosystem. This includes: obtaining soil type parameters and tidal dynamic parameters of the area where the salt marsh plants to be evaluated are located, and constructing environmental impact factors.
[0129] The environmental impact factors were used to dynamically assign weights to the root system soil stabilization and wave prevention effectiveness indicators and the micro-hydrological connectivity restoration effectiveness indicators, generating dynamic weight coefficients.
[0130] A comprehensive evaluation index for the restoration effectiveness of coastal salt marsh ecosystems is generated by calculating the linear combination of dynamic weighting coefficients with root system soil stabilization and wave protection effectiveness indicators and micro-hydrological connectivity restoration effectiveness indicators.
[0131] Specifically, the restoration efficiency of an ecosystem is not simply a matter of piling up individual indicators; its core survival needs and ecological function priorities differ across different habitats. On open beaches with strong hydrodynamics, the primary task of vegetation is to avoid being uprooted (soil stabilization and wave protection); while in calm but silted bays, vegetation's ability to improve ground aeration and water exchange networks becomes crucial for ecological restoration. This step aims to construct a dynamic feedback mechanism by introducing local environmental stress parameters, abandoning traditional fixed-weight algorithms, so that the final comprehensive score can adapt to the geographical characteristics of different sites, thereby providing a quantitative evaluation with real ecological guidance.
[0132] First, soil type parameters and tidal dynamic parameters of the area where the salt marsh plants to be evaluated are located are obtained to construct environmental impact factors. Soil type parameters Tidal dynamic parameters are expressed as a percentage of clay content in the soil. Expressed as mean tidal range in meters. Environmental impact factors. To quantify the physical stress of the environment on vegetation, and to prevent overflow of subsequent weighted logic caused by abnormal measurement data exceeding historical extremes, the system uses a normalization function including a minimum threshold for constraint calculation. The calculation method is as follows:
[0133]
[0134] In the formula, and These are the maximum possible clay content and maximum mean tidal range within the assessment area, used for normalization, for example, based on regional hydrogeological data. 60%, It is 5.0 meters. It is a dimensionless number between 0 and 1.
[0135] Dynamic weighting coefficients were generated by dynamically assigning weights to the root system's soil stabilization and wave protection effectiveness indicators and the micro-hydrological connectivity restoration effectiveness indicators using environmental impact factors. In environments with strong tidal dynamics and easily eroded soil, the root system's soil stabilization and wave protection effectiveness is even more critical. Dynamic weighting coefficients. (correspond )and (correspond The calculation is as follows:
[0136]
[0137]
[0138] In the formula, It is the basic weight of the root system soil stabilization and wave protection effectiveness index, representing the effect under no environmental stress ( The importance of ( ) is set to 0.5, indicating that both are equally important. With Increase It will increase from 0.5 to 1.0, while The corresponding decrease.
[0139] Finally, a linear combination of the dynamic weighting coefficients with the root system soil stabilization and wave protection effectiveness index and the micro-hydrological connectivity restoration effectiveness index was calculated to generate a comprehensive evaluation index of the restoration effectiveness of the coastal salt marsh ecosystem. .
[0140]
[0141] It is a comprehensive score from 0 to 100. The higher the value, the better the comprehensive ecological restoration effect of the salt marsh plant in the current environment.
[0142] For example, based on the calculation results of steps S2 and S3, the physical damping attenuation ratio The physical mass loss is 0.0231. It weighs 5.79 grams.
[0143] First, the physical damping attenuation ratio is converted into an index of root-based soil stabilization and wave protection effectiveness. Based on the first mapping relationship and substituting the parameters... and :
[0144]
[0145] Therefore, the root system's effectiveness in stabilizing soil and preventing waves is 65.02.
[0146] Next, the physical mass loss is transformed into a micro-hydrological connectivity restoration efficiency index. Based on the second mapping relationship, and substituting the reference physical mass loss... gram:
[0147]
[0148] Therefore, the micro-hydrological connectivity restoration efficiency index is 72.38.
[0149] Then, to calculate the dynamic weights, on-site environmental parameters are obtained. Assume the soil type parameters of the area where the salt marsh plants to be evaluated are located. (Clay content) is 30%, tidal dynamic parameters The mean tidal range is 2.5 meters. Normalized parameters are used. and Meters, constructing environmental impact factors:
[0150]
[0151] Using environmental impact factors and basic weights Generate dynamic weight coefficients:
[0152]
[0153]
[0154] Finally, by integrating the root system's soil stabilization and wave protection effectiveness indicators with the micro-hydrological connectivity restoration effectiveness indicators, a comprehensive evaluation index for the restoration effectiveness of coastal salt marsh ecosystems is generated:
[0155]
[0156] The final comprehensive evaluation index of the coastal salt marsh ecosystem restoration effectiveness was 67.78.
[0157] Reference Figure 2 The second aspect of the present invention provides a coastal salt marsh ecosystem restoration efficiency assessment system, comprising: a free mechanical vibration waveform data generation module, a physical damping attenuation ratio calculation module, a physical mass loss calculation module, and a comprehensive assessment index generation module.
[0158] The free mechanical vibration waveform data generation module is connected to the physical damping attenuation ratio calculation module, which in turn is connected to the physical mass loss calculation module. Both the physical damping attenuation ratio calculation module and the physical mass loss calculation module are connected to the comprehensive evaluation index generation module.
[0159] The free mechanical vibration waveform data generation module applies a transverse mechanical transient impact force to the base of the stem of the salt marsh plant to be evaluated for in-situ excitation, collects the plant vibration signal after excitation, and generates free mechanical vibration waveform data.
[0160] The physical damping attenuation ratio calculation module extracts the vibration attenuation characteristics from the free mechanical vibration waveform data and calculates the physical damping attenuation ratio based on the vibration attenuation characteristics.
[0161] The physical mass loss calculation module obtains the initial and final weight data of the physically dissolved block in the microhabitat of the salt marsh plant to be evaluated before and after the hydrological cycle, calculates the difference between the initial and final weight data, and generates the physical mass loss.
[0162] The comprehensive evaluation index generation module integrates the physical damping attenuation ratio and physical mass loss to perform performance mapping and generate a comprehensive evaluation index for the restoration performance of coastal salt marsh ecosystems.
[0163] The above content is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined by the present invention, and all such modifications and additions should fall within the protection scope of the present invention.
Claims
1. A method for evaluating the restoration effectiveness of coastal salt marsh ecosystems, characterized in that, include: S1. Apply a transverse mechanical transient impact force to the base of the stem of the salt marsh plant to be evaluated for in-situ excitation, collect the plant vibration signal after excitation, and generate free mechanical vibration waveform data. S2. Extract the vibration attenuation characteristics from the free mechanical vibration waveform data, and calculate the physical damping attenuation ratio based on the vibration attenuation characteristics; S3. Obtain the initial and final weight data of the physical dissolution block in the microhabitat of the salt marsh plant to be evaluated before and after the hydrological cycle, calculate the difference between the initial and final weight data, and generate the physical mass loss. S4. By integrating the physical damping attenuation ratio and physical mass loss, an effectiveness mapping is performed to generate a comprehensive evaluation index for the restoration effectiveness of coastal salt marsh ecosystems.
2. The method for evaluating the restoration effectiveness of coastal salt marsh ecosystems according to claim 1, characterized in that, The process involves applying a transverse mechanical transient impact force to the base of the stem of the salt marsh plant to be evaluated for in-situ excitation, collecting the plant vibration signal after excitation, and generating free mechanical vibration waveform data, including: Clamp the piezoelectric vibration sensor to the base of the stem of the salt marsh plant to be evaluated to establish a vibration monitoring link; A constant-force physical impact hammer is used to apply a transverse mechanical transient impact force to the base of the stem through a vibration monitoring link, triggering the plant's free mechanical vibration; Mechanical vibration signals during free mechanical vibration are recorded using piezoelectric vibration sensors to generate free mechanical vibration waveform data.
3. The method for evaluating the restoration effectiveness of coastal salt marsh ecosystems according to claim 1, characterized in that, The process of extracting vibration attenuation characteristics from free mechanical vibration waveform data and calculating the physical damping attenuation ratio based on these characteristics includes: Identify the peak amplitude sequence and trough amplitude sequence in free mechanical vibration waveform data, and generate envelope data; Logarithmic decay features are extracted from the envelope data and fitted to generate vibration decay features. Calculate the system energy dissipation rate corresponding to the vibration attenuation characteristics, and convert the system energy dissipation rate into the physical damping attenuation ratio.
4. The method for evaluating the restoration effectiveness of coastal salt marsh ecosystems according to claim 1, characterized in that, The process of obtaining the initial and final weight data of the physically dissolved mass in the microhabitat of the salt marsh plant to be evaluated before and after the hydrological cycle, calculating the difference between the initial and final weight data, and generating the physical mass loss includes: A test entity with a preset geometric surface area is pressed using a salt material with known physical density and water solubility, and the weight of the test entity is measured to generate initial weight data. The test object was fixed in a metal probe with a water-passing grid hole in the pipe wall and inserted into the lateral silt where the roots of the salt marsh plants to be evaluated resided, so that the test object experienced the hydrological cycle in the natural environment. The test object after undergoing the hydrological cycle is taken out, dried in a standardized manner, and weighed to obtain the final weight data. The physical mass loss is generated by subtracting the final weight data from the initial weight data.
5. The method for evaluating the restoration effectiveness of a coastal salt marsh ecosystem according to claim 1, characterized in that, The method integrates physical damping attenuation ratio and physical mass loss for performance mapping, generating a comprehensive evaluation index for the restoration performance of coastal salt marsh ecosystems, including: Establish the first mapping relationship between physical damping attenuation ratio and root anchoring effectiveness, and convert the physical damping attenuation ratio into an index of root soil stabilization and wave prevention effectiveness. Establish a second mapping relationship between physical mass loss and micro-hydrological connectivity effectiveness, and transform physical mass loss into an indicator of micro-hydrological connectivity restoration effectiveness. By integrating the root system soil stabilization and wave protection effectiveness indicators and the micro-hydrological connectivity restoration effectiveness indicators, a comprehensive evaluation index for the restoration effectiveness of coastal salt marsh ecosystems is generated.
6. The method for evaluating the restoration effectiveness of a coastal salt marsh ecosystem according to claim 3, characterized in that, The process of identifying the peak amplitude sequence and trough amplitude sequence in the free mechanical vibration waveform data and generating envelope data includes: Filter high-frequency interference signals caused by environmental wind loads from free mechanical vibration waveform data to generate smooth vibration waveform data; Extract extreme points from smooth vibration waveform data to construct peak amplitude sequences and trough amplitude sequences; By combining the peak amplitude sequence and the trough amplitude sequence, the logarithmic decay rate of adjacent amplitudes is calculated to generate envelope data.
7. The method for evaluating the restoration effectiveness of a coastal salt marsh ecosystem according to claim 4, characterized in that, The process involves pressing a salt-based material with known physical density and water solubility into a test entity with a predetermined geometric surface area, measuring the weight of the test entity to generate initial weight data, including: Hemihydrate calcium sulfate powder with a specific water-cement ratio is mixed and stirred with water to generate hemihydrate calcium sulfate slurry; The hemihydrate calcium sulfate slurry is injected into a mold with a preset geometric surface area and pressed to form an initial test entity. The initial test specimen is dried until its mass is constant, and the test specimen is generated and the initial weight data is measured.
8. The method for evaluating the restoration effectiveness of a coastal salt marsh ecosystem according to claim 4, characterized in that, The fixed test entity is inserted into a metal probe with a water-passing grid in the pipe wall and into the lateral silt where the roots of the salt marsh plants to be evaluated reside, allowing the test entity to undergo a hydrological cycle under natural conditions, including: Identify the lateral silt areas where the roots of the salt marsh plants to be evaluated reside, and determine the micropore development areas as target detection points; Insert a metal probe containing the test object to the target detection point, align the water-passing grid holes with the micropore development zone, and establish a hydrophysical scouring channel for the underground microhabitat; The monitoring of underground microhabitat hydrophysical scouring channels shows that they experience a complete tidal cycle, thus completing the hydrological cycle.
9. The method for evaluating the restoration effectiveness of a coastal salt marsh ecosystem according to claim 5, characterized in that, The root system soil stabilization and wave protection effectiveness indicators and the micro-hydrological connectivity restoration effectiveness indicators are weighted and calculated to generate a comprehensive evaluation index for the restoration effectiveness of coastal salt marsh ecosystems, including: Obtain soil type parameters and tidal dynamic parameters of the area where the salt marsh plants to be evaluated are located, and construct environmental impact factors; The environmental impact factors were used to dynamically assign weights to the root system soil stabilization and wave prevention effectiveness indicators and the micro-hydrological connectivity restoration effectiveness indicators, generating dynamic weight coefficients. A comprehensive evaluation index for the restoration effectiveness of coastal salt marsh ecosystems is generated by calculating the linear combination of dynamic weighting coefficients with root system soil stabilization and wave protection effectiveness indicators and micro-hydrological connectivity restoration effectiveness indicators.
10. A system for evaluating the restoration effectiveness of coastal salt marsh ecosystems, characterized in that, include: The free mechanical vibration waveform data generation module applies a transverse mechanical transient impact force to the base of the stem of the salt marsh plant to be evaluated for in-situ excitation, collects the plant vibration signal after excitation, and generates free mechanical vibration waveform data. The physical damping attenuation ratio calculation module extracts the vibration attenuation characteristics from the free mechanical vibration waveform data and calculates the physical damping attenuation ratio based on the vibration attenuation characteristics. The physical mass loss calculation module obtains the initial and final weight data of the physically dissolved block in the microhabitat of the salt marsh plant to be evaluated before and after the hydrological cycle, calculates the difference between the initial and final weight data, and generates the physical mass loss. The comprehensive evaluation index generation module integrates the physical damping attenuation ratio and physical mass loss to perform performance mapping and generate a comprehensive evaluation index for the restoration performance of coastal salt marsh ecosystems.