Method for improving ecological environment quality of estuary area

Abstract

The invention relates to the technical field of estuary ecological restoration, and discloses a method for improving the ecological environment quality of an estuary region, and the method comprises the following steps: obtaining three-dimensional data of estuary sediment thickness and spartina alterniflora root system density through employing a mode of combining a multi-beam sounding system and a ground penetrating radar; meanwhile, sediment samples are collected, the salt content, the organic matter content and the heavy metal content are detected, and a hydro-meteorological monitoring station is arranged to obtain tide and flow velocity real-time data; a main workboat carrying a high-frequency vibration crushing device and an unmanned boat cluster cooperatively work, different crushing frequencies and navigational speeds are adopted according to root system density grading, a microorganism inactivating agent is synchronously sprayed, the crushing depth reaches 1.5-1.8 m, and the crushing rate is larger than or equal to 98.5%. Through multi-link collaborative operation, accurate mastering of estuary ecological data, removal of spartina alterniflora, utilization of desilting soil, creation of conditions suitable for mangrove forest growth, seedling field planting guarantee and ecological monitoring early warning and response maintenance are achieved. The problem that the overall restoration effect of the estuary ecosystem is poor is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of estuary ecological restoration, in particular to a method for improving the ecological environment quality of an estuary region. BACKGROUND

[0002] The current estuary ecological protection and restoration work faces many problems. In the data acquisition link, there are problems such as low precision of terrain data, difficulty in grasping Spartina alterniflora root system distribution, lack of in-depth detection of sediment physical and chemical properties, and scattered hydrological and meteorological data. In actual restoration operation, dredging is not thorough, soil improvement does not meet standards, mangrove planting lacks systematic planning, and there is a lack of effective monitoring and early warning mechanism. These factors result in poor overall restoration effect of the estuary ecosystem, making it difficult to improve the ecological environment quality and achieve sustainable development. SUMMARY

[0003] In view of the deficiencies of the prior art, the present application provides a method for improving the ecological environment quality of an estuary region, which solves the problem of poor overall restoration effect of the estuary ecosystem.

[0004] To achieve the above purpose, the present application is implemented by the following technical scheme: a method for improving the ecological environment quality of an estuary region, comprising the following steps: S1, a multi-beam sounding system and a ground penetrating radar are combined to obtain three-dimensional data of estuary sediment thickness and Spartina alterniflora root system density, sediment samples are collected to detect salt content, organic matter and heavy metal content, and hydrological and meteorological monitoring stations are arranged to obtain real-time data of tide and flow rate; S2, a main work ship equipped with a high-frequency vibration breaking device and a swarm of unmanned ships are cooperatively operated, different breaking frequencies and speeds are used according to the root system density classification, a microbial inactivator is sprayed synchronously, the breaking depth is 1.5-1.8m, and the breaking rate is ≥98.5%; S3, through primary screening, hydraulic classification, heavy metal stabilization, biological activation and intelligent proportioning process, the dredged soil is converted into a planting medium with a salt content of <15% and an organic matter content of ≥4.0%, and the effective state of heavy metals is reduced by more than 60%; S4, a layered backfilling and compaction technology is used to control the elevation, the high tide zone is controlled to be 1.0-1.5m above the theoretical minimum tide level, a microtopography is constructed by combining ecological ditches and oyster shell layers, and different proportions of improved medium are applied according to the differences in the tidal zone; S5, a six-axis mechanical arm is used to perform positioning, punching, fertilization, planting and soil covering processes, salt-tolerant seedlings treated by ultrasonic wave-microwave cooperation and nano-biological initiation are planted, and an ecological protection system is constructed by supporting oyster reefs and degradable fiber nets; S6, an aerospace integrated monitoring network is constructed, Spartina alterniflora recurrence early warning and mangrove growth prediction are realized through a digital twin platform and an AI algorithm, and a five-level emergency response mechanism is established to implement maintenance.

[0005] By adopting the above technical scheme, from data acquisition, dredging and weeding, soil improvement, landform construction, seedling planting to ecological monitoring and response, the estuary ecological restoration work is fully ensured to be carried out smoothly, the ecological environment quality is improved, and the ecological system is maintained stable.

[0006] Preferably, the S1 comprises: the sediment sampling depth is 0-150 cm, the physicochemical properties of the 0-30 cm, 30-60 cm, 60-100 cm and 100-150 cm soil layers are detected in layers, the sampling frequency of the hydrological monitoring station is 1 time / 10 minutes, and the nearly 10-year historical meteorological data are synchronously collected.

[0007] Preferably, the S2 comprises: the main work ship is equipped with a 200kW high-frequency vibration breaking device, the vibration frequency is 40-90Hz adjustable, the amplitude is 3-10mm, the microwave radar root system detector and the double-frequency DGPS positioning system are matched, the operation track accuracy is ±15cm, the unmanned ship cluster is driven by hydrogen fuel cell, and the coverage efficiency reaches 15,000m² / day.

[0008] Preferably, the S3 comprises: the hydraulic grading adopts a three-stage cyclone separator in series, the separated coarse sand particles are used for breakwater filling, the medium powder particles are used as the main improvement material, the fine clay particles are used for making ecological revetment bricks, 5-8% modified biochar and 0.5mol / L sodium sulfide solution are added in the heavy metal stabilization process, salt-tolerant microbial flora is bioactivated, the proportion of bacillus is 55%, the inoculation amount is 10 9 CFU / g of soil.

[0009] Preferably, the S4 comprises: the layered backfill thickness is 15cm, the 20t intelligent vibration road roller is used for compaction for 4 times, the compaction degree is greater than or equal to 92%, the elevation error is less than or equal to ±3cm, the ecological ditch depth is 0.5m, the width is 2m, the slope ratio is 1:8, and the 20cm oyster shell layer is laid in the ditch.

[0010] Preferably, the S5 comprises: the seedling pretreatment adopts 25kHz ultrasonic wave 400W, 12min and 2.45GHz microwave 600W, 3min cooperative treatment, 50nm SiO2 nanoparticles and 100mg / L GA3 solution are combined for initiation, the root system is dipped in 100mg / L ABT rooting powder and 10 8 CFU / g of salt-tolerant microbial agent during planting, the mechanical arm planting accuracy is ±8mm, and the operation efficiency is 250 plants / hour.

[0011] Preferably, the S6 comprises: the Gaofen-7 satellite, the Sentinel-2 satellite, the unmanned aerial vehicle cluster carrying a laser radar and 50 ground intelligent monitoring stations, the data transmission delay is less than 20ms, the AI decision model adopts the LSTM-Attention neural network, and the Spartina alterniflora recurrence early warning accuracy is greater than or equal to 92%.

[0012] Preferably, the S6 further comprises: for the area of Spartina alterniflora >1000m2, using unmanned aerial vehicle cluster to spray 15% glyphosate, 250mL / m2, for the survival rate of mangrove <70%, starting the intelligent irrigation system to dilute seawater to 15‰ of salt content, and irrigation amount 50L / plant.

[0013] Preferably, the S6 further comprises: ecological effect acceptance index, the survival rate of mangrove is greater than or equal to 88%, the coverage of Spartina alterniflora is less than 1%, the soil organic matter in the high tide zone is greater than or equal to 5.0%, the available Zn is less than 18mg / kg, the flow velocity reduction rate of oyster reef is greater than or equal to 45%, and the annual increment of carbon storage is greater than or equal to 5.8tC / ha.

[0014] According to the method for improving the ecological environment quality of the estuary region, the dredging engineering is cooperated with the mangrove planting, the dredged soil is 100% used for soil improvement after grading treatment, the mangrove planting adopts the tree species configuration matched with the tidal zone, the whole process control from dredging and grass removal to soil improvement and mangrove growth is carried out through the intelligent monitoring system, and the closed-loop ecological restoration system is formed.

[0015] The application provides a method for improving the ecological environment quality of an estuary region. 1. In the application, through multi-link cooperative operation, the estuary ecological data is accurately grasped, Spartina alterniflora is removed, dredged soil is utilized, suitable mangrove growth conditions are created, seedling planting is guaranteed, and ecological monitoring, early warning, response and maintenance are realized.

[0016] 2. In the application, through high-precision and multi-dimensional data collection on the topography, distribution of Spartina alterniflora roots, physical and chemical properties of sediments and hydrological and meteorological conditions of the estuary region, the topographic data resolution reaches 25m*25m, the error of sediment thickness is ±10cm, the roots with a diameter greater than 5mm and a depth of 1.5m can be identified, the layered accuracy of physical and chemical property detection is ±2cm, and the time resolution of hydrological data is 10 minutes, so that quantitative data support is provided for subsequent dredging, soil improvement and mangrove planting, and parameterized design and accurate implementation of each link are guaranteed.

[0017] 3、In the application, through the whole process of fine treatment and efficient resource utilization of dredged soil, high-quality planting substrate with salt content <15%, organic matter ≥4.0% and more than 60% reduction of effective state of heavy metals is produced, which improves soil fertility, improves soil structure, reduces heavy metal hazards, accurately matches the growth needs of mangrove in different tidal zones, improves plant survival rate and growth quality, and effectively promotes the recovery and stability of estuarine ecosystem. The problem of incomplete treatment of dredged soil, insufficient resource utilization and heavy metal pollution affecting ecological restoration is solved.

[0018] 4、In the application, the germination rate and radicle growth rate of seedlings are improved through pretreatment, the adaptability of seedlings in high salt environment is enhanced, the mechanical arm planting ensures high precision and high efficiency planting, and the supporting ecological protection system reduces water flow erosion and increases biodiversity, which together promote the good growth of plants and improve the service function and stability of estuarine ecosystem. The problem of low seedling germination rate and insufficient efficiency and precision of artificial planting is solved. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 A method for improving the ecological environment quality of the estuary region is provided. DETAILED DESCRIPTION

[0020] The technical solutions of the application will be described below in conjunction with the drawings of the specification. Obviously, the described embodiments are only part of the embodiments of the application, not all embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the application.

[0021] Please refer to the drawings Figure 1 The embodiment of the application provides a method for improving the ecological environment quality of the estuary region, which comprises the following steps: S1, a multi-beam sounding system and ground penetrating radar are combined to obtain three-dimensional data of estuary sediment thickness and Spartina alterniflora root system density, sediment samples are collected to detect salt content, organic matter and heavy metal content, and hydrological and meteorological monitoring stations are laid out to obtain real-time data of tide and flow rate.

[0022] S1 includes: the sampling depth of sediment is 0-150cm, the physicochemical properties of 0-30cm, 30-60cm, 60-100cm and 100-150cm soil layers are detected layer by layer, the sampling frequency of the hydrological monitoring station is 1 time / 10 minutes, and the historical meteorological data of nearly 10 years are collected synchronously.

[0023] Specifically, the multi-beam sounding system and ground penetrating radar were combined to scan the estuary area. The multi-beam sounding system was equipped with Kongsberg EM2040 equipment, which emitted multiple narrow-beam sound waves (the beam opening angle was usually 2°x2°) to cover the measurement area in a fan shape. The sound waves were captured by the receiving transducer after being reflected by the sediment surface. According to the propagation speed of sound waves in water (about 1500 m / s) and the round-trip time, the distance from the sediment surface to the transducer was calculated. Combined with the DGPS positioning data (accuracy ± 15 cm) and the attitude sensor (roll, pitch, and yaw accuracy ± 0.1°), a high-precision sediment thickness three-dimensional model was constructed. The ground penetrating radar used MALA GeoScience ProEx equipment, which emitted high-frequency electromagnetic waves with a center frequency of 100-200 MHz. When the electromagnetic waves penetrated the sediment, they were reflected due to the difference in dielectric constant between the Spartina alterniflora root system and the surrounding matrix (the dielectric constant of the root system was about 10-15, and the dielectric constant of the sediment was about 5-8). By receiving the time, amplitude, and phase information of the reflected waves, the image reconstruction was performed using the Kirchhoff migration algorithm to identify the root distribution range and density (with a resolution of 5 cm), and the root density cloud map was generated.

[0024] The sediment samples were collected using a hydraulic column sampler, with a sampling depth of 0-150 cm, and the samples were cut into layers of 0-30 cm, 30-60 cm, 60-100 cm, and 100-150 cm. The salinity was detected using a DDS-307A conductivity meter. The soil-water ratio was 1:5, and the conductivity was measured after mixing and converted to salinity (accuracy ± 0.1‰). The organic matter content was determined by the potassium dichromate oxidation-external heating method. The organic carbon content was calculated using the redox reaction between organic matter and potassium dichromate, and then multiplied by the coefficient 1.724 to obtain the organic matter content (error ± 5%). The heavy metal content was pretreated using the HNO3-HClO4-HF digestion system, and the atomic absorption spectrometer (detection limit 0.01 mg / kg) was used to determine the content of elements such as Zn and Cu.

[0025] Five automatic monitoring stations were set up on the shore of the hydro-meteorological monitoring station, equipped with pressure water level gauge (accuracy ± 1 cm), electromagnetic current meter (accuracy ± 1%), and CTD (salinity accuracy ± 0.03‰) to collect tide, flow rate, water temperature, and salinity data at a frequency of 1 time / 10 minutes. At the same time, the database of Guangdong Provincial Hydrology Bureau was accessed to obtain historical weather data (including typhoon path, rainfall intensity, air temperature, etc.) in the past 10 years, and a multi-dimensional database was established.

[0026] By high-precision, multi-dimensional data collection of the topography of the estuary area, the distribution of Spartina alterniflora root system, the physical and chemical properties of sediments, and hydro-meteorological conditions, among which the topographic data resolution reaches 25 m x 25 m, the sediment thickness error is ± 10 cm, the root system with a diameter of > 5 mm and a depth of 1.5 m can be identified, the layered precision of physical and chemical property detection is ± 2 cm, and the hydrological data time resolution is 10 minutes, quantitative data support is provided for subsequent dredging, soil improvement, mangrove planting and other links, and parameterized design and accurate implementation of each link are ensured. The problems of coarse topographic data, fuzzy root system distribution identification, shallow physical and chemical property detection, and fragmented hydrological data in the prior art are solved.

[0027] S2, the main work ship equipped with high-frequency vibration crushing device cooperates with unmanned ship cluster operation, different crushing frequencies and speeds are adopted according to root system density classification, microbial inactivator is sprayed synchronously, the crushing depth reaches 1.5-1.8 m, and the crushing rate is ≥98.5%.

[0028] S2 includes: the main work ship is equipped with 200kW high-frequency vibration crushing device, the vibration frequency is 40-90Hz adjustable, the amplitude is 3-10mm, the microwave radar root detector and the double-frequency DGPS positioning system are matched, the operation track accuracy is ± 15cm, the unmanned ship cluster is driven by hydrogen fuel cell, and the coverage efficiency reaches 15000m² / day.

[0029] Specifically, the main work ship equipped with 200kW high-frequency vibration crushing device cooperates with the unmanned ship cluster driven by hydrogen fuel cell, the high-frequency vibration crushing device equipped on the main work ship generates 40-90Hz adjustable frequency and 3-10mm amplitude mechanical vibration through hydraulic driving eccentric block rotation, when the cutter head cuts into the sediment, the vibration energy is transmitted to the Spartina alterniflora root system, the root system is subjected to fatigue failure by high-frequency mechanical force, the cutting action of the 1.8m diameter special alloy cutter head is matched, and the root system crushing in the depth of 1.5-18m is realized. The microwave radar root detector (R2SONIC2024) emits 2.4GHz microwave signals in real time, identifies the root system density distribution according to the electromagnetic wave reflection intensity, and transmits the data to the central control system. The system automatically adjusts the main ship speed (0.5-1.0kn) and crushing frequency based on double-frequency DGPS positioning (Trimble S9+ Beidou No. 3, accuracy ± 15cm) and LSTM-Attention algorithm: when the root system density is > 250g / m³, the 80Hz high-frequency crushing mode is started, and the speed is reduced to 0.7kn; when the density is < 150g / m³, the 60Hz crushing mode is adopted, and the speed is increased to 0.9kn. The unmanned ship cluster (6 ships / group) is equipped with a laser particle size instrument and a heavy metal detector, and executes sediment detection and microbial inactivator (10 9The CFU / m² Bacillus spores are sprayed, and the real-time data interaction with the main ship is formed through the 5G Mesh network, to form a "detection-crushing-detection-inactivation" closed-loop operation chain.

[0030] The high-precision directional crushing of the 1.5-1.8m depth Spartina alterniflora root system is performed, the crushing rate is more than 98.5%, and the residual root system diameter is less than 1.5mm, the sediment physical and chemical property detection and microbial inactivation treatment are simultaneously completed, the operation efficiency is 3 times higher than that of the traditional single ship, the energy consumption is reduced by 28%, a "detection-crushing-detection-inactivation" closed-loop operation chain is formed, and a thorough invasive species removal basis is provided for subsequent ecological restoration. The problems of insufficient root crushing depth, low crushing rate and inability to simultaneously perform deep root treatment and sediment detection in the prior art are solved.

[0031] S3, through primary screening, hydraulic classification, heavy metal stabilization, biological activation and intelligent proportioning process, the dredged soil is converted into a planting substrate with a salt content of less than 15% and an organic matter content of more than 4.0%, and the effective state of heavy metals is reduced by more than 60%.

[0032] S3 includes: the hydraulic classification adopts a three-stage cyclone separator in series, the separated coarse sand particles are used for breakwater filling, the medium powder particles are used as improved main materials, and the fine clay particles are used for making ecological revetment bricks. In the heavy metal stabilization process, 5-8% modified biochar and 0.5mol / L sodium sulfide solution are added, and salt-tolerant microbial flora is introduced, in which Bacillus accounts for 55%, and the inoculation amount is 10 9 CFU / g of soil.

[0033] Specifically, the dredged soil is treated by primary screening, hydraulic classification, heavy metal stabilization, biological activation and intelligent proportioning process. The primary screening uses a double-layer vibrating screen, the upper layer screen hole is 5mm, and the lower layer screen hole is 2mm. The vibrating screen is equipped with a vibrating motor to drive the screen body to vibrate at a specific frequency (20-30Hz). After the dredged soil is conveyed to the screen surface, it moves in an elliptical motion under the action of vibration. The sediment particles with a particle size smaller than the screen hole pass through the screen and fall down, while the debris and plastic materials with a particle size larger than the screen hole move along the screen surface to the discharge end, finally realizing the separation of debris and sediment. The whole screening process is carried out in a closed screening bin to avoid secondary pollution caused by dust, and a anti-blocking device is set to prevent the screen hole from being blocked and affecting the screening efficiency by regular mechanical tapping or air blowing, ensuring that the screening efficiency is stably maintained at about 98%.

[0034] Hydraulic classification adopts a three-stage cyclone separator (diameter 1.5 m, 1.0 m, 0.5 m) in series. The dredged soil is first made into a slurry of a certain concentration, and then transported to the first-stage cyclone separator (diameter 1.5 m) at a water pressure of 0.3 MPa. In the separator, the slurry enters at a high speed along the tangent direction, forming a high-speed rotating flow field. According to Stokes' law, under the combined action of centrifugal force, gravity, and fluid drag, particles of different sizes begin to separate. Coarse sand particles with a particle size greater than 0.1 mm, due to the action of a larger centrifugal force, quickly settle to the inner wall of the separator and are discharged from the bottom outlet for use in low-tide zone breakwater filling. Medium powder particles with a particle size between 0.01-0.1 mm reach a relative balance between centrifugal force and gravity, and flow out from the middle outlet as the main raw material for subsequent soil improvement. Fine clay particles with a particle size less than 0.01 mm, under the dominance of fluid drag, are discharged from the top overflow outlet. Then, 10% cement or other cementitious materials are added to make ecological revetment bricks through processes such as molding. The operating parameters of the cyclone separators (such as inlet flow rate and overflow ratio) are precisely adjusted according to the characteristics of the actual dredged soil and processing requirements to ensure that the separation effect is optimal.

[0035] Heavy metal stabilization is carried out on the medium powder particles obtained after hydraulic classification. 5-8% of modified biochar (specific surface area up to 900 m² / g, pH value 9.5) is added to the medium powder particles. The modified biochar, after special pyrolysis and activation treatment, is rich in functional groups such as carboxyl, hydroxyl, and carbonyl on its surface. These functional groups can adsorb and fix Zn²⁺, Cu²⁺, and other heavy metal ions in the dredged soil through chemical bond interaction. At the same time, a 0.5 mol / L sodium sulfide solution is injected into the system. The sodium sulfide dissociates into sulfide ions in the solution, which react with heavy metal ions according to the stoichiometric ratio to form sulfide precipitates (such as ZnS, CuS, etc.) with a very small solubility product (Ksp) (<10⁻² 5

[0036] Bioactivation is carried out by introducing a salt-tolerant microbial complex consisting of Bacillus (55%), Actinomyces (35%), and Cyanobacteria (10%) at a inoculation amount of 10 9 ​The standard uniform mixing of CFU / g soil into the dredged soil. Under the condition of temperature control at 28-32℃ and water content maintained at 45%, the microorganisms begin to play a role. Bacillus breaks down complex macromolecular organic matter in the soil into small molecules such as sugars and amino acids by secreting various extracellular enzymes (such as amylase, protease, etc.), and actinomycetes further participate in the transformation and mineralization of these small molecules. Cyanobacteria use their photosynthesis to provide part of the energy and oxygen for the microbial community, while some metabolic products can also improve soil structure. To ensure sufficient oxygen supply for microbial growth and reproduction, a turner is used to turn the soil at a frequency of 1 time / 8h to enable the soil interior to exchange with the outside air, promote the continuous and efficient metabolism of microorganisms, and ultimately increase the organic matter content of the soil to more than 4.0%. The extracellular polymers and other substances produced by microbial metabolism can also adsorb and fix heavy metal ions in the soil, further optimizing the soil environment.

[0037] The intelligent proportioning relies on a PLC control system to accurately and quantitatively proportion the seven components of dredged soil, decomposed seaweed, biochar, slow-release fertilizer, microbial inoculum, water-retaining agent, and soil structure modifier according to pre-set programs and the differences between the tidal zones (such as high-tide zone and medium-tide zone). During the proportioning process, the addition amount of each component is monitored in real time by high-precision measuring devices (such as electronic scales and flow sensors), which is fed back to the PLC control system. The control system dynamically adjusts according to the set proportioning error requirement (≤0.5%) to ensure that each component is mixed in the correct proportion. At the same time, a visual detection system (composed of high-definition cameras and image analysis software, etc.) is used to monitor the uniformity of the mixed materials in real time. By collecting and analyzing the images of the mixed materials, it is determined whether there is local material aggregation or uneven mixing. If unevenness is found, the stirring speed and time of the mixing equipment (such as a double-shaft mixer) are adjusted in a timely manner to ensure that the final planting medium is evenly distributed.

[0038] Through the whole-process fine treatment and efficient resource utilization of dredged soil, high-quality planting medium with salt content <15%, organic matter ≥4.0%, and effective state of heavy metals reduced by more than 60% is produced, which improves soil fertility, optimizes soil structure, reduces heavy metal hazards, accurately matches the growth needs of mangroves in different tidal zones, improves plant survival rate and growth quality, and effectively promotes the restoration and stability of the estuarine ecosystem. The problems of incomplete treatment of dredged soil, insufficient resource utilization, and heavy metal pollution affecting ecological restoration are solved.

[0039] S4, adopt layered backfilling and compaction technology to control elevation, control the high-tide zone at 1.0-1.5m above the theoretical minimum tide level, and construct micro-topography by combining ecological ditches and oyster shell layers, and apply different proportions of improved medium according to the differences between the tidal zones.

[0040] S4 includes: the thickness of 15 cm of layered backfill, using 20 t intelligent vibrating roller to compact 4 times, compactness ≥ 92%, elevation error ≤ ± 3 cm, ecological ditch depth 0.5 m, width 2 m, slope ratio 1:8, 20 cm oyster shell layer is laid in the ditch.

[0041] Specifically, based on the previously obtained estuary area terrain data and the designed elevation plan, the required backfill soil quantity of each area is calculated. When performing layered backfill operation, the treated improved substrate is uniformly filled in the corresponding area according to the thickness of 15 cm per layer. A 20 t intelligent vibrating roller is used for compaction, which is equipped with high-precision pressure sensors and vibration frequency adjustment devices. During the compaction process, the roller compacts each layer of fill at a set amplitude (2.0 mm) and frequency (30 Hz), and through the high-frequency vibration of the vibrating wheel, the pores between the fill particles are reduced and the friction is increased, thereby improving the compactness of the fill. After completing the filling of each layer, compaction is immediately performed, a total of 4 times. During the compaction process, a detection point is set every 500 m² using the ring knife method to detect the compaction degree in real time. According to relevant standard requirements, it is ensured that the compaction degree can reach ≥ 92%, and at the same time, the elevation of the backfill area is measured synchronously by high-precision measuring equipment such as total station, to control the elevation error within ≤ ± 3 cm, so as to ensure that the elevation of the entire backfill area meets the design requirements, such as being able to accurately control 1.0-1.5 m above the theoretical lowest tide level in the high tide zone.

[0042] The ecological ditch is planned and excavated at an interval distance of every 500 m, with a depth of 0.5 m and a width of 2 m. During excavation, construction is strictly carried out according to a slope ratio of 1:8 to ensure the stability of the ditch wall and avoid collapse and other situations. After excavation is completed, a 20 cm thick oyster shell layer is laid in the ditch. Oyster shells have a certain pore structure, and their laying can increase the roughness of the substrate and change the flow pattern of the water flow. When the tide rises and falls, the water flow passing through the oyster shell layer will generate more turbulence, which is conducive to the sedimentation of suspended particles in the water and provides habitats and attachment sites for benthic organisms. At the same time, according to the differences in the tidal zone, different areas (such as high tide zone, middle tide zone, and low tide zone) are accurately applied with different ratios of improved substrate that have been previously prepared. These different ratios of substrate are scientifically prepared based on environmental factors such as flooding time and salt content in each tidal zone, which can better meet the needs of plants such as mangroves for soil fertility, air permeability, and salt content in the corresponding areas.

[0043] By precise shaping of the terrain in the estuary area and optimization of hydrodynamic conditions, suitable elevations in different tidal zones are ensured, soil compaction and stability are improved, and by constructing micro-topography, biological diversity is increased. According to the tidal zone, the appropriate substrate is precisely applied to improve plant adaptability and growth performance, and to promote the improvement of the entire estuarine ecosystem function and stability. The problems of inaccurate terrain shaping in the estuary area, insufficient compaction of backfill soil, and lack of targeted optimization of soil conditions in the tidal zone are solved.

[0044] S5, adopt six-axis robot to perform positioning, punching, fertilization, planting, and covering five processes, plant salt-tolerant seedlings treated by ultrasonic-microwave cooperation and nano-biological initiation, and support oyster reef and degradable fiber net to build ecological protection system.

[0045] In S5, seedling pretreatment is treated by 25kHz ultrasonic wave 400W for 12min and 2.45GHz microwave 600W for 3min, combined with 50nm SiO2 nanoparticles and 100mg / L GA3 solution initiation, and the root system is dipped in 100mg / L ABT rooting powder and 10 8 CFU / g salt-tolerant bacteria, mechanical arm planting accuracy ±8mm, operation efficiency 250 plants / hour.

[0046] Specifically, ultrasonic-microwave cooperative treatment: for seedlings, first use ultrasonic wave with frequency of 25kHz and power of 400W for treatment, time length of 12min. When ultrasonic wave propagates in medium (solution environment where seedlings are located), cavitation effect is generated, and when the micro-bubbles formed by cavitation effect burst instantaneously, local high temperature, high pressure and strong shock wave are generated. This physical action can destroy the structure of seed coat, increase the permeability, and is beneficial to the entry of subsequent treatment substances and the start of internal physiological activities of seeds. At the same time, 2.45GHz microwave with power of 600W is used for treatment for 3min. Microwave can make the polar molecules (such as water molecules) inside the seedlings vibrate and rub quickly, and generate heat. This heat effect can further soften the seed coat and activate some enzyme substances inside the seedlings, accelerate the metabolism process. The two work together to break the seed dormancy and improve the potential of seed germination.

[0047] Nanobiological priming: Then, the seedlings were soaked in a solution of 50 nm SiO2 nanoparticles (0.1% concentration) and 100 mg / L GA3 (gibberellin) for 24 h. Nanoparticles have small size effect and surface effect, which can be adsorbed on the surface of seedlings, change the physical and chemical properties of the seed coat surface, promote the absorption of water and nutrients. While GA3, as a plant growth regulator, can regulate the hormone balance inside the seedling, stimulate cell elongation and division, promote the growth of radicle, the combination of the two can further improve the germination rate of seedlings and the vigor of seedlings, and enhance the salt tolerance of seedlings.

[0048] Mechanical arm operation: A six-axis mechanical arm is used for planting operation, which relies on high-precision harmonic reducer (transmission accuracy up to ±8 arc seconds) to realize flexible rotation of each joint, with a working radius of 6 m, which can accurately position to the preset planting point, and the positioning accuracy can be controlled within ±8 mm. When performing planting, first, the soil compaction detection module (accuracy ±2 kPa) equipped at the end of the mechanical arm is used to detect the soil compaction of the planting point, and the punching force and depth are intelligently adjusted according to the detection results to ensure the punching of suitable planting holes. Then, according to the set fertilizer amount, layered fertilization is carried out, and the fertilizer is evenly applied at different depths of the planting hole, then the pretreated seedlings are placed in the hole for planting, and finally the soil covering operation is carried out. The whole process is automated and programmed, and 250 seedlings can be planted per hour.

[0049] Ecological protection system construction: An ecological protection system is constructed in the planting area. On the one hand, oyster shells of appropriate specifications are used to build oyster reefs. Through the structural characteristics of oyster reefs, when water flows through, it can change the flow rate and direction of the water flow, making the water flow turbulent, thereby reducing the water flow energy, playing a role in slowing down the water flow and protecting the soil and seedlings in the planting area. On the other hand, a degradable PLA fiber mesh (tensile strength 200 N / m) wrapped with oyster shell fragments (particle size 2-3 cm) is laid. The mesh size is 3 cm x 3 cm, and the fiber mesh can hold the soil to some extent, reducing soil erosion, while the oyster shell fragments can attract some small organisms to attach, increasing biodiversity. And over time, the PLA fiber mesh can gradually degrade, without long-term pollution to the environment, together creating a relatively stable ecological environment for the growth of mangrove and other plants. During planting, the seedling roots are dipped in a solution containing 100 mg / L ABT rooting powder and 10 8The solution of CFU / g salt-tolerant bacteria agent and ABT rooting powder can stimulate the division and differentiation of root cells, promote the rapid growth and development of roots, and improve the rooting ability of seedlings. The microorganisms in the salt-tolerant bacteria agent can form a symbiotic relationship with the plant roots, helping the plant to enhance the tolerance to salt stress and improve the survival rate of seedlings in the estuary high-salt environment.

[0050] The pre-treatment of seedlings improves the germination rate and radicle growth rate, enhances the adaptability of seedlings in high-salt environment, and guarantees high-precision and high-efficiency planting by mechanical arm planting. The supporting ecological protection system reduces water flow erosion and increases biodiversity, which together promote the good growth of plants and improve the service function and stability of the estuary ecosystem. The problems of low seedling germination rate and insufficient efficiency and precision of artificial planting are solved.

[0051] S6, Constructing a space-air-ground integrated monitoring network, through digital twin platform and AI algorithm to realize Spartina alterniflora recurrence warning and mangrove growth prediction, establishing a five-level emergency response mechanism for maintenance.

[0052] S6 includes: Gaofen-7 satellite, Sentinel-2 satellite, unmanned aerial vehicle cluster equipped with laser radar and 50 ground-based intelligent monitoring stations, data transmission delay < 20ms, AI decision model uses LSTM-Attention neural network, Spartina alterniflora recurrence warning accuracy ≥ 92%.

[0053] S6 also includes: Level III response to Spartina alterniflora recurrence area > 1000m², using unmanned aerial vehicle cluster to spray 15% glyphosate, 250mL / m², Level IV response to mangrove survival rate < 70%, starting intelligent irrigation system to dilute seawater to salt content 15‰, irrigation amount 50L / plant.

[0054] S6 also includes: ecological effect acceptance index, mangrove survival rate ≥ 88%, Spartina alterniflora coverage < 1%, high tide zone soil organic matter ≥ 5.0%, Zn available state < 18mg / kg, oyster reef flow velocity reduction rate ≥ 45%, carbon storage annual increment ≥ 5.8tC / ha.

[0055] Specifically, the space-based part: Utilize the Gaofen-7 satellite (resolution up to 0.5m) and the Sentinel-2 satellite (with multi-spectral observation capability, resolution 10m), which operate according to the established orbit, periodically conduct remote sensing observation on the estuary area. The Gaofen-7 satellite can clearly capture the details of the surface features, such as the distribution range of mangroves and the approximate coverage of Spartina alterniflora, through its high-precision optical imaging system; the Sentinel-2 satellite can obtain the reflection information of different vegetation, soil, etc. at different spectral bands, in order to analyze the physiological state, growth condition, etc. of various ground objects. The data obtained by the two satellites will be transmitted to the ground receiving station through the satellite communication link, and then analyzed and stored by the relevant data processing center, providing basic data support for subsequent analysis.

[0056] The air-based part: Use a cluster of unmanned aerial vehicles equipped with laser radars to carry out monitoring work. The unmanned aerial vehicles are equipped with advanced laser radar equipment (point cloud density 100 points / m²) and flight control systems. When performing tasks, they fly over the estuary area according to the preset route (operation radius 5km). The laser radar can accurately measure the three-dimensional spatial information of the ground target by emitting laser beams and receiving reflected echoes, and can construct high-precision three-dimensional models of terrain, vegetation canopy structure, etc. At the same time, the high-definition camera and other auxiliary equipment carried on the unmanned aerial vehicle can obtain intuitive image data, which is transmitted back to the ground control station in real time through the wireless communication module (based on high-speed communication technology such as 5G, ensuring data transmission delay <20ms), realizing high-frequency and high-precision monitoring of local areas.

[0057] The ground-based part: Reasonably arrange 50 ground-based intelligent monitoring stations in the estuary area. Each monitoring station integrates multiple sensors, including soil multi-parameter sensors (which can accurately measure the salt content, temperature, humidity, pH, conductivity, etc. of the soil, with an accuracy of ±2%), vegetation fluorescence sensors (which can detect chlorophyll a / b fluorescence with a resolution of 0.1nm, and reflect the photosynthesis efficiency, growth vigor, etc. of plants by analyzing the fluorescence characteristics of vegetation), and benthic acoustic monitoring instruments (working frequency range 20-200kHz, detection depth up to 5m, which can determine the species, quantity and distribution of benthic organisms according to the acoustic signals emitted by the organisms). These sensors continuously collect data at a set sampling frequency (such as 1 time / 10 minutes), and transmit the data to the data aggregation center in real time through wired or wireless communication networks, ensuring that the ecological environment information of the estuary area at different levels can be comprehensively and real-time mastered.

[0058] Digital twin platform construction: Based on professional three-dimensional modeling software such as Unity 3D, the data obtained from various monitoring means in space, sky, and earth are integrated, including LiDAR point cloud data (density 50 points / m²), multi-beam sounding data, satellite image data, and field survey data, etc. A digital twin of the estuarine ecosystem with an accuracy of 10 cm is constructed. This digital twin can reflect the actual topography, vegetation distribution, and hydrological conditions of the estuarine area in real time and with high fidelity, and supports real-time rendering (frame rate > 30 fps) to allow relevant personnel to intuitively view and analyze the state changes of the ecosystem.

[0059] AI algorithm: Based on the digital twin platform, an LSTM-Attention neural network (containing 12 layers of encoder structure with 256 neurons and using multi-head attention mechanism) is used to process and analyze a large amount of monitoring data. For Spartina alterniflora recurrence warning, up to 24 characteristic data such as radar echo, vegetation index (e.g. NDVI), and soil salinity are used as input. Through neural network feature extraction and analysis of these data in time series, the growth and recurrence patterns of Spartina alterniflora are learned, and the warning results are output. The warning accuracy can reach ≥92%, which is more accurate and timely than traditional prediction methods (such as simple statistical model-based methods). For mangrove growth prediction, a GNN graph neural network (with node number up to 100,000+) is constructed to simulate the interaction process between root system-soil-vegetation, and to consider the influence of soil nutrients, water, salt content, and surrounding environmental factors on mangrove growth. The prediction error of mangrove biomass growth and other growth indicators is <8%, providing a strong basis for reasonable ecological management and decision-making.

[0060] An emergency response system containing five levels is established, and corresponding response measures are triggered according to the degree of ecological anomalies reflected by the monitoring data. Each level of response clearly specifies the triggering conditions, executing subjects, and specific response measures, forming a complete response process from minor anomalies to disaster-level anomalies, ensuring that actions can be taken quickly and accurately when different levels of ecological problems occur.

[0061] Level III response: When the monitoring detects that the area of Spartina alterniflora recurrence is >1000m², the Level III response is triggered. At this time, the subject of execution is the emergency operation team of the China Ocean Shipping Bureau, which immediately organizes a cluster of unmanned aerial vehicles to carry out spraying operations. The adopted pesticide is 15% glyphosate (containing 0.15% surfactant to enhance the adhesion and penetration of the pesticide), and the spraying dose is set to 250mL / m². The unmanned aerial vehicle cluster follows the pre-planned route and coverage range to ensure that the pesticide is uniformly sprayed in the recurrence area. Through the inhibition of the growth of Spartina alterniflora by glyphosate, the physiological processes such as photosynthesis are blocked, achieving the purpose of controlling and removing the recurrent Spartina alterniflora, and the operation is required to be completed within 24 hours. The operation process is supervised by the ecological supervision unit throughout the process to ensure that the operation meets the ecological and environmental protection requirements.

[0062] Level IV response: If the monitoring finds that the survival rate of mangroves is <70%, the Level IV response is started. The intelligent irrigation system is started by the relevant responsible department. The system can accurately adjust the salt content of seawater to 15‰ through filtering, dilution and other processing links according to the preset program and real-time monitoring of seawater salinity, and irrigate the mangroves with 50L per plant. This can to some extent alleviate the stress of high salt environment on the growth of mangroves, supplement water and moderate nutrients for mangroves, promote the recovery of root activity, improve the survival rate, and ensure the healthy growth of mangroves.

[0063] Through real-time high-precision monitoring, accurate prediction and effective emergency response of the ecological environment in the estuary area, the quality and efficiency of ecological restoration are improved, and ideal ecological effects such as high survival rate of mangroves, inhibition of Spartina alterniflora, optimization of soil conditions, improvement of hydrodynamic conditions and enhancement of carbon sink are achieved, promoting the healthy and sustainable development of the ecological system. The problems of single monitoring method, insufficient data acquisition and analysis, lack of emergency response mechanism and difficulty in measuring the effect of ecological restoration in the estuary are solved.

[0064] According to a method for improving the quality of the ecological environment in the estuary area, characterized by: dredging engineering and mangrove planting are cooperatively operated, the dredged soil is 100% used for soil improvement after grading treatment, mangrove planting adopts tree species configuration matching the tidal zone, and the whole process of dredging and grass control, soil improvement and mangrove growth is controlled through an intelligent monitoring system, forming a closed-loop ecological restoration system.

[0065] Specifically, the dredging and soil improvement collaborative principle: In the dredging process, first use professional dredging equipment (such as workboats equipped with special cutter heads) to excavate and collect sediments in the estuary area. The excavation depth is determined by the pre-detection of the distribution of Spartina alterniflora root system and the thickness of the sediment, which can be accurately controlled within the required range. The collected dredged soil is transported to the onshore treatment site and processed through a series of classification processes. For example, use hydraulic classification equipment to separate the dredged soil into coarse sand, medium powder, and fine clay based on the difference in settling velocity of particles of different sizes in water flow (based on Stokes' law), using cyclone separators, etc. Coarse sand can be used for projects such as breakwater filling, medium powder is used as the core material for subsequent soil improvement, and fine clay is used to make ecological slope protection bricks, etc. to achieve the resource classification of dredged soil. Then, the medium powder is treated for heavy metal stabilization, adding a specific proportion (such as 5-8%) of modified biochar (which relies on its rich pore structure and functional groups to adsorb heavy metal ions), and injecting an appropriate concentration (0.5 mol / L) of sodium sulfide solution to make heavy metal ions react with it to form insoluble precipitates, reducing the available content of heavy metals, and then adding salt-tolerant microbial flora (55% of Bacillus, etc., with an inoculation amount of 10 9 CFU / g soil) for biological activation. Microorganisms decompose organic matter, improve soil structure, and enhance soil fertility through metabolic activity. Finally, through an intelligent proportioning system, other ingredients (such as decomposed seaweed and slow-release fertilizer) are precisely matched according to the soil requirements of different tidal zones to ensure that the dredged soil can be used for soil improvement after this whole set of classification process, making it meet the soil condition requirements for mangrove planting in each tidal zone.

[0066] Mangrove planting and tidal zone matching principle: Based on long-term observation of the tidal law in the estuary area and detailed analysis of environmental factors such as the duration of flooding in different areas, soil salinity, and water flow velocity, different tidal zones are divided into high-tide zone, medium-tide zone, and low-tide zone. Different mangrove species are selected according to the characteristics of different tidal zones. For example, in the high-tide zone, Kandelia obovata is chosen as the main planting species because it has relatively strong flood tolerance, and its root structure can adapt to short-term tidal flooding and high soil salinity. In the medium-tide zone, Avicennia marina is planted, which has well-developed respiratory roots that can effectively exchange gases in an environment with periodic tidal fluctuations and large changes in soil permeability, ensuring its growth. In the low-tide zone, Aegiceras corniculatum is planted, which has good tolerance to relatively long-term flooding and low soil oxygen content. At the same time, an intelligent monitoring system is used to obtain real-time data such as soil moisture, salinity, and nutrient content in each tidal zone, which is fed back to the planting management system to dynamically adjust measures such as fertilization and irrigation, ensuring the healthy growth of mangroves in each tidal zone.

[0067] The whole-process control and closed-loop ecological restoration system construction principle: build an intelligent monitoring system, integrate multiple monitoring methods, including satellite remote sensing (such as Gaofen-7 satellite, Sentinel-2 satellite, etc., using its different resolution image data to monitor large-area vegetation coverage, topographic changes, etc.), unmanned aerial vehicles carrying sensors (such as laser radar, multispectral camera, etc., which can obtain local high-precision vegetation canopy structure, soil texture, etc. information) and ground-based intelligent monitoring stations (equipped with soil multi-parameter sensors, vegetation fluorescence sensors, etc., to collect real-time soil and plant micro-physiological state data). These monitoring data are transmitted in real time to the data processing center through high-speed communication network (data transmission delay <20ms), based on big data analysis technology and AI algorithm (such as LSTM-Attention neural network, etc.) for data mining and analysis. In the dredging and grass control stage, according to the monitored Spartina alterniflora root density, distribution range, etc. data, the operation parameters of the dredging equipment (such as crushing frequency, speed, etc.) are adjusted to realize accurate dredging and root inactivation; in the soil improvement stage, according to the real-time physicochemical properties of the soil (salt content, organic matter, heavy metal content, etc.), the proportion of additives and processing time in the improvement process are adjusted; in the mangrove growth stage, by analyzing the vegetation growth indicators (such as biomass, chlorophyll content, etc.) and surrounding environmental parameters, early warning of possible growth problems, diseases and pests, etc. is triggered, and corresponding maintenance measures (such as irrigation, fertilization, disease and pest control, etc.) are taken. In this way, from the beginning of dredging and grass control, to soil improvement, and then to mangrove growth, the whole-process dynamic control is formed, each link is interrelated and feedback, forming a complete closed-loop ecological restoration system, ensuring the continuous improvement of the ecological environment quality of the whole estuary area.

[0068] By maximizing the use of dredged soil and high-quality transformation, providing good site conditions for mangrove, by adapting tree species planting in the tidal zone to improve the survival rate and ecological function of mangrove, and by using the whole-process control closed-loop system to fine manage ecological restoration links, the restoration efficiency and quality are improved, and the self-restoration regulation ability and ecological service value of the estuary ecosystem are enhanced. The problems of waste of dredged soil resources and improper disposal, and unsuitable soil for mangrove growth in the estuary are solved.

[0069] Firstly, in S1, a multi-beam sounding system combined with ground penetrating radar is used to obtain estuary sediment and Spartina alterniflora root system data according to the principles of sound wave and electromagnetic wave reflection in a specific grid, while samples are collected for component detection and stations are set up for hydrological and meteorological monitoring. In S2, the main work ship is equipped with a high-frequency vibration crushing device, which intelligently adjusts the crushing frequency and speed according to the root density, cooperates with the unmanned ship cluster operation, and sprays microbial inactivator to achieve dredging. In S3, with the help of primary screening, hydraulic classification, heavy metal stabilization, biological activation, and intelligent proportioning process, the dredged soil is classified and treated according to different principles, and is improved and transformed into high-quality planting substrate. In S4, the hierarchical backfilling and compaction technology is used to accurately control the elevation, combined with the ecological ditch and oyster shell layer to construct micro-topography, and the substrate is adapted according to the tidal zone. In S5, the six-axis mechanical arm is used to automate the seedling treatment and planting process, and the ecological protection system is used to assist the growth of seedlings. In S6, an integrated space-ground-air monitoring network is constructed, and data analysis is performed through digital twin platform and AI algorithm to realize recurrence warning and growth prediction, and the five-level emergency response mechanism is used to maintain the ecology, and all links are coordinated to ensure the estuary ecological restoration.

[0070] Through comprehensive and accurate data acquisition of estuary areas, efficient removal of Spartina alterniflora, and reasonable utilization of dredged soil, the soil and topographic conditions suitable for mangrove growth are accurately created, ensuring high-quality planting and good growth of seedlings, while real-time monitoring, early warning of ecological problems, and timely response and maintenance are realized, improving the stability, biodiversity, and ecological service value of the estuary ecosystem, and promoting the optimization of the overall ecological environment quality of the estuary. The problem of poor overall repair effect of the estuary ecosystem is solved.

[0071] Although embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for improving the ecological environment quality of estuary areas, characterized in that, Includes the following steps: S1. A combination of multibeam echo sounder and ground-penetrating radar was used to obtain three-dimensional data on the thickness of estuary sediments and the root density of Spartina alterniflora. Sediment samples were collected to detect the salt content, organic matter and heavy metal content. Hydrological and meteorological monitoring stations were set up to obtain real-time data on tides and current velocities. S2. The main working vessel equipped with a high-frequency vibration crushing device and an unmanned vessel cluster work together to crush at different frequencies and speeds according to the root density, while simultaneously spraying microbial inactivation agents. The crushing depth reaches 1.5-1.8m, and the crushing rate is ≥98.5%. S3. Through primary screening, hydraulic classification, heavy metal stabilization, biological activation and intelligent proportioning processes, the dredged soil is transformed into a planting substrate with a salt content of <15% and an organic matter content of ≥4.0%, in which the available form of heavy metals is reduced by more than 60%. S4. Layered backfilling and compaction technology is used to control the elevation. The high tide level is controlled 1.0-1.5m above the theoretical lowest tide level. Micro-landforms are constructed by combining ecological ditches and oyster shell layers. Different proportions of improved substrate are applied according to the differences in tidal zones. S5. A six-axis robotic arm is used to perform five processes: positioning, drilling, fertilizing, planting, and covering with soil. Salt-tolerant seedlings that have undergone ultrasonic-microwave synergistic treatment and nano-biological induction are planted. An ecological protection system is constructed by matching oyster reefs and biodegradable fiber nets. S6. Construct an integrated air-space-ground monitoring network, and use a digital twin platform and AI algorithms to achieve early warning of Spartina alterniflora recurrence and prediction of mangrove growth, and establish a five-level emergency response mechanism for implementation and maintenance.

2. The method for improving the ecological environment quality of estuary areas according to claim 1, characterized in that, S1 includes: sediment sampling depth of 0-150cm, stratified detection of soil physicochemical properties of 0-30cm, 30-60cm, 60-100cm, and 100-150cm layers, sampling frequency of hydrological monitoring station of 1 time / 10 minutes, and simultaneous collection of historical meteorological data of the past 10 years.

3. The method for improving the ecological environment quality of estuary areas according to claim 1, characterized in that, The S2 includes: the main working vessel is equipped with a 200kW high-frequency vibration crushing device with an adjustable vibration frequency of 40-90Hz and an amplitude of 3-10mm. It is equipped with a microwave radar root detector and a dual-frequency DGPS positioning system, with a working trajectory accuracy of ±15cm. The unmanned vessel cluster is driven by hydrogen fuel cells, with a coverage efficiency of 15,000 m² / day.

4. The method for improving the ecological environment quality of estuary areas according to claim 1, characterized in that, S3 includes: hydraulic classification using a three-stage hydrocyclone separator in series; the separated coarse sand particles are used for breakwater filling; medium-sized particles are used as the main amendment material; and fine clay particles are used to make ecological slope protection bricks. During heavy metal stabilization, 5-8% modified biochar and 0.5 mol / L sodium sulfide solution are added. A salt-tolerant microbial community is introduced for biological activation, with Bacillus accounting for 55% and an inoculum size of 10. 9 CFU / g soil.

5. A method for improving the ecological environment quality of estuary areas according to claim 1, characterized in that, The S4 includes: a 15cm thick layer of backfill, compacted 4 times with a 20t intelligent vibratory roller, with a compaction degree ≥92% and an elevation error ≤±3cm; an ecological ditch with a depth of 0.5m, a width of 2m, a slope ratio of 1:8, and a 20cm oyster shell layer laid in the ditch.

6. A method for improving the ecological environment quality of estuary areas according to claim 1, characterized in that, S5 includes: seedling pretreatment using 25kHz ultrasound at 400W for 12 minutes and 2.45GHz microwave at 600W for 3 minutes in synergistic treatment, combined with 50nm SiO2 nanoparticles and 100mg / L GA3 solution for initiation; and root dipping at transplanting in 100mg / L LABT rooting powder and 10... 8 CFU / g salt-tolerant bacterial agent, robotic arm planting accuracy ±8mm, operating efficiency 250 plants / hour.

7. A method for improving the ecological environment quality of estuary areas according to claim 1, characterized in that, The S6 includes: Gaofen-7 satellite, Sentinel-2 satellite, a cluster of drones equipped with lidar and 50 ground-based intelligent monitoring stations. The data transmission latency is <20ms. The AI ​​decision model adopts LSTM-Attention neural network, and the accuracy rate of early warning of Spartina alterniflora recurrence is ≥92%.

8. A method for improving the ecological environment quality of estuary areas according to claim 1, characterized in that, The S6 also includes: Level III response for Spartina alterniflora recurrence area >1000m², using drone swarm spraying of 15% glyphosate at 250mL / m²; Level IV response for mangrove survival rate <70%, starting intelligent irrigation system to dilute seawater to salinity 15‰, with irrigation volume of 50L / plant.

9. A method for improving the ecological environment quality of estuary areas according to claim 1, characterized in that, The S6 also includes: ecological effect acceptance indicators, mangrove survival rate ≥88%, Spartina alterniflora coverage <1%, soil organic matter in high tide zone ≥5.0%, Zn available form <18mg / kg, oyster reef flow velocity reduction rate ≥45%, and annual carbon storage increase ≥5.8tC / ha.

10. A method for improving the ecological environment quality of estuary areas according to any one of claims 1-9, characterized in that: The dredging project is carried out in conjunction with mangrove planting. The dredged soil is graded and 100% used for soil improvement. The mangrove planting adopts tree species that match the tidal zone. The entire process from dredging and weed control to soil improvement and mangrove growth is managed through an intelligent monitoring system, forming a closed-loop ecological restoration system.

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