Modular habitat unit of underwater forest in shallow lake and method for improving water function thereof

Abstract

The present application relates to the technical field of water environment treatment and lake ecological restoration, solves the technical problems that the prior art cannot stably construct underwater forest shadow area, flexibly configure purification and habitat functions, realize engineering quantitative design and long-term optimization, and particularly relates to a shallow lake underwater forest modular habitat unit and a water function improvement method thereof, the habitat unit is composed of a hollow hexagonal bottom support and anchoring base, a three-dimensional support framework, a plant habitat layer and an ecological function core block, the windward side of the bottom support and anchoring base is provided with an inclined water-permeable wave blocking wing plate, the leeward side is provided with an open grid structure with high open area ratio, the inside can be plugged into phosphorus removal, denitrification and habitat enhancement core blocks, the upper multi-layer planting basket plants submerged plants, forming a three-dimensional and directional water power regulation water plant belt. The present application can stably construct the shallow lake underwater forest under the condition of wind and wave, significantly improve the water function, realize the engineering construction of the shallow lake underwater forest and the quantitative improvement of the water function.

Description

Technical Field

[0001] This invention relates to the field of water environment management and lake ecological restoration technology, and in particular to a modular underwater forest habitat unit for shallow lakes and similar slow-flowing water bodies, and a method for enhancing its water function. Background Technology

[0002] Shallow lakes are widely distributed in the plains of eastern and central my country, serving as important carriers for regional water supply, flood control, biodiversity maintenance, and landscape recreation. However, due to long-term impacts from watershed non-point source pollution, urban domestic pollution, and some industrial point source emissions, many shallow lakes are in a state of eutrophication or even severe eutrophication, characterized by high total nitrogen and total phosphorus concentrations, decreased water transparency, frequent algal blooms, and significantly constrained water function zone compliance rates. Relevant water environment governance practices and technical guidelines all indicate that restoring a "grass-type clear water state" dominated by submerged plants and constructing stable aquatic vegetation communities is one of the key pathways to improve the aquatic ecological functions of lakes and maintain water function compliance.

[0003] In freshwater ecosystems, submerged plants are crucial maintainers of water stability. They improve water quality and provide habitats and foraging grounds for fish and benthic animals by suppressing algae growth through shading, absorbing nitrogen and phosphorus from the water and sediment, promoting the settling of suspended particles, and releasing dissolved oxygen. In recent years, the "underwater forest" restoration model, characterized by multi-layered submerged plant communities, has achieved good results in some lake pilot projects. For example, East Lake in Wuhan significantly improved water transparency and aquatic landscape quality by layering various submerged plant species. However, in most eutrophic shallow lakes, aquatic vegetation restoration still faces comprehensive constraints such as high water turbidity, poor sediment physicochemical properties, strong wind and wave disturbances, water level fluctuations, and diverse water function improvement goals. Relying solely on scattered planting or single-form planting devices is insufficient to construct a stable "underwater forest" structure that combines water purification and habitat functions.

[0004] In the prior art, various devices and methods have been proposed for the restoration of underwater vegetation in lakes. For example, utility model publication CN2617130Y discloses an underwater vegetation planting device for lakes. This device uses a combination of a cup-shaped container, a fixing net, and positioning rods to fix aquatic plants and substrate at predetermined positions on the bottom. Its simple structure facilitates mass production and improves the survival rate of individual plants or small-scale submerged vegetation. However, this device mainly targets point-like or small-scale aquatic plant planting, lacking a three-dimensional support structure for forming multi-layered communities along water depth gradients. It also fails to consider integration with nitrogen and phosphorus reduction in eutrophic waters and improvement of bottom habitats. Furthermore, it does not address the design of planting density based on hydrodynamic conditions such as wind, waves, and water depth, nor does it provide quantitative evaluation and feedback control of the water function enhancement effect. Therefore, it has significant limitations in constructing large-scale "underwater forests" and systematically improving water function.

[0005] Another typical technology, such as the utility model with publication number CN211141660U, discloses a device for purifying river and lake water using submerged plants. This device involves uniformly binding submerged plants to aquatic plant attachment ropes, using fixed stakes and floats to suspend the ropes in the water. The suspension depth of the ropes can be adjusted according to transparency and water level, thus enabling ecological water purification in water bodies unsuitable for direct restoration of submerged plants. This technology has certain advantages in improving the survival rate of submerged plants and adapting to different water depths. However, its structural morphology is mainly a linear or ribbon-like "aquatic plant curtain" in the water body, with less consideration given to bottom support structures, three-dimensional habitat space, and coupling with the bottom sediment environment, making it difficult to form a stable three-dimensional "habitat unit." Furthermore, this device lacks integrated ecological functional fillers with significant nitrogen and phosphorus adsorption capacity, and also lacks a quantitative design method for deployment intensity corresponding to lake water function targets (such as transparency, chlorophyll a, total nitrogen, total phosphorus, dissolved oxygen, etc.) and an operational effect evaluation and adjustment mechanism.

[0006] Regarding the construction of "underwater forests," Chinese invention publication CN113371839A proposes a method for constructing underwater forests for aquatic ecological restoration. This method involves laying transplanting pots on a bamboo frame, filling the pots with volcanic rock particles soaked in polyphosphate-accumulating bacteria solution, planting submerged plants, and then gradually lowering the bamboo frame to achieve colonization of the submerged plants on hard sediment and purification of high-phosphorus water. This method can significantly reduce the phosphorus content in water and sediment, and improve the survival rate of transplanted submerged plants. However, this technical solution mainly revolves around a specific bamboo frame and biological carrier system. The overall structure is a large-scale integrated device, and the assembly and operation control are relatively complex, which is not conducive to its large-scale and zoned promotion in shallow lakes. Its focus is on the combined purification of polyphosphate-accumulating bacteria-volcanic rock carrier and submerged plants. It does not adequately consider the modular layout of the near-shore shallow water area of ​​the lake, the integrated design with the habitat space of fish and benthic animals, nor does it involve converting the hydrodynamic exposure characteristics such as water depth, wind and waves, and distance from the shore into deployment intensity indicators. Furthermore, it lacks a comprehensive quantitative assessment model for "water function zone compliance".

[0007] Another example is the Chinese invention patent CN110857236A, which discloses a method for constructing underwater forests in rivers and lakes. This method achieves comprehensive restoration of black and odorous water bodies by stripping and improving heavily polluted sediment, adding sand and microbial agents, and combining regional planting of different functional aquatic plants with aeration and bacterial addition. It also proposes an overall construction concept for "underwater forests." This method focuses on source control of sediment and the synergistic construction of underwater ecosystems by various plants and microorganisms, which has a positive effect on improving the self-purification capacity of water bodies. However, its technical approach is mainly a process-oriented "sediment treatment + zoned planting," lacking a clear modular habitat unit structure design. It does not possess modular engineering components for rapid and standardized deployment on shallow lake shorelines, nor does it propose an operable quantitative relationship between hydrodynamic zoning, deployment density, and water function enhancement, making it difficult to support refined regulation and optimization in long-term operation.

[0008] In summary, existing devices and methods for restoring "underwater forests" and submerged plants in rivers and lakes are, on the one hand, structurally limited to cup-shaped planters, attachment ropes, floating beds, or large frames. They lack directional modular habitat units that combine stable bottom support, a three-dimensional support framework, layered plant habitat zones, and ecological functional fillers. They cannot form stable, low-disturbance "underwater forest shadow zones" in the wave-facing / wave-avoiding direction, nor do they provide standardized "ecological functional core blocks" that can be flexibly replaced and combined according to water quality targets. On the other hand, methodologically, they focus on qualitative experience-based deployment or process combinations, failing to establish clear quantitative correlations between hydrodynamic exposure factors such as water depth, wind speed, wind distance, and distance from the shore, and habitat unit deployment intensity, wave-facing / wave-avoiding configuration, and internal functional core block combinations. Furthermore, they lack functional core block configuration models based on nitrogen and phosphorus load balance and evaluation and iterative optimization mechanisms centered on improving water functions (such as transparency, chlorophyll a, nutrients, and dissolved oxygen). Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a modular habitat unit for underwater forests in shallow lakes and a method for enhancing its water functions. This solves the technical problems of existing technologies, such as the inability to stably construct underwater forest shade areas, flexibly configure purification and habitat functions, and achieve quantitative engineering design and long-term optimization.

[0010] Addressing the practical needs of underwater forest construction and water function enhancement in eutrophic shallow lakes, the specific technical problems to be solved by existing technologies are as follows:

[0011] First, existing devices are mostly cup-shaped planters, attachment ropes, floating beds or large frame structures, which generally lack directional modular habitat units that combine stable bottom support, three-dimensional vegetation habitat layer and ecological function filler. They cannot form a stable, low-disturbance "underwater forest shadow zone" in the direction of the waves, and it is difficult to simultaneously meet the needs of submerged plant colonization, wave dissipation and bottom stabilization, and fish and benthic animal habitat.

[0012] Secondly, existing underwater forest restoration methods mostly use fixed structures or single filler configurations, and lack pluggable ecological functional core block systems based on standard slots. It is difficult to flexibly combine functional modules such as "phosphorus removal, nitrogen removal, and habitat enhancement" within the same habitat unit according to different nitrogen and phosphorus load levels and habitat objectives in different areas, so as to achieve refined configuration and subsequent adjustment of water purification and habitat functions.

[0013] Third, existing methods rely heavily on experience-based layout and process combinations, and have not yet integrated hydrodynamic exposure factors such as water depth, wind speed, wind distance, and distance from the shore with nitrogen and phosphorus load reduction requirements and water function evaluation indicators into the same quantitative framework. They lack a systematic approach that organically couples hydrodynamic zoning, functional core block combination configuration, comprehensive water function index evaluation, and iterative optimization during operation, making it difficult to achieve quantifiable design and long-term dynamic optimization of underwater forest engineering.

[0014] To address the aforementioned technical problems, this invention proposes a modular habitat unit for underwater forests in shallow lakes and a method for enhancing its water function. The method comprises two main aspects: first, a modular habitat unit structure with wave-facing and wave-avoiding characteristics; and second, a deployment and operational control method based on hydrodynamic exposure, nitrogen and phosphorus load, and water function evaluation. These two aspects work synergistically to achieve the engineered construction of "underwater forests" in shallow lakes and the quantitative enhancement of their water function.

[0015] In a first aspect, the present invention provides a modular habitat unit for an "underwater forest" in shallow lakes. The habitat unit includes a bottom support and anchoring base, a three-dimensional support frame, a plant habitat layer, ecological functional core blocks, and modular connection and orientation components.

[0016] Furthermore, the bottom support and anchoring base is a hollow frame structure, divided into two regions in plan: a wave-facing side and a wave-repellent side. The wave-facing side wall is equipped with a set of permeable wave-breaking wing plates, arranged at an angle of 20°–60° upwards relative to the horizontal plane and layered along the water depth direction. This causes the incident wave to be deflected and dissipated at the permeable wave-breaking wing plates, allowing some water to be guided into the bottom support and anchoring base and flow upwards through the ecological functional core block and plant root zone, thus serving both wave dissipation and enhanced material exchange. The wave-repellent side wall adopts an open grid structure with a high porosity, forming an underwater forest shadow zone with significantly reduced disturbance, while maintaining gentle but continuous water exchange. The bottom of the bottom support and anchoring base is equipped with anti-slip protrusions and / or anchoring holes, achieving overall stability through anchor piles, counterweights, or connection to the bank slope structure.

[0017] Furthermore, the bottom support and anchoring base has one or more rows of standardized functional core slots along the wave-facing side to the wave-repelling side. The functional core slots have uniform dimensions and interfaces, used for inserting different types of ecological functional core blocks. The ecological functional core blocks inside the bottom support and anchoring base are replaceable structures. Different types of ecological functional core blocks are distinguished by shape, color, or coding, and all types of ecological functional core blocks have standardized dimensions. They can be arbitrarily combined and arranged in the same habitat unit according to nitrogen load, phosphorus load, and habitat requirements, thereby achieving refined configuration and subsequent adjustment of water purification and habitat functions on the same structural platform.

[0018] Furthermore, ecological functional chips include at least three types: phosphorus removal chips, nitrogen removal chips, and habitat enhancement chips. Phosphorus removal chips are primarily filled with porous aggregates or modified minerals supported by iron-aluminum oxides, exhibiting high phosphorus adsorption capacity. Nitrogen removal chips are primarily filled with high specific surface area biological carriers and carbon source / denitrification fillers, creating a localized hypoxic microenvironment to promote nitrogen conversion and removal. Habitat enhancement chips utilize a high-porosity skeleton and internal cavity structure, providing hiding and breeding space for fish and large invertebrates. Different types of ecological functional chips are distinguished by their appearance color or markings, and their unit volume or unit mass reduction capacity for total nitrogen (TN) and total phosphorus (TP) is determined through experiments. and This constitutes a performance parameter library for ecological functional cores.

[0019] Furthermore, the three-dimensional support frame adopts a telescopic or segmented combination structure. Vertical support components are connected by sleeves or pins to form multiple height levels, enabling the core plant habitat layer on the leeward side to be controlled within a depth range of 0.5 to 1.5 times the transparency, depending on the water depth and operating water level of different lake areas, thus balancing light conditions and wave dissipation. The three-dimensional support frame is fixed above the bottom support and anchoring base, forming a three-dimensional frame structure that penetrates the water depth. The three-dimensional support frame consists of several vertical support components and circumferential support rings or transverse support beams between them. The vertical support components adopt a segmented plug-in or sleeve connection structure, allowing adjustment of the overall height according to different water depth conditions, ensuring the plant habitat layer is always within a suitable light zone. Flexible wave-dissipating nets or rigid perforated baffles are connected to the three-dimensional support frame on the wave-facing side, while the three-dimensional support frame on the leeward side has no wave-dissipating components or only low-obstruction components, creating a hydrodynamic gradient with decreasing disturbance in the vertical and wave-facing / leeward directions within the habitat unit.

[0020] Furthermore, the plant habitat layer is arranged at different elevations within the three-dimensional support framework, comprising two or more layers of planting trays or habitat baskets arranged in stages along the water depth direction. The planting trays adopt a mesh or perforated board structure, with limiting edges and ribs at the bottom to support the planting substrate and prevent loss. On the wave-facing side, the planting trays or habitat baskets of each layer are preferentially planted with submerged plants that have well-developed root systems, high stem rigidity, and tolerance to certain mechanical disturbances, or aquatic plants that also have slope protection functions, to enhance wave dissipation and bottom stabilization. On the leeward side, the middle and upper layers of planting trays or habitat baskets are preferentially planted with submerged plants that have large canopies, are sensitive to turbidity, and have good landscape effects, so that a structural gradient of "protective zone - transition zone - core underwater forest" is formed within a single habitat unit along the wave-facing to leeward direction.

[0021] Furthermore, the modular connection and orientation components are arranged on the outer edge of the bottom support and anchoring base and the outer edge of the three-dimensional support frame, including standardized connecting seats and locking structures, as well as azimuth marking structures for indicating the direction of the wave-facing side, so that the wave-facing side of the habitat unit is aligned with the direction of the dominant wind and waves of the lake during the deployment process. Multiple habitat units can be spliced ​​into a grid-like or honeycomb-like layout on a plane through standardized connecting seats. During on-site installation, the azimuth marking structures are used to uniformly point the wave-facing side of each habitat unit to the direction of the dominant wind and waves or segmentally point it to the direction of the local effective wind and waves, forming a continuous wave-dissipating zone and a wave-shadow area at the community scale.

[0022] A second aspect of the present invention provides a method for enhancing the water function of shallow lakes using the aforementioned modular habitat units. This method organically combines hydrodynamic exposure zoning, nitrogen and phosphorus load constraints, the combination and ratio of ecological function core blocks, and comprehensive water function evaluation with structural integrity feedback, forming a closed-loop control process of "design-deployment-monitoring-adjustment".

[0023] The method includes the following main steps:

[0024] First, a baseline survey is conducted in the target lake area to obtain the water depth of the shallow lake area. Prevailing wind speed Effective blowing range Distance from the shore The water quality and ecological function targets to be achieved should be clearly defined, including the type of sediment, total nitrogen (TN), total phosphorus (TP), chlorophyll a, transparency, and dissolved oxygen.

[0025] Secondly, construct the hydrodynamic exposure index. The intensity of wind and wave disturbance at various spatial locations is quantified. Hydrodynamic exposure index. It can be calculated using the following formula:

[0026]

[0027] in, The prevailing wind direction represents the wind speed; To correspond to the effective blowing range; Due to the local water depth; Distance from the shore; , , , These are the baseline values ​​for each parameter. , , , For the weighting coefficients, satisfying .

[0028] Hydrodynamic exposure index is calculated on a regular grid or functional zoning scale. By setting reasonable thresholds, the area to be restored can be divided into high-exposure areas, medium-exposure areas, and low-exposure areas, providing a basis for the deployment density of habitat units and the intensity of wave-facing and wave-back configuration in different areas.

[0029] Based on this, the water volume, external inflow flux, and internal release flux of each exposed area were estimated to obtain the total nitrogen and total phosphorus mass that needs to be reduced in each exposed area within the design operating cycle T. , .

[0030] Furthermore, the exposed area is divided into several planning units, and the target reduction amount for each planning unit is determined. , That is, the nitrogen and phosphorus loads that need to be reduced in each exposed area during the design operating cycle are respectively denoted as , The unit reduction capacity of each type of ecological function chip is converted into a standardized indicator of unit reduction capacity. , .

[0031] Then, combining the unit reduction capability of various types of ecological function chips in the performance parameter library... , and cost coefficient Establish a combinatorial optimization model to select the number of different types of ecological function chips by satisfying the following constraint. .Right now:

[0032]

[0033] in, This represents the total number of phosphorus removal, nitrogen removal, and habitat enhancement blocks required in the planning unit.

[0034] Under the premise of satisfying the above constraints, the objective function can be selected as minimizing the total number of chips or minimizing the total cost, for example:

[0035]

[0036] The solution yields the combination of the number of phosphorus removal, denitrification, and habitat enhancement chips in each planning unit. Combining the number of slots and space capacity of a single habitat unit, the above results are converted into the required number of habitat units for each area and the combination ratio of ecological function chips within each habitat unit.

[0037] Subsequently, based on the hydrodynamic exposure level and the results of the ecological function chip combination, the habitat unit layout scheme was determined, and the optimal combination scheme with the minimum total number of habitat units or the minimum total installation workload was selected to guide the actual layout. Specifically: in high-exposure areas, the layout density is higher, the spacing between rows and columns of habitat units is smaller, and plants with well-developed root systems and strong resistance to disturbance are used on the wave-facing side, along with a higher proportion of phosphorus and nitrogen removal chips; in medium-exposure areas, the layout density is moderate, balancing protection and underwater forest landscape; in low-exposure areas, the layout density is lower, increasing the proportion of habitat enhancement chips, focusing on improving transparency and habitat enrichment. During on-site deployment, the wave-facing direction is unified through modular connections and directional components, enabling the community composed of multiple habitat units to play a role in wave dissipation, bottom stabilization, and improving hydrodynamics.

[0038] Furthermore, during the operation of the habitat units, water function indicators such as total nitrogen (TN), total phosphorus (TP), chlorophyll a, transparency, and dissolved oxygen, as well as structural indicators such as vegetation cover and habitat unit integrity rate, were regularly monitored in each area, and a comprehensive water function index was introduced. and habitat structure integrity index The project's effectiveness is quantitatively evaluated by introducing a comprehensive water function index. It can be calculated using the following formula:

[0039]

[0040] in, The first measurement during operation Water function indicators; This refers to the baseline value or the target threshold. Let be the weight of each indicator, and .

[0041] Habitat structure integrity index According to the actual plant coverage With target coverage The ratio is determined, that is:

[0042]

[0043] in, This refers to the actual plant cover or habitat unit integrity rate. The preset target coverage.

[0044] Furthermore, when necessary, the integrity rate of habitat unit structure and the integrity rate of ecological function core blocks can also be considered comprehensively. The comprehensive regulation function is defined as follows:

[0045]

[0046] in, .

[0047] This invention is based on the comprehensive water function index and habitat structure integrity index The relationship with preset thresholds determines whether adjustments are needed to the density of habitat units, the configuration of wave-facing and wave-avoiding plants, and the combination of ecological function blocks. Specifically, when water function improvement is insufficient, the number of phosphorus or nitrogen removal blocks in key areas can be increased, habitat units can be densified, or plant species can be adjusted. When water function meets standards but habitat structure degrades, harvesting intensity can be reduced, replanting can be increased, and the proportion of habitat-enhancing blocks can be increased. Through multi-cycle monitoring and adjustments, the underwater forest engineering in shallow lakes can achieve a synergistic and stable improvement in water and ecological functions during long-term operation.

[0048] Through the above-mentioned habitat unit and water function enhancement methods, this invention significantly enhances the directional hydrodynamic regulation capability of habitat units, introduces a pluggable and quantitatively configurable ecological function core block system, and incorporates hydrodynamic exposure, pollution load and water function evaluation into a unified design and feedback framework, realizing the technological transformation of underwater forests in shallow lakes from empirical deployment to model-driven and iteratively optimized technology.

[0049] Meanwhile, in terms of structure, it integrates bottom support and three-dimensional vegetation layer with directional hydrodynamic regulation characteristics, pluggable and combinable ecological functional core blocks and habitat space. In terms of operation method, it introduces hydrodynamic exposure zone, ecological functional core block combination configuration model under load constraint and comprehensive water function evaluation index to quantitatively design and dynamically optimize the layout intensity, internal functional combination and operation and maintenance of habitat units, so as to better support the coordinated improvement of water function and water ecological function of shallow lakes.

[0050] By employing the above technical solution, the present invention provides a modular habitat unit for underwater forests in shallow lakes and a method for enhancing its water function, which has at least the following beneficial effects:

[0051] Directional habitat units form stable underwater forest shade zones. This invention distinguishes between wave-facing and wave-avoiding sides in the unit structure. Through the combination of permeable wave-blocking wing plates and wave-dissipating components on the wave-facing side and an open grid structure with high permeability on the wave-avoiding side, a hydrodynamic gradient of "strong wave-facing disturbance – weak wave-avoiding disturbance" is formed within the habitat unit. Multiple habitat units, when pieced together, form a continuous low-disturbance shade zone at the community scale, significantly improving the habitat stability of submerged plants and benthic animals in shallow water riparian zones.

[0052] The pluggable ecological functional core module enables precise configuration and adjustment of water purification and habitat functions. This invention integrates different functions such as phosphorus removal, nitrogen removal, and habitat enhancement into a standardized, replaceable ecological functional core module. These modules are used in combination through a unified slot interface and configured based on a calibrated unit reduction capacity. The core module ratio can be adjusted according to changes in nitrogen and phosphorus loads and ecological goals, allowing for the tailoring and upgrading of functions on the same structural platform.

[0053] A quantitative design and feedback optimization mechanism integrating hydrodynamic exposure, load, and water function. This invention introduces a hydrodynamic exposure index for water depth. Prevailing wind speed Effective blowing range Distance from the shore Comprehensive characterization is conducted to determine the optimal number of ecological function core blocks for zoning. Simultaneously, the nitrogen and phosphorus load reduction targets for each exposed area are used as constraints. A combined optimization model is established using the unit reduction capacity of ecological function core blocks to determine the optimal combination of ecological function core blocks. The operation period is evaluated and iteratively adjusted through the comprehensive water function index and habitat structure integrity index to achieve a closed loop of "calculation-deployment-monitoring-feedback". Attached Figure Description

[0054] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0055] Figure 1This is a schematic diagram of the habitat unit in Embodiment 1 of the present invention;

[0056] Figure 2 This is a top view of the bottom support and anchoring base in Embodiment 1 of the present invention;

[0057] Figure 3 This is a flowchart of the water function enhancement method in this invention;

[0058] Figure 4 This is a comparison chart of the hydrodynamic exposure indices of different exposed areas in Embodiment 2 of the present invention;

[0059] Figure 5 This is a comparison chart of the total nitrogen (TN) reduction targets and ecological function chip capabilities in each exposed area in Example 2 of the present invention;

[0060] Figure 6 This is a comparison chart of the total phosphorus (TP) reduction targets and ecological function chip capabilities in each exposed area in Example 2 of the present invention;

[0061] Figure 7 This is a graph showing the changes in the comprehensive index of F, H, and G at different operating stages in Embodiment 3 of the present invention.

[0062] In the picture:

[0063] 1. Bottom support and anchoring base; 11. Permeable wave-breaking wing plate; 12. Open grid structure; 13. Functional core slot;

[0064] 2. Three-dimensional support frame; 21. Wave-damping components;

[0065] 3. Plant habitat layer; 31. Planting basket;

[0066] 4. Ecological functional core blocks; 14a. Phosphorus removal core blocks; 14b. Nitrogen removal core blocks; 14c. Habitat enhancement core blocks;

[0067] 5. Module connection and orientation components; 51. Connecting latches; 52. Orientation marking structure. Detailed Implementation

[0068] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. This will allow for a full understanding of how the present application uses technical means to solve technical problems and achieve technical effects, and to facilitate its implementation.

[0069] Example 1: Structure and fabrication of modular habitat units.

[0070] like Figure 1As shown, this embodiment provides the structural parameters and manufacturing process of an underwater forest directional modular habitat unit suitable for shallow lake shore zones with water depths of 1.2 to 1.6 meters, to illustrate the specific structure of the device of the present invention and its feasibility under typical working conditions.

[0071] (a) Design conditions and overall dimensions

[0072] A section of the shoreline on the east bank of a shallow lake was selected as a typical operating condition: under normal water level conditions, the water depth in this section of the shoreline within 5 to 30 meters from the shore is about 1.3 to 1.5 meters; the prevailing wind direction is southeast, with a representative wind speed of about 6 m / s and a corresponding effective wind distance of about 2.0 km; estimated by empirical formula, the representative significant wave height in this water area is about 0.20 meters.

[0073] Based on this, the plan of each habitat unit is designed as a regular hexagon with a side-to-side spacing of 2.0m. With side length Existence Relationship ,but:

[0074]

[0075] Area of ​​a regular hexagon for:

[0076]

[0077] In this embodiment, the height of the bottom support and anchoring base is 0.60m, and the total height of the three-dimensional support frame is 1.20m.

[0078] (ii) Bottom support and anchoring base

[0079] 1. Calculation of the structure and volume of the bottom support and anchoring base.

[0080] The bottom support and anchoring base is a hollow hexagonal frame structure, including a bottom plate and annular side walls: the bottom plate thickness is 0.12m; the side wall height is 0.60m and the wall thickness is 0.12m; the material is ecological concrete (C30), and about 20% (volume fraction) of porous ceramsite with a particle size of 5-20mm is added to the aggregate.

[0081] Based on the aforementioned area The volume of the base plate is:

[0082]

[0083] The perimeter of the regular hexagon is:

[0084]

[0085] The volume of the sidewall is:

[0086]

[0087] The total volume of the concrete supporting the bottom and anchoring base is approximately:

[0088]

[0089] If the density of the ecological concrete is calculated to be 2400 kg / m³, then the self-weight of the bottom support and anchoring base is:

[0090]

[0091] When this volume is completely submerged in water, the buoyancy is:

[0092]

[0093] The net downward pressure of the bottom support and anchoring base in the water is approximately:

[0094]

[0095] This net weight can provide a basis for subsequent calculations of anti-slip and anti-tipping stability.

[0096] 2. Wave-facing and wave-avoiding structures.

[0097] To achieve directional hydrodynamic control, the bottom support and anchoring base plane is divided into wave-facing and wave-avoiding sides according to the prevailing wind direction, each occupying half of the hexagon's perimeter, as follows:

[0098] An inclined wave-damping wing plate is fixed on the outer side of the wave-facing side wall: the wing plate is 0.40m wide, 0.05m thick, and its length is equivalent to that of the corresponding side wall. When installed, it is tilted outward at 30° relative to the horizontal surface, and a gap of about 0.10m is left between the wing plates to take into account both wave dissipation and water exchange.

[0099] The back wave sidewall is equipped with a high-aperture-ratio grating: the grating height is 0.50m, the aperture is about 0.10m×0.10m, the aperture ratio is about 60%, the lower edge of the grating is 0.05m from the bottom plate, and the upper edge is 0.05m from the top surface of the sidewall. The material is a combination of stainless steel or fiberglass frame and polypropylene grating strips.

[0100] Through the above structure, the wave-facing side deflects and dissipates the incident wave, while the wave-repelling side forms an underwater forest shadow zone with significantly reduced disturbance.

[0101] 3. Slots and anchoring structures.

[0102] like Figure 2As shown, the bottom support and anchoring base has two rows of functional core slots arranged from the wave-facing side to the wave-repelling side, totaling 10 slots. Each slot has a cross-section of 0.20m × 0.20m and a length of 0.40m, arranged from the bottom plate upwards, and the slots are separated by 0.10m thick reinforcing plates. An additional 0.20m of space is reserved in the upper part of the bottom support and anchoring base, which is filled with gravel with a particle size of 5–20mm and some planting substrate to improve the near-bottom water-sediment interface environment.

[0103] Four 20mm diameter stainless steel anchoring rings are pre-embedded in the hexagonal base plate. After the habitat unit is in place, it is connected to four concrete anchor blocks weighing about 150kg each by four anchor chains. The total anchor weight is about 600kg, which can further improve the resistance to displacement under extreme wind and waves.

[0104] (III) Ecological Functional Core Module Design

[0105] To balance nitrogen and phosphorus reduction with habitat function, this embodiment uses three types of functional core blocks, all with uniform dimensions of 0.20m × 0.20m × 0.40m and a volume of:

[0106]

[0107] Dephosphorization cartridges:

[0108] The phosphorus removal cartridges use blast furnace slag-based porous aggregate as the matrix, with an iron and aluminum oxide coating on the surface. Each cartridge has a dry weight of approximately 25 kg. Certified by indoor continuous flow column tests at approximately pH 7.5 and a water temperature of 20℃, the material's average annual total phosphorus reduction capacity per unit volume is denoted as:

[0109]

[0110] The average annual phosphorus removal amount corresponding to a single chip is:

[0111]

[0112] Denitrification cartridge:

[0113] The denitrification cartridge uses porous ceramsite as a framework, with sawdust and slow-release carbon source fillers mixed into the pores to create a microenvironment conducive to the growth of denitrifying bacteria. A single cartridge has a dry weight of approximately 18 kg. Indoor fixed-bed tests calibrated its annual average total nitrogen reduction capacity per unit volume as follows:

[0114]

[0115] The average annual nitrogen removal rate per chip is:

[0116]

[0117] Habitat Enhancement Chip:

[0118] The habitat reinforcement core uses a high-strength porous concrete or HDPE skeleton, with an internal design of multi-level cavities and labyrinthine flow channels, resulting in an overall porosity greater than 50%, and a single block volume of 0.016m³. 3 The dry weight is approximately 12 kg. This core does not primarily reduce nutrients, but rather provides hiding, foraging, and habitat space for fish and large invertebrates. The typical diameter of the internal cavity is 0.03–0.06 m, which can allow common small fish to enter and exit freely.

[0119] In this embodiment, 4 phosphorus removal core blocks, 3 nitrogen removal core blocks, and 3 habitat enhancement core blocks are pre-installed in the 10 functional core slots.

[0120] (iv) Three-dimensional support framework and plant habitat layer

[0121] 1. Three-dimensional support frame

[0122] Six stainless steel columns, each with a cross-sectional dimension of 40mm × 40mm square tubing, are installed at the six corners of the bottom support and anchoring base. These columns are fixed to the bottom support and anchoring base via pre-embedded sleeves. Each column consists of a bottom section and a top section, each 0.60m high, connected by a pin joint, for a total height of 1.20m. This meets the deployment requirements for water depths of 1.3–1.5m in this embodiment.

[0123] At heights of approximately 0.40m, 0.80m, and 1.10m, a ring of circumferential support is installed, constructed by welding 25mm diameter stainless steel tubing to the columns to form a three-layer support frame. A flexible wave-dissipating net, covering a height of 0.20–1.00m with approximately 10mm mesh, is fixed between the columns on the wave-facing side to attenuate wave energy in the upper and middle water layers. On the wave-repelling side, only necessary horizontal tie rods are installed without adding additional obstructive components to maintain slow water flow in the shaded area.

[0124] 2. Plant habitat layer

[0125] Planting baskets are evenly suspended on a three-layer circumferential support ring. Six planting baskets are placed on each layer, for a total of 18. Each planting basket has a planar dimension of approximately 0.35m × 0.35m, and the effective planting area inside is approximately:

[0126]

[0127] The total effective area of ​​the three-tiered planting basket is:

[0128]

[0129] The floor area of ​​the base supporting and anchoring the bottom of the habitat unit is approximately 3.46 m². 3 In comparison, the total projected area of ​​the planting basket accounts for approximately:

[0130]

[0131] With the combined effect of circumferential uniform distribution and vertical stratification, a porous three-dimensional plant community can be formed within the unit.

[0132] The planting configuration is as follows: On the wave-facing side, each layer of planting baskets should be planted with submerged plants A (such as goldfish algae) that have well-developed root systems and strong resistance to current, with 3 plants per basket and an initial plant height of approximately 0.20m. On the leeward side, the middle and upper layers of planting baskets should be planted with submerged plants B (such as Vallisneria natans) that have larger canopies and are more sensitive to turbidity, with 3 plants per basket. Some lower-layer baskets on the leeward side can be planted with a mixed community of A and B. Each planting basket should be filled with a mixed substrate (river sand with a particle size of 2-8mm and a small amount of humus) to a thickness of approximately 0.10m and wrapped with fine mesh to prevent loss.

[0133] Under normal water level conditions, the center of the bottom planting basket is approximately 0.40m above the bottom support and anchoring base plate, the middle layer is approximately 0.80m above the bottom, and the top layer is approximately 1.10m above the bottom. Considering a water depth of 1.3–1.5m, the tops of the plants on the leeward side are roughly 0.10–0.40m below the water surface, falling entirely within the main light zone, which is conducive to the formation of a stable underwater forest canopy.

[0134] (v) Module connection and wave orientation

[0135] Each side of the hexagonal base supporting and anchoring has a pre-installed stainless steel connecting seat, which is made of 10mm thick steel plate with a U-shaped slot structure. The connecting seats are fixed to the concrete by embedded parts. Adjacent habitat units can reliably fasten their respective connecting seats with pins, thus splicing them into a strip or honeycomb pattern on the plane.

[0136] A clear directional marking structure is sprayed on the upper surface of the bottom support and anchoring base on the wave-facing side, and wave-facing direction indicator signs are set on the columns. During construction and layout, according to the local wind and wave rose diagram, all habitat units are aligned with the prevailing southeast wind direction to ensure that the directional structure plays a coordinated role in wave dissipation and bottom stabilization at the community scale.

[0137] (vi) Assembly and installation process

[0138] In this embodiment, the fabrication and installation of the modular habitat unit generally includes the following steps:

[0139] In the prefabrication yard, a template is made according to the aforementioned dimensions, and a hexagonal ecological concrete bottom support and anchoring base is poured. The positions for anchoring rings and connecting seats are reserved, and the concrete is cured until it reaches the design strength.

[0140] After the bottom support and anchoring base are formed, the permeable wave-blocking wing plate on the wave-facing side and the open grid structure on the wave-repellent side are installed to complete the anti-corrosion treatment.

[0141] According to the functional core block design, phosphorus removal core blocks, denitrification core blocks and habitat enhancement core blocks are prepared respectively, and inserted into 10 functional core slots inside the bottom support and anchoring base to form an array of functional core blocks arranged in an alternating manner.

[0142] Install columns and circumferential support rings, hang flexible wave-dissipating nets on the wave-facing side, fix three layers of planting baskets, fill with substrate and plant aquatic plants;

[0143] The assembled habitat unit is transported to the designated water area using lifting equipment, placed at the design coordinates, and the bottom support and anchoring base anchoring ring are connected to the four concrete anchor blocks by anchor chains.

[0144] Multiple habitat units are spliced ​​together according to the designed row and column spacing, and the orientation marker structure facing the waves is corrected so that the overall layout forms a strip-shaped or honeycomb-shaped underwater forest community.

[0145] As can be seen from the structure and numerical values ​​of this embodiment, the single directional modular habitat unit of the present invention has a clear and self-consistent design in terms of size, volume, weight and functional core parameters, and can remain stable under typical shallow lake wind and wave conditions, providing a reliable physical basis for the hydrodynamic zoning, functional core combination configuration and water function enhancement method in subsequent embodiments.

[0146] Example 2: Layout of underwater forest habitat units and configuration of ecological functional core blocks.

[0147] This embodiment selects a 300m long shoreline on the east bank of a eutrophic shallow lake and deploys underwater forest directional modular habitat units along the shore towards the center of the lake. Through hydrodynamic exposure index calculation, nitrogen and phosphorus load estimation and functional core block combination calculation, a specific deployment and configuration scheme is given.

[0148] In this embodiment, the structural parameters of a single habitat unit (size, volume and weight of the bottom support and anchoring base, specifications of the functional core block, arrangement of the three-dimensional support and planting basket, etc.) are all determined according to Embodiment 1, and will not be repeated here. Only the spatial layout and functional configuration are described.

[0149] (I) Overview and Zoning of the Project Area

[0150] A section of shoreline approximately 300m long was selected, with a width of 50m extending towards the center of the lake as the engineering layout zone. The total area is:

[0151]

[0152] Based on the distance from the shore and the measured water depth, the zone is divided into three parallel shoreline sections:

[0153] High Exposure Zone (Zone I): 0–20m from the shore, area

[0154]

[0155] Average water depth , representing the distance from the shore .

[0156] Intermediate Exposure Zone (Zone II): 20–35 m from the shore, area

[0157]

[0158] Average water depth , representing the distance from the shore .

[0159] Low exposure zone (Zone III): 35–50 m from the shore, area

[0160]

[0161] Average water depth , representing the distance from the shore .

[0162] Monitoring indicates that the prevailing wind direction in this coastal zone is southeast, and the representative wind speed is [missing information]. Effective blowing distance along the prevailing wind direction .

[0163] (II) Calculation of Hydrodynamic Exposure Index and Exposure Zoning

[0164] To quantitatively identify the intensity of wind and wave disturbance in different zones, this embodiment uses the following hydrodynamic exposure index. ,Right now:

[0165]

[0166] in: The prevailing wind direction represents the wind speed. ; To correspond to the effective blowing distance, we take 2000m; This represents the average water depth of the zone. To represent the distance from the shore;

[0167] This is the normalized baseline value;

[0168] Weighting coefficients ,satisfy .

[0169] Substitute the parameters into the calculation:

[0170] High-exposure zone (Zone I):

[0171]

[0172]

[0173] Intermediate Exposure Zone (Zone II):

[0174]

[0175]

[0176] Low exposure zone (Zone III):

[0177]

[0178]

[0179] Therefore, it can be seen that: Zone I has the highest hydrodynamic exposure intensity, followed by Zone II, and Zone III is relatively weaker. Figure 4 As shown. For ease of project zoning, this embodiment uses: Defined as a high-exposure area; Defined as a medium exposure zone; Defined as a low-exposure zone. Therefore, the corresponding zones in this project are: Zone I: High-exposure zone; Zone II: Medium-exposure zone; Zone III: Low-exposure zone.

[0180] (III) Nitrogen and Phosphorus Load Estimation and Reduction Targets

[0181] Monitoring results indicate that the concentrations of total nitrogen (TN) and total phosphorus (TP) in the riparian waters are relatively high, with a typical annual value of TN ≈ 2.0. Total phosphorus (TP) ≈ 0.16 .

[0182] To ensure that nearshore underwater forests make a substantial contribution to the overall improvement of water function, this embodiment sets out that within each zone, through the action of underwater forest habitat units and their ecological function core blocks, the average total nitrogen (TN) concentration will be reduced by 0.5%. The average concentration of total phosphorus (TP) decreased by 0.08%. .therefore: ; .

[0183] The volumes of the three water bodies are as follows:

[0184]

[0185]

[0186]

[0187] The mass of total nitrogen (TN) and total phosphorus (TP) that need to be reduced annually in each zone is:

[0188] Total nitrogen (TN) is:

[0189]

[0190]

[0191]

[0192] The total nitrogen (TN) reduction target is approximately .

[0193] Total phosphorus (TP) is:

[0194]

[0195]

[0196]

[0197] The total phosphorus (TP) reduction target is approximately .

[0198] The above-mentioned load is the annual reduction target that the underwater forest belt needs to bear in this embodiment, which will be used for subsequent functional chip configuration.

[0199] (iv) Calculation of ecological functional core block combination and configuration of habitat unit quantity

[0200] The unit reduction capacity of the ecological functional chip was determined by the test calibration results described in Example 1:

[0201] Single dephosphorization core block volume The corresponding annual total phosphorus reduction capacity is:

[0202]

[0203] Single denitrification core volume The corresponding annual total nitrogen reduction capacity is:

[0204]

[0205] Each habitat unit has 10 functional core slots inside its bottom support and anchoring base. This embodiment considers different combination schemes for different exposure areas and provides a set of configurations and unit numbers that meet the reduction objectives, such as... Figure 5 and Figure 6 As shown.

[0206] 1. High Exposure Zone (Zone I)

[0207] To enhance the wave dissipation and reduction capabilities of the nearshore zone, 30 habitat units will be established in Zone I. The area is [area missing]. The unit density is:

[0208]

[0209] The planar area of ​​a single habitat unit is approximately Therefore, the total coverage area of ​​the 30 units is approximately:

[0210]

[0211] Coverage is approximately .

[0212] Within each habitat unit, the slots are configured as follows: 2 denitrification core blocks; 1 phosphorus removal core block; and 7 habitat enhancement core blocks. Therefore, the total nitrogen and phosphorus removal capacity of zone I is:

[0213]

[0214]

[0215] Comparison with target value: TN: Safety factor approximately 1.33; TP: The safety factor is approximately 2.5.

[0216] 2. Intermediate Exposure Zone (Zone II)

[0217] Zone II area 4500 Twenty habitat units were deployed, with a unit density of:

[0218]

[0219] The coverage area is:

[0220]

[0221] Coverage is approximately .

[0222] Each habitat unit in Zone II is also equipped with: 2 denitrification cartridges; 1 phosphorus removal cartridge; and 7 habitat enhancement cartridges. Therefore, the total nitrogen and phosphorus removal capacity of Zone II is:

[0223]

[0224]

[0225] Comparison with target value: TN: Safety factor approximately 1.02; TP: The safety factor is approximately 1.90.

[0226] 3. Low Exposure Zone (Zone III)

[0227] Ⅲ zone area 4500 Fifteen habitat units were deployed, with a unit density of:

[0228]

[0229] The coverage area is:

[0230]

[0231] Coverage is approximately .

[0232] Considering the relatively weak hydrodynamics and higher habitat requirements of this zone, this embodiment adopts a combination that slightly enhances nitrogen removal capacity. Each habitat unit is equipped with: 3 nitrogen removal cartridges; 1 phosphorus removal cartridge; and 6 habitat enhancement cartridges. Therefore, the total nitrogen and phosphorus removal capacity of zone III is:

[0233]

[0234]

[0235] Comparison with target value: TN: Safety factor is 1.00; TP: The safety factor is approximately 1.25.

[0236] 4. Overall reduction capacity and safety margin

[0237] Taking into account the three zones, the total reduction capacity provided by the 65 habitat units (30+20+15) deployed in this embodiment is:

[0238]

[0239]

[0240] Compared to the overall reduction target of 10.35% of total nitrogen (TN), 1.656% of total phosphorus (TP) The safety factor of TN is about 1.12, and the safety factor of TP is about 1.88, which meets the requirement of slight redundancy in engineering design.

[0241] (v) Habitat unit layout and wave orientation

[0242] During deployment, the high-exposure zone, medium-exposure zone, and low-exposure zone are arranged in three parallel zones along the shoreline: High-exposure zone: 30 habitat units are arranged in 3 rows × 10 rows or 2 rows × 15 rows along the shoreline, with the row and column spacing controlled between 6 and 8 meters, and located within 0 to 20 meters from the shore; Medium-exposure zone: 20 habitat units are arranged within 20 to 35 meters from the shore, with the row and column spacing slightly larger than that of the high-exposure zone; Low-exposure zone: 15 habitat units are arranged within 35 to 50 meters from the shore, with the spacing further increased, primarily for habitat function. After all habitat units are hoisted into the water, their orientation is adjusted by the wave-facing direction markings on the bottom support and anchoring base, so that the wave-facing side wave-blocking wing plates and wave-dissipating nets are oriented towards the prevailing southeast wind direction, thus forming a continuous wave-dissipating zone and a back-wave shadow area on a strip scale.

[0243] This embodiment demonstrates that, given specific conditions of water depth, waves, and load in a shallow lake shoreline, the present invention can utilize the hydrodynamic exposure index. Complete partitioning, and reduce targets using TN and TP. With functional chip reduction capability The combined calculations yield the specific number of habitat units and the internal core block ratio for each zone, forming a data-consistent underwater forest layout and configuration scheme that can be directly used for engineering design, providing clear initial operating conditions for operation monitoring and dynamic optimization in subsequent embodiments.

[0244] Example 3: Operational evaluation and optimization based on comprehensive water function index and habitat structure integrity.

[0245] Based on the deployment scheme in Example 2, this embodiment monitors and evaluates the operational effectiveness of the underwater forest directional modular habitat unit for a full year, and calculates the comprehensive water function index. and habitat structure integrity index The comprehensive control function is obtained. Based on this, the layout of habitat units and the configuration of ecological function core blocks are optimized and adjusted, demonstrating the present invention. Figure 3 The practical application process of the method shown.

[0246] (I) Operating conditions and monitoring plan

[0247] In Example 2, a total of 65 habitat units were deployed along a 300m shoreline and within a 50m radius towards the center of the lake in the engineering area. These units were: 30 units in the high-exposure zone (Zone I, 0–20m); 20 units in the medium-exposure zone (Zone II, 20–35m); and 15 units in the low-exposure zone (Zone III, 35–50m). The functional core block combinations and unit density configurations for each zone are detailed in Example 2 and will not be repeated here.

[0248] No new water quality engineering measures were added during operation; only routine inspections and necessary replanting of vegetation were carried out on the habitat units. The monitoring plan was as follows: two representative monitoring sections were set up in each zone, and water samples were collected quarterly to measure total nitrogen (TN), total phosphorus (TP), chlorophyll a (Chl-a), transparency (SD), and dissolved oxygen (DO). The annual average value was used as the evaluation data for this embodiment. At the same time, the submerged plant coverage in the area where the habitat unit was located was counted through underwater photography and manual inspection, which was used as one of the indicators of habitat structure integrity.

[0249] (ii) Baseline values ​​and water function indicators after one year of operation

[0250] The typical annual average values ​​obtained from the baseline survey (before project implementation) are set as follows (regional average): Total Nitrogen Total phosphorus ;Chlorophyll a ;transparency Dissolved oxygen .

[0251] After one year of operation of the habitat unit, the average values ​​were obtained by monitoring for four quarters and taking the average values ​​for the project area: total nitrogen. Total phosphorus ;Chlorophyll a ;transparency Dissolved oxygen It can be seen that TN, TP, and Chl-a all decreased significantly, while transparency and DO increased to varying degrees, which is in line with the expected direction of "reducing nutrient content, controlling algae, and improving transparency and dissolved oxygen".

[0252] (III) Comprehensive Water Function Index Calculation

[0253] In this embodiment, the comprehensive water function index Five indicators were selected for evaluation: TN, TP, Chl-a, transparency (SD), and DO. Among them, TN, TP, and Chl-a were indicators that were "better to decrease", while transparency and DO were indicators that were "better to increase".

[0254] The relative improvement of a single indicator Defined as:

[0255] For the indicators that need to be reduced (TN, TP, Chl-a):

[0256]

[0257] For indicators that need to be improved (SD, DO):

[0258]

[0259] in Baseline value, This is the value after one year of operation.

[0260] The calculations are as follows:

[0261]

[0262]

[0263]

[0264]

[0265]

[0266] In this embodiment, the weights of each indicator are given as follows:

[0267] , , ;

[0268] , ;

[0269] satisfy .

[0270] The comprehensive water function index for:

[0271]

[0272] In this embodiment, a preset comprehensive water function compliance threshold is provided. .because This indicates that after one year of operation, the overall improvement in water function has exceeded the predetermined target.

[0273] (iv) Habitat structure integrity index Calculation

[0274] Habitat structure integrity is mainly assessed by submerged plant coverage and habitat unit structure integrity rate. This embodiment focuses on coverage as a key metric. The target coverage was set as follows during the design phase. (i.e., 0.70). After one year of operation, on-site investigation showed that some plants on the wave-facing side of the high-exposure units suffered mechanical damage; the top plants in some units of the medium and low-exposure areas experienced light inhibition but their overall survival was good.

[0275] Statistics show that the average submerged plant coverage of the entire underwater forest zone is approximately (i.e., 0.55). The habitat structure integrity index is then defined as:

[0276]

[0277] in This indicates that the target coverage has been achieved. This indicates a weak habitat structure. This means that the coverage exceeds the design target.

[0278] (V) Comprehensive Regulation Function Operating status determination

[0279] To simultaneously consider both water function enhancement and habitat structure integrity, this embodiment employs a comprehensive control function. ,Right now:

[0280]

[0281] Where the tradeoff coefficient is taken This indicates that the weighting of water function improvement is slightly higher than that of structural integrity. This embodiment presets a comprehensive compliance threshold. .

[0282] Substitution , have to:

[0283]

[0284] Therefore, it can be seen that: This indicates that the overall water function improvement effect has met the standards; This indicates that the overall assessment, which takes into account both water function and habitat structure, is still slightly below the target, with the main problem stemming from low coverage. This means that water quality has improved significantly in the first year of operation, but the habitat structure is not yet stable and sufficient. Appropriate adjustments need to be made to the layout of habitat units and the configuration of plants and functional blocks, focusing on improving coverage and habitat quality, rather than simply pursuing stronger nutrient reduction capabilities.

[0285] (vi) According to , , Optimization and adjustment measures implemented

[0286] Based on the above evaluation results, this embodiment adopts the following optimization strategy: In the high-exposure zone (Zone I), eight habitat units with severe damage on the wave-facing side are centrally replanted and repaired. The planting density of plant A in the planting basket on the wave-facing side is increased by approximately 20%, and the planting quantity of plant B on the leeward side is moderately increased to restore overall coverage. In the medium-exposure zone (Zone II), five habitat units are selected, and one phosphorus removal core block in each unit is replaced with one habitat enhancement core block. While ensuring that the TP reduction capacity still meets the objectives of Embodiment 2, the habitat space in the pores is increased, reducing the risk of plant nutrient limitation caused by excessive local "purification". In the low-exposure zone (Zone III), the configuration of nitrogen removal and phosphorus removal core blocks remains unchanged. Priority is given to improving the coverage and structural integrity of this zone by reducing the harvesting frequency, minimizing disturbance to the core "underwater forest" canopy on the leeward side, and moderately replanting shade-tolerant and turbidity-tolerant submerged plants. The above adjustments do not increase the number of habitat units; they mainly improve coverage through optimization of internal structure and functional combination. and comprehensive At the same time, maintain Instead of decreasing, it increased.

[0287] (vii) Operational performance and re-evaluation in the second year after adjustment

[0288] After completing the above adjustments, the second operating year will be monitored using the same monitoring plan, such as... Figure 7 As shown. According to statistics, the representative annual average water function index for that year is: ; ; ; ; .

[0289] The survey results on submerged plant coverage showed that the average coverage of the "underwater forest" zone was: (0.75), which has significantly exceeded the original design target by 70%.

[0290] 1. Comprehensive water function index in the second year .

[0291] Based on the aforementioned definition, calculate the relative improvement amount for the second year:

[0292]

[0293]

[0294]

[0295]

[0296]

[0297] Still using , , ,but:

[0298]

[0299] 2. Habitat structure integrity index in the second year .

[0300]

[0301] This indicates that the habitat structure has exceeded the design goals.

[0302] 3. Comprehensive control function for the second year .

[0303]

[0304] Comparison with threshold: The improvement in water function has further increased; Taking into account both water function and habitat structure, the overall condition is significantly better than the design target.

[0305] Therefore, the underwater forest directional modular habitat unit and its water function enhancement method proposed in this invention can calculate the comprehensive water function index by measuring water function indicators such as TN, TP, Chl-a, transparency, and DO, as well as the submerged plant coverage, under a given layout scheme. Habitat structure integrity index and comprehensive control function The system identifies operational states where "water function meets standards but habitat structure is weak," and accordingly makes targeted adjustments to the functional core block combinations and plant configurations within habitat units. After one round of optimization, the second year of operation showed that the comprehensive water function index... and comprehensive control function Both were significantly improved, achieving a synergistic enhancement of water function and habitat structure, thus verifying the feasibility and effectiveness of the method of the present invention.

[0306] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0307] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. Since the above embodiments are substantially similar to the method embodiments, their descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0308] The above embodiments provide a detailed description of the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A shallow lake underwater forest modular habitat unit, characterized in that, It comprises: The bottom support and anchoring base (1) of the hollow frame structure form two areas of the wave-approaching side and the wave-receding side in the horizontal direction, the wave-approaching side wall is continuously provided with a water-permeable wave-blocking wing plate (11), and the wave-receding side wall is provided with an open grid structure (12) with a high open ratio to form a directional water dynamic regulation with high roughness on the wave-approaching side and low roughness on the wave-receding side; The water-permeable wave-blocking wing plate (11) is arranged upwardly inclined at an angle of 20°-60° relative to the horizontal plane and is arranged in stages along the water depth direction, so that part of the incident wave energy is converted into vertical flow through the ecological function core block (4) and the plant root zone to achieve wave dissipation and material exchange enhancement; The open grid structure (12) forms an underwater forest shadow area with significantly weakened disturbance on the wave-receding side, and the open grid structure (12) has an open ratio of not less than 40% to achieve a moderate but continuous water exchange in the underwater forest shadow area; The three-dimensional support framework (2) is fixed to the upper portion of the bottom support and anchoring base (1) to form a three-dimensional frame structure penetrating through the water depth, and the three-dimensional support framework (2) on the wave-approaching side is provided with vertical or inclined wave-dissipating members (21) to form a relatively low-disturbance underwater forest shadow area on the wave-receding side of the habitat unit; The plant habitat layer (3) is arranged in stages along the elevation direction of the three-dimensional support framework (2) and comprises at least two layers of planting baskets (31) for planting submerged plants or aquatic plants to form a three-dimensional aquatic vegetation belt with directional water dynamic regulation; The ecological function core block (4) comprises one or more rows of plug-in function core slots (13) arranged in the horizontal direction inside the bottom support and anchoring base (1) from the wave-approaching side to the wave-receding side, and each function core slot (13) can be combined with the ecological function core block (4); The module connection and directional member (5) is arranged at the outer edge of the bottom support and anchoring base (1) and the outer edge of the three-dimensional support framework (2) and comprises a connection lock (51) and a direction marker structure (52) for indicating the direction of the wave-approaching side.

2. The habitat unit of claim 1, wherein, The three-dimensional support framework (2) is composed of vertical support members and annular support rings or horizontal support beams therebetween, the vertical support members adopt segmented plug-in or sleeve connection structure to adjust the overall height according to different water depth conditions, so that the plant habitat layer (3) is always located in the suitable light belt; The wave-dissipating member (21) includes any one of flexible wave-dissipating mesh or rigid perforated baffle.

3. The habitat unit of claim 1, wherein, The planting basket (31) includes planting trays or habitat baskets arranged in stages along the water depth direction, and the planting basket (31) adopts a mesh or perforated plate structure with a limiting edge and a protruding rib at the bottom for carrying planting medium and preventing loss; The unit area root volume density of the plants arranged in the wave-approaching side planting basket (31) is greater than that of the wave-receding side, and the unit crown coverage of the plants in the upper layer planting basket (31) on the wave-receding side is greater than that on the wave-approaching side, so that an inhabiting structure gradient of "protection-transition-core underwater forest" is formed along the wave-approaching-wave-receding direction in the single inhabiting unit.

4. The habitat unit of claim 1, wherein, The ecological function core block (4) comprises at least one of the following three types: A phosphorus removal core (14a) mainly composed of high-phosphorus adsorption material; A nitrogen removal core (14b) mainly composed of high specific surface area carrier and denitrification filler; A habitat enhancement core (14c) mainly composed of large-porosity structure and habitat cavity.

5. The habitat unit of claim 1, wherein, The module connection and orientation member (5) includes standardized connection seats arranged around the bottom support and anchoring base (1), and a plug or connection lock (51) matched therewith. Adjacent habitat units are spliced in a hexagonal or rectangular grid shape through the standardized connection seats, and after splicing, an underwater forest belt composed of multiple directional unit cells is formed. The wave-approaching directions of different directional unit cells can be kept consistent or adjusted in segments according to the shoreline curvature.

6. A method for improving water function of a modular habitat unit of underwater forest in a shallow lake, using the habitat unit according to any one of claims 1-5, characterized in that, The method comprises the following steps: S1, obtaining water depth of target shallow lake area , dominant wind speed , effective blowing distance , distance from shore and bottom type, and baseline monitoring data including total nitrogen TN, total phosphorus TP, chlorophyll a, transparency and dissolved oxygen indicators, delineate the area to be repaired and determine the water function improvement target; S2, calculating a hydrodynamic exposure index for quantifying the intensity of wind wave disturbance for each spatial location and dividing the region to be repaired into exposure zones including a low exposure zone, a medium exposure zone, and a high exposure zone; S3, estimating the total nitrogen TN and total phosphorus TP reduction required by each exposure area in the design operation period, and combining the unit reduction capacity of different types of ecological function cores to determine the number of habitat units required by each exposure area and the combination ratio of internal ecological function cores; S4, according to the dominant wind and wave direction of each exposure area, the wave-approaching side of the habitat unit is aligned with the dominant wind and wave direction by using the module connection and orientation member, and the habitat unit is laid out and inserted according to the number of habitat units and the combination ratio of ecological function cores. In the high exposure area, plants with developed root systems and high stiffness are configured on the wave-approaching side, and a high proportion of phosphorus removal cores are used. In the low exposure area, a large crown width and a high proportion of habitat enhancement cores are used. S5, during the operation of the habitat unit, the baseline monitoring data for evaluating the water function improvement effect in each exposure area is regularly monitored, and the ecological function core combination and habitat unit density in part of the habitat unit are adjusted according to the evaluation result, so as to realize the synergistic improvement of water function and habitat function.

7. The water function boosting method of claim 6, wherein, The hydrodynamic exposure index The formula for calculating the hydrodynamic exposure index is: ； wherein, is the representative wind speed of the dominant wind direction; is the corresponding effective blowing distance; is the local water depth; is the distance from the shore; is the reference value of each parameter, is the weight coefficient, satisfying .

8. The water function boosting method of claim 6, wherein, In step S3, the following steps are included: The exposure area is divided into several planning units, and the target reduction amount of total nitrogen TN and total phosphorus TP required by each planning unit is determined and combined with the unit reduction capacity of each type of ecological function core block in the performance parameter library and A combination optimization model is established, namely: ； wherein, is the total number of phosphorus removal prills, denitrification prills, and habitat enhancement prills needed in the planning unit; Taking the minimum total core number or the minimum total cost as the objective function, the optimal number combination of phosphorus removal cores, nitrogen removal cores and habitat enhancement cores in each planning unit is solved; The optimal number combination is converted into the number of habitat units required by each exposure area and the combination ratio of ecological function cores inside each habitat unit in combination with the number of insertion slots and the space capacity of a single habitat unit.

9. The water function boosting method of claim 6, wherein, During the habitat unit operation, the water function improvement effect of each exposure area is evaluated by introducing a comprehensive water function index and a habitat structure integrity index , which are calculated according to the following relationship: ； wherein, is the baseline value or target threshold value of the i-th water function index measured in the running period; is the baseline value or target threshold value of the i-th water function index measured in the running period; is the baseline value or target threshold value of the i-th water function index measured in the running period; is the weight of each index, and ; is the actual plant coverage or habitat unit integrity rate, is the preset target coverage. Combining the comprehensive water function index and the habitat structure integrity index Establishing a comprehensive control function for quantitative evaluation of engineering effects i.e.: ； wherein ; When the comprehensive regulation function When the water function and habitat function are below the preset threshold, the underwater forest community is optimized by replacing the type of ecological function core block inside part of the habitat unit, adjusting the layout density of the habitat unit, and configuring the structure in the direction of facing the wave and the back of the wave, until the water function and habitat function simultaneously reach the expected target.

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