Optimization model establishment method based on oyster reef ecological submerged breakwater

Abstract

The invention discloses an optimization model establishment method based on an oyster reef ecological submerged dike, and belongs to the field of ecological submerged dikes, and the method comprises the following steps: 1, model design: carrying out model design by adopting a D-optimal method, and processing model data by adopting a weighted K-means method to obtain parameter arrangement of the oyster reef ecological submerged dike with optimal wave absorption performance; step 2, model establishment: according to the parameter arrangement obtained in the step 1, establishing an optimization model based on the oyster reef ecological submerged embankment, the optimization model based on the oyster reef ecological submerged embankment comprising oyster reefs located on two sides and a waterproof structural body located in the middle; and thirdly, the oyster reefs located on the two sides naturally grow, the waterproof structural body in the middle is extruded, and the oyster reef ecological submerged dike stable in structure is formed. According to the optimization model establishment method based on the oyster reef ecological submerged breakwater, the problem that the wave absorbing performance is reduced due to the fact that the oyster reef breakwater has pore bodies is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of ecological submerged breakwaters, and in particular to a method for establishing an optimization model based on an oyster reef ecological submerged breakwater. Background Art

[0002] With the intensification of global climate change and human activities, problems such as coastal erosion and sea-level rise have become increasingly serious, posing higher requirements for coastal protection projects. Although traditional rigid protection structures (such as concrete dams) can effectively resist wave erosion, they have a negative impact on the ecological environment. In recent years, nature-based protection structures (such as oyster reefs, coral reefs, etc.) have gradually received attention because they can not only dissipate wave energy, but also promote biodiversity, improve water quality and restore ecosystems.

[0003] In the prior art, traditional underwater breakwaters are mainly composed of materials such as metal, reinforced concrete and wood, and their basic principles are mainly achieved through the following mechanisms: 1. Friction and turbulence: When waves pass through an underwater breakwater, the water body generates resistance due to friction with the breakwater surface, and at the same time, the breakwater structure (such as porous materials, rough surfaces or rubble mounds) will trigger turbulence, consuming the kinetic energy of the waves. 2. Wave breaking: If the water depth at the top of the breakwater is relatively shallow, the waves will deform and break due to bottom friction, converting the energy into foam and turbulence, significantly reducing the wave height. 3. Reflection: The underwater breakwater will reflect part of the incident wave, changing the wave propagation direction and reducing the energy directly impacting the coast. Through the above three points, the underwater breakwater can consume part of the wave energy and achieve the purpose of dissipating wave energy. And there are at least two advantages in choosing oyster reefs as the main body of the breakwater: 1. As an integral part of the ecosystem, the reasonable distribution of oyster reefs will not cause too much negative impact on the local ecological environment. On the contrary, the ecological characteristics of oyster reefs play an important role in maintaining ecological stability and increasing nearshore biodiversity. 2. The porous characteristics of the oyster reef surface can increase the friction between the waves and the breakwater, and at the same time, the water flow entering the pores will be repeatedly reflected and refracted between the pores, further consuming more wave energy and enhancing the wave dissipation performance of the oyster reef breakwater.

[0004] Most of the existing oyster reef breakwaters are studied for oyster reefs of different shapes. However, due to the existence of many pore bodies in the oyster reef itself, the water flow of the incoming waves at the submerged breakwater can flow through these pore bodies, making the oyster reef submerged breakwater unable to effectively consume wave energy and reducing the wave dissipation performance of the oyster reef submerged breakwater. Summary of the Invention

[0005] The object of the present invention is to provide a method for establishing an optimization model based on an oyster reef ecological submerged breakwater, so as to solve the problem that the pore bodies of the oyster reef breakwater in the above background art reduce the wave dissipation performance.

[0006] To achieve the above object, the present invention provides a method for establishing an optimization model based on an oyster reef ecological submerged dike, comprising the following steps: Step 1, model design: The D-optimal method is used for model design, and the weighted K-means method is used to process the model data to obtain the parameter arrangement of the oyster reef ecological submerged dike with the best wave dissipation performance; Step 2, model establishment: According to the parameter arrangement obtained in Step 1, an optimization model based on the oyster reef ecological submerged dike is established. The optimization model based on the oyster reef ecological submerged dike includes oyster reefs on both sides and an impermeable structure in the middle; Step 3, the oyster reefs on both sides grow naturally and squeeze the impermeable structure in the middle to form a structurally stable oyster reef ecological submerged dike.

[0007] Preferably, in Step 1, the transmission coefficient of the oyster reef ecological submerged dike has the following calculation formula: ; wherein, is the amplitude of the transmitted wave, is the amplitude of the incident wave; The fitting model established based on the D-optimal method is as follows: ; wherein, is the wave dissipation performance of the oyster reef, is the offset, is the linear offset coefficient, is the second-order offset coefficient, is the interaction effect coefficient, , are different influencing factors.

[0008] Preferably, the weighted K-means method adds weights on the basis of the K-means method. After considering the influence of each independent variable parameter, the selected weight distribution is as follows: ω =[0.04, 0.04, 0.04, 0.04, 0.04, 0.04, 0.04, 0.72]; For each sample point , calculate the weighted distance of the sample point to the cluster center: ;

[0009] wherein, ω is the corresponding weight, is the number of cluster centers, is the coordinate position of the cluster center; Classify the sample points to the nearest cluster center according to the calculation results and recalculate the cluster center. The new cluster center is the weighted average of all data points in this class. Finally, calculate the change amount between the new cluster center and the previous cluster center. If the change amount is less than the preset threshold, stop the iteration; otherwise, perform the clustering operation again according to the new cluster center until convergence.

[0010] Preferably, the ratio of the height of the oyster reef ecological submerged breakwater to the water depth ranges from 0.55 to 0.70.

[0011] Preferably, the ratio of the length of the oyster reef ecological submerged breakwater to the incoming wave wavelength ranges from 0.22 to 0.30.

[0012] Preferably, the number of oyster reefs is 3 or 4.

[0013] Preferably, the material of the oyster reef ecological submerged breakwater is oyster shells.

[0014] Preferably, the impervious structure adopts a hard and non-porous material.

[0015] Therefore, the present invention adopts the above-mentioned method for establishing an optimization model based on an oyster reef ecological submerged breakwater, and has the following beneficial effects: 1. The present invention uses oyster reefs as the main body of the breakwater, avoiding the damage of the traditional hard structure to the nearshore ecological environment. At the same time, due to the ecological characteristics of oyster reefs, while ensuring good wave dissipation performance, it maintains the stability of the nearshore ecosystem and increases biodiversity; 2. The method for establishing an optimization model based on an oyster reef ecological submerged breakwater adopted by the present invention overcomes the deficiencies of traditional oyster reef submerged breakwaters, and can effectively reduce the wave height of passing waves in the marine environment. At the same time, oyster reefs play an important role in water purification, enhancement of fish resources, alleviation of coastline erosion, carbon sequestration, enhancement of biodiversity and overall ecosystem stability, and can be widely used in coastal protection projects.

[0016] The following will further describe the technical solutions of the present invention in detail through the drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is the layout schematic diagram of the embodiment of the optimization model based on an oyster reef ecological submerged breakwater of the present invention; Figure 2 is the schematic diagram of the initial model of the oyster reef ecological submerged breakwater of the embodiment of the present invention; Figure 3 is the schematic diagram of the intermediate model of the oyster reef ecological submerged breakwater of the embodiment of the present invention; Figure 4Schematic diagram of the final model of the oyster reef ecological submerged dike according to an embodiment of the present invention; Figure 5 Schematic diagram of the intermediate structure according to an embodiment of the present invention. Detailed implementation manners

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the following further describes the embodiments of the present invention in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention, and are not used to limit the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts fall within the scope of protection of this application. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout.

[0019] It should be noted that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or server that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0020] Similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0021] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0022] In the description of the present invention, it should also be noted that unless otherwise clearly defined and limited, the terms "set", "installed", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0023] Embodiment As Figure 1As shown in the figure, a method for establishing an optimization model of an oyster reef ecological submerged dyke according to the present invention includes the following steps: Step 1, model design: The D-optimal method is used for model design, and the weighted K-means method is used to process the model data to obtain the parameter arrangement of the oyster reef ecological submerged dyke with the best wave dissipation performance.

[0024] In order to make the transmission coefficient of the underwater submerged dyke as small as possible, the D-optimal method is used for experimental design, and the weighted K-means method is used to process the experimental data, and finally the parameter arrangement of the oyster reef ecological submerged dyke with the best wave dissipation performance is obtained.

[0025] The transmission coefficient of the oyster reef ecological submerged dyke The calculation formula is: ; Among them, is the amplitude of the transmitted wave, is the amplitude of the incident wave; The fitting model established based on the D-optimal method is as follows: ; Among them, is the wave dissipation performance of the oyster reef, is the offset, is the linear offset coefficient, is the second-order offset coefficient, is the interaction effect coefficient, , are different influencing factors.

[0026] Through the D-optimal method, on the premise of ensuring sufficient information, the number of experimental groups required for the experiment can be greatly reduced (reduced to five ten-thousandths of the original in the present invention). Then, the weighted K-means method is used to analyze the experimental data to obtain the parameter arrangement of the oyster reef ecological submerged dyke with the best wave dissipation performance.

[0027] The weighted K-means method adds a weight item on the basis of the K-means method. After considering the influence of each independent variable parameter, the selected weight distribution is as follows: ω =[0.04,0.04,0.04,0.04,0.04,0.0.4,0.04,0.72] For each sample point , calculate the weighted distance from the sample point to the cluster center: ;

[0028] Among them,ω is the corresponding weight, is the number of cluster centers, is the coordinate position of the cluster center.

[0029] According to the calculation results, the sample points are classified into the nearest cluster center and the cluster center is recalculated. The new cluster center is the weighted average of all data points in this class. Finally, calculate the change amount between the new cluster center and the previous cluster center. If the change amount is less than the preset threshold, stop the iteration; otherwise, perform the clustering operation again according to the new cluster center until convergence.

[0030] From the experimental results, when the oyster reef ecological submerged breakwater reaches the best wave dissipation performance, the value ranges of its key parameters are as follows: The ratio of the height of the oyster reef ecological submerged breakwater to the water depth ( / ) ranges from 0.55 to 0.70. The ratio of the length of the oyster reef ecological submerged breakwater to the incoming wave wavelength ( ) ranges from 0.22 to 0.30. The number of oyster reefs is 3 or 4. The oyster reef ecological submerged breakwater uses oyster shells as the main material, and the impermeable structure uses hard non-porous materials (concrete structures can be used).

[0031] Step 2, model establishment: According to the parameter layout obtained in Step 1, establish an optimization model based on the oyster reef ecological submerged breakwater.

[0032] Step 3, based on the optimization model of the oyster reef ecological submerged breakwater, which consists of two traditional oyster reef submerged breakwaters on the left and right. In order to prevent water flow from passing through the oyster reefs, an impermeable structure (as shown in Figure 5 ) is arranged between the two oyster reefs. Then, with the natural growth of the oyster reefs, a structurally stable oyster reef ecological submerged breakwater is formed.

[0033] As shown in Figure 2 , this is the initial form of the present invention, which consists of two natural oyster reefs on the left and right and an impermeable structure in the middle. However, at this time, the middle structure is not stable, and the wave dissipation performance of the combination is not as good as that of a single oyster reef breakwater. With the natural growth of the oyster reefs (as shown in Figure 3 ), the impermeable structure in the middle becomes more and more stable due to the extrusion of the oyster reefs on both sides. At the same time, the overall wave dissipation performance will gradually improve until the left and right oyster reefs are combined into a whole (as shown in Figure 4 ). At this time, compared with a single oyster reef breakwater, due to the role of the impermeable structure in the middle, the present invention can better prevent water flow from passing through the oyster reef breakwater through the pore body of the oyster reef, thereby greatly improving the wave dissipation performance of the oyster reef breakwater.

[0034] Generally speaking, the higher the height of the oyster reef breakwater, the better the wave dissipation effect. The height of the oyster reef ecological submerged breakwater proposed by the present invention needs to be set according to the water depth. The height of the oyster reef ecological submerged breakwater and the water depth The ratio between them ( / ) within 0.55 - 0.70 can produce a better wave dissipation effect.

[0035] The ratio of the length of different optimized models of oyster reef ecological submerged breakwaters and the incoming wave wavelength can produce different wave dissipation effects. This ratio within 0.22 - 0.30 can produce a better wave dissipation effect.

[0036] Generally speaking, the more the number of oyster reefs, the better the wave dissipation performance. However, considering the cost and wave dissipation effect, the number of oyster reefs being 3 or 4 can achieve a good wave dissipation effect.

[0037] The ecological breakwater provided by the present invention has a good wave dissipation effect on the waves under general sea conditions. The test data shows that under reasonable arrangement, the transmitted wave height can be reduced to less than 50% of the incident wave height, that is, the wave energy is reduced to 1 / 4 of the original, having good wave dissipation performance.

[0038] Since the present invention uses ecological oyster reefs as the main material, it will not cause too much impact on the local ecological environment. On the contrary, oyster reefs can play an important role in maintaining the stability of the ecosystem and increasing biodiversity. The present invention not only has a relatively obvious reduction effect on waves with different wavelengths and different periods (its transmission coefficient can be reduced to below 0.5), but also will play a certain positive role in the restoration of the near - shore ecological environment, and can be widely applied to the field of coastal protection engineering.

[0039] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions of the present invention or make equivalent replacements, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.​

Claims

1. A method for establishing an optimization model based on an oyster reef ecological submerged dyke, characterized in that: It includes the following steps: Step 1, model design: The D-optimal method is used for model design, and the weighted K-means method is used to process the model data to obtain the parameter layout with the best wave-dissipating performance of the oyster reef ecological submerged breakwater; Step 2, model establishment: According to the parameter layout obtained in Step 1, an optimization model based on the oyster reef ecological submerged breakwater is established. The optimization model based on the oyster reef ecological submerged breakwater includes oyster reefs on both sides and an impervious structure in the middle; Step 3, the oyster reefs on both sides grow naturally and squeeze the impervious structure in the middle to form an oyster reef ecological submerged breakwater with stable structure.

2. The method for establishing an optimization model based on an oyster reef ecological submerged dyke according to claim 1, wherein: In Step 1, the transmission coefficient of the oyster reef ecological submerged breakwater is calculated by the formula: ； Among them, is the amplitude of the transmitted wave, is the amplitude of the incident wave; The fitting model established based on the D-optimal method is as follows: ； Among them, is the wave-dissipating performance of oyster reefs, is the offset, is the linear offset coefficient, is the second-order offset coefficient, is the interaction effect coefficient, , are different influencing factors.

3. The method for establishing an optimization model based on an oyster reef ecological submerged dyke according to claim 2, wherein: The weighted K-means method adds weights on the basis of the K-means method. After considering the influence of each independent variable parameter, the selected weight distribution vector is shown as follows: ω =[0.04,0.04,0.04,0.04,0.04,0.0.4,0.04,0.72]； For each sample point , calculate the weighted distance from the sample point to the cluster center: ； wherein, ω is the corresponding weight, is the number of cluster centers, is the coordinate position of the cluster center; Classify the sample points into the nearest cluster center according to the calculation results and recalculate the cluster center. The new cluster center is the weighted average of all data points in this class. Finally, calculate the difference between the new cluster center and the previous cluster center. If the difference is less than the preset threshold, stop the iteration; otherwise, perform the clustering operation again according to the new cluster center until convergence.

4. The method for establishing an optimization model based on an oyster reef ecological submerged dyke according to Claim 3, wherein: The height of the oyster reef ecological submerged breakwater and the water depth The value range of the ratio between them is 0.55 - 0.

70.

5. The method for establishing an optimization model based on an oyster reef ecological submerged dyke according to claim 3, characterized in that: The length of the oyster reef ecological submerged dike and the incoming wave length The value range of the ratio is 0.22 to 0.

30.

6. The method for establishing an optimization model based on an oyster reef ecological submerged dike according to claim 3, characterized in that: The number of oyster reefs is 3 or 4.

7. The method for establishing an optimization model based on an oyster reef ecological submerged dike according to claim 3, wherein: The material of the oyster reef ecological submerged breakwater is oyster shells.

8. The method for establishing an optimization model based on an oyster reef ecological submerged dyke according to claim 3, characterized in that: The impervious structure uses hard non-porous materials.

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