Optimized Design Method and Device for Shoal Wetland Construction Project

Abstract

The present invention provides an optimized design method and device for a shoal wetland construction project. The method includes: obtaining the ground object contour line and DEM with a specific precision in the study area by collecting the characteristic data of the study area; determining the construction position, construction quantity and size of the ecological bird islands by obtaining the corner positions of the dikes in the study area through the DEM with a specific precision; obtaining the shoal wetland construction project plan according to the construction position, construction quantity, size of the ecological bird islands and the pre-defined spatial type; evaluating the shoal wetland construction project plan through the eccentricity and landscape pattern index, and obtaining the shoal wetland construction project plan that meets the predetermined results by adjusting the quantity and size of the ecological bird islands. The present invention creates a shoal wetland with a diversified habitat of "land - shallow water - deep water" with continuous transition by demolishing the dikes and constructing ecological bird islands at the corners.

Description

Technical Field

[0001] This document relates to the technical field of shoal wetland transformation, and particularly relates to an optimized design method and device for a shoal wetland construction project. Background Art

[0002] Dikes and dykes are the crystallization of the wisdom of the working people in our country. People build dikes and dykes by excavating the silt at the bottom of lakes for economic activities such as aquaculture and crop planting, thereby increasing industrial income. At present, there are different research plans for the transformation of dikes and dykes in lake wetlands, but the optimized design and evaluation methods for the plans still need to be further studied. Summary of the Invention

[0003] The present invention provides an optimized design method and device for a shoal wetland construction project, aiming to solve the above problems.

[0004] The present invention provides an optimized design method for a shoal wetland construction project, including:

[0005] Obtaining the characteristic data of the study area, where the characteristic data includes: vector boundary, remote sensing image, topographic survey data, and the average water level of a specific year, performing edge detection and processing on the remote sensing image to obtain the ground object contour line within the study area, and obtaining a DEM with a specific accuracy based on the ground object contour line in combination with the topographic survey data;

[0006] Determining the construction positions and the number of ecological bird islands based on the corner positions of the dykes within the study area according to the DEM with a specific accuracy, calculating the earthwork volume of the dykes according to the area and average height of the dykes, and obtaining the size of the ecological bird islands based on the earthwork volume of the dykes and the number of ecological bird islands;

[0007] Obtaining a shoal wetland construction project plan based on the construction positions of the ecological bird islands, the number of the construction, the size of the ecological bird islands, and the pre-defined spatial type;

[0008] Evaluating the shoal wetland construction project plan through eccentricity and landscape pattern index to obtain an evaluation result. If the evaluation result meets the predetermined result, then the shoal wetland construction project plan is used as the final construction plan. If the evaluation result does not meet the predetermined result, then adjust the number of ecological bird islands and the size of the ecological bird islands until the evaluation result meets the predetermined result.

[0009] The present invention provides an optimized design device for a shoal wetland construction project, including:

[0010] A data acquisition module, which is used to acquire the characteristic data of the study area. The characteristic data includes: vector boundary, remote sensing image, topographic survey data, and the average water level of a specific year. Edge detection and processing are performed on the remote sensing image to obtain the ground object contour line within the study area, and a DEM with a specific accuracy is obtained based on the ground object contour line in combination with the topographic survey data;

[0011] A bird island planning module, which is used to determine the construction location and quantity of ecological bird islands based on the corner positions of the dikes within the study area obtained from the DEM with a specific accuracy, calculate the earthwork volume of the dikes according to the area and average height of the dikes, and obtain the size of the ecological bird islands based on the earthwork volume of the dikes and the quantity of ecological bird islands;

[0012] A scheme generation module, which is used to obtain the shallow wetland construction project scheme based on the construction location, quantity, size of the ecological bird islands, and the pre-defined spatial type;

[0013] A scheme optimization module, which is used to evaluate the shallow wetland construction project scheme through the eccentricity and landscape pattern index to obtain the evaluation result. If the evaluation result meets the predetermined result, the shallow wetland construction project scheme is used as the final construction scheme. If the evaluation result does not meet the predetermined result, the quantity and size of the ecological bird islands are adjusted until the evaluation result meets the predetermined result.

[0014] By adopting the embodiments of the present invention, ecological bird islands are constructed at the corners of the dikes to create a shallow wetland with a diverse habitat of "land - shallow water - deep water" with continuous transition. At the same time, the boundary eccentricity and landscape pattern index before and after construction are used as the selection and judgment indicators for the shallow wetland construction project scheme. This method not only considers the earthwork balance and soil stability, but also follows the principles of small disturbance and low economic cost. The calculation of the wetland construction optimization evaluation index is simple, and its physical, economic, and ecological meanings are clear, which has important reference value for guiding the construction of shallow wetlands. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions in one or more embodiments of this specification or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments recorded in this specification. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 It is a flowchart of an optimization design method for a shallow wetland construction project according to an embodiment of the present invention;

[0017] Figure 2 It is a schematic diagram of an optimization design device for a shallow wetland construction project according to an embodiment of the present invention. Detailed implementation manners

[0018] In order to enable those skilled in the art of the present technology to better understand the technical solutions in one or more embodiments of this specification, the following will clearly and completely describe the technical solutions in one or more embodiments of this specification in conjunction with the accompanying drawings in one or more embodiments of this specification. Obviously, the described embodiments are only a part of the embodiments of this specification, rather than all the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this document.

[0019] Method embodiments

[0020] According to an embodiment of the present invention, there is provided an optimized design method for a shoal wetland construction project. Figure 1 The following is a flowchart of an optimized design method for a shoal wetland construction project according to an embodiment of the present invention. As Figure 1 shown, the optimized design method for a shoal wetland construction project according to an embodiment of the present invention specifically includes:

[0021] Step S101, obtaining characteristic data of the study area. The characteristic data includes: vector boundary, remote sensing image, topographic survey data, and the average water level in a specific year. Edge detection and processing are performed on the remote sensing image to obtain the contour lines of the ground objects in the study area. Based on the contour lines of the ground objects and combined with the topographic survey data, a DEM with a specific accuracy is obtained. Step S101 specifically includes:

[0022] (1) Data collection. The data mainly includes the vector boundary of the study area, the remote sensing image of the study area, the topographic survey data of the study area, the average annual water level of the study area, etc.;

[0023] (2) Obtaining contour lines of ground objects and high-precision DEM. First, the Sobel operator is used to perform edge detection on the remote sensing image of the study area to obtain the contour lines of the ground objects in the study area; then, the surface vector polygons enclosed by the contour lines of the ground objects are obtained, and the ground object vectors with similar similarities are partitioned and merged; then, the boundary of the ground object vector is corrected in combination with the remote sensing image and on-site investigation to obtain the contour lines of different ground objects such as dikes, reed fields, and water surfaces; then, according to the topographic survey data, the geostatistical interpolation method is used to obtain the high-precision DEM grid data of each ground object vector partition; finally, the grid data of each ground object vector partition is mosaicked and merged into the high-precision DEM data of the study area.

[0024] Step S102: Determine the construction locations and quantities of ecological bird islands based on the corner positions of the dikes in the study area obtained from the DEM with a specific precision. Calculate the earthwork volume of the dikes according to the area and average height of the dikes, and obtain the dimensions of the ecological bird islands based on the earthwork volume of the dikes and the construction quantity of the ecological bird islands. Step S102 specifically includes:

[0025] (1) Determination of the layout plan for the shallow wetland.

[0026] Construct ecological bird islands to create a shallow wetland. Therefore, it is necessary to determine the quantity and location of the ecological bird islands. By identifying the intersection points of the vector boundaries of the dikes, determine the corner positions of the dikes, and determine the corner positions as the construction locations of the ecological bird islands. Among them, ecological bird islands are not constructed at adjacent corners with a spacing of no more than 50m. Thus, finally determine the distribution locations of the ecological bird islands and conduct quantity statistics.

[0027] (2) Calculation of the engineering quantity of the shallow wetland.

[0028] Mainly calculate the available earthwork volume of the ecological bird islands. Calculate the earthwork volume of the dikes according to the area of the dikes and the average height of the dikes. Among them, the area of the dikes is obtained from the vector boundary of the dikes, and the average height of the dikes is obtained by subtracting the average bottom elevation from the average top elevation of the dikes.

[0029] Q = S 围 ×(h 顶 - h 底 )

[0030] In the formula, Q represents the available earthwork volume, m 3 ; S 围 represents the area of the dikes, m 2 ; h 顶 represents the average top elevation of the dikes, m; h 底 represents the average bottom elevation of the dikes, m.

[0031] (3) Design of the construction dimensions of the shallow wetland.

[0032] Mainly determine the dimensions of the ecological bird islands. Determine the earthwork volume used for a single ecological bird island through the available earthwork volume of the ecological bird islands and the number of ecological bird islands. The calculation formula is as follows:

[0033]

[0034] In the formula, Q0 represents the available earthwork volume for a single ecological bird island, m 3 ; Q represents the available earthwork volume of the ecological bird islands, m 3 ; N represents the number of ecological bird islands.

[0035] Considering the bank slope stability and the water flow field, the bird island is set as a frustum of a cone, with the top elevation 0.5 m above the average annual water level, the slope ratio not less than 1:3, and the upper base radius and the lower base radius adjusted according to the actual situation, but the earthwork balance should be achieved. The calculation formula for the volume of the frustum of a cone is as follows:

[0036]

[0037] In the formula, V represents the volume of the frustum of a cone, which is the available earthwork volume Q0 of a single ecological bird island, m 3 ; H is the height of the frustum of a cone, 0.5 m higher than the normal water level, m; R 底 is the lower base radius of the frustum of a cone, m; R 顶 is the upper base radius of the frustum of a cone, m.

[0038] Step S103: Obtain the shallow wetland construction project plan according to the construction location of the ecological bird island, the number of the constructed ones, the size of the ecological bird island, and the pre-defined space type; Step S103 specifically includes:

[0039] Determine according to the shallow wetland layout plan in Step S102, design the construction size of the shallow wetland, and divide according to the pre-defined ecological space type to obtain the optimized landscape pattern.

[0040] Among them, the specific division of the pre-defined ecological space type includes:

[0041] According to the average annual water level in the study area, the area above the water surface is divided into terrestrial space. Considering the water surface fluctuation and the wet-dry alternation caused by natural factors, two demarcation values of 0.6 m and 2.0 m above the water surface are set. The area below the water surface is divided into aquatic space. Considering the suitable water depth for the germination of reeds and the specific habitat requirements of fish, shrimps, swimming birds and wading birds, two demarcation values of 0.3 m and 2.0 m below the water surface are set. According to the above classification criteria, the ecological space before and after construction can be divided into 6 ecological space types, namely terrestrial space 1 (>2.0 m), terrestrial space 2 (0.6 - 2.0 m), terrestrial space 3 (0 - 0.6 m), aquatic space 1 (-0.3 - 0 m), aquatic space 2 (-2.0 - -0.3 m) and aquatic space 3 (<-2.0 m).

[0042] Step S104: Evaluate the shallow wetland construction project plan through the eccentricity and landscape pattern index to obtain the evaluation result. If the evaluation result meets the predetermined result, take the shallow wetland construction project plan as the final construction plan. If the evaluation result does not meet the predetermined result, adjust the number of ecological bird islands and the size of the ecological bird islands until the evaluation result meets the predetermined result. Step S104 specifically includes:

[0043] Use indicators such as eccentricity and landscape pattern index to evaluate the spatial pattern construction effect after the construction of ecological bird islands.

[0044] The eccentricity is the ratio of the offset distance between the centroid of the levee and dike vector graph and the centroid of the transformed bird island to the radius of the circumcircle of the levee and dike vector graph. The offset distance of the centroid can be used for estimating the project quantity. The smaller the value, the shorter the transportation distance of the earthwork for construction and the smaller the project quantity. The eccentricity can be used as a comprehensive judgment index for evaluating the project economy and the degree of ecological disturbance. When the eccentricity is greater than 1, it indicates that a new wetland is built in a different location after construction, which not only reduces the project economy but also causes greater ecological disturbance to the study area; when the eccentricity is greater than 0.2 and less than 1, it indicates that the wetland scope after construction coincides with the original levee and dike scope, which can reduce part of the project quantity and also reduce the ecological disturbance to a certain extent; when the eccentricity is less than 0.2, it is more reasonable to build the wetland because the earthwork transportation is less, the project quantity is small, and the disturbance to the study area is light, which is both economical and environmentally friendly. The centroid point and the circumradius can be directly obtained through relevant functions in GIS. The specific calculation formula for the eccentricity is as follows:

[0045]

[0046] In the formula, γ represents the eccentricity, (x1, y1) represents the projected coordinates of the centroid of the levee and dike vector graph, (x2, y2) represents the projected coordinates of the centroid of the transformed bird island, and R is the radius of the circumcircle of the levee and dike vector graph, in m.

[0047] Landscape pattern indices are mainly used to analyze the rationality of landscape patterns, and are mainly evaluated from landscape connectivity and landscape diversity. Enhancing landscape connectivity can promote the flow of ecological flows such as material flow, energy flow, and information flow, and increasing landscape diversity can provide habitat diversity, resulting in increased biodiversity. Landscape connectivity mainly uses three indicators: landscape connectance (Connectance Index / CONNECT), patch cohesion index (Patch Cohesion Index / COHESION), and aggregation index (Aggregation Index / AI). The larger the value, the stronger the connectivity; landscape diversity is characterized by the Shannon's Diversity Index (SHDI). The larger the value, the stronger the diversity. The value range of landscape connectance is 0 - 1, and the value ranges of the patch cohesion index and the aggregation index are both 0 - 100. The calculation formulas for each index are as follows, and specifically, the Fragstats software can be used for calculation.

[0048]

[0049] In the formula, n i is the number of wetland landscape patches of the i-th type, c ijkIt is the connection status between the j-th and i-th wetland landscape patches within the threshold distance. 0 indicates unconnected, and 1 indicates connected.

[0050]

[0051] In the formula, m is the number of landscape types; n is the number of landscape type patches; a ij is the area of the j-th patch of the i-th type, and A i is the total area of the i-th type of landscape, and P ij is the area of the j-th patch of the i-th type.

[0052]

[0053] In the formula, p i is the proportion of a certain type of patch in the landscape, and g ii is the number of pixels between different patches of the same patch type i, and maxg ii is the maximum possible number of pixels between different patches of the same patch type i.

[0054]

[0055] In the formula, m is the number of landscape types, and p i is the proportion of a certain type of patch in the landscape.

[0056] When the eccentricity is greater than 0.2, and the relevant indices of landscape connectivity and landscape diversity are less than the calculated results before construction, the quantity and scale of ecological bird islands are adjusted. Specifically, the quantity of ecological bird islands is mainly adjusted by changing the positions far from the centroid points of the dikes and dams, and the size of ecological bird islands is mainly adjusted by changing the upper base radius and the lower base radius until the basic optimization goals are met, that is, the eccentricity is less than 0.2, and both the landscape connectivity index and the diversity index are improved. There are slight differences in the landscape connection degree, patch cohesion degree, and aggregation degree indices in the landscape connectivity index. When two of these indices increase, it is considered that the landscape connectivity is improved, and thus the construction plan is finally confirmed.

[0057] By adopting the embodiments of the present invention, the following beneficial effects are achieved:

[0058] The embodiments of the present invention are based on the principles of earthwork balance and soil body stability, following the principles of small disturbance and low economic cost. By demolishing the dikes and dams and constructing ecological bird islands at the corners, a shallow wetland with a diverse habitat of "land - shallow water - deep water" with continuous transition is created. At the same time, using the boundary eccentricity and landscape pattern indices before and after construction as the decision-making criteria for scheme comparison and selection, not only considering earthwork balance and soil body stability, but also following the principles of small disturbance and low economic cost, the wetland construction optimization evaluation indices are simple to calculate, and have clear physical, economic, and ecological meanings, which have important reference value for guiding the construction of shallow wetlands.

[0059] Device Embodiment

[0060] According to an embodiment of the present invention, an optimized design device for a shoal wetland construction project is provided. Figure 2 As shown in the schematic diagram of an optimized design device for a shoal wetland construction project according to an embodiment of the present invention, Figure 2 as described, the optimized design device for a shoal wetland construction project according to an embodiment of the present invention specifically includes:

[0061] A data acquisition module 20, configured to acquire characteristic data of the study area. The characteristic data includes: vector boundary, remote sensing image, topographic survey data, and average water level of a specific year. Edge detection and processing are performed on the remote sensing image to obtain the contour lines of the ground objects in the study area, and a DEM with a specific accuracy is obtained by combining the contour lines of the ground objects with the topographic survey data. The data acquisition module 20 is specifically configured to:

[0062] (1) Data collection. The data mainly includes the vector boundary of the study area, the remote sensing image of the study area, the topographic survey data of the study area, the average water level of the study area over the years, etc.;

[0063] (2) Acquisition of contour lines of ground objects and high-precision DEM. First, the Sobel operator is used to perform edge detection on the remote sensing image of the study area to obtain the contour lines of the ground objects in the study area; then, the surface vector polygon enclosed by the contour lines of the ground objects is obtained, and the ground object vectors with similar similarity are partitioned and merged; then, the boundary of the ground object vector is corrected by combining the remote sensing image and on-site investigation to obtain the contour lines of different ground objects such as dikes, reed fields, and water surfaces; then, according to the topographic survey data, the geostatistical interpolation method is used to obtain the high-precision DEM grid data of each ground object vector partition; finally, the grid data of each ground object vector partition is mosaicked and merged into the high-precision DEM data of the study area.

[0064] A bird island planning module 22, configured to determine the construction position and number of ecological bird islands according to the corner positions of the dikes in the study area obtained from the DEM with a specific accuracy, calculate the earthwork volume of the dikes according to the area and average height of the dikes, and obtain the size of the ecological bird islands according to the earthwork volume of the dikes and the number of ecological bird islands constructed. The bird island planning module is specifically configured to:

[0065] (1) Determination of the layout plan for the shoal wetland.

[0066] The shoal wetland is constructed by building ecological bird islands. Therefore, it is necessary to determine the number and location of the ecological bird islands. By identifying the intersection points of the vector boundaries of the dikes, the corner positions of the dikes are determined, and the corner positions are determined as the construction positions of the ecological bird islands. Among them, adjacent corners with a spacing of no more than 50 m do not construct ecological bird islands. Thus, the distribution positions of the ecological bird islands are finally determined, and the quantity is counted;

[0067] (2) Calculation of the project quantity of the shoal wetland.

[0068] Mainly calculate the available earthwork volume of the ecological bird island. Calculate the earthwork volume of the cofferdam according to the cofferdam area and the average height of the cofferdam. Among them, the cofferdam area is obtained from the vector boundary of the cofferdam, and the average height of the cofferdam is obtained by subtracting the average bottom elevation of the cofferdam from the average top elevation of the cofferdam;

[0069] Q = S 围 ×(h 顶 - h 底 )

[0070] In the formula, Q represents the available earthwork volume, m 3 ; S 围 represents the cofferdam area, m 2 ; h 顶 represents the average top elevation of the cofferdam, m; h 底 represents the average bottom elevation of the cofferdam, m.

[0071] (3) Design of the construction size of the shoal wetland.

[0072] Mainly determine the size of the ecological bird island. Determine the earthwork volume used for a single ecological bird island based on the available earthwork volume of the ecological bird island and the number of ecological bird islands. The calculation formula is as follows:

[0073]

[0074] In the formula, Q0 represents the available earthwork volume for a single ecological bird island, m 3 ; Q represents the available earthwork volume of the ecological bird island, m 3 ; N represents the number of ecological bird islands.

[0075] Considering the bank slope stability and the water flow field, the bird island is set as a frustum of a cone. The top elevation is 0.5 m above the annual average water level, and the slope ratio is not less than 1:3. The upper bottom radius and the lower bottom radius are adjusted according to the actual situation, but the earthwork balance should be achieved. The frustum volume calculation formula is as follows:

[0076]

[0077] In the formula, V represents the frustum volume, which is the available earthwork volume Q0 for a single ecological bird island, m 3 ; H is the frustum height, 0.5 m higher than the normal water level, m; R 底 the lower bottom radius of the frustum, m; R 顶 the upper bottom radius of the frustum, m.

[0078] The scheme generation module 24 is used to obtain the construction scheme of the shoal wetland according to the construction location, construction quantity, size of the ecological bird island, and the pre-defined space type. The scheme generation module 24 is specifically used for:

[0079] The landscape pattern is optimized according to the shallow wetland layout plan in the Bird Island planning module, the shallow wetland construction size design and the pre-delineated ecological space type division.

[0080] The pre-delineated ecological space types include:

[0081] According to the multi-year average water level in the study area, the area above the water surface is divided into terrestrial space. Considering the fluctuation of the water surface and the alternation of dryness and wetness caused by natural factors, two boundary values ​​of 0.6m and 2.0m above the water surface are set. The area below the water surface is divided into aquatic space. Considering the suitable water depth for reed germination and the specific habitat requirements of fish, shrimp, waterfowl and wading birds, two boundary values ​​of 0.3m and 2.0m below the water surface are set. According to the above classification standards, the ecological space before and after construction can be divided into 6 types of ecological space: terrestrial space 1 (>2.0m), terrestrial space 2 (0.6~2.0m), terrestrial space 3 (0~0.6m), aquatic space 1 (-0.3~0m), aquatic space 2 (-2.0~-0.3m) and aquatic space 3 (<-2.0m).

[0082] The scheme optimization module 26 is used to evaluate the shallow wetland construction project scheme through eccentricity and landscape pattern index to obtain the evaluation result. If the evaluation result meets the predetermined result, the shallow wetland construction project scheme is used as the final construction plan. If the evaluation result does not meet the predetermined result, the number and size of the ecological bird islands are adjusted until the evaluation result meets the predetermined result. The scheme optimization module 26 is specifically used for:

[0083] Indicators such as eccentricity and landscape pattern index are used to evaluate the spatial pattern creation effect after the construction of the ecological bird island.

[0084] The eccentricity is the ratio of the offset distance between the centroid of the dike and embankment vector diagram and the centroid of the bird island after transformation and the radius of the circumscribed circle of the dike and embankment vector diagram. The offset distance of the centroid can be used for engineering quantity estimation. The smaller the value, the shorter the earthwork transportation route and the smaller the engineering quantity. The eccentricity can be used as a comprehensive indicator for evaluating the economic efficiency and ecological disturbance degree of the project. When the eccentricity is greater than 1, it indicates that the wetland is newly built in another place after construction, which not only reduces the economic efficiency of the project but also causes greater ecological disturbance to the study area; when the eccentricity is greater than 0.2 and less than 1, it indicates that the wetland range after construction overlaps with the original dike and embankment range, which can reduce part of the engineering quantity and reduce ecological disturbance to a certain extent; when the eccentricity is less than 0.2, it is more reasonable to build a wetland, because there is less earthwork to be transported, the engineering quantity is less, and the disturbance to the study area is less, which is both economical and environmentally friendly. The centroid point and the circumscribed circle radius can be directly calculated through the relevant functions in GIS. The specific calculation formula of eccentricity is as follows:

[0085]

[0086] In the formula, γ represents the eccentricity, (x1, y1) represents the projected coordinates of the centroid of the dike and levee vector graph, (x2, y2) represents the projected coordinates of the centroid of the transformed bird island, and R is the radius of the circumscribed circle of the dike and levee vector graph, m.

[0087] Landscape pattern indices are mainly used to analyze the rationality of landscape patterns. They are mainly evaluated from landscape connectivity and landscape diversity. Enhancing landscape connectivity can promote the flow of ecological flows such as material flow, energy flow, and information flow, while increasing landscape diversity can provide habitat diversity, leading to an increase in biodiversity. Landscape connectivity is mainly measured by three indicators: landscape connectance (Connectance Index / CONNECT), patch cohesion index (Patch Cohesion Index / COHESION), and aggregation index (Aggregation Index / AI). The larger the value, the stronger the connectivity. Landscape diversity is characterized by the Shannon's diversity index (Shannon's Diversity Index / SHDI). The larger the value, the stronger the diversity. The value range of landscape connectance is 0 - 1, and the value ranges of patch cohesion index and aggregation index are both 0 - 100. The calculation formulas for each indicator are as follows, and specifically, the Fragstats software can be used for calculation.

[0088]

[0089] In the formula, n i is the number of wetland landscape patches of the i-th type, and c ijk is the connection status between the j-th and i-th patches of the i-th wetland landscape within the threshold distance. 0 indicates unconnected, and 1 indicates connected.

[0090]

[0091] In the formula, m is the number of landscape types; n is the number of landscape type patches; a ij is the area of the j-th patch of the i-th type, and A i is the total area of the i-th type of landscape, and P ij is the area of the j-th patch of the i-th type.

[0092]

[0093] In the formula, p i is the proportion of a certain type of patch in the landscape, and g ii is the number of pixels between different patches of the same patch type i, and maxg ii is the maximum possible number of pixels between different patches of the same patch type i.

[0094]

[0095] In the formula, m is the number of landscape types, and p i is the proportion of patches of a certain type in the landscape.

[0096] When the eccentricity is greater than 0.2, and the relevant indices of landscape connectivity and landscape diversity are less than the calculated results before construction, the quantity and scale of ecological bird islands are adjusted. Specifically, the quantity of ecological bird islands is mainly adjusted by changing the positions far from the centroid points of the dikes and dams, and the size of ecological bird islands is mainly adjusted by changing the upper base radius and the lower base radius until the basic optimization objectives are met, that is, the eccentricity is less than 0.2, and both the landscape connectivity index and the diversity index are improved. There are slight differences in the landscape connection degree, patch cohesion degree, and aggregation degree indices in the landscape connectivity index. When two of these indices increase, it is considered that the landscape connectivity is improved, and thus the construction plan is finally confirmed.

[0097] By adopting the embodiments of the present invention, the following beneficial effects are achieved:

[0098] Based on the principles of earthwork balance and soil stability, and following the principles of small disturbance and low economic cost, the embodiments of the present invention break the dikes and dams and construct ecological bird islands at the corners to create a shallow wetland with a diverse habitat of "land - shallow water - deep water" with continuous transition. At the same time, taking the boundary eccentricity and landscape pattern indices before and after construction as the decision-making indicators for scheme comparison and selection, it not only considers earthwork balance and soil stability but also follows the principles of small disturbance and low economic cost. The calculation of the wetland construction optimization evaluation index is simple, and its physical, economic, and ecological meanings are clear, which has important reference value for guiding the construction of shallow wetlands.

[0099] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An optimized design method for a shoal wetland construction project, characterized in that, Including: Obtain the characteristic data of the study area, where the characteristic data includes: vector boundary, remote sensing image, topographic survey data, and the average water level over the years. Perform edge detection and processing on the remote sensing image to obtain the contour lines of the ground objects in the study area, and obtain a high-precision DEM based on the contour lines of the ground objects in combination with the topographic survey data; Determine the construction locations and the number of ecological bird islands according to the corner positions of the dikes in the study area based on the high-precision DEM. Calculate the earthwork volume of the dikes according to the area and average height of the dikes, and obtain the size of the ecological bird islands according to the earthwork volume of the dikes and the number of ecological bird islands constructed; Obtain a shallow wetland construction project plan according to the construction locations of the ecological bird islands, the number of constructed islands, the size of the ecological bird islands, and the pre-defined spatial types; Evaluate the shallow wetland construction project plan through eccentricity and landscape pattern indices to obtain an evaluation result. If the evaluation result meets the predetermined result, use the shallow wetland construction project plan as the final construction plan. If the evaluation result does not meet the predetermined result, adjust the number of ecological bird islands and the size of the ecological bird islands until the evaluation result meets the predetermined result; The evaluation of the shallow wetland construction project plan through eccentricity and landscape pattern indices to obtain an evaluation result specifically includes: Obtain the eccentricity according to Formula 4; Formula 4; Among them, represents the eccentricity, ( ) represents the projection coordinates of the centroid of the dike and levee vector graphic, ( ) represents the projection coordinates of the centroid of the ecological bird island after transformation, R is the circumradius of the circumcircle of the dike and levee vector diagram; Obtain the landscape pattern index through landscape connectivity and landscape diversity. The landscape connectivity includes: obtaining landscape connectivity through landscape connectivity, patch cohesion, and aggregation index, and the landscape diversity is characterized by the Shannon diversity index; Obtain the landscape connectivity according to Formula 5; Formula 5; Among them, n i is the number of wetland landscape patches of the i category, is the i category of wetland landscape patches j and the connection status of the patches i within the threshold distance, where 0 means unconnected and 1 means connected; Obtain the patch cohesion according to Formula 6; Formula 6; Among them, m is the number of landscape types; n is the number of patches of landscape types; is the i th j patch area of the A i is the i total area of the P ij is the i th j patch area of the Obtain the aggregation index according to Formula 7; Formula 7; Among them, p i is the proportion of a certain type of patch in the landscape, is the number of pixels between different patches of the same patch type i and is the maximum possible number of pixels between different patches of the same patch type; i ​ Obtain the Shannon diversity index according to Formula 8; Formula 8; Among them, m is the number of landscape types, p i is the proportion of a certain type of patch in the landscape.

2. The method according to claim 1, characterized in that, The obtaining of the contour lines of the ground objects in the study area by performing edge detection and processing on the remote sensing image specifically includes: Perform edge detection on the remote sensing image using the Sobel operator to obtain the initial contour lines of the ground objects in the study area; Obtain the planar vector polygon enclosed by the initial contour lines of the ground objects, and merge the ground object vectors with similar similarities by region; Calibrate the boundaries of the ground object vector partitions through the remote sensing image and on-site investigation to obtain the contour lines of the ground objects in the study area.

3. The method according to claim 2, characterized in that, The obtaining of a high-precision DEM based on the contour lines of the ground objects in combination with the topographic survey data specifically includes: Obtain the high-precision DEM grid data of each ground object vector partition using the geostatistical interpolation method according to the topographic survey data; Perform mosaic processing on the high-precision DEM grid data of each ground object vector partition and merge them into the high-precision DEM data of the study area.

4. The method according to claim 1, characterized in that, The determination of the construction locations and the number of ecological bird islands according to the corner positions of the dikes in the study area based on the high-precision DEM specifically includes: The corners of the cofferdam are determined by identifying the vector boundary intersection points of the cofferdam, the positions and the number of the corners of the cofferdam are obtained, the positions of the corners of the cofferdam are determined as the construction positions of the ecological bird islands, and the number of the corners of the cofferdam is determined as the construction quantity of the ecological bird islands.

5. The method according to claim 1, characterized in that, Calculating the earthwork volume of the cofferdam according to the area and average height of the cofferdam, and obtaining the size of the ecological bird island according to the earthwork volume of the cofferdam and the construction quantity of the ecological bird island, specifically including: Obtaining the earthwork volume of the cofferdam according to Formula 1, and taking the earthwork volume of the cofferdam as the available earthwork volume of the ecological bird island; Formula 1; Among them, Q represents the available earthwork volume of the ecological bird island; represents the area of the cofferdam; represents the average top elevation of the cofferdam; represents the average bottom elevation of the cofferdam; Obtaining the earthwork volume used for a single ecological bird island according to the available earthwork volume of the ecological bird island and the number of ecological bird islands through Formula 2; = Formula 2; Among them, represents the available earthwork volume of a single ecological bird island, Q represents the available earthwork volume of ecological bird islands, represents the number of ecological bird islands; Adjusting the upper bottom radius and lower bottom radius of the ecological bird island according to Formula 3, so as to determine the size of the ecological bird island; Formula 3; In the formula, V represents the volume of the frustum of a cone, which is the available earthwork volume for a single ecological bird island , H is the height of the frustum of a cone, is the radius of the lower base of the frustum of a cone, is the radius of the upper base of the frustum of a cone.

6. The method according to claim 1, wherein If the evaluation result meets the predetermined result, then taking the shallow wetland construction engineering plan as the final construction plan, specifically including: If the eccentricity is less than 0.2 and the landscape connectivity and landscape diversity are greater than the calculated results before construction, then taking the shallow wetland construction engineering plan as the final construction plan.

7. The method according to claim 1, wherein If the evaluation result does not meet the predetermined result, then adjusting through the number and size of the ecological bird islands, specifically including: If the eccentricity is greater than 0.2 and the landscape connectivity and landscape diversity are less than the calculated results before construction, then adjusting the number and size of the ecological bird islands, wherein adjusting the number and size of the ecological bird islands specifically includes: Changing the number of the ecological bird islands by adjusting the positions far away from the centroid point of the cofferdam within the study area; Adjusting the size of the ecological bird island by changing the upper bottom radius and lower bottom radius of the ecological bird island.

8. An optimized design device for a shoal wetland construction project, characterized in that Including: A data acquisition module, configured to acquire characteristic data of the study area, where the characteristic data includes: vector boundary, remote sensing image, topographic survey data, and average water level for many years, performing edge detection and processing on the remote sensing image to obtain the ground object contour line within the study area, and obtaining a high-precision DEM according to the ground object contour line in combination with the topographic survey data; A bird island planning module, configured to determine the construction positions and construction quantity of the ecological bird islands according to the corner positions of the cofferdam within the study area obtained from the high-precision DEM, calculate the earthwork volume of the cofferdam according to the area and average height of the cofferdam, and obtain the size of the ecological bird island according to the earthwork volume of the cofferdam and the construction quantity of the ecological bird islands; A plan generation module, configured to obtain a shallow wetland construction engineering plan according to the construction positions of the ecological bird islands, the construction quantity, the size of the ecological bird islands, and the pre-defined spatial types; A plan optimization module, configured to evaluate the shallow wetland construction engineering plan through the eccentricity and landscape pattern index to obtain an evaluation result, if the evaluation result meets the predetermined result, then taking the shallow wetland construction engineering plan as the final construction plan, if the evaluation result does not meet the predetermined result, then adjusting the number of the ecological bird islands and the size of the ecological bird islands until the evaluation result meets the predetermined result; Among them, evaluating the shallow wetland construction project plan through eccentricity and landscape pattern index to obtain an evaluation result specifically includes: Obtaining the eccentricity according to Formula 4; Formula 4; Among them, represents the eccentricity, ( ) represents the projected coordinates of the centroid of the dike and cofferdam vector graphic, ( ) represents the projected coordinates of the centroid of the ecological bird island after transformation, R is the radius of the circumscribed circle of the dike and cofferdam vector diagram; Obtaining the landscape pattern index through landscape connectivity and landscape diversity. The landscape connectivity includes: obtaining landscape connectivity through landscape connectivity degree, patch cohesion degree, and aggregation index, and the landscape diversity is characterized by the Shannon diversity index; Obtaining the landscape connectivity degree according to Formula 5; Formula 5; Among them, n i is the number of wetland landscape patches of the i th class, is the i th class of wetland landscape patches j and the connection status of the patches i within the threshold distance, where 0 means unconnected and 1 means connected; Obtaining the patch cohesion degree according to Formula 6; Formula 6; Among them, m is the number of landscape types; n is the number of landscape type patches; is the i th j area of the A i th i landscape type; P ij is the i th j area of the Obtaining the aggregation index according to Formula 7; Formula 7; Among them, p i is the proportion of a certain type of patch in the landscape, is the number of pixels between different patches of the same patch type i and is the maximum possible number of pixels between different patches of the same patch type; i i Obtaining the Shannon diversity index according to Formula 8; Formula 8; Among them, m is the number of landscape types, p i is the proportion of a certain type of patch in the landscape.

9. The device according to claim 8, whereinThe scheme optimization module is specifically used for: Judging the eccentricity, landscape connectivity, and landscape diversity. If the eccentricity is less than 0.2 and the landscape connectivity and landscape diversity are greater than the calculation results before construction, then take the shallow wetland construction project plan as the final construction plan; If the eccentricity is greater than 0.2 and the landscape connectivity and landscape diversity are less than the calculation results before construction, then adjust the quantity and size of the ecological bird islands. Among them, adjusting the quantity and size of the ecological bird islands specifically includes: Changing the quantity of the ecological bird islands by adjusting the positions farther away from the centroid point of the inner embankment in the study area; Adjusting the size of the ecological bird islands by changing the upper base radius and lower base radius of the ecological bird islands.

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