An ecological restoration method for mine slope micro-topography construction

Abstract

The present invention discloses an ecological restoration method for the construction of micro-topography on a mine slope, which belongs to the field of micro-topography ecological restoration. The method comprises using a drone to collect three-dimensional images of a mine slope restoration area to obtain orthophoto data; according to the orthophoto data, using a feature matching algorithm to obtain corresponding points between images, and calculating the three-dimensional coordinates of each corresponding point in space to obtain rough point cloud data of the mine slope restoration area; according to the rough point cloud data of the mine slope restoration area, using Poisson reconstruction to construct a three-dimensional terrain model of the mine slope; according to the three-dimensional terrain model of the mine slope, using the section curvature to perform micro-topography zoning to obtain micro-topography zoning results; using the micro-topography zoning results, performing micro-topography transformation and implementing slope greening restoration to complete the ecological restoration of the construction of micro-topography on the mine slope. The present invention solves the problems of large engineering workload and high cost of the existing ecological restoration methods, and being extremely inconsistent with the surrounding ecological landscape after restoration.

Description

Technical Field

[0001] The invention belongs to the field of micro-topography ecological restoration, and in particular relates to an ecological restoration method for micro-topography construction on a mine slope. Background Art

[0002] Open-pit mining has caused changes in the original landform, difficult site conditions, exposed bedrock, and formed high and steep slopes. In particular, a large number of open-pit mines in the early days were affected by the strong demand for stone materials in urban construction, and were mostly concentrated near the city, seriously affecting the urban landscape and causing the deterioration of the ecological environment in which humans live. In addition, open-pit mining will strip off the topsoil. Early disorderly mining often resulted in no soil or little soil, lack of water, poor plant growth conditions, and difficulty in regreening vegetation in the mining area.

[0003] At present, the restoration measures mostly used for the greening of high and steep slopes of mines include spraying greening, retaining wall slope greening, slope drilling greening, and platform greening. These measures involve large amounts of work and high costs, and the restored slopes are extremely inconsistent with the surrounding ecological landscape. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides an ecological restoration method for constructing micro-topography on mine slopes, which solves the problems of large engineering workload, high cost, and extreme incompatibility with the surrounding ecological landscape after restoration in the prior art.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is: an ecological restoration method for the construction of mine slope micro-topography, comprising the following steps:

[0006] S1. Use drones to collect three-dimensional images of the mine slope restoration area to obtain orthophoto data;

[0007] S2. Based on the orthophoto data, the corresponding points between the images are obtained using a feature matching algorithm, and the three-dimensional coordinates of each corresponding point in space are calculated to obtain the rough model point cloud data of the mine slope restoration area;

[0008] S3. Based on the rough model point cloud data of the mine slope restoration area, a three-dimensional terrain model of the mine slope is constructed using Poisson reconstruction;

[0009] S4. Based on the three-dimensional terrain model of the mine slope, the micro-topography is divided by using the section curvature to obtain the micro-topography division result;

[0010] S5. Utilize the results of micro-topography zoning to carry out micro-topography transformation and implement slope regreening and restoration to complete the ecological restoration of the mine slope micro-topography construction.

[0011] The beneficial effects of the present invention are as follows: the present invention utilizes close-up photogrammetry, micro-topography transformation, and plant growth component configuration to construct near-natural plant growth site conditions, thereby forming a slope restoration scene that is in harmony with the surrounding ecological landscape; adding a correction coefficient based on drone resolution can reduce the error caused by drone resolution, improve the accuracy of profile curvature, and prepare for subsequent micro-topography zoning.

[0012] Furthermore, the step S1 is specifically as follows:

[0013] S101, determining the flight altitude of the drone, and calculating the field of view angle coverage width according to the flight altitude of the drone;

[0014] S102, determining the overlap degree, and calculating the longitudinal route spacing according to the overlap degree;

[0015] S103, determining the lateral route spacing according to the field of view angle coverage width;

[0016] S104, obtaining a planned route according to the longitudinal route spacing and the lateral route spacing;

[0017] S105. According to the planned route, the UAV is used to collect three-dimensional images of the mine slope restoration area to obtain orthophoto data.

[0018] The beneficial effects of the above further scheme are: first, use drones for rough mining to obtain orthophoto data of the mine slope restoration area, which provides source data for the subsequent rough model point cloud data of the mine slope restoration area, that is, the rough mining results.

[0019] Furthermore, the expression of the field angle coverage width in step S101 is:

[0020]

[0021] Where D is the coverage width of the field of view; H is the flight altitude of the drone; tan() is the tangent function; FOV is the field of view of the drone camera.

[0022] The beneficial effect of the above further scheme is: determining the coverage width of the field of view angle and providing reference data for the lateral route spacing of the route planning during the rough mining process.

[0023] Furthermore, the expression of the longitudinal route spacing in step S102 is:

[0024] S=H×(1-O)

[0025] Among them, S is the longitudinal route spacing; H is the flight altitude of the UAV; O is the overlap.

[0026] The beneficial effect of the above further solution is: based on the setting of the overlap, the longitudinal route spacing is calculated, and combined with the lateral route spacing, preparation is made for obtaining the planned route.

[0027] Furthermore, the step S2 is specifically as follows:

[0028] S201, performing dedistortion, brightness adjustment and image enhancement processing on the orthophoto data to obtain pre-processed orthophoto data;

[0029] S202, performing image matching using a feature matching algorithm based on the pre-processed orthophoto data to obtain corresponding points between images;

[0030] S203, according to the UAV flight parameters and camera parameters, using the stereo vision principle and triangulation method to calculate the three-dimensional coordinates of each corresponding point in space, and obtain the three-dimensional point cloud data of each corresponding point;

[0031] S204, denoising, filtering and point cloud data homogenization are performed on the three-dimensional point cloud data of each corresponding point to obtain the rough model point cloud data of the mine slope restoration area.

[0032] The beneficial effects of the above further scheme are: pre-processing operations are performed on the orthophoto data to eliminate poor quality data, and combining feature matching algorithms to obtain corresponding points between images, thereby improving the quality of the orthophoto data while also improving the quality of the rough model point cloud data of the mine slope restoration area.

[0033] Furthermore, the step S3 is specifically as follows:

[0034] S301, based on the rough model point cloud data of the mine slope restoration area, a route planning close to photography is performed to obtain a wonderful mining route;

[0035] S302, according to the fine mining route, use drones to carry out drone close-up photogrammetry and fine mining of the mine slope restoration area at different heights and angles to obtain fine mining image data;

[0036] S303, performing image dedistortion, registration and color balance on the fine-collected image data to obtain pre-processed fine-collected image data;

[0037] S304, based on the pre-processed fine-sampled image data, using motion recovery structure technology and multi-view stereo matching algorithm to restore the three-dimensional structure of the scene to obtain dense point cloud data;

[0038] S305, performing point cloud filtering, classification and denoising according to the dense point cloud data to obtain effective terrain feature points;

[0039] S306. Construct a three-dimensional terrain model of the mine slope using Poisson reconstruction based on effective terrain feature points.

[0040] The beneficial effects of the above further scheme are: based on the rough point cloud data of the mine slope restoration area, a more detailed route is planned, and based on the data collected from the fine mining route, a three-dimensional terrain model of the mine slope is constructed, thereby improving the accuracy of the three-dimensional terrain model of the mine slope.

[0041] Furthermore, the step S4 is specifically as follows: calculating the profile curvature of the three-dimensional terrain model of the mine slope in sequence with a window area of ​​a cm×a cm, and performing micro-topography partitioning according to the profile curvature to obtain a micro-topography partitioning result; wherein a is the window width.

[0042] The beneficial effects of the above further scheme are: the window area is set automatically, and the profile curvature of the three-dimensional terrain model of the mine slope is calculated in sequence with a window of a cm × a cm, preparing for the subsequent micro-topography zoning. At the same time, micro-topography zoning based on profile curvature can better distinguish the operations of ecological restoration.

[0043] Furthermore, the expression of the cross-sectional curvature is:

[0044] K p '=C r ·K p

[0045]

[0046] Among them, K p ' is the section curvature; C r K is the correction factor based on the resolution of the drone; p is the standard section curvature; f xx is the second-order partial derivative of the effective terrain feature point in the X direction; f xy For effective terrain feature points, first calculate the partial derivative in the X direction and then calculate the second-order partial derivative in the Y direction; f x is the partial derivative of the effective terrain feature point in the X direction; f y is the partial derivative of the effective terrain feature point in the Y direction; f yy is the second-order partial derivative of the effective terrain feature point in the Y direction.

[0047] The beneficial effect of the above further scheme is that adding a correction coefficient based on the UAV resolution can reduce the error caused by the UAV resolution, improve the accuracy of the profile curvature, and prepare for the subsequent micro-topography zoning.

[0048] Furthermore, the micro-topography partitioning is performed according to the section curvature to obtain the micro-topography partitioning result, which is specifically:

[0049] Strong concave terrain: K p '<-0.75;

[0050] Slightly concave terrain: -0.75≤Kp '<-0.015;

[0051] Flat terrain: -0.015≤K p '<0.015;

[0052] Slightly convex terrain: 0.015≤K p '<0.75;

[0053] Strong convex terrain: K p '>0.75.

[0054] The beneficial effect of the above further scheme is that micro-topography zoning based on profile curvature can better distinguish the operations of ecological restoration.

[0055] Furthermore, in step S5, the micro-topography zoning result is used to transform the micro-topography and implement slope greening restoration to complete the ecological restoration of the mine slope micro-topography construction, specifically:

[0056] When the area of ​​strongly concave terrain is larger than the area of ​​flat terrain or the area of ​​strongly concave terrain is larger than the area of ​​strongly convex terrain, and the area difference exceeds 50%: the slope top is fully transformed;

[0057] When the area of ​​strongly concave terrain is larger than the area of ​​flat terrain or the area of ​​strongly concave terrain is larger than the area of ​​strongly convex terrain, and the area difference does not exceed 50%: Distributed drainage condition transformation in local depression areas;

[0058] When the area of ​​strongly convex terrain is larger than that of flat terrain or the area of ​​strongly convex terrain is larger than that of strongly concave terrain, and the area difference exceeds 50%: adjust the slope scour conditions;

[0059] When the area of ​​strongly convex terrain is larger than the area of ​​flat terrain or the area of ​​strongly convex terrain is larger than the area of ​​strongly concave terrain, and the area difference does not exceed 50%: set up ecological stick platforms in areas with more obvious convex terrain;

[0060] When the area of ​​flat terrain is larger than the area of ​​strongly concave terrain or the area of ​​flat terrain is larger than the area of ​​strongly convex terrain, and the area difference exceeds 50%: no micro-topography transformation is performed;

[0061] When the area of ​​flat terrain is larger than that of strongly concave terrain or the area of ​​flat terrain is larger than that of strongly convex terrain, and the area difference does not exceed 50%: local micro-topography transformation is carried out in the strongly convex area.

[0062] The beneficial effect of the above further scheme is that micro-topography zoning based on profile curvature can better distinguish the operations of ecological restoration. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0064] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0065] like Figure 1 As shown, in one embodiment of the present invention, an ecological restoration method for constructing a mine slope micro-topography comprises the following steps:

[0066] S1. Use drones to collect three-dimensional images of the mine slope restoration area to obtain orthophoto data;

[0067] S2. Based on the orthophoto data, the corresponding points between the images are obtained using a feature matching algorithm, and the three-dimensional coordinates of each corresponding point in space are calculated to obtain the rough model point cloud data of the mine slope restoration area;

[0068] S3. Based on the rough model point cloud data of the mine slope restoration area, a three-dimensional terrain model of the mine slope is constructed using Poisson reconstruction;

[0069] S4. Based on the three-dimensional terrain model of the mine slope, the micro-topography is divided by using the section curvature to obtain the micro-topography division result;

[0070] S5. Utilize the results of micro-topography zoning to carry out micro-topography transformation and implement slope regreening and restoration to complete the ecological restoration of the mine slope micro-topography construction.

[0071] In this embodiment, the present invention utilizes close-up photogrammetry, micro-topography transformation, and plant growth component configuration to construct near-natural plant growth site conditions, thereby forming a slope regreening scene that is consistent with the surrounding ecological landscape.

[0072] The step S1 is specifically as follows:

[0073] S101, determining the flight altitude of the drone, and calculating the field of view angle coverage width according to the flight altitude of the drone; the expression of the field of view angle coverage width is:

[0074]

[0075] Where D is the coverage width of the field of view; H is the flight altitude of the drone; tan() is the tangent function; FOV is the field of view of the drone camera;

[0076] S102, determining the overlap degree, and calculating the longitudinal route spacing according to the overlap degree; the expression of the longitudinal route spacing is:

[0077] S=H×(1-O)

[0078] Among them, S is the longitudinal route spacing; H is the flight altitude of the UAV; O is the overlap;

[0079] S103, determining the lateral route spacing according to the field of view angle coverage width;

[0080] S104, obtaining a planned route according to the longitudinal route spacing and the lateral route spacing;

[0081] S105. According to the planned route, the UAV is used to collect three-dimensional images of the mine slope restoration area to obtain orthophoto data.

[0082] In this embodiment, the three-dimensional image acquisition using a drone mainly includes two parts: rough acquisition and detailed acquisition.

[0083] (1) First, an RTK-equipped drone was used to collect orthophoto data of the mine slope restoration area.

[0084] The first step is to determine the flight altitude H of the drone, which is mainly determined by repairing the height of the mine slope. Generally, the flight altitude is 20m higher than the height of the object to be measured. If there is vegetation on the top of the slope, the flight altitude should be higher than the sum of the slope height and the maximum height of the vegetation.

[0085] The second step is to calculate the field of view angle coverage width;

[0086] The third step is to plan the lateral route spacing: Based on the calculated coverage width, plan the lateral route spacing to ensure that the camera field of view of each route covers the edges of adjacent routes.

[0087] The fourth step is to determine the overlap degree O: longitudinal overlap degree 70-80%; transverse overlap degree: 30-60%;

[0088] The fifth step is to calculate the longitudinal route spacing S;

[0089] The sixth step is to combine D and S to plan the route;

[0090] The seventh step is to collect orthophoto data.

[0091] The step S2 is specifically as follows:

[0092] S201, performing dedistortion, brightness adjustment and image enhancement processing on the orthophoto data to obtain pre-processed orthophoto data;

[0093] S202, performing image matching using a feature matching algorithm based on the pre-processed orthophoto data to obtain corresponding points between images;

[0094] S203, according to the UAV flight parameters and camera parameters, using the stereo vision principle and triangulation method to calculate the three-dimensional coordinates of each corresponding point in space, and obtain the three-dimensional point cloud data of each corresponding point;

[0095] S204, denoising, filtering and point cloud data homogenization are performed on the three-dimensional point cloud data of each corresponding point to obtain the rough model point cloud data of the mine slope restoration area.

[0096] In this embodiment, the collected orthophotos are preprocessed, including distortion removal, brightness adjustment, and image enhancement processing; a feature matching algorithm is used to find corresponding points between different images; and image matching is used to obtain corresponding points. Combined with the flight parameters of the drone and the camera parameters, the three-dimensional coordinates of each corresponding point in space are calculated through the principle of stereo vision and triangulation method to generate three-dimensional point cloud data; the generated three-dimensional point cloud data is subjected to preliminary processing such as denoising, filtering, and point cloud data homogenization to obtain coarse-model point cloud data of the mine slope restoration area.

[0097] The step S3 is specifically as follows:

[0098] S301, based on the rough model point cloud data of the mine slope restoration area, a route planning close to photography is performed to obtain a wonderful mining route;

[0099] S302, according to the fine mining route, use drones to carry out drone close-up photogrammetry and fine mining of the mine slope restoration area at different heights and angles to obtain fine mining image data;

[0100] S303, performing image dedistortion, registration and color balance on the fine-collected image data to obtain pre-processed fine-collected image data;

[0101] S304, based on the pre-processed fine-sampled image data, using motion recovery structure technology and multi-view stereo matching algorithm to restore the three-dimensional structure of the scene to obtain dense point cloud data;

[0102] S305, performing point cloud filtering, classification and denoising according to the dense point cloud data to obtain effective terrain feature points;

[0103] S306. Construct a three-dimensional terrain model of the mine slope using Poisson reconstruction based on effective terrain feature points.

[0104] In this embodiment, the rough model point cloud data of the mine slope restoration area is used to carry out refined close-to-route planning to ensure full coverage of all angles of the high and steep slopes in the restoration area:

[0105] The first step is to set the orthophoto shooting angle, with the camera facing downwards, mainly to obtain the terrain information below the ground, and the overlap of adjacent longitudinal routes is 75-85%;

[0106] The second step is to set the left and right cross-direction shooting angles. The camera is sideways, mainly to obtain the topographic undulations of the mine slope, and the overlap of adjacent lateral routes is 60-70%;

[0107] The third step is to set the vertical and horizontal shooting angles. The camera is tilted at a low angle to obtain images from different angles, with an overlap of 60-70% between layers.

[0108] The fourth step is to accurately plan the route based on the required overlap and shooting angle, referring to (1).

[0109] After the route is set, drone close-up photogrammetry is carried out at different heights and angles to quickly capture the geometric features of the depressions in the rock and soil bodies on the steep slopes of the mine and build a high-precision three-dimensional image model (i.e., a three-dimensional terrain model of the mine slope):

[0110] In the first step, the drone automatically flies along a predetermined route to collect high-resolution photos covering the entire mine slope;

[0111] The second step is image preprocessing, including image dedistortion, registration, and color balancing;

[0112] The third step is image matching and point cloud generation, which mainly uses structure from motion technology and multi-view stereo matching algorithm to recover the three-dimensional structure of the scene from multiple images and generate dense point cloud data;

[0113] The fourth step is to filter, classify and denoise the generated dense point cloud data to extract effective terrain feature points;

[0114] The fifth step is to construct a high-precision three-dimensional terrain model based on the processed point cloud using Poisson reconstruction.

[0115] The step S4 is specifically as follows: calculating the section curvature of the three-dimensional terrain model of the mine slope in sequence with a cm×a cm window area, and performing micro-topography partitioning according to the section curvature to obtain micro-topography partitioning results; wherein a is the window width.

[0116] In this embodiment, the cross-sectional curvature is calculated based on a window area of ​​3×3 cm.

[0117] The expression of the cross-sectional curvature is:

[0118] K p '=C r ·K p

[0119]

[0120] Among them, K p ' is the section curvature; C r K is the correction factor based on the resolution of the drone; p is the standard section curvature; fxx is the second-order partial derivative of the effective terrain feature point in the X direction; f xy For effective terrain feature points, first calculate the partial derivative in the X direction and then calculate the second-order partial derivative in the Y direction; f x is the partial derivative of the effective terrain feature point in the X direction; f y is the partial derivative of the effective terrain feature point in the Y direction; f yy is the second-order partial derivative of the effective terrain feature point in the Y direction.

[0121] In this embodiment, if the resolution of the drone is 10 cm, C r =1.5; if the resolution of the drone is 5cm, C r =1.3; if the resolution of the drone is 3cm, C r =1; if the drone resolution is 1cm, C r =0.8.

[0122] The micro-topography partition is performed according to the profile curvature to obtain the micro-topography partition result, which is specifically:

[0123] Strong concave terrain: K p '<-0.75;

[0124] Slightly concave terrain: -0.75≤K p '<-0.015;

[0125] Flat terrain: -0.015≤K p '<0.015;

[0126] Slightly convex terrain: 0.015≤K p '<0.75;

[0127] Strong convex terrain: K p '>0.75.

[0128] In step S5, the micro-topography zoning result is used to transform the micro-topography and implement slope greening restoration to complete the ecological restoration of the mine slope micro-topography construction, specifically:

[0129] When the area of ​​strongly concave terrain is larger than the area of ​​flat terrain or the area of ​​strongly concave terrain is larger than the area of ​​strongly convex terrain, and the area difference exceeds 50%: the slope top is fully transformed;

[0130] When the area of ​​strongly concave terrain is larger than the area of ​​flat terrain or the area of ​​strongly concave terrain is larger than the area of ​​strongly convex terrain, and the area difference does not exceed 50%: Distributed drainage condition transformation in local depression areas;

[0131] When the area of ​​strongly convex terrain is larger than that of flat terrain or the area of ​​strongly convex terrain is larger than that of strongly concave terrain, and the area difference exceeds 50%: adjust the slope scour conditions;

[0132] When the area of ​​strongly convex terrain is larger than the area of ​​flat terrain or the area of ​​strongly convex terrain is larger than the area of ​​strongly concave terrain, and the area difference does not exceed 50%: set up ecological stick platforms in areas with more obvious convex terrain;

[0133] When the area of ​​flat terrain is larger than the area of ​​strongly concave terrain or the area of ​​flat terrain is larger than the area of ​​strongly convex terrain, and the area difference exceeds 50%: no micro-topography transformation is performed;

[0134] When the area of ​​flat terrain is larger than that of strongly concave terrain or the area of ​​flat terrain is larger than that of strongly convex terrain, and the area difference does not exceed 50%: local micro-topography transformation is carried out in the strongly convex area.

[0135] In this embodiment, the micro-topography zoning results are used to carry out micro-topography transformation and implement slope regreening and restoration.

[0136] (1) When the area of ​​strongly concave terrain (Sqa) is greater than the area of ​​flat terrain (Spt) or the area of ​​strongly convex terrain (Sqt), and the area difference exceeds 50%, the micro-topography transformation is mainly based on the transformation of the full drainage conditions on the top of the slope. Micro-drainage ditches should be set up on the upper edge of the concave area to transform the local terrain and reduce the regional water accumulation effect. The size of the micro-drainage ditch is 30-50cm, the depth is 20-30cm, the slope is 1-5%, and the prefabricated lightweight concrete drainage trough is fixed on the slope with anchors. For concave terrain areas, directly use cavity spraying or point covering to regreen the cavity, mainly with shrubs or herbaceous plants.

[0137] (2) When the area of ​​strongly concave terrain (Sqa) is greater than the area of ​​flat terrain (Spt) or the area of ​​strongly convex terrain (Sqt), and the area difference does not exceed 50%, the micro-topography transformation is mainly based on the transformation of distributed drainage conditions in local depression areas. For specific methods, see (1).

[0138] (3) When the area of ​​strongly convex terrain (Sqt) is greater than the area of ​​flat terrain (Spt) or the area of ​​strongly concave terrain (Sqa), and the area difference exceeds 50%, the micro-topography transformation is mainly based on adjusting the slope scouring conditions. Lightweight platforms should be set up at intervals of 10m in the convex area to reduce direct scouring of the slope by rainwater, and space for planting vegetation can be provided on the upper part of the platform. The width of the lightweight platform is 10cm, the height is 5cm, and the slope is 1-5%. The eco-rod is fixed to the slope with anchors, and a geonet support is placed horizontally at the bottom of the eco-rod. Biodegradable straw and coconut shell fiber are placed in the eco-rod, and shrubs and climbing vines are planted.

[0139] (4) When the area of ​​strongly convex terrain (Sqt) is greater than the area of ​​flat terrain (Spt) or the area of ​​strongly concave terrain (Sqa), and the area difference does not exceed 50%, micro-topography reconstruction mainly involves setting up ecological rod platforms in areas with more obvious convex terrain. See (3) for specific restoration methods.

[0140] (5) When the flat terrain area (Spt) is greater than the strongly concave terrain area (Sqa) or the strongly convex terrain area (Sqt), and the area difference exceeds 50%, no micro-topography reconstruction is performed. The main methods of restoration are spraying and regreening or planting drooping plants on the top of the slope.

[0141] (6) When the flat terrain area (Spt) is greater than the strongly concave terrain area (Sqa) or the strongly convex terrain area (Sqt), and the area difference does not exceed 50%, local micro-topography transformation should be mainly carried out in the strongly convex area. Local erosion reduction measures should be carried out in the strongly convex area, and ecological barriers with smaller cross-sections should be set up, with dimensions of 40 cm in height, 30 cm in width, and 2 m in length. The slope of the back of the barrier is 1:1.5. The barrier body is made of biodegradable wood or bamboo, and the filling material is a 10 cm bottom drainage gravel layer and fertile soil on top. During restoration, spraying and greening are mainly used in flat areas or concave areas, and climbing vines are planted on the ecological barriers in convex areas.

Claims

1. An ecological restoration method for the construction of mine slope micro-topography, It is characterized in that The following steps are involved: S1. Using a drone to collect three-dimensional images of the mine slope restoration area to obtain orthophoto data; the step S1 is specifically as follows: S101, determining the flight height of the drone, and calculating the field of view angle coverage width according to the flight height of the drone; the expression of the field of view angle coverage width in step S101 is: Where D is the coverage width of the field of view; H is the flight altitude of the drone; tan() is the tangent function; FOV is the field of view of the drone camera; S102, determining the overlap degree, and calculating the longitudinal route spacing according to the overlap degree; the expression of the longitudinal route spacing in step S102 is: S=H×(1-O) Among them, S is the longitudinal route spacing; H is the flight altitude of the UAV; O is the overlap; S103, determining the lateral route spacing according to the coverage width of the field of view angle; S104, obtaining a planned route according to the longitudinal route spacing and the lateral route spacing; S105. According to the planned route, the UAV is used to collect three-dimensional images of the mine slope restoration area to obtain orthophoto data; S2. Based on the orthophoto data, the corresponding points between the images are obtained using a feature matching algorithm, and the three-dimensional coordinates of each corresponding point in space are calculated to obtain the rough model point cloud data of the mine slope restoration area; S3. Based on the rough model point cloud data of the mine slope restoration area, a three-dimensional terrain model of the mine slope is constructed using Poisson reconstruction; S4. Based on the three-dimensional terrain model of the mine slope, the micro-topography is divided by using the section curvature to obtain the micro-topography division result; S5. Utilize the results of micro-topography zoning to carry out micro-topography transformation and implement slope regreening and restoration to complete the ecological restoration of the mine slope micro-topography construction.

2. The ecological restoration method for the construction of mine slope micro-topography according to claim 1, It is characterized in that The step S2 is specifically as follows: S201, performing dedistortion, brightness adjustment and image enhancement processing on the orthophoto data to obtain pre-processed orthophoto data; S202, performing image matching using a feature matching algorithm based on the pre-processed orthophoto data to obtain corresponding points between images; S203, according to the UAV flight parameters and camera parameters, using the stereo vision principle and triangulation method to calculate the three-dimensional coordinates of each corresponding point in space, and obtain the three-dimensional point cloud data of each corresponding point; S204, denoising, filtering and point cloud data homogenization are performed on the three-dimensional point cloud data of each corresponding point to obtain the rough model point cloud data of the mine slope restoration area.

3. The ecological restoration method for the construction of mine slope micro-topography according to claim 1, It is characterized in that The step S3 is specifically as follows: S301, based on the rough model point cloud data of the mine slope restoration area, a route planning close to photography is performed to obtain a wonderful mining route; S302, according to the fine mining route, use drones to carry out drone close-up photogrammetry and fine mining of the mine slope restoration area at different heights and angles to obtain fine mining image data; S303, performing image dedistortion, registration and color balance on the fine-collected image data to obtain pre-processed fine-collected image data; S304, based on the pre-processed fine-sampled image data, using motion recovery structure technology and multi-view stereo matching algorithm to restore the three-dimensional structure of the scene to obtain dense point cloud data; S305, performing point cloud filtering, classification and denoising according to the dense point cloud data to obtain effective terrain feature points; S306. Construct a three-dimensional terrain model of the mine slope using Poisson reconstruction based on effective terrain feature points.

4. The ecological restoration method for the construction of mine slope micro-topography according to claim 1, It is characterized in that The step S4 is specifically as follows: calculating the section curvature of the three-dimensional terrain model of the mine slope in sequence with a cm×a cm window area, and performing micro-topography partitioning according to the section curvature to obtain micro-topography partitioning results; wherein a is the window width.

5. The ecological restoration method for the construction of micro-topography on the mine slope according to claim 4, It is characterized in that The expression of the cross-sectional curvature is: K p '=C r ·K p Among them, K p ' is the section curvature; C r K is the correction factor based on the resolution of the drone; p is the standard section curvature; f xx is the second-order partial derivative of the effective terrain feature point in the X direction; f xy For effective terrain feature points, first calculate the partial derivative in the X direction and then calculate the second-order partial derivative in the Y direction; f x is the partial derivative of the effective terrain feature point in the X direction; f y is the partial derivative of the effective terrain feature point in the Y direction; f yy is the second-order partial derivative of the effective terrain feature point in the Y direction.

6. The ecological restoration method for the construction of micro-topography on the mine slope according to claim 5, It is characterized in that The micro-topography partition is performed according to the profile curvature to obtain the micro-topography partition result, which is specifically: Strong concave terrain: K p '<-0.75; Slightly concave terrain: -0.75≤K p '<-0.015; Flat terrain: -0.015≤K p '<0.015; Slightly convex terrain: 0.015≤K p '<0.75; Strong convex terrain: K p '>0.

75.

7. The ecological restoration method for the construction of micro-topography on the mine slope according to claim 6, It is characterized in that In step S5, the micro-topography zoning result is used to transform the micro-topography and implement slope greening restoration to complete the ecological restoration of the mine slope micro-topography construction, specifically: When the area of ​​strongly concave terrain is larger than the area of ​​flat terrain or the area of ​​strongly concave terrain is larger than the area of ​​strongly convex terrain, and the area difference exceeds 50%: the slope top is fully transformed; When the area of ​​strongly concave terrain is larger than the area of ​​flat terrain or the area of ​​strongly concave terrain is larger than the area of ​​strongly convex terrain, and the area difference does not exceed 50%: Distributed drainage condition transformation in local depression areas; When the area of ​​strongly convex terrain is larger than that of flat terrain or the area of ​​strongly convex terrain is larger than that of strongly concave terrain, and the area difference exceeds 50%: adjust the slope scour conditions; When the area of ​​strongly convex terrain is larger than the area of ​​flat terrain or the area of ​​strongly convex terrain is larger than the area of ​​strongly concave terrain, and the area difference does not exceed 50%: set up ecological stick platforms in areas with more obvious convex terrain; When the area of ​​flat terrain is larger than the area of ​​strongly concave terrain or the area of ​​flat terrain is larger than the area of ​​strongly convex terrain, and the area difference exceeds 50%: no micro-topography transformation is performed; When the area of ​​flat terrain is larger than that of strongly concave terrain or the area of ​​flat terrain is larger than that of strongly convex terrain, and the area difference does not exceed 50%: local micro-topography transformation is carried out in the strongly convex area.

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