Evaluation method for greening rate of slope ecological engineering

Abstract

The invention relates to the technical field of slope greening perception, and discloses a slope ecological engineering greening rate evaluation method, which comprises the following steps: acquiring a digital elevation map and an orthoimage of a slope; according to the orthoimage, dividing the slope into a vegetation coverage area and a non-vegetation coverage area based on a visible light difference vegetation index; according to the digital elevation map of the vegetation coverage area, the slope division method is adopted to calculate the overall slope greening rate and the slope greening rates of different slope intervals; and according to the digital elevation map of the vegetation coverage area, calculating the side slope green vision rates and the average side slope green vision rate of different observation positions by adopting an observation point vision field analysis method. According to the slope greening evaluation method, the overall slope greening rate for describing slope ecological functionality, the slope greening rates of different slope intervals, the slope greening rate of a specific observation position for evaluating landscape functionality and the average greening rate for evaluating the overall landscape functionality are established, and a more comprehensive and accurate slope greening evaluation effect can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of slope greening perception, and in particular to a method for evaluating the greening rate of a slope ecological engineering project. Background Art

[0002] The ecological engineering of road slopes and mine slopes is an important part of ecological civilization construction and is of great significance to the beautification of the ecological environment. At present, there is a lack of clear greening effect evaluation methods for slope ecological engineering, which restricts the economic design, effect monitoring and acceptance of ecological engineering. Traditional greening effect evaluation mostly uses the projected area greening rate as an evaluation index, that is, the ratio of the projected area of ​​the vegetation area on the horizontal plane to the total projected area. However, the projected area greening rate index seriously ignores the slope effect and viewshed problems of the slope. The slope effect refers to the fact that the slope area of ​​the same projected area with different slopes is not the same, and the steeper the slope, the larger the slope area; the viewshed problem refers to the blind spot formed by the near-field objects or terrain blocking the vision, and the objects in the distant field cannot be observed. Therefore, the evaluation result of the projected area greening rate without considering the slope effect and viewshed problems not only overestimates the actual greening situation of the slope, but also overestimates the greening effect perceived by the human eye, and cannot objectively evaluate the functional and landscape characteristics of the slope ecological engineering.

[0003] In order to objectively describe the degree of slope greening and human perception of greening, and to clarify the existing problems of slope greening, it is of great significance to introduce slope greening rate, greening rate in different slope intervals, and green view rate at different observation distances into the evaluation of slope greening effect. The slope greening rate can reflect the area of ​​real plant growth and better reflect the functional characteristics of the ecosystem than the projected greening rate. At the same time, the green view rate can more accurately reflect human perception and better evaluate the landscape characteristics of the greening project.

[0004] At present, the measurement of slope greening rate often adopts traditional measurement or estimation based on slope characteristics, while the calculation of green view rate often adopts on-site photography and image processing. The measurement of these two parameters is time-consuming, labor-intensive and costly, and cannot fully and accurately describe the results, let alone show the greening characteristics of different slopes and the observation results of different observation angles and distances. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for evaluating the greening rate of a slope ecological engineering project.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is: A method for evaluating the greening rate of a slope ecological project comprises the following steps: Obtain digital elevation maps and orthophotos of the slopes; According to the orthophoto, the slope is divided into vegetation-covered area and non-vegetation-covered area based on the visible light difference vegetation index; According to the digital elevation map of the vegetation coverage area, the slope division method is used to calculate the overall slope greening rate and the slope greening rate of different slope intervals; According to the digital elevation map of the vegetation coverage area, the observation point viewshed analysis method was used to calculate the slope green view rate and the average slope green view rate at different observation positions.

[0007] Optionally, based on the orthophoto, the slope is divided into vegetation covered areas and non-vegetation covered areas based on the visible light difference vegetation index, including: The visible light difference vegetation index is calculated based on the orthophoto, expressed as:

[0008] in, represents the visible light difference vegetation index, Represents the green band, red band, and blue band of the RGB image. Indicates the position number of the raster file in the horizontal and vertical directions; The slopes whose visible light difference vegetation index is greater than the set threshold are divided into vegetation-covered areas, and the slopes whose visible light difference vegetation index is less than or equal to the set threshold are divided into non-vegetation-covered areas.

[0009] Optionally, based on the digital elevation map of the vegetation coverage area, the slope division method is used to calculate the overall slope greening rate and the slope greening rate of different slope intervals, including: Grid the digital elevation map of the vegetation-covered area and calculate the overall slope greening rate; The digital elevation map of the vegetation coverage area is divided into slopes, and the slope greening rates of different slope ranges are calculated.

[0010] Optionally, the digital elevation map of the vegetation-covered area is gridded to calculate the overall slope greening rate, including: Divide the digital elevation map of the vegetation-covered area into grids and calculate the slope value corresponding to each grid; According to the slope value corresponding to each grid, calculate the slope area value corresponding to each grid; The slope area value and vegetation coverage area determination value corresponding to each grid are matrixed and then Hadamard multiplication operation is performed to obtain the slope area value of the vegetation coverage area; The overall slope greening rate is calculated based on the slope area value of the vegetation coverage area and the slope area value corresponding to each grid.

[0011] As an alternative, the overall slope greening rate is calculated as follows:

[0012] in, Represents the overall slope greening rate, Indicates the slope area value of the vegetation coverage area. Indicates the slope area value. Indicates the position number of the raster file in the horizontal and vertical directions.

[0013] Optionally, the digital elevation map of the vegetation coverage area is divided into slopes, and the slope greening rates of different slope intervals are calculated, including: According to the set slope interval, the digital elevation map of the vegetation coverage area is divided into multiple slope intervals; Calculate the slope area value corresponding to each slope interval; The slope area values ​​and vegetation coverage area determination values ​​corresponding to each slope interval are matrixed and then Hadamard multiplication is performed to obtain the slope area values ​​of the vegetation coverage area under each slope interval; The slope greening rate of each slope interval is calculated based on the slope area value of the vegetation coverage area under each slope interval and the slope area value corresponding to each slope interval.

[0014] As an option, the slope greening rate of each slope interval is calculated as follows:

[0015] in, represents the slope greening rate, Indicates the slope area value of the vegetation coverage area. Indicates the slope area value. Indicates the position number of the raster file in the horizontal and vertical directions. Indicates the slope interval number.

[0016] Optionally, based on the digital elevation map of the vegetation coverage area, the observation point viewshed analysis method is used to calculate the slope green view rate and the average slope green view rate at different observation positions, including: Observation points are arranged in the observation area, and the locations of the observation points are determined based on the digital elevation map of the vegetation-covered area; Perform viewshed analysis on each observation point one by one to obtain the slope viewshed results; The perceived area value of the slope is calculated based on the pitch angle of the observation point and the ratio of distance and size; After matrix processing of the slope perception area value and the slope viewshed result, Hadamard multiplication operation is performed to obtain the perception area value within the viewshed range; After matrix processing of the perceived area value and the vegetation coverage area determination value within the visual range, Hadamard multiplication operation is performed to obtain the vegetation perceived area value within the visual range; According to the perceived area value within the visual range and the perceived area value of vegetation within the visual range, the green viewing rate of the slope at different observation positions is calculated; After eliminating abnormal data of the green viewing rate of the slope at different observation positions, the average green viewing rate is calculated to obtain the average green viewing rate of the slope.

[0017] Alternatively, the slope-aware area value is calculated as:

[0018] in, represents the slope perception area value, Indicates the slope value, represents the size of the grid cell, Indicates observation point iii and the observed position The distance between Indicates the pitch viewing angle.

[0019] As an option, the slope green view rate at different observation positions is calculated as follows:

[0020] in, Indicates observation point iii The slope green view rate, Indicates the perceived area value of vegetation within the field of view. Represents the perceived area value within the field of view. Indicates the position number of the raster file in the horizontal and vertical directions.

[0021] The present invention has the following beneficial effects: The present invention can achieve a more comprehensive and accurate slope greening evaluation effect by establishing an overall slope greening rate that describes the ecological functionality of the slope, the slope greening rates in different slope ranges, the slope greening rate at a specific observation position for evaluating landscape functionality, and the average greening rate for evaluating the overall landscape functionality. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a flow chart of a slope ecological engineering greening rate assessment method; Figure 2 This is a schematic diagram of the segmentation of vegetation-covered areas and non-vegetation-covered areas; Figure 3 It is a schematic diagram for slope, slope area calculation and slope classification; Figure 4 Schematic diagram for observation point layout; Figure 5 This is a schematic diagram of the slope viewshed results; Figure 6 Schematic diagram of slope perception area value calculation. DETAILED DESCRIPTION

[0023] 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.

[0024] In view of the technical problem that the existing technology lacks rapid evaluation indicators and evaluation methods for greening effects of ecological projects on complex slope terrain, the present invention proposes a rapid evaluation method for the functional and landscape greening effects of slope ecological projects, and proposes a low-cost corresponding automatic extraction method, which can be used for the acceptance and monitoring of greening projects. The details are as follows: (a) In view of the current lack of evaluation methods for slope greening effects, the present invention proposes a technical method for modeling by low-altitude photography by unmanned aerial vehicles, calculating the slope greening rate, and calculating the green visibility rate at different custom observation positions.

[0025] (b) In response to the current use of projected area greening rate, this study proposed an evaluation method for slope greening rate and greening rate in different slope intervals, which can evaluate the greening effect more comprehensively and accurately.

[0026] (c) Compared with the current green view rate evaluation method using fixed-point photography, the method proposed in the present invention can realize green view rate evaluation at a custom location after a survey and modeling.

[0027] (d) Compared with the use of expensive mobile 3D laser scanning equipment, the present invention uses drone photography modeling to solve the problems of high cost and limited shooting angles.

[0028] (e) Compared with the existing green view rate analysis which uses a complex identification model, the present invention adopts the visible light difference vegetation index to divide the slope plant area, targeting the slope greening projects which often have simple ecological structures and significant differences between vegetation and non-vegetation areas.

[0029] like Figure 1 As shown, a slope ecological engineering greening rate assessment method provided by an embodiment of the present invention includes the following steps S1 to S4: S1. Obtain digital elevation map and orthophoto of the slope; In an optional embodiment of the present invention, step S1 performs drone photography of the slope to be assessed to obtain a digital elevation map and orthophoto of the slope to be assessed with a specified resolution.

[0030] Step S1: Fly at low altitude over the slope (less than 30m from the slope surface), and clip the high-precision digital elevation map and orthophoto using the slope range to be evaluated, and resample the result based on the average crown diameter d of the slope vegetation. The resampling technique adopts bilinear interpolation.

[0031] S2. Based on the orthophoto, the slope is divided into vegetation-covered area and non-vegetation-covered area based on the visible light difference vegetation index; In an optional embodiment of the present invention, step S2 divides the slope into vegetation-covered areas and non-vegetation-covered areas based on the orthophoto and the visible light difference vegetation index, including: The visible light difference vegetation index is calculated based on the orthophoto, expressed as:

[0032] in, represents the visible light difference vegetation index, Represents the green band, red band, and blue band of the RGB image. Indicates the position number of the raster file in the horizontal and vertical directions; The slopes with visible light difference vegetation index greater than the set threshold are divided into vegetation covered areas, and the slopes with visible light difference vegetation index less than or equal to the set threshold are divided into non-vegetation covered areas, which can be expressed as:

[0033] in, Indicates the vegetation coverage area determination value.

[0034] In this embodiment, the greening area and the non-greening area are often significantly different in slope reforestation projects. The visible difference vegetation index (VDVI) is used as the division index. The threshold value is set to 0.1 by default, that is, areas above 0.1 are vegetation areas, and areas below 0.1 are non-vegetation areas. Figure 2 shown.

[0035] S3. According to the digital elevation map of the vegetation coverage area, the slope division method is used to calculate the overall slope greening rate and the slope greening rate of different slope intervals; In an optional embodiment of the present invention, step S3 calculates the overall slope greening rate and the slope greening rate of different slope intervals using a slope division method according to a digital elevation map of the vegetation coverage area, including: Grid the digital elevation map of the vegetation-covered area and calculate the overall slope greening rate; The digital elevation map of the vegetation coverage area is divided into slopes, and the slope greening rates of different slope ranges are calculated.

[0036] In this embodiment, the digital elevation map of the vegetation coverage area is gridded and the overall slope greening rate is calculated, such as Figure 3 As shown, including: The digital elevation map of the vegetation-covered area is divided into grids, and the slope value corresponding to each grid is calculated, which is expressed as:

[0037]

[0038]

[0039] Among them, dem represents the grid unit, dzdx represents the slope in the x direction, and dzdy represents the slope in the y direction. Respectively represent the position numbers of the grid units in the horizontal and vertical directions; Indicates horizontal i , vertical j The slope value corresponding to each grid cell; According to the slope value corresponding to each grid, the slope area value corresponding to each grid is calculated, which is expressed as:

[0040] in, express; After matrix processing of the slope area value and vegetation coverage area judgment value corresponding to each grid, Hadamard multiplication operation is performed to obtain the slope area value of the vegetation coverage area, which is expressed as:

[0041] According to the slope area value of the vegetation coverage area and the slope area value corresponding to each grid, the overall slope greening rate is calculated and expressed as:

[0042] in, Represents the overall slope greening rate, Indicates the slope area value of the vegetation coverage area. Indicates the slope area value. Indicates the position number of the raster file in the horizontal and vertical directions.

[0043] In this embodiment, the digital elevation map of the vegetation coverage area is divided into slopes, and the slope greening rates of different slope intervals are calculated, including: According to the set slope interval , the digital elevation map of the vegetation coverage area is divided into multiple slope intervals, namely ; Calculate the slope area value corresponding to each slope interval, expressed as:

[0044] in, Indicates the slope interval number, which is 1~n; The slope area values ​​and vegetation coverage area determination values ​​corresponding to each slope interval are matrixed and then Hadamard multiplication is performed to obtain the slope area values ​​of the vegetation coverage area under each slope interval, which is expressed as:

[0045] According to the slope area value of the vegetation coverage area under each slope interval and the slope area value corresponding to each slope interval, the slope greening rate of each slope interval is calculated, which is expressed as:

[0046] in, represents the slope greening rate, Indicates the slope area value of the vegetation coverage area. Indicates the slope area value. Indicates the position number of the raster file in the horizontal and vertical directions. Indicates the slope interval number.

[0047] S4. Based on the digital elevation map of the vegetation coverage area, the observation point view analysis method is used to calculate the slope green viewing rate and the average slope green viewing rate at different observation positions.

[0048] In an optional embodiment of the present invention, step S4 calculates the slope green viewing rate and the slope average green viewing rate at different observation positions using an observation point viewshed analysis method according to a digital elevation map of the vegetation coverage area, including: Observation points are arranged in the observation area, and the positions of the observation points are determined based on the digital elevation map of the vegetation coverage area. Specifically, this embodiment determines the potential observation area. For linear areas such as roads, the observation points are arranged at equal intervals on the front of the slope (one observation point every 25m), and the observation points outside the slope are arranged in a geometric series (25m, 50m, 100m). For planar areas, the observation points are radiated outward along the front of the slope in a geometric series (25m, 50m, 100m). The altitude of the observation points is extracted from the regional digital elevation map. , with the average eye height of 1.6m, calculate the height of the observation point The observation point location is recorded as ,like Figure 4 shown.

[0049] The viewshed analysis is performed on each observation point one by one to obtain the viewshed result of the slope. Specifically, this embodiment uses the viewshed analysis tool of ArcGIS Pro software to perform viewshed analysis on each observation point one by one. The viewshed result of the investigated slope is:

[0050] in, iii is the observation point number, i,j is the grid cell projection coordinate of the slope. Figure 5 shown.

[0051] The perceived area value of the slope is calculated according to the pitch angle of the sight line of the observation point and the ratio of the distance. Specifically, this embodiment calculates the perceived area value of the slope according to the pitch angle of the sight line of the observation point and the ratio of the distance, wherein the upward result is calculated by vertical projection, the downward result is calculated by horizontal projection, and the distance effect is obtained by dividing the projection area by the observation distance, and is expressed as:

[0052]

[0053]

[0054] in, represents the slope perception area value, Indicates the slope value, represents the size of the grid cell, Indicates observation point iii and the observed position The distance between Indicates the pitch angle. Figure 6 shown.

[0055] After matrix processing of the slope perception area value and the slope viewshed result, Hadamard multiplication operation is performed to obtain the perception area value within the viewshed, which is expressed as:

[0056] Among them, the area with a result of 0 is the invisible area, and the area with a non-zero result is the perceived area of ​​the visible area.

[0057] After matrix processing of the perceived area value and the vegetation coverage area determination value within the field of view, Hadamard multiplication operation is performed to obtain the vegetation perception area value within the field of view, which is expressed as:

[0058] According to the perceived area value within the visual range and the perceived area value of vegetation within the visual range, the slope green viewing rate at different observation positions is calculated and expressed as:

[0059] in, Indicates observation point iii The slope green view rate, Indicates the perceived area value of vegetation within the field of view. Represents the perceived area value within the field of view. Indicates the position number of the raster file in the horizontal and vertical directions.

[0060] After eliminating abnormal data of the green viewing rate of the slope at different observation positions, the average green viewing rate is calculated to obtain the average green viewing rate of the slope.

[0061] This embodiment uses the interquartile range method to eliminate abnormal data of green view rate, and obtains the average value of green view rate after eliminating abnormal values. The result is the average result of green view rate of the investigated slope.

[0062] The present invention can be used for rapid evaluation of the greening effect of slope ecological engineering. The present invention can be used in the design stage, such as not planting precious plants in non-visible ranges; it can be used for detection in construction and maintenance projects to quantitatively reveal locations and areas with poor greening effects; it can be used for acceptance evaluation of slope ecological engineering to quantitatively describe the greening effect and describe the benefits of the project in terms of functionality and landscape.

[0063] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0064] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0065] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0066] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

[0067] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A method for evaluating the greening rate of a slope ecological project, characterized in that: The following steps are involved: Obtain digital elevation maps and orthophotos of the slopes; According to the orthophoto, the slope is divided into vegetation-covered area and non-vegetation-covered area based on the visible light difference vegetation index; According to the digital elevation map of the vegetation coverage area, the slope division method is used to calculate the overall slope greening rate and the slope greening rate of different slope intervals; According to the digital elevation map of the vegetation coverage area, the observation point viewshed analysis method was used to calculate the slope green view rate and the average slope green view rate at different observation positions.

2. A slope ecological engineering greening rate assessment method according to claim 1, characterized in that: According to the orthophoto, the slope is divided into vegetation-covered area and non-vegetation-covered area based on the visible light difference vegetation index, including: The visible light difference vegetation index is calculated based on the orthophoto, expressed as: in, represents the visible light difference vegetation index, Represents the green band, red band, and blue band of the RGB image. Indicates the position number of the raster file in the horizontal and vertical directions; The slopes whose visible light difference vegetation index is greater than the set threshold are divided into vegetation-covered areas, and the slopes whose visible light difference vegetation index is less than or equal to the set threshold are divided into non-vegetation-covered areas.

3. The method for evaluating the greening rate of a slope ecological project according to claim 1 is characterized in that: According to the digital elevation map of the vegetation coverage area, the slope division method is used to calculate the overall slope greening rate and the slope greening rate of different slope intervals, including: Grid the digital elevation map of the vegetation-covered area and calculate the overall slope greening rate; The digital elevation map of the vegetation coverage area is divided into slopes, and the slope greening rates of different slope ranges are calculated.

4. A slope ecological engineering greening rate assessment method according to claim 3, characterized in that: Grid the digital elevation map of the vegetation-covered area and calculate the overall slope greening rate, including: Divide the digital elevation map of the vegetation-covered area into grids and calculate the slope value corresponding to each grid; According to the slope value corresponding to each grid, calculate the slope area value corresponding to each grid; The slope area value and vegetation coverage area determination value corresponding to each grid are matrixed and then Hadamard multiplication operation is performed to obtain the slope area value of the vegetation coverage area; The overall slope greening rate is calculated based on the slope area value of the vegetation coverage area and the slope area value corresponding to each grid.

5. A slope ecological engineering greening rate assessment method according to claim 4, characterized in that: The calculation method of the overall slope greening rate is: in, Represents the overall slope greening rate, Indicates the slope area value of the vegetation coverage area. Indicates the slope area value. Indicates the position number of the raster file in the horizontal and vertical directions.

6. A slope ecological engineering greening rate assessment method according to claim 3, characterized in that: The digital elevation map of the vegetation coverage area is divided into slopes, and the slope greening rate of different slope intervals is calculated, including: According to the set slope interval, the digital elevation map of the vegetation coverage area is divided into multiple slope intervals; Calculate the slope area value corresponding to each slope interval; The slope area values ​​and vegetation coverage area determination values ​​corresponding to each slope interval are matrixed and then Hadamard multiplication is performed to obtain the slope area values ​​of the vegetation coverage area under each slope interval; The slope greening rate of each slope interval is calculated based on the slope area value of the vegetation coverage area under each slope interval and the slope area value corresponding to each slope interval.

7. A slope ecological engineering greening rate assessment method according to claim 6, characterized in that: The calculation method of slope greening rate in each slope interval is: in, represents the slope greening rate, Indicates the slope area value of the vegetation coverage area. Indicates the slope area value. Indicates the position number of the raster file in the horizontal and vertical directions. Indicates the slope interval number.

8. The method for evaluating the greening rate of a slope ecological project according to claim 1 is characterized in that: According to the digital elevation map of the vegetation coverage area, the observation point viewshed analysis method is used to calculate the slope green view rate and the average slope green view rate at different observation positions, including: Observation points are arranged in the observation area, and the locations of the observation points are determined based on the digital elevation map of the vegetation-covered area; Perform viewshed analysis on each observation point one by one to obtain the slope viewshed results; The perceived area value of the slope is calculated based on the pitch angle of the observation point and the ratio of distance and size; After matrix processing of the slope perception area value and the slope viewshed result, Hadamard multiplication operation is performed to obtain the perception area value within the viewshed range; After matrix processing of the perceived area value and the vegetation coverage area determination value within the visual range, Hadamard multiplication operation is performed to obtain the vegetation perceived area value within the visual range; According to the perceived area value within the visual range and the perceived area value of vegetation within the visual range, the green viewing rate of the slope at different observation positions is calculated; After eliminating abnormal data of the green viewing rate of the slope at different observation positions, the average green viewing rate is calculated to obtain the average green viewing rate of the slope.

9. A slope ecological engineering greening rate assessment method according to claim 8, characterized in that: The slope perception area value is calculated as follows: in, represents the slope perception area value, Indicates the slope value, represents the size of the grid cell, Indicates observation point iii and the observed position The distance between Indicates the pitch viewing angle.

10. A slope ecological engineering greening rate assessment method according to claim 8, characterized in that: The calculation method of slope green view rate at different observation positions is: in, Indicates observation point iii The slope green view rate, Indicates the perceived area value of vegetation within the field of view. Represents the perceived area value within the field of view. Indicates the position number of the raster file in the horizontal and vertical directions.

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