Method and device for determining ecological influence boundary of open-pit mining

Abstract

A method for determining an ecological influence boundary of open-pit mining is applied to delimiting the influence boundary of open-pit mining in a grassland mining area, the boundary comprises a direct influence range boundary and an indirect influence range boundary, and the method comprises the following steps: obtaining a first target area and a second target area on the basis of obtained time sequence remote sensing data of the first target area and the second target area; determining ecological index space and time sequence information of different pixels of the first target area and the second target area; determining an ecological threshold value based on the ecological index space information; based on the ecological index time sequence information and an ecological threshold value, determining an influence information type on vegetation in the mining-reclamation process; based on the influence information type, determining the boundary of the direct influence range of open-pit mining; determining a relation line between the ecological index and the distance according to the boundary of the direct influence range; and determining the boundary of the indirect influence range of the open-pit mining based on the relation line and an ecological threshold value. The method can be used for determining the boundary of the influence of the mining activity of the strip mine area on the surface ecology.

Description

Technical Field

[0001] The present invention relates to the technical field of remote sensing mapping, and in particular to a method and device for determining an ecological impact boundary of open-pit mining. Background Art

[0002] Due to differences in regional geological conditions, natural climate characteristics, soil vegetation, development scale and intensity, etc., the degree, scope, manifestation and regional ecological restoration methods of the impact of coal mining on the ecological environment are also different. In China, the traditional impact range definition method usually follows the regulations and standards in the "Land Reclamation Plan Preparation Regulations" (TDT1031-2011) and the "Buildings, Water Bodies, Railways and Main Shafts and Coal Pillars Retention and Coal Mining Regulations". The "Land Reclamation Plan Preparation Regulations" mainly starts from the degree of land damage, comprehensively considers indicators such as surface subsidence, and uses terrain conditions, underground water level and vegetation productivity as evaluation criteria for land damage in mining areas, and uses the boundary of the light damage range as the coal mining impact boundary; the "Buildings, Water Bodies, Railways and Main Shafts and Coal Pillars Retention and Coal Mining Regulations" uses the 10mm contour line of surface subsidence as the coal mining impact boundary, which is mostly applicable to underground coal mining areas. At present, there is no unified quantitative standard for the ecological impact range of open-pit mining at home and abroad. Considering the differences in mining methods and regional applicability, there is still widespread controversy over the application of the above methods to the determination of the impact range of grassland open-pit mines. Therefore, in order to meet the growing energy demand and the need for ecological protection in grassland mining areas, and to alleviate the contradiction between mining development and land resources, it is necessary to determine the ecological impact boundary of open-pit mining. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the embodiments of the present application provide a method, apparatus, computing device, computer storage medium and product containing a computer program for determining the ecological impact boundary of open-pit mining, which can determine the impact boundary of the mining activities in the open-pit mining area on the surface ecology.

[0004] In the first aspect, an embodiment of the present application provides a method for determining the ecological impact boundary of open-pit mining, which is applied to the delineation of the impact boundary of open-pit mining in grassland mining areas, wherein the boundary includes the boundary of a direct impact range and the boundary of an indirect impact range, and the method includes: based on the time series remote sensing data of the first target area and the second target area obtained, determining the time series information and spatial information of the ecological indicators of different pixels in the first target area and the second target area, the ecological indicators include the normalized difference vegetation index NDVI, and determining the ecological threshold based on the spatial information of the ecological indicators; wherein the first target area represents the mining area of ​​the mining area, and the second target area represents the undisturbed area under the same phenological conditions as the first target area; based on the time series information of the ecological indicators and the ecological threshold, determining the type of impact information on vegetation during the mining-reclamation process; based on the impact information type, determining the boundary of the direct impact range of open-pit mining; according to the boundary of the direct impact range, determining the relationship line between the ecological indicator and the distance; extracting the relationship line between the ecological indicator and the distance; based on the relationship line and the ecological threshold, determining the boundary of the indirect impact range of open-pit mining.

[0005] In some possible implementations, the ecological threshold includes a first ecological threshold, a second ecological threshold, and a third ecological threshold; wherein the first ecological threshold is used to characterize the NDVI value with a significant confidence value less than 0.5, the second ecological threshold is used to characterize the NDVI value with a cumulative frequency value of 50, and the third ecological threshold is used to characterize the average NDVI value.

[0006] In some possible implementations, the relationship line between the ecological indicator and the distance is extracted based on the vegetation index, including: establishing a buffer zone of a preset distance based on the boundary of the direct influence range; establishing a relationship line perpendicular to the boundary of the direct influence range with an interval of 1°; and extracting the ecological indicator value on each relationship line pixel by pixel in a clockwise direction.

[0007] In some possible implementations, the impact information types include severe damage, moderate damage, slight damage, slight impact, and no impact.

[0008] In some possible implementations, based on the relationship line, the boundary of the indirect impact range of open-pit mining is determined, including: determining the size of a sliding window, including a number of consecutive pixels in the sliding window, and the consecutive pixels have the same impact information type; starting from the direct impact boundary, the sliding window slides along the relationship line with a fixed step length; determining the NDVI value of each sliding window, when the NDVI i+1 <NDVI i When , the sliding window stops sliding; the cumulative sum of pixels under ecological threshold conditions in the NDVI trajectory of each relationship line is taken as the boundary of the indirect impact range.

[0009] In some possible implementations, the boundary of the indirect impact range is calculated according to the following formula:

[0010]

[0011] In the formula, S represents the indirect impact distance, △x represents the distance constant, α represents different buffer directions, n = 1, 2, 3, k represents the distance parameter, c0 represents the first ecological threshold, c1 represents the second ecological threshold, and c2 represents the third ecological threshold. s1 represents the end position of severe damage calculation, and s2 represents the end position of moderate damage calculation.

[0012] In some possible implementations, after extracting the relationship line between the ecological indicator and the distance, the method further includes: processing the outliers in the relationship line to determine the processed ecological indicator curve; determining the determination method and influence range of the cross-influence multi-source disturbance response characteristics based on the processed ecological indicator curve; and calculating the cross-influence intensity between adjacent disturbance sources based on the determination method and influence range.

[0013] In some possible implementations, the boundaries of the direct impact range of open-pit mining are determined based on the impact information type, including: performing spatial aggregation analysis on image data with impact information types of very serious damage, moderate damage, slight damage, slight impact, and weak positive; calculating the Euclidean distance of patches with different impact levels; determining the continuous area of ​​direct impact through spatial aggregation analysis, and using the edge of the continuous area of ​​direct impact as the boundary of the direct impact range.

[0014] In some possible implementations, the method further includes: visualizing the boundary of the direct impact range and the boundary of the indirect impact range whose impact information type is severe damage, moderate damage, and slight damage.

[0015] In a second aspect, an embodiment of the present application provides an apparatus for determining the ecological impact boundary of open-pit mining, which is deployed on a computing device. The computing device is used to delineate the impact boundary of open-pit mining in grassland mining areas, and the boundary includes a direct impact range boundary and an indirect impact range boundary. The apparatus includes: an acquisition module, which is used to acquire time-series remote sensing data of a first target area and a second target area; a processing module, which determines the time-series information and spatial information of ecological indicators of the first target area and the second target area based on the time-series remote sensing data acquired for the first target area and the second target area, and the ecological indicator includes the Normalized Difference Vegetation Index (NDVI); based on the spatial information of the ecological indicator, the ecological threshold is determined; wherein the first target area represents the mining area of ​​the mining area, and the second target area represents the undisturbed area under the same phenological conditions as the first target area; the processing module is also used to determine the type of impact information on vegetation during the mining-reclamation process based on the time-series information of the ecological indicator and the ecological threshold; the processing module is also used to determine the boundary of the direct impact range of open-pit mining based on the impact information type; the processing module is also used to determine the relationship line between the ecological indicator and the distance according to the boundary of the direct impact range; the processing module is also used to determine the boundary of the indirect impact range of open-pit mining based on the relationship line and the ecological threshold.

[0016] In a third aspect, an embodiment of the present application provides a computer-readable storage medium, comprising computer-readable instructions. When a computer reads and executes the computer-readable instructions, the computer executes the method described in any one of the first aspects.

[0017] In a fourth aspect, an embodiment of the present application provides a computing device, comprising a processor and a memory, wherein the memory stores computer program instructions, and when the computer program instructions are executed by the processor, the method described in any one of the first aspects is executed.

[0018] In a fifth aspect, an embodiment of the present application provides a product comprising a computer program. When the computer program product runs on a processor, the processor executes the method as described in any one of the first aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0020] Figure 1 This is a schematic diagram of the fluctuation trajectory of the normalized vegetation index in a grassland mining area under multi-source disturbance provided by an embodiment of the present application;

[0021] Figure 2It is a flow chart of a method for determining the ecological impact boundary of open-pit mining provided in an embodiment of the present application;

[0022] Figure 3 It is a schematic diagram of an impact type provided by an embodiment of the present application;

[0023] Figure 4 is a schematic diagram of a buffer zone relationship line provided in an embodiment of the present application;

[0024] Figure 5 is a schematic diagram of an outlier processing provided by an embodiment of the present application;

[0025] Figure 6 It is a schematic diagram of a method for determining the type of environmental impact spatial relationship between adjacent disturbance sources provided in an embodiment of the present application;

[0026] Figure 7 It is a schematic diagram of spatial distribution information of the intensity and boundary of direct impact of open-pit mining on vegetation provided by an embodiment of the present application;

[0027] Figure 8 It is a schematic diagram of the indirect impact distance of a mining area under different impact degrees provided in an embodiment of the present application;

[0028] Fig. 9 This is a schematic diagram of a direct impact range and an indirect impact range of a certain mining area of ​​open-pit mining provided by an embodiment of the present application;

[0029] Fig.10 It is a structural schematic diagram of a device for determining an ecological impact boundary of open-pit mining provided in an embodiment of the present application;

[0030] Fig.11 It is a structural diagram of a computing device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The term "and / or" in this article is a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The symbol " / " in this article indicates that the associated objects are in an or relationship, for example, A / B means A or B.

[0033] The terms "first" and "second" in the specification and claims herein are used to distinguish different objects rather than to describe a specific order of the objects. For example, a first response message and a second response message are used to distinguish different response messages rather than to describe a specific order of the response messages.

[0034] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0035] In the description of the embodiments of the present application, unless otherwise specified, "multiple" means two or more than two. For example, multiple processing units refer to two or more processing units, etc.; multiple elements refer to two or more elements, etc.

[0036] To facilitate the understanding of the embodiments of the present application, the following will further explain and illustrate specific embodiments in conjunction with the accompanying drawings. The embodiments do not constitute a limitation on the embodiments of the present invention.

[0037] As the attention to the impact range of coal mining increases, some researchers believe that mining activities also have a certain impact on the surrounding environment. For the surrounding environmental areas of coal mining areas, by using remote sensing (RS) and geographic information system (GIS) analysis methods, combined with ground monitoring data, using buffer principle and gradient analysis, to quantify the sensitive range of vegetation changes in a single mine or the entire mining area within a specific buffer zone, the impact range of coal mining can be defined. In addition, control areas and buffer zones can be set, and information on the spatial impact range of coal mining can be extracted by analyzing the spatiotemporal differences of ecological evaluation indicators. A derivative model can also be established to fit the curve of ecological indicators around the mining area with distance, so as to define the stable position of trend change as the impact boundary of coal mining. It is also possible to focus on the site scale, collect ground sampling data, refer to relevant policy standards to define the impact range, and use single-factor variance analysis to analyze the heavy metal content of soil outside the mining site to obtain the impact range of coal mining activities. It is also possible to determine the impact range of coal mining by constructing an algorithm model based on the geographic spatial differences of the ecological environment.

[0038] However, there is no unified standard for delineating the impact boundary of open-pit mining in grassland mining areas. When assessing the impact scope, the inevitability of the impact of coal mining on the environment is often ignored. The compound process of "mining-reclamation" is taken into account, and there is a lack of a comprehensive assessment framework for the environmental impact of coal mining in grassland mining areas. This has resulted in unclear definition of the concept of the impact scope of coal mining in grassland mining areas and unclear types of impacts of coal mining on grassland environment. At the same time, there is a lack of unified laws and regulations for the accurate delineation of the impact scope of coal mining, resulting in insufficient adaptability of the existing regulations on the delineation of the impact scope of coal mining. The existing quantitative methods are not competent for complex actual scenarios. The delineation of the impact boundary of coal mining does not fully consider the law of change of ecological factors with distance, nor does it consider the spatial relationship between coal mining and other surrounding human activities, which directly affects the accurate identification of the impact boundary.

[0039] For example, please refer to Figure 1 , Figure 1 The figure shows the fluctuation trajectory of the normalized difference vegetation index (NDVI) in the grassland mining area under multi-source disturbance. Figure 1 As shown in the figure, the fluctuation range of the NDVI trajectory is usually between 0.2 and 0.3. In the interactive impact area, the fluctuation value of the NDVI trajectory is between 0.05 and 0.1. This shows that in the semi-arid grassland area, although the NDVI trajectory will have a certain spatial fluctuation, the fluctuation amplitude is relatively small. Therefore, the traditional method of fitting trajectory trends to determine the indirect impact range of coal mining is obviously inapplicable. It is mainly reflected in the neglect of the spatial overlap of the environmental impacts of multiple human activities, that is, the existence of cross-impacts, and when fitting the trajectory of ecological indicators that change with distance, over- or under-fitting may occur, resulting in the range quantification results being too large or too small, which affects the effectiveness of the results of the delineation of the mining impact range. In addition, previous research methods have not clearly defined the key factor of the dominant impact source.

[0040] In view of this, the embodiment of the present application provides a method for determining the ecological impact boundary of open-pit mining, which obtains long-term remote sensing image data based on a remote sensing cloud computing platform, and uses a random forest and vegetation index (RF-NDVI) threshold algorithm to obtain the direct impact boundary; at the same time, the ecological threshold is integrated, and the direct impact boundary is used as a benchmark to construct an automatic recognition algorithm for the boundaries of different degrees of impact within the indirect impact range dominated by open-pit mining. It effectively realizes the determination of the direct and indirect impact boundaries of open-pit mining on the ecology in response to complex human activity scenarios in grassland mining areas, and provides a quantitative method reference and scientific basis for the demarcation of the scope of ecological governance in mining areas and the identification of degradation ranges.

[0041] For example, Figure 2 The flowchart of a method for determining the ecological impact boundary of open-pit mining provided by an embodiment of the present application is shown. The method can be applied to complex human activity scenarios, areas where the scope of indirect impact dominated by coal mining is unclear, and areas where there are disputes over the scope of ecological governance and ecological compensation. Figure 2 As shown, the method may include the following steps:

[0042] S21: Determine ecological indicators of the first target area and the second target area based on the acquired time series remote sensing data of the first target area and the second target area, and determine ecological thresholds based on the ecological indicators.

[0043] In this embodiment, the time series remote sensing image data of the target area (i.e., the first target area) of open-pit coal mining can be obtained through the Google Earth Engine (GEE) platform. At the same time, in order to determine the ecological threshold, it is also necessary to select an area that is not affected by mining activities (i.e., the second target area) to obtain the time series remote sensing image data of the second target area. The second target area can be a nature reserve across the natural river isolation zone under the same phenological conditions, or an area at a certain distance from the mining area that is not disturbed by human activities, especially not disturbed by mining activities in the first target area, that is, an undisturbed area under the same phenological conditions as the first target area, as a control area for the first target area. Remote sensing data includes time series information and spatial information. After obtaining the time series remote sensing image data, the data can be preliminarily processed. For example, a cloud mask algorithm can be used to remove more than 30% of the high cloud pixels in the image data to ensure data quality and availability. Through data processing, these processed data can provide reliable data support to obtain vegetation coverage information in the study area. Ecological indicators may include normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), etc. Among them, NDVI is an important indicator reflecting the surface vegetation coverage and its production vitality. It is one of the most widely used vegetation indices and has the advantages of high vegetation detection sensitivity. In this embodiment, NDVI can be selected as an ecological indicator. In the embodiment of the present application, NDVI is used as an example for description, but it does not constitute a limitation on the present application. As a remote sensing indicator characterizing the growth of vegetation in a mining area, NDVI can serve as a direct indicator of the ecological environment for coal mining. After acquiring the remote sensing image data, the NDVI values ​​of the time-series remote sensing image data of the first target area and the second target area can be determined image by image based on the near-infrared band data and the red light band data. The calculation formula of NDVI is as follows:

[0044]

[0045] In the formula, R NIR Characterize near infrared band data, R RED Characterize the red light band data.

[0046] After determining the NDVI values ​​of the remote sensing image data of the first target area and the second target area image by image, the interannual NDVI time series information can be determined. Specifically, interannual image data can be selected, and the interannual MVC NDVI data can be obtained through the maximum value composition (MVC) technology to represent the actual state of vegetation growth in the study area each year. Then, for the extracted interannual maximum composite NDVI time series, select a suitable time reconstruction method (such as Savitzky-Golay, BISE-WT, etc.) to eliminate abnormal data, smooth the NDVI time series, and determine the time series trajectory of NDVI. It is worth noting that the NDVI sequence here is the time series of the NDVI of a pixel point in the target area, which represents the time series information of the remote sensing data.

[0047] Next, the NDVI average values ​​of the first target area and the second target area can be calculated based on the determined smooth curve of the NDVI time series. That is, the NDVI here is the average value of a surface, which characterizes the spatial information of the remote sensing data. Specifically, the average NDVI value before the mining time point of the first target area is used as the background value (also referred to as pre-mining data). The ecological threshold includes a first ecological threshold, a second ecological threshold, and a third ecological threshold. Among them, the first ecological threshold is used to characterize the NDVI value with a significant confidence value (denoted as p) less than 0.5, the second ecological threshold is used to characterize the NDVI value with a cumulative frequency (denoted as α) value of 50, and the third ecological threshold is used to characterize the average NDVI value.

[0048] S22: Based on ecological indicators and ecological thresholds, determine the type of information on the impact of coal mining and reclamation on vegetation.

[0049] In this embodiment, the impact information type may include severe damage, moderate damage, slight damage, slight impact, and no impact. Figure 3 , Figure 3It is a schematic diagram of the impact type provided in the embodiment of the present application. Among them, severe damage means that the NDVI time series trajectory shows that the trajectory drops to NDVI less than the first ecological threshold, and there is no upward trend for more than 3 steps. If the impact information type is severe damage, the first target area is almost covered with vegetation and does need ecological restoration. The impact on the land vegetation is very serious, causing extremely serious impacts, referred to as D1. Moderate damage means that the NDVI time series trajectory shows that the trajectory first drops below the first ecological threshold and then rises slowly. The NDVI of the rising pixel is limited to less than the second ecological threshold and greater than the first ecological threshold, and the change process exceeds 3 steps. If the impact information type is moderate damage, the first target area is covered with vegetation but lower than the second target area, and ecological restoration is required. The impact on the land vegetation is moderate, causing serious impacts, referred to as D2. Mild damage means that the NDVI time series trajectory shows that the trajectory first drops and then rises slowly. The NDVI of the rising pixel is limited to greater than the second ecological threshold and less than the third ecological threshold, and the change process exceeds 3 steps. If the impact information type is slight damage, the first target area shows that the regional vegetation coverage is close to the undisturbed area, and ecological restoration may be required. The impact on land vegetation is slight, causing medium impact, referred to as D3. Slight impact means that the NDVI time series trajectory shows that the trajectory first decreases and then slowly rises to exceed the third ecological threshold and the NDVI background value, and then the trajectory remains stable, and the change process exceeds 3 steps. If the impact information type is slight impact, the first target area shows that mining activities have no negative impact on vegetation, or the vegetation coverage exceeds the original landform, showing a weak positive impact, and no ecological restoration is required. The impact on land vegetation is weakly positive, causing a weak positive impact, referred to as D5. No impact means that the NDVI time series trajectory has almost no fluctuation or the NDVI time series fluctuation range is not lower than the first ecological threshold, then it is judged that the first target area is not directly affected by mining activities. At the same time, it is observed that the NDVI time series trajectory shows a trend of rising or falling in 3 time intervals. For situations of short-term damage followed by rapid recovery, they are classified as no-impact types and can be filtered out during classification and screening, referred to as D6 for short.

[0050] In some possible embodiments, mild damage may also include that the NDVI time series trajectory shows that the trajectory first decreases and then slowly increases, the NDVI value of the rising pixel is greater than the third ecological threshold, but the NDVI trajectory is not stable, and then the NDVI trajectory decreases, the NDVI value is less than the pre-mining level, and the NDVI change is limited to greater than the third ecological threshold and less than the NDVI background value, and the change process exceeds 3 steps. At this time, the image information type is mild damage, and the vegetation coverage of the first target area is close to the pre-mining level. Ecological restoration or natural recovery can be considered. Its impact on land vegetation is slight, causing a weak impact, referred to as D4.

[0051] S23: Based on the type of impact information, determine the boundaries of the direct impact area of ​​open-pit mining.

[0052] In this embodiment, after determining the type of impact information, a spatial aggregation analysis is performed on the image data of very serious damage, moderate damage, slight damage, slight impact, and weak positive types, and the Euclidean distance of patches with different impact degrees is calculated. Through the spatial aggregation analysis, the directly affected continuous area can be determined, and the edge of the directly affected continuous area is used as the boundary of the direct impact of coal open-pit mining (i.e., the first target area).

[0053] S24: Based on the boundary of the direct impact range, determine the relationship line between the ecological indicator and the distance, and extract the relationship line.

[0054] In this embodiment, please refer to Figure 4 , Figure 4 A schematic diagram of a relationship line provided in an embodiment of the present application is shown. Figure 4 As shown in the figure, a buffer zone with a certain preset range (such as 10 km) is established with the boundary of the direct impact range of open-pit mining as the benchmark (for the convenience of demonstration, the direct impact range is taken as a square as an example). In the buffer zone, the relationship line is extracted in a clockwise direction with a 1° interval perpendicular to the boundary of the direct impact range. When extracting, the NDVI value on each buffer radius sample line is extracted pixel by pixel as the relationship line between the ecological indicator and the distance, which is defined as the ecological indicator ~ distance-NDVI curve (ED-NDVI).

[0055] In some possible embodiments, outliers in the relationship line may also be processed.

[0056] In this embodiment, the NDVI curve trajectory obtained in step S24 can be subjected to outlier removal and ED-NDVI curve smoothing. Specifically, the data results of ED-NDVI on the extracted 360 buffer lines can be converted into space-time cube data, and then the exponential smoothing prediction method is used to identify outliers at each position of the space-time cube. Values ​​that are extremely higher than the fitting value are regarded as outliers. After the identified extreme outliers are removed, the weighted average of the adjacent n pixels on the left and right is selected for filling to reduce the impact of outliers. The calculation formula is as follows:

[0057]

[0058] In the formula, Characterize the fitting value, w i The weight representing the value, x iIt represents the value of the adjacent pixels of the pixel where the outlier is located, and n represents the number of adjacent pixels.

[0059] Next, the entire set of series can be processed using a polynomial smoothing algorithm (e.g., 5-point cubic polynomial smoothing) to determine the final NDVI curve, which is calculated as follows:

[0060]

[0061] In the formula, represents the smoothed data point, p represents the size of the moving window, C i represents the convolution coefficient, and the value range of i is (-p, p), N represents the length of the data processed by the filter, and Y represents the sequence data after removing outliers.

[0062] For example, please refer to Figure 5 , Figure 5 A schematic diagram of outlier processing is shown. Figure 5 As shown in the figure, there are data points in the original value that are extremely higher than the fitted value, and these data points are removed as outliers. Then fill the removed values ​​to reduce the impact of outliers while retaining the trend information of the sequence.

[0063] In some possible embodiments, the determination method and impact range of the cross-influence multi-source disturbance response characteristics may also be determined based on the NDVI curve after processing the outliers.

[0064] In this embodiment, the determination method of cross-influence and multi-source disturbance response characteristics, as well as the identification of cross-influence range can be defined. Specifically, the spatial morphological characteristics of the NDVI curve trajectory after removing outliers can be analyzed, the response law of the grassland around the mining area to human activities can be analyzed, and the NDVI trajectory characteristics under single disturbance source and multi-source disturbance can be defined respectively. Among them, multi-source disturbance can also be referred to as adjacent influence source disturbance or adjacent disturbance source. According to the principle of geometry, by screening samples of the NDVI curve, the changing characteristics of the NDVI trajectory under different influence modes in the grassland mining area and their corresponding spatial relationships are delineated. Please refer to Figure 6 For the case of multi-source disturbance, the relationship types of environmental impacts between adjacent disturbance sources can be divided into four types, namely spatial intersection, spatial inclusion, spatial proximity, and spatial separation. Among them, spatial intersection and spatial inclusion are considered to have cross-impacts. Through the maximum likelihood classification method and the last-shift matching, all the extracted NDVI trajectories are classified and processed to determine the spatial relationship type of the environmental impact of the target mining area as the main disturbance source and the adjacent disturbance sources, and draw a spatial relationship diagram of the environmental impacts between adjacent disturbance sources.

[0065] In some possible embodiments, the cross-influence strength between adjacent disturbance sources may also be calculated.

[0066] In this embodiment, in order to obtain the intensity of cross-influence between coal mining in a mining area and its adjacent disturbance sources, the cross-intensity can be quantified based on the obtained NDVI curve and using the ecological threshold information as auxiliary information. According to the cross-influence area, the more frequent the activities between adjacent disturbance sources, the more drastic the fluctuation of the NDVI trajectory. Combined with the principles of mathematical statistics, the fluctuation amplitude of the NDVI curve is used to represent the severity of this change. Among them, the positive and negative amplitude indicates the positive and negative superposition of adjacent influences, and the larger the amplitude value, the greater the cross-influence intensity. The calculation principle is expressed as the following formula:

[0067]

[0068] In the formula, A ji Characterizes the amplitude at position i on the buffer line α in the interactive influence area j, α ji represents the NDVI value of the pixel at the relative position i on the buffer line α in the region j, m represents the fitting value of the NDVI and the distance parameter in the buffer line α, k represents the distance parameter, Characterizes the maximum intensity in region j, m(c -ibo ) represents the interval c on the buffer line α -ibo The fitted NDVI values ​​within the range represent the range from the first disturbance source to the next disturbance source, c0 represents the first ecological threshold, c1 represents the second ecological threshold, and c2 represents the third ecological threshold.

[0069] S25: Based on the relationship line and ecological threshold, determine the boundaries of the indirect impact range under different impact levels of open-pit mining.

[0070] In this embodiment, as the distance from the mine increases, the impact of mining activities on vegetation decays exponentially, and the growth of vegetation shows a certain time lag. Therefore, the spatial location information of the indirect impact range can be quantified based on the size of the pixel resolution. Specifically, the degree of impact (impact information type) from strong to weak under the defined threshold conditions is statistically determined within the threshold range to obtain the indirect impact distance from the direct impact boundary to the corresponding impact intensity. The indirect impact distance is characterized by the cumulative sum of pixels under the defined threshold conditions in the NDVI trajectory of each buffer line. Since only the impacts of severe damage (D1), moderate damage (D2), and mild damage (D3) in the image information type require ecological restoration, only these three impact types need to be considered when determining the indirect impact distance. The calculation formula is as follows:

[0071]

[0072] In the formula, S represents the indirect impact distance, △x represents the distance constant, which is usually 30m, α represents different buffer directions (i.e., buffer lines of 0°, 1°, 2°, ..., 360°), n = 1, 2, 3, k represents the distance parameter, and k∈(1, 2, ..., iD), iD represents the number of pixels with different impact levels, for example, the number of pixels with medium impact level is 4, then k can be 4, c0 represents the first ecological threshold, c1 represents the second ecological threshold, and c2 represents the third ecological threshold. s1 represents the calculation end position of severe impact (i.e., the impact information type is severe damage), and s2 represents the calculation end position of moderate impact (i.e., the impact information type is moderate damage).

[0073] In the process of implementing the algorithm, the size of the sliding window is first determined. The sliding window contains several consecutive pixels, and the consecutive pixels have the same impact information type. The sliding window starts from the direct impact boundary and slides along the relationship line with a step size of 4 pixels. By determining the NDVI value of each sliding window, a set of NDVI series can be obtained. Theoretically speaking, the farther away from the direct impact boundary, the less the land vegetation should be affected by mining, which is reflected in the NDVI value, that is, the value of the i+1th NDVI should be greater than the i-th NDVI. That is, the NDVI values ​​of several consecutive pixels in the sliding window satisfy the NDVI i+1 -NDVI i >0, that is, NDVI i+1 >NDVI i However, when the ecological threshold changes, the impact of mining on land vegetation will change accordingly. At this time, the value of the i+1th NDVI should be less than the i-th NDVI, that is, NDVI i+1 <NDVI i In other words, the NDVI changes during the sliding window i+1 <NDVI i In this way, the limitation of using a single threshold to define the impact range is avoided.

[0074] In some possible embodiments, the sliding window size is 4 pixels. After a large number of experimental studies, it is found that when the sliding window contains 4 consecutive pixels, the indirect influence distance obtained is closest to the actual situation.

[0075] In some possible embodiments, the boundaries of the direct impact range and the boundaries of the indirect impact range with impact information types of severe damage, moderate damage, and slight damage may also be visualized.

[0076] Taking a specific example, the scheme is fully introduced with a certain open-pit mining area as the first target area. The area not affected by mining activities is selected as the second target area, and the second target area is used as the control area. The Landsat TM / ETM+ / OLI top of atmosphere reflectance data (TOA) from January 1, 1989 to December 31, 2022 are obtained on the GEE platform for the first target area and the second target area respectively. The cloud mask algorithm provided by the GEE platform is used to remove more than 30% of high cloud pixels to ensure data quality and availability. The spectral operation is performed on the selected pixels in the screened image to obtain the normalized vegetation index. The imageCollection.qualityMosaic() function is used to extract the interannual maximum synthetic NDVI time series for each pixel of the selected interannual image. The BISE-WT filtering method is then used to reconstruct the time series to remove abnormal data and obtain NDVI time series information. At the same time, the interannual NDVI in the control area is calculated. The average NDVI values ​​of the study area and the control area before mining are extracted as the vegetation background value. As well as the NDVI values ​​with significant confidence p value < 0.05, the NDVI values ​​with cumulative frequency α value of 50, and the average NDVI value. The NDVI threshold extraction results for the study area in 1989 (no mining activities), 1999 (initial mining period), and 2022 are shown in Table 1 below.

[0077] Table 1

[0078] years The first ecological threshold The second ecological threshold The third ecological threshold 1989 0.4546 0.478 0.601 1999 0.4046 0.458 0.561 2022 0.5480 0.643 0.850

[0079] Within the scope of the first target area, 500 training points were randomly selected to obtain the NDVI time series trajectory of the training points. The first ecological threshold, the second ecological threshold, and the third ecological threshold were used as limiting conditions, and three time windows were used as intervals. Combined with the synergistic process of coal "mining-reclamation" and the actual situation of the mining area, the impact level type (impact information type) corresponding to the time series NDVI trajectory of the NDVI training points was defined. After determining the impact level type, the Euclidean distance between patches of different impact levels was calculated through spatial aggregation analysis, the edge information of the directly affected continuous area was extracted, and the direct impact range was determined. Please refer to Figure 7 , Figure 7 The figure is a schematic diagram of the spatial distribution information of the direct impact intensity and boundary of open-pit mining on vegetation. Based on the extracted direct impact boundary, the ED-NDVI curve on each buffer line within 10km of the mining area is extracted according to the scale of the mining area. The acquired NDVI trajectory features are matched with the defined spatial relationship type track to determine the spatial relationship of different human activities around the mining area. Under cross-impact, the cross-impact range is intercepted, and the NDVI trajectory is substituted into the amplitude model for calculation to obtain the cross-impact intensity.

[0080] After clarifying the spatial relationship of human activities around the mining area, the indirect impact boundary of open-pit mining is calculated according to the impact type and ED-NDVI curve. Visualize the direct impact range and indirect impact range. Please refer to Figure 8 as well as Fig. 9 , Figure 8 This is a schematic diagram of the indirect impact distance of the mining area at different impact levels. Fig. 9 Schematic diagram visualizing the direct and indirect impacts of open pit mining for the mine site.

[0081] The above is an introduction to the method for determining the ecological impact boundary of open-pit mining provided in the embodiment of the present application. In view of the difficulty that the boundary definition and identification method of open-pit coal mining impact is difficult to adapt to the complex reality scene, the time series trajectory classification method based on the RF-NDVI threshold of this method has obvious advantages over the previously commonly used trend threshold model algorithm. The traditional method mainly relies on the setting of vegetation thresholds, and it is often difficult to accurately distinguish the direct and indirect effects of coal mining. For example, other disturbances lead to only surface vegetation stripping, which is easy to cause the misjudgment of the type of open-pit mining impact. And compared with the method of selecting a fixed vegetation threshold to extract interannual disturbance information of coal mining in previous studies, this algorithm effectively avoids these problems, as well as the interference of some uncertain factors such as phenology, and greatly improves the data processing speed and efficiency. Secondly, given the determination method of the spatial relationship of ecological response under multi-source disturbance and the evaluation method of the intensity of cross-impact, the spatial relationship type of environmental impact between various human activities and its ecological significance are proposed for the first time. On this basis, an algorithm for automatically extracting the indirect impact boundary under the dominance of coal mining is established-a dynamic threshold distance algorithm, which can solve the problem that the previous quantitative method cannot adapt to the complex reality scene of grassland mining areas. The method provided in this application aims to clearly define the scope and extent of the impact of open-pit mining on the environment, cope with complex real-life scenarios with multi-source disturbances, and automatically extract the spatial location information of impact boundaries with different degrees of impact dominated by open-pit mining, so as to provide basic information reference for quantifying environmental damage, delineating ecological restoration and protection of degraded areas, etc.

[0082] The Recommended Methods for Environmental Damage Assessment (II Edition) states that it is necessary to assess the scope and extent of environmental damage caused by an action and quantify the scope of environmental damage. The quantitative methods involved in this plan more clearly define the extent and scope of the impact of open-pit mining, which will help provide a reference for the pertinence, standardization and scientific nature of environmental damage assessment work.

[0083] The "Green Mine Construction Evaluation Indicators" takes the mining area environment as one of the first-level evaluation indicators. The quantitative method involved in this plan can not only realize the automatic identification of the impact boundary of open-pit mining under the long-term surface scale of the mine, but also realize the temporal and spatial differences of the direct and indirect impact types of coal mining on the environment, ensure the effective promotion of mine ecological restoration and ecological governance, and provide quantitative data support for the sustainable development of green mines.

[0084] The "Regulations on Ecological Protection Compensation" mentions the implementation of inter-regional horizontal ecological protection compensation in the inter-regional horizontal compensation. It mentions that for areas where important ecological and environmental elements are located and other areas with important ecological functions, the specific scope of compensation and the ecological protection responsibilities of ecological areas should be clarified first. In addition to coal mining, mining areas often carry various human activities. For example, in the Inner Mongolia grassland mining area, there are a series of activities related to residents' production and life, such as animal husbandry, farming, urban construction, and industry. The spatial relationship between the ecological environment generated by various human activities is also complex and diverse. Not only that, the environmental impacts caused by mining between different mining companies in the region will also have certain intersections. For each mine, this plan can determine the reasonable delineation of the scope of ecological compensation damage assessment based on its dominant influence range.

[0085] It is understandable that the size of the sequence number of each step in the above-mentioned embodiments does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. In addition, in some possible implementations, the steps in the above-mentioned embodiments can be selectively executed according to actual conditions, and can be partially executed or fully executed, which is not limited here. All or part of any features of any embodiment of the present application can be freely and arbitrarily combined without contradiction. The combined technical solution is also within the scope of the present application.

[0086] Based on the method in the above embodiment, the embodiment of the present application also provides a device for determining the ecological impact boundary of open-pit mining. For example, Fig.10 The present invention shows a device for determining the ecological impact boundary of open-pit mining, which is deployed in a computing device and is used for delineating the impact boundary of open-pit mining in grassland mining areas, and the boundary includes the direct impact range boundary and the indirect impact range boundary. The device for determining the ecological impact boundary of open-pit mining 1000 includes: an acquisition module 1001 and a processing module 1002.

[0087] Wherein, the acquisition module 1001 is used to acquire time-series remote sensing data of the first target area and the second target area;

[0088] The processing module 1002 is used to determine the sequence of the normalized vegetation index NDVI of the first target area and the second target area based on the acquired time series remote sensing data of the first target area and the second target area, and determine the ecological threshold based on the NDVI sequence;

[0089] The processing module 1002 is further used to determine the type of information on the impact of the mining-reclamation process on vegetation based on the ecological threshold;

[0090] The processing module 1002 is further used to determine the boundary of the direct impact range of open-pit mining based on the impact information type;

[0091] The processing module 1002 is also used to extract the relationship line between the ecological index and the distance based on the vegetation index; the ecological index includes NDVI;

[0092] The processing module 1002 is further used to determine the boundary of the indirect impact range of open-pit mining based on the relationship line.

[0093] It should be understood that the above-mentioned device is used to execute the method in the above-mentioned embodiment. The implementation principle and technical effect of the corresponding program module in the device are similar to those described in the above-mentioned method. The working process of the device can refer to the corresponding process in the above-mentioned method, which will not be repeated here.

[0094] The present application also provides a computing device 1100. Fig.11 As shown, the computing device 1100 includes: a bus 1102, a processor 1104, a memory 1106, and a communication interface 1108. The processor 1104, the memory 1106, and the communication interface 1108 communicate through the bus 1102. The computing device 1100 can be a server or a terminal device. It should be understood that the present application does not limit the number of processors and memories in the computing device 1100.

[0095] The bus 1102 may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig.11 The bus 1104 may include a path for transmitting information between various components of the computing device 1100 (eg, the memory 1106, the processor 1104, and the communication interface 1108).

[0096] The processor 1104 may include any one or more of a central processing unit (CPU), a graphics processing unit (GPU), a microprocessor (MP), or a digital signal processor (DSP).

[0097] The memory 1106 may include a volatile memory, such as a random access memory (RAM). The processor 1104 may also include a non-volatile memory, such as a read-only memory (ROM), a flash memory, a hard disk drive (HDD), or a solid state drive (SSD).

[0098] The memory 1106 stores executable program codes, and the processor 1104 executes the executable program codes to respectively implement the functions of the acquisition module 1001 and the processing module 1002, thereby implementing all or part of the steps of the method in the above embodiment. That is, the memory 1106 stores instructions for executing all or part of the steps in the method in the above embodiment.

[0099] Alternatively, the memory 1106 stores executable codes, and the processor 1104 executes the executable codes to respectively implement the functions of the open-pit mining ecological impact boundary determination device 1000, thereby implementing all or part of the steps in the above-mentioned embodiment method. That is, the memory 1106 stores instructions for executing all or part of the steps in the above-mentioned embodiment method.

[0100] The communication interface 1108 uses a transceiver module such as, but not limited to, a network interface card or a transceiver to implement communication between the computing device 1100 and other devices or a communication network.

[0101] Based on the methods in the above embodiments, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program runs on a processor, the processor executes the methods in the above embodiments.

[0102] Based on the methods in the above embodiments, an embodiment of the present application provides a computer program product. When the computer program product runs on a processor, the processor executes the methods in the above embodiments.

[0103] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0104] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, mobile hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can be located in an ASIC.

[0105] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions may be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid state disk (SSD)), etc.

[0106] It should be understood that the various numerical numbers involved in the embodiments of the present application are only used for the convenience of description and are not used to limit the scope of the embodiments of the present application.

Claims

1. A method for determining the ecological impact boundary of open-pit mining, characterized in that: Applied to the delineation of the impact boundary of open-pit mining in grassland mining areas, the boundary includes the direct impact range boundary and the indirect impact range boundary, and the method includes: Based on the time series remote sensing data of the first target area and the second target area, the time series information and spatial information of the ecological indicators of different pixels in the first target area and the second target area are determined, wherein the ecological indicators include the Normalized Difference Vegetation Index (NDVI), and the ecological threshold is determined based on the spatial information of the ecological indicators; wherein the first target area represents the mining area, and the second target area represents the undisturbed area under the same phenological conditions as the first target area; Determining the type of information on the impact of mining and reclamation on vegetation based on the ecological indicator time series information and the ecological threshold; Based on the type of impact information, determine the boundaries of the direct impact area of ​​open-pit mining; Determine the relationship line between the ecological indicator and the distance according to the boundary of the direct impact range; Based on the relationship line and the ecological threshold, the boundary of the indirect impact range of open-pit mining is determined.

2. The method according to claim 1, characterized in that The ecological threshold includes a first ecological threshold, a second ecological threshold, and a third ecological threshold; wherein the first ecological threshold is used to characterize the NDVI value with a significant confidence value less than 0.5, the second ecological threshold is used to characterize the NDVI value with a cumulative frequency value of 50, and the third ecological threshold is used to characterize the average NDVI value.

3. The method according to claim 1, characterized in that The extraction of the relationship line between the ecological index and the distance based on the vegetation index includes: Based on the boundary of the direct impact range, a buffer zone of a preset distance is established; In the buffer zone, relationship lines are established at intervals of 1° perpendicular to the boundary of the direct influence range; In a clockwise or counterclockwise direction, starting from the boundary of the direct impact range until the end of the buffer zone boundary line, the ecological indicator value on each relationship line is extracted pixel by pixel.

4. The method according to claim 1, characterized in that: The types of impact information include severe damage, moderate damage, slight damage, slight impact, and no impact.

5. The method according to claim 4, characterized in that Determining the boundary of the indirect impact range of open-pit mining based on the relationship line includes: Determine the size of a sliding window, wherein a plurality of continuous pixels are included in the sliding window, and the continuous pixels have the same type of the impact information; The sliding window starts from the direct impact boundary and slides along the relationship line with a fixed step length; Determine the NDVI value for each sliding window. i+1 <NDVI i When , the sliding window stops sliding; The cumulative sum of pixels under the ecological threshold condition in the NDVI trajectory of each relationship line is taken as the boundary of the indirect impact range.

6. The method according to claim 5, characterized in that The boundary of the indirect impact range is calculated according to the following formula: In the formula, S represents the indirect impact distance, △x represents the distance constant, α represents different buffer directions, n = 1, 2, 3, k represents the distance parameter, c0 represents the first ecological threshold, c1 represents the second ecological threshold, and c2 represents the third ecological threshold. s1 represents the end position of severe damage calculation, and s2 represents the end position of moderate damage calculation.

7. The method according to claim 1, characterized in that After determining the relationship line between the ecological indicator and the distance, the method further includes: Processing the abnormal values ​​in the relationship line to determine the processed ecological indicator curve; According to the processed ecological indicator curve, determining the determination method and impact range of cross-impact multi-source disturbance response characteristics; Based on the determination method and the influence range, the cross-influence intensity between adjacent disturbance sources is calculated.

8. The method according to claim 1, characterized in that Determining the boundary of the direct impact range of open-pit mining based on the impact information type includes: For the image data of the impact information type of severe damage, moderate damage, slight damage, and slight impact, a spatial aggregation analysis operation is performed; Calculate the Euclidean distance of patches with different impact levels; Through spatial concentration analysis, the continuous area of ​​direct impact is determined, and the edge of the continuous area of ​​direct impact is used as the boundary of the direct impact range.

9. The method according to claim 1, characterized in that: The method further includes: visualizing the boundary of the direct impact range and the boundary of the indirect impact range whose impact information type is severe damage, moderate damage, and slight damage.

10. A device for determining the ecological impact boundary of open-pit mining, characterized in that: Deployed on a computing device, the computing device is used to delineate the impact boundary of open-pit mining in grassland mining areas, the boundary includes a direct impact range boundary and an indirect impact range boundary, and the device includes: An acquisition module, used for acquiring time series remote sensing data of the first target area and the second target area; A processing module, based on the acquired time series remote sensing data of the first target area and the second target area, determines the time series information and spatial information of the ecological indicators of the first target area and the second target area, wherein the ecological indicators include the Normalized Difference Vegetation Index (NDVI), and determines the ecological threshold based on the spatial information of the ecological indicators; wherein the first target area represents the mining area, and the second target area represents the undisturbed area under the same phenological conditions as the first target area; The processing module is further used to determine the type of information on the impact of mining-reclamation on vegetation based on the ecological indicator time series information and the ecological threshold; The processing module is further used to determine the boundary of the direct impact range of open-pit mining based on the impact information type; The processing module is further used to determine the relationship line between the ecological indicator and the distance according to the boundary of the direct impact range; The processing module is further used to determine the boundary of the indirect impact range of open-pit mining based on the relationship line and the ecological threshold.

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