Decision-making method for ecological restoration direction of abandoned surface mine

Abstract

The invention provides a decision-making method for an ecological restoration direction of an abandoned surface mine, and belongs to the technical field of ecological environment restoration. On the basis of investigating each attribute condition of a surface mine to be restored, decision direction judgment is performed on each attribute condition in a decision model in a hierarchical and step-by-step manner, so that an ecological restoration direction suitable for each mining area attribute condition is explained; according to the accumulated attribute conditions of each ecological restoration direction, one item meeting the most attribute conditions is determined as the most suitable restoration direction, and meanwhile, other suitable directions are screened out, so that combination and selection during project implementation are facilitated. According to the method, the problem that in the field of mine ecological restoration, the restoration direction and target are not clear before the project establishment of the surface mine ecological restoration engineering project is solved, and a decision-making method and basis are provided for the subsequent determination of the surface mine ecological restoration direction. By applying the method, the effects of fully utilizing restoration funds, guaranteeing the ecological restoration effect of the mining area and assisting high-quality development of social economy can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of ecological environment restoration, and in particular to a decision-making method for the ecological restoration direction of an abandoned open-pit mine. Background Art

[0002] From the initial single-point mine geological environment restoration and management to mine ecological restoration, and then to the integrated protection and restoration of mountains, rivers, forests, fields, lakes, grasslands and sands, over the past 20 years, multiple batches of mine ecological restoration projects have been carried out across the country, achieving huge ecological, social and economic benefits. With the continuous acceleration of the development of ecological civilization construction, and the continuous progress and improvement of scientific theories and restoration concepts of mine ecological restoration, higher requirements have been put forward for mine ecological restoration work; through mine ecological restoration, the transformation of ecological value and regional sustainable development can be achieved, and the development and investment of industries such as ecological agriculture, cultural tourism, and new energy can be driven, and the industrial chain and value chain can be expanded. This is a new model for mine ecological restoration. Some mines that have already carried out restoration work and have obvious benefits have played a certain demonstration effect, but the multi-batch, multi-level, and multi-channel mine ecological restoration work has led to different ecological restoration concepts and uneven results in various mines.

[0003] The determination of the direction of mine ecological restoration is related to the design of mine ecological restoration plans, fund raising, project construction and effectiveness evaluation, and plays a decisive role in the benefits that can be achieved by mine ecological restoration projects. In order to make full use of restoration funds at all levels, ensure the effectiveness of mine ecological restoration projects, protect the ecological security pattern, and promote the green and sustainable development of the social economy, it is necessary to summarize previous experience, select appropriate restoration directions for mines to be restored, clarify restoration goals, and actively explore the optimal model of mine ecological restoration, so as to provide a basis and guidance for the subsequent ecological restoration work of various mines.

[0004] Currently, there is no research on the relevant theories and methods for decision-making on the direction of ecological restoration of abandoned open-pit mines. Summary of the invention

[0005] The purpose of the present invention is to address the above-mentioned deficiencies of the existing technical methods and provide a decision-making method for the direction of ecological restoration of abandoned open-pit mines. It innovatively proposes the attribute conditions and decision-making model required for decision-making, and discusses the decision-making method. It can solve the problem of unclear restoration direction in the early stage of ecological restoration of abandoned open-pit mines and ensure the effectiveness of mine ecological restoration.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: The present invention provides a decision-making method for the ecological restoration direction of abandoned open-pit mines, comprising the following steps: S1. Build a database Collect and analyze typical cases of ecological restoration of abandoned open-pit mines at home and abroad, and summarize the restoration directions or combinations of restoration directions in the cases; S2. Establish a decision model By summarizing and analyzing the data in the database of step S1, a decision model is established hierarchically. The decision model includes three levels: The first level is to classify the types of restoration directions of abandoned open-pit mines to be restored into ecological restoration and ecological restoration combinations. The ecological restoration combination includes "ecological restoration + reclamation and greening", "ecological restoration + engineering construction", and "ecological restoration + transformation and utilization" at the next level; The second level is to classify the types of restoration directions of abandoned open-pit mines to be restored into "ecological restoration + reclamation and greening", "ecological restoration + engineering construction", and "ecological restoration + transformation and utilization"; The third level is to classify the types of restoration directions of abandoned open-pit mines to be restored into "ecological restoration + cultivated land", "ecological restoration + gardens", "ecological restoration + forest land", "ecological restoration + grassland", "ecological restoration + aquaculture water surface", "ecological restoration + residential", "ecological restoration + industry", "ecological restoration + commercial services", "ecological restoration + entertainment and sports", "ecological restoration + ecological tourism", "ecological restoration + health care and medical care", "ecological restoration + ecological cemetery", "ecological restoration + photovoltaic power generation" and "ecological restoration + others"; S3. Decision-making method Based on the investigation and evaluation of the four major attribute conditions of abandoned open-pit mines, the attribute conditions of abandoned open-pit mines are traversed through the decision model. Each condition reaches a node once and counts as 1. If it reaches a first-level node and cannot be further subdivided, all target classes below it are counted as 1. Finally, the counts of each target class are added up, and the type corresponding to the largest number is the most suitable restoration mode for this mine. The four categories of attribute conditions are natural conditions, policy conditions, current conditions of abandoned open-pit mines and social conditions; The attributes of the natural conditions include location and transportation, landform and landscape, meteorology and water conservancy, and regional ecosystem structure and its stability; The attributes examined in the policy conditions include land use type, regional development planning, and project funding sources; The attributes of the abandoned open-pit mine status survey include rock and soil attributes, water environment quality, soil environment quality, vegetation retention status and soil and water conservation status; The attributes examined in the social conditions include population, economy, industry and social needs.

[0007] Furthermore, when making a decision based on the natural condition attributes, the decision-making method is as follows: Decisions are made based on location and transportation attributes. For mines in remote geographical locations or areas with no temporary reuse plans, and which are not within the "three zones and three lines" delineated in the county-level land and space planning or the important ecological barrier zones delineated in the land and space development and protection pattern, and which are more than 10 km away from county roads and have no advantages in location and transportation, ecological restoration will be adopted; otherwise, a combination of ecological restoration will be adopted.

[0008] Furthermore, decisions are made based on the landform and landscape attributes. When the landform and landscape of the abandoned open-pit mine is not severely damaged and is not too abrupt with the surrounding landscape, ecological restoration is adopted. If the landform and landscape is severely damaged, causing serious visual pollution and affecting the overall landscape image, a combination of ecological restoration is adopted.

[0009] Furthermore, decisions are made based on meteorological and water conservancy attributes. When the annual rainfall is ≥400 mm and the climatic conditions are suitable for vegetation growth, ecological restoration is adopted. When the annual rainfall is <400 mm, there is available surface water and groundwater, as well as water conservancy facilities that are convenient for irrigation and maintenance, and an ecological restoration combination is adopted.

[0010] Furthermore, decisions are made based on the regional ecosystem structure and its stability attributes, and the ratio β of the number of vegetation species per unit area in the mining area to the number of vegetation species per unit area in the undisturbed area is calculated. If β ≥ 80%, the species are well preserved and the ecosystem structure is relatively complete, and ecological restoration is adopted; if β < 80%, an ecological restoration combination is adopted.

[0011] Furthermore, when making a decision based on the abandoned open-pit mine policy condition attributes, the decision-making method is as follows: When making decisions based on land use type attributes, priority will be given to restoring the land use attributes before mining, based on the land type before mining of the abandoned open-pit mine. If the land was cultivated land, orchards, woodlands, grasslands, aquaculture water surfaces, or construction land before mining, it will be restored to the corresponding type before mining, and an ecological restoration combination will be adopted, specifically including at least one of “ecological restoration + cultivated land”, “ecological restoration + orchards”, “ecological restoration + woodlands”, “ecological restoration + grasslands”, “ecological restoration + aquaculture water surfaces”, “ecological restoration + residential”, “ecological restoration + industry”, “ecological restoration + commercial services” or “ecological restoration + entertainment and sports”.

[0012] Furthermore, when making decisions based on the attributes of regional development plans, the corresponding land types should be restored according to the county and city-level land space planning, land space use control system, land space ecological restoration plan, social economy and tourism development land space ecological restoration plan, land space use control, regional tourism development plan and other corresponding plans, and an ecological restoration combination should be adopted, specifically including at least one of "ecological restoration + cultivated land", "ecological restoration + gardens", "ecological restoration + forest land", "ecological restoration + grassland", "ecological restoration + aquaculture water surface", "ecological restoration + residential", "ecological restoration + industry", "ecological restoration + commercial services" or "ecological restoration + entertainment and sports".

[0013] Furthermore, when making decisions based on the attributes of project funding sources, if the project funding sources are fiscal funds and local matching funds, the land will be restored to agriculture, forestry, animal husbandry and fishery land or construction land; if the funding source is social funds, it will be restored to construction land or transformed for use according to the wishes of the investor.

[0014] Furthermore, when making a decision based on the current condition attributes of the abandoned open-pit mine, the decision-making method is as follows: Decisions are made based on the stability properties of rock and soil masses. On the basis of the rock and soil stability evaluation, if the stability of the slope rock and soil masses is basically stable or unstable, that is, there are geological safety hazards such as collapse and landslide, and engineering measures are needed to reinforce support, cut slopes and reduce loads, a combination of ecological restoration will be adopted; if the stability of the slope rock and soil masses is stable or relatively stable, ecological restoration will be adopted.

[0015] Furthermore, decisions are made based on water environment quality attributes. If water pollution exists, an ecological restoration combination is adopted; if water pollution does not exist, there are no constraints on the choice of ecological restoration model.

[0016] Furthermore, decisions can be made based on soil environmental quality attributes. When the soil is not polluted, a combination of ecological reforestation or ecological restoration can be adopted.

[0017] Furthermore, decisions are made based on the attributes of vegetation retention status. When vegetation coverage is ≥60%, ecological regreening is adopted; when vegetation coverage is <60%, an ecological restoration combination is adopted.

[0018] Furthermore, decisions are made based on soil and water conservation conditions. When the soil erosion degree of more than 50% of the mining area is level one to level two, ecological restoration is adopted; when the soil erosion degree of more than 50% of the mining area is level three to level four, a combination of ecological restoration is adopted.

[0019] Furthermore, when making a decision based on the social condition attributes of the abandoned open-pit mine, the decision-making method is as follows: When making decisions based on population attributes, when there are no permanent residents within 5 kilometers of an abandoned open-pit mine, ecological restoration is adopted; if the permanent population within 20 kilometers does not exceed 300,000, an ecological restoration combination is adopted, which includes at least one of "ecological restoration + cultivated land", "ecological restoration + gardens", "ecological restoration + forest land", "ecological restoration + grassland", and "ecological restoration + aquaculture water surface".

[0020] Furthermore, when making decisions based on economic attributes, for areas with per capita GDP of less than 20,000 yuan, remote mountainous areas, and underdeveloped economies, the “ecological restoration + cultivated land / gardens / forest land / grassland / aquaculture water surface” approach will be adopted; for areas with developed economies and annual per capita GDP of more than 42,800 yuan, the restoration types adopted will be “ecological restoration + engineering construction” or “ecological restoration + ecological cultural tourism”.

[0021] Furthermore, when making decisions based on industrial attributes, the industries in the areas surrounding abandoned open-pit mines are mainly agricultural, and there are no leading enterprises, industry-leading enterprises and projects. The restoration types adopted are "ecological restoration + cultivated land", "ecological restoration + gardens", "ecological restoration + forest land", "ecological restoration + grassland" and "ecological restoration + aquaculture water surface"; the industries in the surrounding areas are mainly industrial, and "ecological restoration + engineering construction" is adopted; if there are corresponding leading enterprises, industry-leading enterprises, cultural tourism projects, and cultural landscapes, "ecological restoration + ecological cultural tourism" is adopted.

[0022] Furthermore, when making decisions based on the attributes of social needs, the public has strong actual needs for urban green spaces, resting places, production and life, and an ecological restoration combination is adopted; when there is a need for popular science propaganda, cultural and educational entertainment, physical exercise or scientific production, "ecological restoration + culture and entertainment and sports" is adopted; when there is a need to build a science and technology museum, a museum, an oceanarium, a gymnasium or a farm, "ecological restoration + ecotourism" is adopted; when there is a need for health care, "ecological restoration + health care and medical care" is adopted; when there is a power gap and a need for the development of new energy, "ecological restoration + photovoltaic power generation" can be adopted.

[0023] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention proposes a decision-making method for the direction of ecological restoration of open-pit mines. By drawing on the relevant theories and methods of decision tree classification, hierarchical judgment can be made and the decision path can be clearly displayed, which is easy to understand and explain. It does not require complex data preprocessing, such as normalization or standardization. It can process numerical and categorical data at the same time. It does not require any assumptions, and the decision-making is fast and low-cost. In addition, because the various attribute conditions of a mine to be restored are certain, the idea of ​​decision classification is drawn, and no human influence such as index value classification, expert scoring, and weight setting is introduced, which can avoid turning a certain problem into an evaluation problem with uncertainty.

[0024] (2) The present invention has guiding significance for the selection of ecological restoration directions for open-pit mines. By applying the technical method of the present invention, on the basis of investigating the various attribute conditions of the open-pit mines to be restored, each attribute condition is hierarchically and step-by-step judged in the decision-making model to illustrate the ecological restoration direction suitable for the attribute conditions of each mining area; through the accumulated attribute conditions of each ecological restoration direction, the one that meets the most attribute conditions is determined as the most suitable restoration direction, and other more suitable directions are also screened out to facilitate the combined selection of project implementation. This method solves the problem of unclear restoration directions and goals before the establishment of open-pit mine ecological restoration projects in the field of mine ecological restoration, and provides a decision-making method and basis for determining the subsequent direction of open-pit mine ecological restoration. The application of this method can make full use of restoration funds, ensure the effectiveness of ecological restoration in mining areas, and promote high-quality social and economic development. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the structure of a decision-making model for ecological restoration direction of abandoned open-pit mines provided by the present invention; Figure 2 The decision-making attribute condition framework diagram of the abandoned open-pit mine ecological restoration direction provided by the present invention; Figure 3 This is the decision result diagram of the ecological restoration direction of the abandoned open-pit mine in Example 1. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention clearer, embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0027] Terms and definitions used in this invention: (1) Abandoned open pit Open pit mines are closed mines left over after the development of mineral resources has ended.

[0028] (2) Mine ecological restoration It refers to relying on natural forces or through artificial intervention to repair mining ecological problems such as geological safety hazards, land damage and vegetation destruction caused by mineral resource mining activities, so that the mining geological environment can be stabilized, the damaged land can be reclaimed and utilized, and the ecosystem function can be restored and improved.

[0029] (3) Mine ecological restoration project It refers to the process and activities of systematically repairing and comprehensively managing problems such as mine geological environment damage, land damage and vegetation damage in areas damaged by mineral resource mining activities and affected areas, so that the mine geological environment can be stabilized, the damaged land can be reclaimed and utilized, and the ecosystem functions can be restored and improved.

[0030] (4) Direction of mine ecological restoration After the implementation of the mine ecological restoration project, the development trend of the open-pit mining area and the expected restoration goals.

[0031] (5) Isolated for natural growth Stop human interference in the ecosystem to reduce load pressure, and rely on the ecosystem's self-regulation and self-organization capabilities to enable it to naturally succeed and renew in an orderly direction.

[0032] (6) Assisted to ecological greening Make full use of the self-recovery ability of the ecosystem, supplemented by simple tasks such as covering the soil, fertilizing, sowing grass seeds, replanting, etc., so that the degraded and damaged ecosystem can gradually recover and enter a virtuous cycle.

[0033] (7) Ecological restoration combination (ecological restoration + ecological restoration and comprehensive utilization) It refers to the reconstruction of ecosystems through engineering technology methods, mainly through artificial measures, when ecological functions are damaged, the self-recovery ability of ecosystems is lost, or irreversible changes occur, and to enable them to enter a virtuous cycle, and then to carry out comprehensive utilization on this basis.

[0034] To achieve the above objectives, based on the collection, collation and analysis of relevant information and cases, we first summarize the main restoration directions of abandoned open-pit mines and establish a decision-making model; analyze the mine attribute conditions related to the ecological restoration direction; identify the decision direction within the model; and determine the most suitable restoration direction for abandoned open-pit mines based on the number of attribute conditions reaching the node.

[0035] The technical methods used are as follows: (1) Data collection and organization Collect and analyze typical cases of ecological restoration of abandoned open-pit mines at home and abroad, and summarize the restoration directions or combinations of restoration directions in the cases.

[0036] (2) Establish a decision-making model Through inductive analysis, a decision model is established hierarchically, such as Figure 1 shown.

[0037] The directions of ecological restoration of abandoned open-pit mines can be mainly summarized as ecological restoration, ecological restoration + reclamation and greening (agriculture, forestry, animal husbandry and fishery), ecological restoration + engineering construction, and ecological restoration + transformation and utilization.

[0038] Among them, ecological restoration includes two methods: natural recovery and assisted regeneration; "ecological restoration + reclamation and greening (agriculture, forestry, animal husbandry and fishery)" includes "ecological restoration + cultivated land", "ecological restoration + gardens", "ecological restoration + forest land", "ecological restoration + grassland", and "ecological restoration + aquaculture water surface"; "ecological restoration + engineering construction" includes "ecological restoration + housing", "ecological restoration + industry", "ecological restoration + commercial services", and "ecological restoration + culture and sports"; "ecological restoration + transformation and utilization" includes "ecological restoration + ecological culture and tourism", "ecological restoration + health care", "ecological restoration + ecological cemetery", "ecological restoration + photovoltaic power generation", and "ecological restoration + others". Among them, "ecological restoration + others" includes some situations that are not included in this model, such as military training shooting ranges and live-fire drills, which can be increased or decreased according to actual conditions.

[0039] (3) Analysis of mine property conditions Mine attribute conditions are the basis for classification. The decision-making process of ecological restoration of each abandoned open-pit mine refers to many attribute conditions. They are summarized into four categories: natural conditions, policy conditions, current conditions of abandoned mines, and social conditions. Each category contains multiple factors, such as Figure 2 shown.

[0040] 1) Natural conditions ①Location and transportation The regional location of the abandoned open-pit mine and its transportation convenience by land, water and air.

[0041] ②Landscape The topography, landforms and landscape conditions of abandoned open-pit mines and surrounding areas.

[0042] ③Meteorological and water conservancy The temperature, sunshine, humidity, rainfall, wind direction, wind speed and other climatic conditions at the location of the abandoned open-pit mine, the conditions of available surface water and groundwater such as rivers, streams, reservoirs, mountain springs, and the surrounding water conservancy facilities such as water diversion channels, wells, reservoirs, pumping stations, etc.

[0043] ④ Regional ecosystem structure and its stability It mainly refers to the stability of the structure and function of the ecosystem in abandoned open-pit mines and surrounding areas. Mining areas with good original ecosystem structure and function stability generally have higher ecological thresholds. On the one hand, under the influence of mining activities, they can still maintain the integrity of their own structure and function, and the system will not mutate, showing strong stress resistance; on the other hand, after the external influence is eliminated, the ecosystem can self-adjust and naturally repair, showing strong self-repair.

[0044] 2) Policy conditions ①Land use type It refers to the land type before the abandoned open-pit mine was mined, which is generally determined by the natural resources authority based on the land use type map issued by the authority.

[0045] ②Regional development planning The regional land space planning, land space use control system, land space ecological restoration planning, social economy and tourism development and other corresponding plans issued by departments at all levels include the five-year plan for the area where the mine is located.

[0046] ③Source of project funds According to the source of project funds, it is divided into provincial and ministerial fiscal funds (which require local matching), local government matching funds, and social funds contributed by social groups or individuals.

[0047] 3) Current conditions of abandoned open-pit mines ① Rock and soil stability Determine the stability of rock and soil based on the current mine investigation and geological hazard risk assessment.

[0048] ②Water environment quality According to the "Groundwater Quality Standard GB / T 14848-2017", "Surface Water Environmental Quality Standard (GB 3838-2002)" and other corresponding standards such as fishery water quality standards, industrial water quality standards, agricultural irrigation water quality standards, swimming and scenic water quality standards, the surface water and groundwater environmental quality of abandoned open-pit mines is evaluated in order to select the corresponding direction.

[0049] ③Soil environmental quality According to the "Soil Environmental Quality Agricultural Land Soil Pollution Risk Control Standard (Trial) GB15618-2018", "Soil Environmental Quality Construction Land Soil Pollution Risk Control Standard (Trial) GB36600-2018" and the corresponding control requirements for agricultural crops on pollution elements or pollutants, the soil environmental quality is evaluated in order to select the corresponding direction.

[0050] ④ Vegetation preservation status Investigate the stability of the ecosystem in abandoned open-pit mines and surrounding areas, including vegetation coverage, species types and community structure, and evaluate the stability of biodiversity and community structure.

[0051] ⑤Soil and water conservation status Investigate the soil and water loss situation and evaluate the degree of soil and water loss in order to choose the corresponding direction.

[0052] 4) Social conditions ① Population The main considerations are the permanent population and the potential number of tourists when developing tourism.

[0053] ②Economy It refers to the economic development of the region where the abandoned open-pit mine is located, determined based on the regional gross domestic product and per capita GDP.

[0054] ③Industry It refers to the industrial structure of the area surrounding abandoned open-pit mines, and whether there are leading enterprises and projects that can drive economic development and boost local industries and tourism.

[0055] ④Social needs It refers to the actual needs generated by social conditions, public will, etc. during the period of ecological restoration of abandoned open-pit mines.

[0056] (4) Node direction judgment Drawing on the relevant theories and methods of decision tree classification, starting from the root node of the model (the abandoned open-pit mine to be repaired), to classify the attribute conditions of a specific mine into a leaf node (class label), it is necessary to determine the direction of the attribute condition after reaching the internal node, that is, it is necessary to use corresponding rules to judge the direction in which the attribute condition meets the requirements.

[0057] 1) Natural conditions ①Location and transportation Mines that are geographically remote or have no reuse plans, are not within the "three zones and three lines" delineated in the county-level land and space planning or the important ecological barrier zone delineated in the land and space development and protection pattern, are more than 10 km away from county roads, and have no advantages in location and transportation, usually adopt ecological restoration. Mines outside these areas adopt the "ecological restoration + *" model.

[0058] ②Landscape If the terrain and landforms of abandoned open-pit mines are not severely damaged and are not too abrupt in contrast to the surrounding landscape, ecological restoration is usually adopted. If the terrain and landforms are severely damaged, causing serious visual pollution and affecting the overall landscape image, the "ecological restoration + *" model is adopted.

[0059] The degree of damage to the topographic landscape is measured by visual sensitivity. Visual sensitivity is mainly expressed by the visually accessible terrain factor - relative slope. The relative slope refers to the angle between the landscape surface and the tourist's line of sight. The larger the angle, the higher the visual sensitivity of the landscape, and the greater the degree of attention paid to the landscape by tourists. This also shows that the landscape in the area has a high visual appeal to people. Similarly, the higher the visual sensitivity of the landscape, the easier it is to pay attention to the damaged mountains and damaged land, and the more serious the visual pollution.

[0060] In the process of experiencing the landscape, people's perspectives can be divided into three types of observation angles: looking up, looking straight, and looking down. The angle α is actually the slope of the terrain. The projection area of ​​the landscape surface along the direction of people's sight can be used to express the landscape sensitivity Sa of the relative slope, that is, Sa=Sinα(0°≤α≤90°). Considering that the more upright the pit wall of the open-pit mine is, the smaller the projection area on the plane is, it is stipulated that when the area with Sa≥0.5 (α=30°) accounts for one-quarter or more of the total area, the topographic landscape of the abandoned open-pit mine is severely damaged, and when the area with Sa≥0.5 (α=30°) accounts for less than one-quarter of the total area, the topographic landscape of the abandoned open-pit mine is not seriously damaged.

[0061] ③Meteorological and water conservancy When the annual rainfall is ≥400mm and the climatic conditions are suitable for vegetation growth, ecological restoration is usually adopted; when the annual rainfall is <400mm, there is available surface water and groundwater, as well as water conservancy facilities that are convenient for irrigation and maintenance, the "ecological restoration + *" model can be adopted.

[0062] ④ Regional ecosystem structure and its stability The structure and stability of the ecosystem are measured by the number of vegetation species. In mining areas with good ecosystem structure and functional stability, the land damaged by mining can be gradually restored by relying on the self-regulation ability of the ecosystem, without the need for engineering intervention. Or the self-recovery ability of the mining area is poor, and simple auxiliary work such as covering soil, fertilizing, and sowing grass seeds is needed to gradually restore the damaged ecosystem. Ecological restoration is adopted. On the contrary, if the structure and function of the ecosystem are greatly damaged, the ecosystem is fragile, and it is difficult to restore to a higher stability by self-organization and positive succession. The "ecological restoration + *" model is adopted. Calculate the ratio of the number of vegetation species per unit area in the mining area to the number of vegetation species per unit area in the undisturbed area, β. If β ≥ 80%, the species are well preserved and the ecosystem structure is relatively complete, and ecological restoration can be adopted; if β < 80%, the "ecological restoration + *" model is adopted.

[0063] 2) Policy conditions ①Land use type According to the land type before the abandoned open-pit mine was mined (based on the latest results of the third national land survey and subsequent change surveys), priority will be given to restoring the land use attributes before mining when carrying out restoration. If the land was cultivated land, orchards, woodlands, grasslands, aquaculture water surfaces, or construction land before mining, it will be restored to the corresponding type before mining.

[0064] ②Regional development planning According to the corresponding plans such as county and city-level land and space planning, land and space use control system, land and space ecological restoration plan, social economy and tourism development land and space ecological restoration plan, land and space use control, regional tourism development plan, etc., the corresponding land types are restored, mainly including agricultural land (arable land, orchards), forest land, grassland, aquaculture water surface, residential, industrial, commercial and service, cultural and sports land in construction land, and corresponding planned land for transformation and utilization.

[0065] ③Source of project funds According to the source of project funds, if it is fiscal funds and local matching funds, priority will be given to restoration as agriculture, forestry, animal husbandry and fishery land or construction land; if the source of funds is social funds, it will be restored as construction land or transformed for use according to the wishes of the investor.

[0066] 3) Current conditions of abandoned open-pit mines ① Rock and soil stability On the basis of the rock and soil stability evaluation, if the stability of the slope rock and soil is basically stable or unstable, that is, there are geological safety hazards such as collapse and landslide, and engineering measures are needed to strengthen support, cut slopes and reduce loads, the "ecological restoration + *" model will be adopted; if the stability of the slope rock and soil is stable or relatively stable, ecological restoration is usually adopted.

[0067] The rock and soil stability evaluation index system and classification are shown in Table 1: Table 1 Rock and soil stability evaluation index system and classification

[0068] Based on the actual situation and expert experience, various indicators are graded and assigned values, and the mine slope units are scored. Finally, the stability score of each slope unit is obtained. According to the score, the slope stability level is divided into four levels: stable, relatively stable, basically stable, and unstable.

[0069] ②Water environment quality There is no water pollution and no constraints on the choice of ecological restoration model.

[0070] If there is water pollution, the "ecological restoration + *" model is adopted, referring to the corresponding national, industry, group and local water quality standards for fishery water (GB11607-1992), industrial water quality standards, agricultural irrigation water quality standards (GB 5084-2021), swimming pool water quality and sanitation standards, and water quality standards for scenic water bodies. * is the utilization type corresponding to the corresponding water quality evaluation standard. Fishery standards correspond to fisheries, and "ecological restoration + aquaculture water surface" is adopted; industrial standards correspond to restoration for engineering construction land, and "ecological restoration + industry" is adopted; agriculture and forestry standards correspond to agricultural land (arable land, gardens) and woodlands, and "ecological restoration + arable land / gardens / woodlands" is adopted; grassland water quality standards correspond to grasslands, and "ecological restoration + grasslands" is adopted; swimming and scenic water bodies correspond to suburban parks, water parks, etc., and "ecological restoration + ecological cultural tourism" is adopted. When pollutants seriously exceed the standard and do not meet any of the above use requirements, the pollution is repaired by ecological restoration (pollution control) + woodlands (ecological greening).

[0071] ③Soil environmental quality There is no pollution or basically no pollution, and it meets all standards. There are no constraints and it can be any direction of ecological restoration or "ecological restoration + *".

[0072] If there is pollution, it will be restored to a land type that meets the corresponding pollution risk control standards. If it meets the "Soil Environmental Quality Construction Land Soil Pollution Risk Control Standards", it will be restored to construction land for engineering construction, using "ecological restoration + residential / industrial / commercial services / entertainment and sports"; if it meets the "Soil Environmental Quality Agricultural Land Soil Pollution Risk Control Standards", it will be restored to cultivated land, gardens, woodlands, and grasslands, using "ecological restoration + cultivated land / gardens / woodlands / grasslands"; when the pollution value seriously exceeds the standard and does not meet any of the above use requirements, the pollution will be repaired by using ecological restoration (pollution control) + forest land (ecological greening) methods.

[0073] ④ Vegetation preservation status Vegetation coverage is used to measure the vegetation preservation of abandoned open-pit mines. Vegetation coverage refers to the percentage of the vertical projection area of ​​vegetation (including leaves, stems, and branches) on the ground to the total area of ​​the statistical area. When the vegetation coverage is ≥60%, ecological restoration is adopted; when the vegetation coverage is less than 60%, or the vegetation is severely damaged and it is expected that it cannot be restored by natural closure or ecological restoration within two years, the "ecological restoration + *" method is adopted for restoration.

[0074] ⑤Soil and water conservation status The soil erosion degree is used to measure the soil and water conservation of abandoned open-pit mines. The weaker the soil erosion, the more stable the soil is and the less likely it is to suffer from soil and water loss. Except for arid and semi-arid areas, most of the soil erosion in abandoned open-pit mines is usually hydraulic erosion. The Chinese Soil Loss Equation (CSLE) is used to calculate the hydraulic erosion intensity of the mining area, and the soil erosion classification and grading standards (SL190-2007) issued by the Ministry of Water Resources are used for reference. The soil micro-erosion area is divided into the first level; the light erosion area is divided into the second level; the moderate erosion area is divided into the third level; and the strong erosion area is divided into the fourth level.

[0075] On the basis of soil erosion classification, if more than 50% of the mining area has soil erosion of level one to level two, the surface soil is well preserved, there is no soil erosion, or there is mild or micro soil erosion, ecological restoration can be adopted, or "ecological restoration + cultivated land / gardens / forest land / grassland / aquaculture water surface" can be adopted; if more than 50% of the mining area has soil erosion of level three to level four, and the surface soil is stripped or damaged, if there is no source of foreign soil and it is suitable for engineering construction, "ecological restoration + residential / industry / commercial services / entertainment and sports" can be adopted; if there is a source of foreign soil, "ecological restoration + cultivated land / gardens / grassland / forest land / ecological culture and tourism" can be adopted.

[0076] 4) Social conditions ① Population If there is no permanent population within 5 kilometers of an abandoned open-pit mine, ecological restoration will be adopted; if the permanent population within 20 kilometers does not exceed 300,000, "ecological restoration + cultivated land / gardens / forest land / grassland / aquaculture water surface" will be adopted; if the permanent population within 20 kilometers exceeds 300,000, "ecological restoration + residential / industrial / commercial services / entertainment and sports" can be adopted; the macro-total target forecast method and the tourist destination life cycle method are used to conduct macro-market forecasts, combined with the scenic spot development stage forecast, market penetration forecast, scenic spot competitiveness analysis, core selling points, etc., to predict the project tourist volume. If the number of tourists can meet the project expectations (calculated based on the project scale, investment payback period, rate of return, etc.), "ecological restoration + ecological cultural tourism" can be adopted.

[0077] ②Economy For areas with per capita GDP of less than 20,000 yuan, remote mountainous areas, and underdeveloped economies, priority will be given to "ecological restoration + cultivated land / gardens / forest land / grassland / aquaculture water surface." For areas with developed economies and annual per capita GDP of more than 42,800 yuan (or determined according to relevant calculation standards for the tourism industry), "ecological restoration + engineering construction / ecological cultural tourism" can be considered.

[0078] ③Industry The industries in the areas surrounding abandoned open-pit mines are mainly agricultural, and there are no leading enterprises, industry-leading enterprises and projects. The “ecological restoration + cultivated land / gardens / forest land / grassland / aquaculture water surface” is adopted; the industries in the surrounding areas are mainly industrial, and the “ecological restoration + engineering construction” is adopted; if there are corresponding leading enterprises, industry-leading enterprises, cultural tourism projects, and cultural landscapes, “ecological restoration + ecological cultural tourism” can be considered.

[0079] ④Social needs The public has a strong practical demand for urban green space, resting places, production and life, and "ecological restoration +" can be adopted. If there is a demand for popular science propaganda, cultural and educational entertainment, physical exercise, scientific production, etc., "ecological restoration + entertainment and sports" can be adopted to build science and technology museums, museums, oceanariums, gymnasiums, farms, etc., or "ecological restoration + ecotourism" can be adopted to build mining parks, geological parks, suburban parks, landscape parks, open green spaces, botanical gardens, youth quality development camps, etc. If there is a demand for health care, "ecological restoration + health care and medical care" can be used to establish a health care complex in the suburbs of the city. When there is a power gap and a demand for the development of new energy, "ecological restoration + photovoltaic power generation" can be adopted.

[0080] (5) Decision-making method Based on the investigation and evaluation of the four major attribute conditions of abandoned open-pit mines, the various conditions of the abandoned open-pit mines are traversed through the decision-making model. Each condition is counted as 1 when it reaches a node. If it reaches the first-level node and cannot be further subdivided, all the target classes below it are counted as 1 (for example, through a certain attribute condition, it can only be judged that it can be used for engineering construction, then the third-stage residential, industrial, commercial service, and entertainment and sports land under the construction area are all counted as 1); finally, the counts of each target class are added up, and the type corresponding to the largest number is the most suitable restoration mode for this mine, because it meets the most attribute conditions required by this target class.

[0081] In the decision-making method provided by the present invention, the attribute conditions determine the decision direction at the nodes of the decision-making model. The attribute conditions of each mine are different and need to be considered comprehensively. The corresponding rules for node direction judgment are mainly based on policy regulations, standard specifications (such as water and soil environmental quality standards, agricultural land reclamation related standards), general calculation methods (such as calculation of the number of potential tourists), and objective conditions such as society, economy, and population of the mine and surrounding areas. If a certain attribute condition can only reach the internal node after judgment, but cannot directly reach the node of the final level, then the internal node and all nodes under its branches are counted as 1. The grassland under the direction of agricultural, forestry, animal husbandry and fishery restoration refers to the grassland used for animal husbandry. The direction of ecological restoration can also be restored to grassland, but it mainly refers to increasing vegetation. Grasslands planted for the purpose of regreening areas and improving landscapes; Different ecological restoration directions are not isolated and mutually exclusive, and can be combined in actual restoration work to seek the most appropriate solution; the * in "ecological restoration + *" represents different directions. The internal nodes represent agriculture, forestry, animal husbandry and fishery, engineering construction, and transformation utilization, and the final leaf nodes represent specific types such as cultivated land and forest land, among which cultivated land, gardens, forest land, grasslands, aquaculture water surfaces, residential areas, industries, commercial services, and entertainment and sports also refer to corresponding land use types and restoration directions; in the specific implementation process, the decision-making model can be adjusted first, and the unfeasible restoration directions can be deleted, and the potentially feasible and needed restoration directions can be increased, which is conducive to faster and more accurate decisions on the direction of ecological restoration.

[0082] Example 1 Take a mine ecological restoration project in Jiangxia District, Wuhan City as an example.

[0083] (1) Attribute conditions before restoration 1) Natural conditions ①Location and transportation The mine is located in a village in a street in Jiangxia District, Wuhan City. It is located in the core area of ​​the two "golden triangles" formed by Jiangxia's "three mountains" (Longquan Mountain, Qinglong Mountain and Tianzi Mountain) and Jiangxia's "three lakes" (Liangzi Lake, Lu Lake and Tangxun Lake); it is about 8 kilometers away from the urban area of ​​Jiangxia District and about 30 kilometers away from the main urban area of ​​Wuhan City; it is adjacent to three provincial roads in the east, south and west, and about 6 kilometers away from the Shanghai-Chongqing Expressway (Wuhan Ring Expressway) in the north. In addition, the ecological restoration project area of ​​the mine is about 6 kilometers away from the subway station, about 1 km away from the Wuxian Urban Railway Station, and there is a national highway passing by on the west side, and the location and transportation advantages are very obvious.

[0084] ②Landscape Limited by mining conditions, the mining area mainly uses blasting operations to strip the rock mass. Long-term disorderly mining has resulted in many exposed and bare mining sites in the mines within the management area, causing great damage to the topography and landscape, and affecting the aesthetic perception and tourism landscape resources in the area.

[0085] ③Meteorological and water conservancy Jiangxia District, where the mining area is located, has a mid-subtropical transitional humid monsoon climate. The average annual temperature is between 15.9 and 17.9°C, and the historical average is 16.8°C. The total annual precipitation is 889.2 to 1862.6 mm, and the historical average precipitation is 1347.7 mm. The sunshine hours are between 1450 and 2050 hours. It is warm and humid, with distinct four seasons, abundant heat, plentiful rainfall, sufficient sunshine, rain and heat at the same time, and a frost-free period of 268 days. The climatic conditions are extremely suitable for vegetation growth.

[0086] There is abundant surface water and groundwater around the mining area, and there is also water accumulation in the mining pits. The construction of appropriate water conservancy facilities can meet the water needs for later irrigation, vegetation maintenance and other production and living needs.

[0087] ④ Regional ecosystem structure and its stability Due to quarrying in the mining area, the original ecosystem structure and function have been completely destroyed. Without plant growth, it is difficult to achieve the goal of ecological restoration through self-repair.

[0088] 2) Policy conditions ①Land use type It was forest land before mining. Open-pit quarrying occupied and destroyed the land. Before restoration, there were open-pit mines and slag piles in the mining area. Because the past mining emphasized economic benefits without considering the protection of land resources, a large amount of waste slag was piled up in disorder, the land could not be used, and the land resources were seriously damaged.

[0089] ②Regional development planning According to planning documents such as the "General Plan for the Land and Space of Jiangxia District, Wuhan City (2021-2035)" and the "Ecological Restoration Plan for the Land and Space of Wuhan City (2021-2035)", the mining area is located on the north-south urban-rural development axis and the comprehensive area for improving the urban living environment.

[0090] ③Source of project funds The Jiangxia District Government has introduced social forces to promote the restoration of the mountain in the mining area, carried out work such as mine environmental governance, ecological restoration, reclamation and utilization, and industrial integration, and actively explored new models for effectively restoring abandoned mines and improving land use efficiency through market mechanisms. The source of funds is social funds.

[0091] 3) Current conditions of abandoned mines ① Rock and soil stability Due to years of quarrying, the mining area suffers from landslides, dangerous rocks, deep mine pits, soil erosion, mining waste and slag everywhere, serious damage to the land vegetation, and prominent geological safety hazards and ecological environment problems.

[0092] The mining area is composed of hard rocks, mainly limestone, with well-developed joints, fissures and dissolution phenomena. Under the influence of rainfall, rainwater infiltrates along the fissure surfaces in large quantities, which not only increases the bulk density of the rock mass, but also reduces the mechanical parameters of the fissure surfaces, increasing the probability of collapse and landslides.

[0093] ②Water environment quality The ecological environment around the mining area is good, and the surface water, groundwater and mine water are unpolluted, meeting all water quality standards.

[0094] ③Soil environmental quality Due to the stripping of topsoil during ore mining, there is no soil in the mining area.

[0095] ④ Vegetation preservation status The vegetation has been severely damaged, with no vegetation growing in the mining pits, slopes or rock walls.

[0096] ⑤Soil and water conservation status There are forests, farmlands and villages around. Before restoration, the soil layer in the mining area was missing, dusty and barren, but the mine resources are distinctive. During the ecological restoration process, abandoned soil from the foundation pit was absorbed from the outside world for covering, and there is a source of foreign soil.

[0097] 4) Social conditions ① Population The mining area mainly attracts tourists from Wuhan City, and the number of tourists is related to the permanent population of Wuhan City. At the end of 2022, the permanent population of Wuhan City was 13.739 million, an increase of 90,100 from the end of the previous year. The tourism market is huge, with 6 million potential customers in southern Wuhan alone (from the Jiangxia District Government website of Wuhan City).

[0098] ②Economy In 2022, Wuhan will achieve a gross regional product (GDP) of 1,886.643 billion yuan (Jiangxia District's GDP in 2022 will be 108.076 billion yuan), with a per capita GDP of 138,215 yuan; the city's consumer price index will rise by 2.3% over the previous year, and education, culture and entertainment will rise by 2.7%. Residents have great potential for spending on eco-tourism. In recent years, the tourism economy has continued to grow faster than GDP, and the tourism market has also been growing steadily.

[0099] ③Industry Jiangxia District has now formed five major leading industries, including big health, automobiles and parts, modern equipment manufacturing, optoelectronics, the Internet and modern logistics. It has won the title of "China's Top 100 Districts" and has been awarded the title of "China's Top 100 Industrial Districts" for five consecutive years. More than a dozen natural villages and bays in the surrounding area have preserved the original rural texture, providing space for the creation of rural-style homestays for the mining area ecological restoration project. There are farmland land in the project site, forming a beautiful pastoral landscape, providing space for the later farming experience and agricultural theme science projects. In addition, Jiangxia has a rich and colorful Three Kingdoms culture, Peking Opera culture, red culture, intangible cultural heritage and cultural business cards "Chutian First County", "Yunmengze" cultural birthplace and Chu culture traceability. The five cultural business cards of Zhongshan Ship, Finger Painting, Jiangxia Yellow, Peking Opera Tanmen, and Husi Ancient Kiln Site Group demonstrate Jiangxia's profound cultural heritage.

[0100] ④Social needs The project area has diverse terrain and abundant resources. The mines and fields are picturesque, and farmhouses are scattered all over the place. Before the ecological restoration work was carried out, it had attracted many mountaineering and rock climbing enthusiasts from the surrounding areas to come spontaneously. The public demand is relatively high.

[0101] (2) Decision-making process In order to intuitively analyze which category a certain attribute condition falls into, the attribute conditions are numbered in sequence: ① location and transportation, ② landform and landscape, ③ meteorology and water conservancy, ④ regional ecosystem structure and its stability, ⑤ land use type, ⑥ regional development plan, ⑦ project funding source, ⑧ rock and soil stability, ⑨ water environment quality, ⑩ soil environment quality, ⑪ vegetation retention status, ⑫ soil and water conservation status, ⑬ population, ⑭ economy, ⑮ industry, ⑯ social demand.

[0102] Establish a decision model. Traverse the attribute conditions through the classification model, refer to Figure 1 The node direction determination is to determine the decision direction of each node, depending on which category the attribute condition belongs to: Attribute conditions ① Location and transportation: Applicable to the "ecological restoration + reclamation and greening / transformation and utilization" model, but it cannot be further subdivided, so each category number under reclamation and greening and transformation and utilization is met and counted as 1.

[0103] Attribute condition ② Landform and landscape: Applicable to the "ecological restoration + *" model, but cannot be further subdivided, so each category number under reclamation and greening, engineering construction and transformation and utilization is met and counted as 1.

[0104] Attribute condition ③ Meteorological and water conservancy: Applicable to any mode of “ecological restoration” and “ecological restoration + *”, but cannot be further subdivided, so each class number meets the requirements and is counted as 1.

[0105] Attribute condition ④ Regional ecosystem structure and its stability: Applicable to the "ecological restoration + *" model, but cannot be further subdivided, so each category number under reclamation and greening, engineering construction and transformation and utilization is met and counted as 1.

[0106] Attribute condition ⑤ Land use type: Applicable to the "ecological restoration + forest land" model, directly classified into this category, counted as 1.

[0107] Attribute condition ⑥ Regional development plan: mainly considers the development and improvement of the human living environment, applicable to "ecological restoration + engineering construction / ecological cultural tourism", classified into the corresponding category number, all counted as 1.

[0108] Attribute condition ⑦ Source of project funds: The source is social funds, which are large in scale. The investor’s intention is eco-tourism, which is classified as “ecological restoration + ecological cultural tourism”, totaling 1.

[0109] Attribute condition ⑧ Rock and soil stability: process control measures are needed to eliminate safety hazards, and it is classified as "ecological restoration + *". It is not suitable for construction land with excessive population concentration, but it cannot be further subdivided. Therefore, each category number under reclamation and greening and transformation utilization is applicable, and all are counted as 1.

[0110] Attribute condition ⑨ Water environment quality: There is no water pollution, and each class number is met, all counted as 1.

[0111] Attribute condition ⑩ Soil environmental quality: There is no soil pollution, and each class number is met, all counted as 1.

[0112] Attribute condition ⑪ Vegetation retention status: The vegetation is severely damaged and cannot be restored naturally or regenerated with assistance. "Ecological restoration + *" must be adopted. Therefore, each category number under reclamation and greening, engineering construction and transformation and utilization is met and counted as 1.

[0113] Attribute condition ⑫ Soil and water conservation status: soil layer is missing, there is a source of foreign soil, which is suitable for "ecological restoration +*", but it cannot be further subdivided. Therefore, each category number under reclamation and greening, engineering construction and transformation and utilization is met and counted as 1.

[0114] Attribute condition ⑬ Population: Based on the population of nearby villages and bays, it is applicable to "ecological restoration + cultivated land / woodland / garden / grassland / fish pond"; based on the number of potential tourists that can be absorbed, it is applicable to "ecological restoration + ecological cultural tourism" and is classified into the corresponding category number, all of which are counted as 1.

[0115] Attribute condition ⑭ Economy: According to the economic development level of nearby villages, Jiangxia District and Wuhan City, "ecological restoration + ecological cultural tourism" can be adopted and classified into the corresponding category number, with a total of 1.

[0116] Attribute condition ⑮ Industry: The surrounding industries have cultural landscapes and projects, which are suitable for "ecological restoration + ecological cultural tourism" and are included in this category, with a total of 1.

[0117] Attribute condition ⑯ Social demand: The public has certain demand for outdoor recreation, which is classified as "ecological restoration + ecological cultural tourism" and is included in this category, with a total of 1.

[0118] The top five counts from largest to smallest are: ecological restoration + ecological tourism (15), ecological restoration + forest land (11), ecological restoration + cultivated land (10), ecological restoration + garden land (10), ecological restoration + grassland (10), and ecological restoration + aquaculture water surface (10), which means that the most suitable way for the mining area is to develop ecological tourism, followed by the restoration of agricultural, forestry, animal husbandry and fishery land; the ecological restoration count is only 3, which means that the mining area cannot achieve good benefits by only adopting natural restoration or assisted regeneration. Developing ecological tourism and restoring forest land and cultivated land are also the main modes adopted by the mining area in subsequent ecological restoration, which shows that the restoration directions can be combined with each other in actual restoration work to seek the optimal combination in order to maximize the benefits.

[0119] After the attribute conditions of the mining area before ecological restoration were classified by the classification model, the classification results are as follows: Figure 3 shown.

[0120] For matters not mentioned above, the prior art applies.

[0121] Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art should understand that the above examples are for illustration only and are not intended to limit the scope of the present invention. Those skilled in the art to which the present invention belongs may make various modifications or supplements to the specific embodiments described or replace them in a similar manner, but they will not deviate from the direction of the present invention or exceed the scope defined by the attached claims. Those skilled in the art should understand that any modifications, equivalent substitutions, improvements, etc. made to the above embodiments based on the technical essence of the present invention should be included in the protection scope of the present invention.

Claims

1. A decision-making method for the ecological restoration direction of abandoned open-pit mines, characterized in that: The following steps are involved: S1. Build a database Collect and analyze typical cases of ecological restoration of abandoned open-pit mines at home and abroad, and summarize the restoration directions or combinations of restoration directions in the cases; S2. Establish a decision model By summarizing and analyzing the data in the database of step S1, a hierarchical decision model is established, and the decision model includes three levels: The first level is to classify the types of restoration directions of abandoned open-pit mines to be restored into ecological restoration or ecological restoration combinations. The ecological restoration combinations include "ecological restoration + reclamation and greening", "ecological restoration + engineering construction", and "ecological restoration + transformation and utilization" at the next level; The second level is to classify the types of restoration directions of abandoned open-pit mines to be restored into "ecological restoration + reclamation and greening", "ecological restoration + engineering construction", and "ecological restoration + transformation and utilization"; The third level is to classify the types of restoration directions of abandoned open-pit mines to be restored into "ecological restoration + cultivated land", "ecological restoration + gardens", "ecological restoration + forest land", "ecological restoration + grassland", "ecological restoration + aquaculture water surface", "ecological restoration + residential", "ecological restoration + industry", "ecological restoration + commercial services", "ecological restoration + entertainment and sports", "ecological restoration + ecological tourism", "ecological restoration + health care and medical care", "ecological restoration + ecological cemetery", "ecological restoration + photovoltaic power generation" and "ecological restoration + others"; S3. Decision-making method Based on the investigation and evaluation of the four major attribute conditions of abandoned open-pit mines, the attribute conditions of abandoned open-pit mines are traversed through the decision model. Each condition reaches a node once and counts as 1. If it reaches a first-level node and cannot be further subdivided, all target classes below it are counted as 1. Finally, the counts of each target class are added up, and the type corresponding to the largest number is the most suitable restoration mode for this mine. The four categories of attribute conditions are natural conditions, policy conditions, current conditions of abandoned open-pit mines and social conditions; The attributes of the natural conditions include location and transportation, landforms and landscapes, meteorology and water conservancy, and regional ecosystem structure and its stability; The attributes examined in the policy conditions include land use type, regional development planning, and project funding sources; The attributes of the abandoned open-pit mine status survey include rock and soil attributes, water environment quality, soil environment quality, vegetation retention status and soil and water conservation status; The attributes examined in the social conditions include population, economy, industry and social needs.

2. The decision-making method according to claim 1, characterized in that: When making decisions based on the above natural condition attributes, the decision-making method is as follows: When making decisions based on location and transportation attributes, if the mine is located in a remote geographical location or has no reuse plan area temporarily, and is not within the "three zones and three lines" delineated in the county-level land and space planning or the important ecological barrier zone delineated in the land and space development and protection pattern, and is more than 10km away from the county road, and has no advantages in location and transportation, ecological restoration should be adopted; otherwise, a combination of ecological restoration should be adopted; When making decisions based on landform and landscape attributes, if the landform and landscape of the abandoned open-pit mine is not severely damaged and is not too abrupt with the surrounding area, ecological restoration is adopted; if the landform and landscape is severely damaged, causing serious visual pollution and affecting the overall landscape image, a combination of ecological restoration is adopted; When making decisions based on meteorological and water conservancy attributes, when annual rainfall is ≥400 mm, the climate conditions are suitable for vegetation growth, and ecological restoration is adopted; When annual rainfall is less than 400 mm, there is available surface water and groundwater, as well as water conservancy facilities that are convenient for irrigation and maintenance, and an ecological restoration combination is adopted; When making decisions based on the regional ecosystem structure and its stability attributes, the ratio β of the number of vegetation species per unit area in the mining area to the number of vegetation species per unit area in the undisturbed area is calculated. If β ≥ 80%, the species are well preserved and the ecosystem structure is relatively complete, and ecological restoration is adopted. If β < 80%, an ecological restoration combination is adopted.

3. The decision-making method according to claim 1, characterized in that: When making decisions through the abandoned open-pit mine policy condition attributes, the decision-making method is as follows: When making decisions based on land use type attributes, priority should be given to restoring the land use attributes before mining based on the land type of abandoned open-pit mines before mining. If the land was cultivated land, garden land, forest land, grassland, aquaculture water surface, or construction land before mining, it should be restored to the corresponding type before mining, and an ecological restoration combination should be adopted, including at least one of "ecological restoration + cultivated land", "ecological restoration + garden land", "ecological restoration + forest land", "ecological restoration + grassland", "ecological restoration + aquaculture water surface", "ecological restoration + residential area", "ecological restoration + industry", "ecological restoration + commercial service", or "ecological restoration + entertainment and sports"; When making decisions based on the attributes of regional development planning, according to the corresponding plans such as county-level land space planning, land space use control system, land space ecological restoration plan, social economy and tourism development land space ecological restoration plan, land space use control, and regional tourism development plan, the corresponding land type should be restored and an ecological restoration combination should be adopted, including at least one of "ecological restoration + cultivated land", "ecological restoration + garden", "ecological restoration + forest land", "ecological restoration + grassland", "ecological restoration + aquaculture water surface", "ecological restoration + residential", "ecological restoration + industry", "ecological restoration + commercial services" or "ecological restoration + entertainment and sports"; When making decisions based on the attributes of project funding sources, if the project funding sources are fiscal funds and local matching funds, the land will be restored to agriculture, forestry, animal husbandry and fishery land or construction land; if the funding source is social funds, it will be restored to construction land or transformed for use according to the wishes of the investor.

4. The decision-making method according to claim 1, characterized in that: When making a decision based on the current condition attributes of the abandoned open-pit mine, the decision-making method is as follows: When making decisions based on the rock and soil stability attributes, on the basis of the rock and soil stability evaluation, if the slope rock and soil stability is basically stable or unstable, that is, there are geological safety hazards such as collapse and landslide, and engineering measures are needed to strengthen support, cut slopes and reduce loads, the ecological restoration combination is adopted; if the slope rock and soil stability is stable or relatively stable, ecological greening is adopted; When making decisions based on water environment quality attributes, if there is water pollution, an ecological restoration combination is adopted; if there is no water pollution, there is no constraint on the choice of ecological restoration mode; When making decisions based on soil environmental quality attributes, if the soil is not polluted, a combination of ecological reforestation or ecological restoration can be used; When making decisions based on the attributes of vegetation retention status, when the vegetation coverage is ≥60%, ecological restoration is adopted; when the vegetation coverage is <60%, an ecological restoration combination is adopted; When making decisions based on soil and water conservation conditions, when the soil erosion degree of more than 50% of the mining area is level 1 to 2, ecological restoration is adopted; when the soil erosion degree of more than 50% of the mining area is level 3 to 4, an ecological restoration combination is adopted.

5. The decision-making method according to claim 1, characterized in that: When making decisions through social condition attributes, the decision-making method is as follows: When making decisions based on population attributes, when there are no permanent residents within 5 kilometers of an abandoned open-pit mine, ecological restoration is adopted; when the permanent population within 20 kilometers does not exceed 300,000, an ecological restoration combination is adopted, which includes at least one of "ecological restoration + cultivated land", "ecological restoration + gardens", "ecological restoration + woodland", "ecological restoration + grassland", and "ecological restoration + aquaculture water surface".

6. The decision-making method according to claim 5, characterized in that: When making decisions through social condition attributes, the decision-making method is as follows: When making decisions based on economic attributes, if the per capita GDP is less than 20,000 yuan, the area is in remote mountainous areas, and the economy is underdeveloped, the "ecological restoration + cultivated land / gardens / forest land / grassland / aquaculture water surface" approach will be adopted; if the economy is developed and the annual per capita GDP exceeds 42,800 yuan, the restoration type will be "ecological restoration + engineering construction" or "ecological restoration + ecological cultural tourism".

7. The decision-making method according to claim 6, characterized in that: When making decisions through social condition attributes, the decision-making method is as follows: When making decisions based on industrial attributes, the industries in the areas surrounding abandoned open-pit mines are mainly agricultural, and there are no leading enterprises, industry-leading enterprises and projects. The restoration types adopted are "ecological restoration + cultivated land", "ecological restoration + gardens", "ecological restoration + woodlands", "ecological restoration + grasslands" and "ecological restoration + aquaculture water surface"; the industries in the surrounding areas are mainly industrial, and "ecological restoration + engineering construction" is adopted; if there are corresponding leading enterprises, industry-leading enterprises, cultural tourism projects, and cultural landscapes, "ecological restoration + ecological cultural tourism" is adopted.

8. The decision-making method according to claim 7, characterized in that: When making decisions through social condition attributes, the decision-making method is as follows: When making decisions based on the attributes of social needs, the public has strong actual needs for urban green spaces, resting places, production and life, and an ecological restoration combination is adopted; when there is a need for popular science propaganda, cultural and educational entertainment, physical exercise or scientific production, "ecological restoration + entertainment and sports" is adopted; when it is necessary to build a science and technology museum, museum, oceanarium, gymnasium or farm, "ecological restoration + ecotourism" is adopted; when there is a need for health care, "ecological restoration + health care and medical care" is adopted; when there is a power gap and a need for the development of new energy, "ecological restoration + photovoltaic power generation" can be adopted.

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