Vegetation substrate spraying and water retention integrated method for ecological restoration of strip mine slope

Abstract

The invention belongs to the technical field of strip mine ecological restoration, and particularly relates to a strip mine slope ecological restoration vegetation base material spraying and water retention integrated method, which comprises the following steps: S1, slope pretreatment: carrying out gradient measurement, slope surface cleaning and stability evaluation on a strip mine slope, removing slope surface pumice stones, dangerous stones and weed root systems, and carrying out slope surface treatment; the cracks existing on the slope surface are filled and repaired with a cement-based grouting material, and a smooth and stable repairing base surface is formed; s2, basic parameter acquisition and analysis: acquiring terrain parameters, soil physicochemical properties, meteorological data and hydrological characteristics of a slope area through an unmanned aerial vehicle remote sensing technology, a soil sensor array and a meteorological station network, and establishing a slope ecological restoration basic database; according to the method, precise, efficient and long-term slope ecological restoration is achieved through precise collection of basic parameters, optimization of a plant growing base material formula, dynamic adjustment of spraying parameters, integrated spraying construction and full-period monitoring and evaluation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of ecological restoration of open-pit mines, and particularly relates to a method for integrated spraying and water retention of vegetation substrate for ecological restoration of open-pit mine slopes. BACKGROUND

[0002] During the mining process of open-pit mines, large areas of bare slopes are formed. Such slopes have problems such as poor soil, loose structure, poor water retention capacity, and serious water and soil loss, which not only destroy the regional ecological environment, but also have the risk of landslides, collapses and other geological disasters. Ecological restoration is the core means to solve the problems of open-pit mine slopes, and the spraying technology of vegetation substrate is widely used due to its high construction efficiency and strong adaptability.

[0003] At present, the existing vegetation substrate spraying technology has the following defects: first, the formula of the vegetation substrate lacks pertinence, and is mostly used in slopes with different geological and climatic conditions with uniform proportioning, resulting in poor adaptability of the substrate to the slope environment and low vegetation germination rate; second, the spraying parameters are mostly fixed values, without considering the topographic differences such as slope gradient and slope position, which easily causes uneven thickness of the sprayed layer and insufficient adhesion; third, the water retention measures are single, mostly relying on the water retention components of the substrate, without forming an integrated water retention system of "substrate-water retention membrane-dynamic maintenance", which has poor water retention effect in arid and semi-arid areas and is difficult to meet the long-term growth needs of vegetation; fourth, the evaluation index of ecological effect is not perfect, which cannot fully reflect the restoration quality, resulting in a lack of scientific basis for re-spraying decision-making.

[0004] In view of the above problems, it is urgent to develop a method for integrated spraying and water retention of vegetation substrate with optimized and accurate formula, controllable spraying parameters, long-lasting water retention effect and quantifiable restoration effect, so as to improve the scientificity and effectiveness of ecological restoration of open-pit mine slopes. SUMMARY

[0005] The present application aims to overcome the shortcomings of the existing ecological restoration technology of open-pit mine slopes, and provides a method for integrated spraying and water retention of vegetation substrate for ecological restoration of open-pit mine slopes. Through accurate collection of basic parameters, optimization of vegetation substrate formula, dynamic adjustment of spraying parameters, integrated spraying construction and whole-cycle monitoring and evaluation, the method realizes the precision, efficiency and long-term effect of ecological restoration of slopes.

[0006] The technical solutions adopted by the present application are as follows: The method for integrated spraying and water retention of vegetation substrate for ecological restoration of open-pit mine slopes comprises the following steps: S1, slope pretreatment: measuring the slope gradient, cleaning the slope surface and evaluating the stability of the open-pit mine slope, removing loose stones, dangerous stones and weed roots on the slope surface, filling and repairing the cracks on the slope surface with cement-based grouting material, and forming a flat and stable restoration base surface; S2, basic parameter collection and analysis: through unmanned aerial vehicle remote sensing technology, soil sensor array and weather station networking, the terrain parameters, soil physical and chemical properties, meteorological data and hydrological characteristics of the slope region are collected, and the basic database of slope ecological restoration is established; Among them, the terrain parameters include: slope angle a, unit °; slope length L, unit m; slope aspect θ, unit °, and the positive north direction is 0°, clockwise increasing; The soil physical and chemical properties include: soil moisture content ω0, unit %; soil porosity n, unit %; soil organic matter content OM, unit g; The meteorological data include: annual average precipitation P, unit mm; annual average evaporation E, unit mm; monthly average air temperature T 均 , unit ℃; The hydrological characteristics include: groundwater level depth H, unit m; S3, optimization of plant growth substrate formula: based on the basic parameters collected in step S2, the optimal ratio of each component of the plant growth substrate is determined through the plant growth substrate adaptability algorithm, the plant growth substrate includes matrix main material, water retention functional agent, nutrient regulator and plant seeds, wherein the water retention functional agent is composed of modified polyacrylamide and humic acid; S4, dynamic adjustment of spraying parameters: according to the slope angle a and the slope position coordinates (x, y), the spraying pressure P(x, y) and the spraying flow Q of the spraying equipment are adjusted in real time through the spraying pressure self-adaptive algorithm, to ensure that the plant growth substrate forms a spraying layer with uniform thickness on the slope surface; S5, integrated spraying construction: a double-pipe synchronous spraying system is adopted, the optimized plant growth substrate and water retention enhancer are respectively conveyed to the spraying gun head through the main pipe and the auxiliary pipe, and then sprayed on the slope surface after mixing in the gun head, to form a plant growth substrate spraying layer; S6, water retention layer construction and monitoring: a degradable water retention film is sprayed on the surface of the plant growth substrate spraying layer, the water content, temperature and vegetation growth state inside the spraying layer are monitored in real time through a wireless sensor network, and the maintenance strategy is dynamically adjusted according to the monitoring data through the water retention control algorithm; S7, ecological effect evaluation: after 6 months of repair, the ecological repair effect is evaluated through vegetation coverage, species diversity and soil physical and chemical property improvement degree, and if the preset standard is not reached, the plant growth substrate formula is re-optimized and re-sprayed.

[0007] The plant growth substrate adaptability algorithm in step S3 is specifically: S301, first, the substrate plant growth substrate adaptability evaluation index system is constructed, the soil improvement effect index F1, the water retention duration capacity index F2 and the vegetation germination rate index F3 are selected as the core evaluation indexes, and the weights of each index are determined as ω1, ω2 and ω3 through the analytic hierarchy process, satisfying ω1+ω2+ω3=1; S302. Calculate the values ​​of each indicator; (1) Soil improvement effect index F1: (1); In formula (1), OM´ is the soil organic matter content after adding vegetation substrate, in g; OM0 is the original slope soil organic matter content, in g; n´ is the soil porosity after adding vegetation substrate, in %; n0 is the original slope soil porosity, in %; CEC´ is the soil cation exchange capacity after adding vegetation substrate, in cmol / kg; CEC0 is the original slope soil cation exchange capacity, in cmol / kg; (2) Water retention capacity index F2: (2); In equation (2), θ max The maximum water holding capacity of the plant substrate is expressed in %; θ min The moisture content corresponding to the wilting coefficient of the plant substrate is expressed in %; θ avg The average moisture content of the plant substrate is expressed in % (t). s t0 represents the duration for which the moisture content of the plant substrate is maintained within the suitable range for crops, in hours; t0 represents the duration for which the standard plant substrate retains water, in hours. (3) Vegetation germination rate index : (3); In equation (3), G act This represents the actual seed germination rate, expressed in %; G std Seed germination rate under standard conditions, in %; H act The actual average height of seedlings is given in cm; H std The average height of seedlings under standard conditions is expressed in cm. (4) Calculate the overall suitability score S1 for the vegetation substrate: S1 = F1×ω1 + F2×ω2 + F3×ω3. When S1 ≥ 0.85, it is determined to be the optimal formula. If S1 < 0.85, the proportion of each component is adjusted by particle swarm optimization algorithm until the score requirement is met. The expression for the adaptive spray pressure algorithm in step S4 is: (4) In equation (4), P(x,y) is the spray pressure at the slope coordinates (x,y), in MPa; P0 is the reference spray pressure, ranging from 0.8 to 1.2 MPa; k1 is the slope correction coefficient, k1=0.15 when α≤30°; k1=0.3 when 30°<α≤60°; k1=0.5 when α>60°; k2 is the evaporation-to-precipitation ratio correction coefficient, ranging from 0.2 to 0.4; k3 is the initial moisture content correction coefficient, ranging from 0.1 to 0.25; ω opt The optimal moisture content for vegetation growth is 20%-35%; x represents the horizontal coordinate value of the slope. The spray flow rate Q and the spray pressure P(x,y) satisfy the following relationship: (5); In equation (5), k is the flow coefficient, with a value of 0.85-0.95, A is the cross-sectional area of ​​the spray gun nozzle outlet, in square meters, and ρ is the density of the plant substrate mixture, in kilograms per cubic meter.

[0008] In a preferred embodiment, the slope stability assessment in step S1 employs the limit equilibrium method, with the specific assessment formula as follows: (6); In equation (6), F s For the slope stability safety factor, when F s When the slope is ≥1.2, it is considered a stable slope and spraying can be carried out directly; when 1.0≤F s When the value is less than 1.2, anchor bolts must be installed for reinforcement before construction; when F s When the value is less than 1.0, slope reduction and load reduction treatment must be carried out first; c i L represents the cohesion of the i-th sliding surface, in kPa. i W is the length of the i-th sliding surface, in meters. i Let be the weight of the i-th slider, in kN. i Let be the internal friction angle of the i-th sliding surface, in degrees; The spacing d of the anchor bolt reinforcement is determined by the stability compensation formula: (7); In equation (7), F starget The target stability safety factor is set to 1.3, k is the anchor bolt safety factor set to 1.5, and τ is the anchor bolt tensile strength in MPa.

[0009] In a preferred embodiment, the components of the plant substrate in step S3 are as follows by weight: 60-80 parts of main substrate, 5-12 parts of water-retaining agent, 3-8 parts of nutrient regulator, 0.5-2 parts of plant seeds, and 20-35 parts of water. The main matrix material is composed of humus, perlite and fly ash in a weight ratio of 5:3:2. The fly ash needs to be activated. The activation method is as follows: mix fly ash with a sulfuric acid solution with a mass fraction of 10%-15% in a liquid-solid ratio of 3:1, stir and react at 60-80℃ for 2-3 hours, filter and wash until neutral, and then dry and pulverize. The preparation method of the water-retaining functional agent is as follows: polyacrylamide and humic acid are mixed at a weight ratio of 4:1 to form a mixture, and 3%-5% of silane coupling agent KH-550 is added to the total weight of the mixture. The mixture is melt-blended at 120-150℃ for 15-20 minutes, cooled, and then pulverized to a particle size of 50-100μm. The nutrient regulator is a mixture of slow-release nitrogen fertilizer, superphosphate, potassium chloride and trace element fertilizer in a weight ratio of 6:3:2:1, wherein the slow-release nitrogen fertilizer is urea coated with urea-formaldehyde resin with a coating thickness of 50-100μm. The selection of plant seeds must meet regional adaptability requirements, using a mixture of native herbaceous and shrub seeds, with the specific ratio determined through a niche complementarity algorithm: (8) In equation (8), i is the species number of herbaceous seeds, and N i S represents the weight percentage of the i-th type of herbaceous seed. i G represents the drought resistance score of the i-th herbaceous seed. i R represents the growth rate of the i-th herbaceous seed, expressed in cm / month. i S represents the soil-binding capacity coefficient of the i-th herbaceous seed, ranging from 0.5 to 1.2; j represents the species number of the shrub seed. j G represents the drought resistance score of the j-th shrub seed. j R represents the growth rate of the j-th shrub seed, expressed in cm / month. j This represents the soil-binding capacity coefficient of the j-th shrub seed, with a value ranging from 0.5 to 1.2.

[0010] In a preferred embodiment, the dual-pipeline synchronous spraying system in step S5 includes a plant substrate storage tank, a water-retaining agent storage tank, a twin-screw pump, a flow sensor, a pressure sensor, and a mixing spray gun. The plant substrate storage tank is equipped with a stirring device. The stirring speed v is dynamically adjusted according to the viscosity μ of the plant substrate, and the adjustment formula is as follows: (9) In equation (9), v0 is the reference stirring speed, which is 150-200 r / min, and μ0 is the reference viscosity, which is 500-800 mPa·s; The water-retaining and reinforcing agent is a composite solution of modified cellulose and polyethylene glycol, with a mass ratio of modified cellulose to polyethylene glycol of 1:4. The mass concentration of the water-retaining and reinforcing agent is 8%-12%, and the mixing ratio η of the water-retaining and reinforcing agent with the vegetation substrate is dynamically adjusted according to the average annual evaporation E of the slope. (10) In equation (10), the unit of E is mm, and the value of η ranges from 0.02 to 0.1. The mixing spray gun has a spiral mixer inside its nozzle. The pitch p of the spiral mixer is matched with the spray flow rate Q, and the matching relationship is as follows: Where Q is in L / min and p is in mm.

[0011] In a preferred embodiment, the biodegradable water-retaining membrane in step S6 is made by blending polylactic acid and chitosan in a weight ratio of 7:3, and the membrane thickness h is determined by a water retention requirement algorithm. (11); In formula (11), h0 is the reference film thickness, which is 0.08-0.15 mm. When the calculated h < 0.05 mm, h = 0.05 mm is used; when h > 0.2 mm, h = 0.2 mm is used. The wireless sensor network adopts the ZigBee communication protocol, and the spacing D of the sensor nodes is determined according to the slope length L and slope α. (12); In equation (12), the unit of D is m, and its value ranges from 3 to 8 m. n max This represents the maximum number of soil sensor nodes that can be deployed. The water retention regulation algorithm adjusts the irrigation amount I in real time based on the monitored water content ω inside the spray layer. The specific formula is as follows: When ω≤ω low When, I=I max ×(ω opt -ω) / (ω opt -ω low (13); When ω high ≥ω>ω low When I=0 (14); When ω>ω high At that time, drainage measures should be initiated; In equations (13)-(14), ω low The lower limit threshold for soil moisture content is ω. opt ×0.6, ω high The upper limit threshold for soil moisture content is ω. opt ×1.2, Imax The maximum single irrigation volume is 2-5 L / m².

[0012] In a preferred embodiment, the ecological effect assessment in step S7 adopts the comprehensive evaluation index method, and the formula for calculating the comprehensive evaluation index Eval is as follows: E val =0.4×C+0.3×σ+0.3×S2(15; In formula (15), C is the vegetation coverage rate, % is the percentage of the vertical projection area of ​​the vegetation coverage area to the total area; σ is the species diversity index, calculated using the Shannon-Wiener index, with no unit; S2 is the comprehensive soil improvement index. The formula for calculating the comprehensive soil improvement index S is: The formula for calculating the comprehensive soil improvement index S2 is as follows: S2=0.3×(OM´ / OM0)+0.25×(n´ / n0)+0.2×(ω avg / ω opt )+0.25×(pH´ / pH opt (16); In formula (16), pH´ is the pH value of the remediated soil, pH opt The optimal pH value for vegetation is 6.5-7.5. When E val When the value is ≥0.8, the repair is considered satisfactory; when the value is ≤0.6, the repair is considered satisfactory. val When the thickness is less than 0.8, localized touch-up spraying is required, with the touch-up area accounting for (0.8-E). val ) / 0.2; when E val If the concentration is less than 0.6, a complete overspray is required, and the process should be repeated in step S3 to re-optimize the plant substrate formula.

[0013] In a preferred embodiment, the UAV remote sensing technology in step S2 employs a multispectral camera with a resolution of not less than 0.1m, and the extraction accuracy of slope topographic parameters is controlled by an error correction algorithm. α corr =α meas +Δα(17) In equation (17), α corr To correct the slope, α meas The slope is the measured slope, and Δα is the error correction value, Δα = 0.5 × sin(α). meas (All units are degrees;) The soil sensor array includes a moisture content sensor, a conductivity sensor, and a temperature sensor. The measurement data is processed using a Kalman filter algorithm for noise reduction. The Kalman filter algorithm formula is as follows: X q =A zy·X q-1 +B·u q-1 +w q-1 (18); Z q =Y·X q +v q (19); V q =P q｜q-1 ·Y T ·(Y·P q｜q-1 ·Y T +R) -1 (20); X q｜q =X q｜q-1 +V q · (Z) q -Y·X q｜q-1 )(twenty one); P q｜q =(ξ-V q ·Y)·P q｜q-1 (twenty two); In equations (18)-(22), X k Let q be the system state vector, containing soil moisture content. A. Conductivity, temperature monitored by temperature sensors, and other parameters. zy Let B be the state transition matrix, and let U be the control input matrix. q-1 For the control input at time q-1, w q-1 For process noise, Z q Let Y be the observation value at time q, and Y be the observation matrix. T v is the transpose of matrix Y. q To observe the noise, V q For Kalman gain, P q｜q-1 Let X be the prior error covariance matrix at time q, R be the observation noise covariance matrix, ξ be the identity matrix, and X be the prior error covariance matrix at time q. q｜q P is the optimal state estimate at time q. q｜q Let X be the posterior error covariance matrix at time q. q-1 Let be the system state vector at time q-1.

[0014] In a preferred embodiment, the spraying process in step S4 employs a layered spraying method, consisting of a base layer, a middle layer, and a surface layer. The thickness ratio of each layer is determined based on the slope gradient α. When α≤30°, the ratio of bottom layer: middle layer: top layer is 3:4:3; When 30° < α ≤ 60°, the ratio of bottom layer: middle layer: top layer is 4:4:2; When α > 60°, the ratio of bottom layer: middle layer: top layer = 5:3:2; The spraying interval t between each layer is based on the solidification rate v of the plant substrate. s Sure: t=h layer / v s (twenty three); In equation (23), h layer The thickness of a single layer, whether it is the bottom layer, middle layer, or top layer, is expressed in cm. s v represents the solidification rate of the plant substrate. s =0.12×(1+0.05×T 环 ), in mm / h, T 环 This refers to the ambient temperature, expressed in °C. During the application of the base layer, glass fiber reinforcement material is added at a rate of 1%-2% of the total weight of the plant substrate. The lengths of the glass fibers l and h are [not specified in the original text]. layer The relationship is l = 5 × h layer This ensures that the fibers form a three-dimensional support network at the bottom layer, improving the adhesion between the sprayed layer and the slope; adhesion F f The calculation formula is: (twenty four); In equation (24), F f The unit is MPa.

[0015] In a preferred embodiment, the particle swarm optimization algorithm in step S3 is used to adjust the proportions of each component of the plant substrate. The objective function of the algorithm is max(S1) = max(F1×ω1 + F2×ω2 + F3×ω3), where max(S1) represents maximizing the value of the objective function S1. The constraints are as follows: 0.6≤m1 / (m1+m2+m3+m4)≤0.8(25); 0.05≤m2 / (m1+m2+m3+m4)≤0.12(26); 0.03≤m3 / (m1+m2+m3+m4)≤0.08(27); 0.005≤m4 / (m1+m2+m3+m4)≤0.02(28); In formulas (25)-(28), m1 is the weight of the main substrate material in g; m2 is the weight of the water-retaining agent in g; m3 is the weight of the nutrient regulator in g; and m4 is the weight of the plant seed in g. The parameters of the particle swarm optimization algorithm are set as follows: number of particles N=30, inertia weight ω=0.729, cognitive coefficient c1=1.494, social coefficient c2=1.494, maximum number of iterations λ=50, and the objective function value changes by less than 10 after 5 consecutive iterations. -3 When the time is reached, stop the iteration and output the component ratio corresponding to the current particle as the optimal formula.

[0016] In a preferred embodiment, the method further includes winter insulation measures, when the monthly average temperature T collected in step S2... 均 At ≤0℃, an antifreeze agent is added to the plant substrate, and the amount of antifreeze agent added is m. antifreeze Determined through an antifreeze requirement algorithm: m antifreeze =m base ×(0-T min ) / 100 (29); In equation (29), m base The total weight of the plant substrate is expressed in grams (g); m antifreeze The addition ratio shall not exceed 5% of the total weight of the plant substrate; The antifreeze agent is a mixture of propylene glycol and glycerin in a weight ratio of 2:1, and its freezing point depression ΔT is related to the amount added m. antifreeze The relationship is: ΔT = 1.86 × (m) antifreeze / (M×m water ))×1000(30; In equation (30), M is the average molar mass of the antifreeze, taken as 76 g / mol, and m water The weight of water in the plant substrate is used to ensure the freezing point T of the plant substrate after the addition of antifreeze. min ≤-5℃ to prevent damage to the sprayed layer due to freeze-thaw cycles in winter.

[0017] Compared with the prior art, the technical effects achieved by the present invention are as follows: (1) Precision optimization of formulation. This invention constructs an adaptability algorithm based on the basic parameters of the slope and combines it with particle swarm optimization technology to realize the personalized customization of vegetation substrate formulation, which solves the problem of poor adaptability caused by the "one-size-fits-all" formulation of traditional formulations and significantly improves vegetation germination rate and growth quality.

[0018] (2) Controllable spraying process. This invention achieves dynamic adjustment of spraying parameters under different slope conditions through an adaptive spraying pressure algorithm and layered spraying technology, ensuring uniform thickness and strong adhesion of the sprayed layer, and effectively reducing the risk of sprayed layer detachment on steep slopes.

[0019] (3) Long-term water retention system. This invention constructs an integrated water retention system of “vegetation substrate - water retention enhancer - biodegradable water retention film - dynamic maintenance”, and combines it with a wireless sensor network to realize real-time monitoring and precise control of water retention status, which greatly improves the water retention effect of slopes in arid areas and meets the long-term growth needs of vegetation.

[0020] (4) The restoration effect can be quantified. This invention establishes a multi-dimensional ecological effect evaluation system and uses a comprehensive evaluation index method to achieve quantitative evaluation of restoration quality, providing a scientific basis for respraying decisions and improving the systematicness and reliability of ecological restoration.

[0021] (5) Good ecological and environmental protection. The plant substrate of this invention uses native plant seeds and modified industrial solid waste materials, and the water-retaining membrane uses biodegradable materials to avoid secondary pollution and achieve the coordinated development of ecological restoration and resource recycling. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the integrated method for ecological restoration of open-pit mine slopes using vegetation substrate spraying and water retention, according to the present invention. Detailed Implementation

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0024] Please see Figure 1 As shown, this invention provides an integrated method for ecological restoration of open-pit mine slopes, combining vegetation substrate spraying with water retention, comprising the following steps: S1. Slope pretreatment: Slope measurement, slope cleaning and stability assessment of open-pit mine slopes, removal of loose rocks, dangerous rocks and weed roots, filling and repairing cracks on the slope with cement-based grouting material to form a flat and stable repair base. S2. Basic parameter collection and analysis: Through UAV remote sensing technology, soil sensor array and meteorological station network, collect topographic parameters, soil physicochemical properties, meteorological data and hydrological characteristics of the slope area, and establish a basic database for slope ecological restoration. The topographic parameters include: slope gradient α, in °; slope length L, in m; slope orientation θ, in °, with due north as 0° and increasing clockwise. Soil physicochemical properties include: soil moisture content ω0 (in grams); soil porosity n (in grams); and soil organic matter content OM (in grams). Meteorological data include: annual average precipitation P (in mm); annual average evaporation E (in mm); and monthly average temperature T. 均 The unit is ℃; Hydrological characteristics include: groundwater level depth H, in meters; S3. Optimization of plant substrate formulation: Based on the basic parameters collected in step S2, the optimal ratio of each component of the plant substrate is determined by the plant substrate compatibility algorithm. The plant substrate includes the main substrate material, water-retaining functional agent, nutrient regulator and plant seeds. The water-retaining functional agent is composed of modified polyacrylamide and humic acid. S4. Dynamic adjustment of spraying parameters: Based on the slope gradient α and the slope position coordinates (x, y), the working pressure and spraying flow rate of the spraying equipment are adjusted in real time through the adaptive spraying pressure algorithm to ensure that the vegetation substrate forms a sprayed layer of uniform thickness on the slope. S5. Integrated spraying construction: A dual-pipeline synchronous spraying system is adopted to deliver the optimized vegetation substrate and water-retaining strengthening agent to the spraying nozzle through the main and auxiliary pipelines respectively. After mixing inside the nozzle, the mixture is sprayed onto the slope base surface to form a vegetation substrate spraying layer. S6. Construction and monitoring of water-retaining layer: A biodegradable water-retaining film is sprayed onto the surface of the spray layer of the vegetation substrate. The water content, temperature and vegetation growth status inside the spray layer are monitored in real time through a wireless sensor network. The maintenance strategy is dynamically adjusted according to the monitoring data through a water-retaining regulation algorithm. S7. Ecological effect assessment: Six months after restoration, the ecological restoration effect is assessed by vegetation coverage, species diversity and the degree of improvement of soil physicochemical properties. If the preset standard is not met, return to step S3 to re-optimize the substrate formula and perform re-spraying.

[0025] The specific algorithm for adaptability of vegetation substrates in step S3 is as follows: S301. First, construct an evaluation index system for the compatibility of vegetation substrates. Select soil improvement effect index F1, water retention capacity index F2, and vegetation germination rate index F3 as core evaluation indicators. The weights of each indicator are determined by the analytic hierarchy process as ω1, ω2, and ω3, satisfying ω1+ω2+ω3=1. S302. Calculate the values ​​of each indicator; (1) Soil improvement effect index F1: (1); In formula (1), OM´ is the soil organic matter content after adding vegetation substrate, in g; OM0 is the original slope soil organic matter content, in g; n´ is the soil porosity after adding vegetation substrate, in %; n0 is the original slope soil porosity, in %; CEC´ is the soil cation exchange capacity after adding vegetation substrate, in cmol / kg; CEC0 is the original slope soil cation exchange capacity, in cmol / kg; (2) Water retention capacity index F2: (2); In equation (2), θ max The maximum water holding capacity of the plant substrate is expressed in %; θ min The moisture content corresponding to the wilting coefficient of the plant substrate is expressed in %; θ avg The average moisture content of the plant substrate is expressed in % (t). st0 represents the duration for which the moisture content of the plant substrate is maintained within the suitable range for crops, in hours; t0 represents the duration for which the standard plant substrate retains water, in hours. (3) Vegetation germination rate index : (3); In equation (3), G act This represents the actual seed germination rate, expressed in %; G std Seed germination rate under standard conditions, in %; H act The actual average height of seedlings is given in cm; H std The average height of seedlings under standard conditions is expressed in cm. (4) Calculate the overall suitability score S1 for the vegetation substrate: S1 = F1×ω1 + F2×ω2 + F3×ω3. When S1 ≥ 0.85, it is determined to be the optimal formula. If S1 < 0.85, the proportion of each component is adjusted by particle swarm optimization algorithm until the score requirement is met. The expression for the adaptive spray pressure algorithm in step S4 is: (4); In equation (4), P(x,y) is the spray pressure at the slope coordinates (x,y), in MPa; P0 is the reference spray pressure, ranging from 0.8 to 1.2 MPa; k1 is the slope correction coefficient, k1=0.15 when α≤30°; k1=0.3 when 30°<α≤60°; k1=0.5 when α>60°; k2 is the evaporation-to-precipitation ratio correction coefficient, ranging from 0.2 to 0.4; k3 is the initial moisture content correction coefficient, ranging from 0.1 to 0.25; ω opt The optimal moisture content for vegetation growth is 20%-35%; x represents the horizontal coordinate value of the slope. The spray flow rate Q and the spray pressure P(x,y) satisfy the following relationship: (5); In equation (5), k is the flow coefficient, with a value of 0.85-0.95, A is the cross-sectional area of ​​the spray gun nozzle outlet, in square meters, and ρ is the density of the plant substrate mixture, in kilograms per cubic meter.

[0026] The slope stability assessment in step S1 uses the limit equilibrium method, and the specific assessment formula is as follows: (6); In equation (6), F s For the slope stability safety factor, when F s When the slope is ≥1.2, it is considered a stable slope and spraying can be carried out directly; when 1.0≤F sWhen the value is less than 1.2, anchor bolts must be installed for reinforcement before construction; when F s When the value is less than 1.0, slope reduction and load reduction treatment must be carried out first; c i L represents the cohesion of the i-th sliding surface, in kPa. i W is the length of the i-th sliding surface, in meters. i Let be the weight of the i-th slider, in kN. i Let be the internal friction angle of the i-th sliding surface, in degrees; The spacing d of the anchor bolts is determined by the stability compensation formula: (7); In equation (7), F starget β is the target stability safety factor, with a value of 1.3; β is the anchor bolt safety factor, with a value of 1.5; and τ is the anchor bolt tensile strength, in MPa.

[0027] The components of the plant substrate in step S3 are as follows by weight: 60-80 parts of main substrate, 5-12 parts of water-retaining agent, 3-8 parts of nutrient regulator, 0.5-2 parts of plant seeds, and 20-35 parts of water. The main matrix material is composed of humus, perlite and fly ash in a weight ratio of 5:3:2. The fly ash needs to be activated. The activation method is as follows: mix fly ash with a sulfuric acid solution with a mass fraction of 10%-15% in a liquid-solid ratio of 3:1, stir and react at 60-80℃ for 2-3 hours, filter and wash until neutral, and then dry and pulverize. The preparation method of the water-retaining functional agent is as follows: polyacrylamide and humic acid are mixed at a weight ratio of 4:1 to form a mixture, and 3%-5% of silane coupling agent KH-550 is added to the total weight of the mixture. The mixture is melt-blended at 120-150℃ for 15-20 minutes, cooled, and then pulverized to a particle size of 50-100μm. The nutrient regulator is a mixture of slow-release nitrogen fertilizer, superphosphate, potassium chloride and trace element fertilizer in a weight ratio of 6:3:2:1. The slow-release nitrogen fertilizer is urea coated with urea-formaldehyde resin with a coating thickness of 50-100μm. The selection of plant seeds needs to meet regional suitability requirements, using a mixture of native herbaceous and shrub seeds, with the specific ratio determined using a niche complementarity algorithm: (8); In equation (8), i is the species number of herbaceous seeds, and N i S represents the weight percentage of the i-th type of herbaceous seed. i G represents the drought resistance score of the i-th herbaceous seed. i R represents the growth rate of the i-th herbaceous seed, expressed in cm / month. iS represents the soil-binding capacity coefficient of the i-th herbaceous seed, ranging from 0.5 to 1.2; j represents the species number of the shrub seed. j G represents the drought resistance score of the j-th shrub seed. j R represents the growth rate of the j-th shrub seed, expressed in cm / month. j This represents the soil-binding capacity coefficient of the j-th shrub seed, with a value ranging from 0.5 to 1.2.

[0028] The dual-pipeline synchronous spraying system in step S5 includes a plant substrate storage tank, a water-retaining and strengthening agent storage tank, a twin-screw pump, a flow sensor, a pressure sensor, and a mixing spray gun; The storage tank for the plant substrate is equipped with a stirring device. The stirring speed v is dynamically adjusted according to the viscosity μ of the plant substrate. The adjustment formula is as follows: (9); In equation (9), v0 is the reference stirring speed, which is 150-200 r / min, and μ0 is the reference viscosity, which is 500-800 mPa·s; The water-retaining agent is a composite solution of modified cellulose and polyethylene glycol, with a mass ratio of modified cellulose to polyethylene glycol of 1:4. The mass concentration of the water-retaining agent is 8%-12%. The mixing ratio η of the water-retaining agent and the vegetation substrate is dynamically adjusted according to the average annual evaporation E of the slope. (10); In equation (10), the unit of η is mm, and the value range of η is 0.02-0.1; The mixing spray gun has a spiral mixer inside its nozzle. The pitch p of the spiral mixer is matched with the spray flow rate Q, and the matching relationship is as follows: Where Q is in L / min and p is in mm.

[0029] The biodegradable water-retaining membrane in step S6 is made by blending polylactic acid and chitosan in a weight ratio of 7:3. The thickness h of the biodegradable water-retaining membrane is determined by a water retention requirement algorithm. (11); In formula (11), h0 is the reference film thickness, which is 0.08-0.15 mm. When the calculated h < 0.05 mm, h = 0.05 mm is used; when h > 0.2 mm, h = 0.2 mm is used. The wireless sensor network adopts the ZigBee communication protocol. The spacing D between each sensor node in the soil sensor array is determined based on the slope length L and slope α. (12); In equation (12), the unit of D is m, and its value ranges from 3 to 8 m. nmax This represents the maximum number of soil sensor nodes that can be deployed. The water retention regulation algorithm adjusts the irrigation amount I in real time based on the monitored water content ω inside the spray layer. The specific formula is as follows: When ω≤ω low When, I=I max ×(ω opt -ω) / (ω opt -ω low (13); When ω high ≥ω>ω low When I=0 (14); When ω>ω high At that time, drainage measures should be initiated; In equations (13)-(14), ω low The lower limit threshold for soil moisture content is ω. opt ×0.6, ω high The upper limit threshold for soil moisture content is ω. opt ×1.2, I max The maximum single irrigation volume is 2-5 L / m².

[0030] The ecological effect assessment in step S7 adopts the comprehensive evaluation index method, with the comprehensive evaluation index E. val The calculation formula is: E val =0.4×C+0.3×σ+0.3×S2(15; In formula (15), C is the vegetation coverage rate, % is the percentage of the vertical projection area of ​​the vegetation coverage area to the total area; σ is the species diversity index, calculated using the Shannon-Wiener index, with no unit; S2 is the comprehensive soil improvement index. The formula for calculating the comprehensive soil improvement index S is: S2=0.3×(OM´ / OM0)+0.25×(n´ / n0)+0.2×(ω avg / ω opt )+0.25×(pH´ / pH opt (16); In formula (16), pH´ is the pH value of the remediated soil, pH opt The optimal pH value for vegetation is 6.5-7.5. When E val When the value is ≥0.8, the repair is considered satisfactory; when the value is ≤0.6, the repair is considered satisfactory. val When the thickness is less than 0.8, localized touch-up spraying is required, with the touch-up area accounting for (0.8-E). val ) / 0.2; when E valIf the concentration is less than 0.6, a complete overspray is required, and the process should be repeated in step S3 to re-optimize the plant substrate formula.

[0031] The UAV remote sensing technology in step S2 uses a multispectral camera with a resolution of no less than 0.1m, and the accuracy of slope topographic parameter extraction is controlled by an error correction algorithm. α corr =α meas +Δα(17) In equation (17), α corr To correct the slope, α meas The slope is the measured slope, and Δα is the error correction value, Δα = 0.5 × sin(α). meas (All units are degrees;) The soil sensor array includes a moisture sensor, a conductivity sensor, and a temperature sensor. The measurement data is processed using a Kalman filter algorithm for noise reduction. The Kalman filter algorithm formula is as follows: X q =A zy ·X q-1 +B·u q-1 +w q-1 (18); Z q =Y·X q +v q (19); V q =P q｜q-1 ·Y T ·(Y·P q｜q-1 ·Y T +R) -1 (20); X q｜q =X q｜q-1 +V q · (Z) q -Y·X q｜q-1 )(twenty one); P q｜q =(ξ-V q ·Y)·P q｜q-1 (twenty two); In equations (18)-(22), X k Let q be the system state vector, containing soil moisture content. A. Conductivity, temperature monitored by temperature sensors, and other parameters. zy Let B be the state transition matrix, and let U be the control input matrix. q-1 For the control input at time q-1, w q-1 For process noise, Z q Let Y be the observation value at time q, and Y be the observation matrix. T v is the transpose of matrix Y. qTo observe the noise, V q For Kalman gain, P q｜q-1 Let X be the prior error covariance matrix at time q, R be the observation noise covariance matrix, ξ be the identity matrix, and X be the prior error covariance matrix at time q. q｜q Let P be the optimal state estimate at time q. q｜q Let X be the posterior error covariance matrix at time q. q-1 Let be the system state vector at time q-1.

[0032] The spraying process in step S4 adopts a layered spraying method, consisting of a base layer, a middle layer, and a top layer. The thickness ratio of each layer is determined according to the slope angle α. When α≤30°, the ratio of bottom layer: middle layer: top layer is 3:4:3; When 30° < α ≤ 60°, the ratio of bottom layer: middle layer: top layer is 4:4:2; When α > 60°, the ratio of bottom layer: middle layer: top layer = 5:3:2; The spraying interval t between each layer is based on the solidification rate v of the plant substrate. s Sure: t=h layer / v s (twenty three); In equation (23), h layer The thickness of a single layer, whether it is the bottom layer, middle layer, or top layer, is expressed in cm. s v represents the solidification rate of the plant substrate. s =0.12×(1+0.05×T 环 ), in mm / h, T 环 This refers to the ambient temperature, expressed in °C. Glass fiber reinforcement is added during the base coat application, at a rate of 1%-2% of the total weight of the plant substrate. The length of the glass fiber (l) and its length (h) are... layer The relationship is l = 5 × h layer This ensures that the fibers form a three-dimensional support network at the bottom layer, improving the adhesion between the sprayed layer and the slope; adhesion F f The test value must meet the requirement of F≥0.3MPa, adhesion F f The calculation formula is: (twenty four); In equation (24), F f The unit is MPa.

[0033] The particle swarm optimization algorithm in step S3 is used to adjust the proportions of each component of the plant substrate. The objective function of the algorithm is max(S1) = max(F1×ω1 + F2×ω2 + F3×ω3), where max(S1) represents maximizing the value of the objective function S1. The constraints are as follows: 0.6≤m1 / (m1+m2+m3+m4)≤0.8(25); 0.05≤m2 / (m1+m2+m3+m4)≤0.12(26); 0.03≤m3 / (m1+m2+m3+m4)≤0.08(27); 0.005≤m4 / (m1+m2+m3+m4)≤0.02(28); In formulas (25)-(28), m1 is the weight of the main substrate material in g; m2 is the weight of the water-retaining agent in g; m3 is the weight of the nutrient regulator in g; and m4 is the weight of the plant seed in g. The parameters of the particle swarm optimization algorithm are set as follows: number of particles N=30, inertia weight ω=0.729, cognitive coefficient c1=1.494, social coefficient c2=1.494, maximum number of iterations λ=50, and the objective function value changes by less than 10 after 5 consecutive iterations. -3 When the time is reached, stop the iteration and output the component ratio corresponding to the current particle as the optimal formula.

[0034] The method also includes winter insulation measures, when the monthly average temperature T collected in step S2 is... 均 At ≤0℃, an antifreeze agent is added to the plant substrate, and the amount of antifreeze agent added is m. antifreeze Determined through an antifreeze requirement algorithm: m antifreeze =m base ×(0-T min ) / 100 (29); In equation (29), m base The total weight of the plant substrate is expressed in grams (g); m antifreeze The addition ratio shall not exceed 5% of the total weight of the plant substrate; The antifreeze agent is a mixture of propylene glycol and glycerin in a weight ratio of 2:1, and its freezing point depression ΔT is related to the amount added m. antifreeze The relationship is: ΔT = 1.86 × (m) antifreeze / (M×m water ))×1000(30; In equation (30), M is the average molar mass of the antifreeze, taken as 76 g / mol, and m water The weight of water in the plant substrate is used to ensure the freezing point T of the plant substrate after the addition of antifreeze. min ≤-5℃ to prevent damage to the sprayed layer due to freeze-thaw cycles in winter.

[0035] This invention constructs an adaptability algorithm based on basic slope parameters and combines it with particle swarm optimization technology to achieve personalized customization of vegetation substrate formulations. This solves the problem of poor adaptability caused by the "one-size-fits-all" approach of traditional formulations, significantly improving vegetation germination rate and growth quality. Through an adaptive spraying pressure algorithm and layered spraying technology, the spraying parameters are dynamically adjusted under different slope conditions, ensuring uniform spray layer thickness and strong adhesion, effectively reducing the risk of spray layer detachment on steep slopes. An integrated water retention system of "vegetation substrate - water-retaining enhancer - biodegradable water-retaining film - dynamic maintenance" is constructed. Combined with a wireless sensor network, real-time monitoring and precise control of water retention status are achieved, greatly improving the water retention effect of slopes in arid areas and meeting the long-term growth needs of vegetation. A multi-dimensional ecological effect evaluation system is established, and a comprehensive evaluation index method is used to achieve quantitative evaluation of restoration quality, providing a scientific basis for respraying decisions and improving the systematicness and reliability of ecological restoration. The vegetation substrate uses native plant seeds and industrial solid waste modified materials, and the water-retaining film uses biodegradable materials to avoid secondary pollution, achieving coordinated development of ecological restoration and resource recycling.

[0036] The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described or explained in this invention are implemented according to conventional methods in the art unless otherwise specified or limited.

Claims

1. A method for ecological restoration of open-pit mine slopes that integrates vegetation substrate spraying with water retention, characterized in that: Includes the following steps: S1. Slope pretreatment: Slope measurement, slope cleaning and stability assessment of open-pit mine slopes, removal of loose rocks, dangerous rocks and weed roots, filling and repairing cracks on the slope with cement-based grouting material to form a flat and stable repair base. S2. Basic parameter collection and analysis: Through UAV remote sensing technology, soil sensor array and meteorological station network, collect topographic parameters, soil physicochemical properties, meteorological data and hydrological characteristics of the slope area, and establish a basic database for slope ecological restoration. The topographic parameters include: slope gradient α, in °; slope length L, in m; slope orientation θ, in °, with due north as 0° and increasing clockwise. Soil physicochemical properties include: soil moisture content ω0 (in grams); soil porosity n (in grams); and soil organic matter content OM (in grams). Meteorological data include: annual average precipitation P (in mm); annual average evaporation E (in mm); and monthly average temperature T. 均 The unit is ℃; Hydrological characteristics include: groundwater level depth H, in meters; S3. Optimization of plant substrate formulation: Based on the basic parameters collected in step S2, the optimal ratio of each component of the plant substrate is determined by the plant substrate compatibility algorithm. The plant substrate includes the main substrate material, water-retaining functional agent, nutrient regulator and plant seeds. The water-retaining functional agent is composed of modified polyacrylamide and humic acid. S4. Dynamic adjustment of spraying parameters: Based on the slope gradient α and the slope position coordinates (x,y), the spraying pressure P(x,y) and spraying flow rate Q of the spraying equipment are adjusted in real time through the adaptive spraying pressure algorithm to ensure that the vegetation substrate forms a sprayed layer of uniform thickness on the slope. S5. Integrated spraying construction: A dual-pipeline synchronous spraying system is adopted to deliver the optimized vegetation substrate and water-retaining strengthening agent to the spraying nozzle through the main and auxiliary pipelines respectively. After mixing inside the nozzle, the mixture is sprayed onto the slope base surface to form a vegetation substrate spraying layer. S6. Construction and monitoring of water-retaining layer: A biodegradable water-retaining film is sprayed onto the surface of the spray layer of the vegetation substrate. The water content, temperature and vegetation growth status inside the spray layer are monitored in real time through a wireless sensor network. The maintenance strategy is dynamically adjusted according to the monitoring data through a water-retaining regulation algorithm. S7. Ecological effect assessment: Six months after restoration, the ecological restoration effect is assessed by vegetation coverage, species diversity and the degree of improvement of soil physicochemical properties. If the preset standard is not met, return to step S3 to re-optimize the vegetation substrate formula and perform re-spraying. The specific algorithm for the plant substrate compatibility in step S3 is as follows: S301. First, construct an evaluation index system for the compatibility of vegetation substrates. Select soil improvement effect index F1, water retention capacity index F2, and vegetation germination rate index F3 as core evaluation indicators. The weights of each indicator are determined by the analytic hierarchy process as ω1, ω2, and ω3, satisfying ω1+ω2+ω3=1. S302. Calculate the values ​​of each indicator; (1) Soil improvement effect index F1: （1）； In formula (1), OM´ is the soil organic matter content after adding vegetation substrate, in g; OM0 is the original slope soil organic matter content, in g; n´ is the soil porosity after adding vegetation substrate, in %; n0 is the original slope soil porosity, in %; CEC´ is the soil cation exchange capacity after adding vegetation substrate, in cmol / kg; CEC0 is the original slope soil cation exchange capacity, in cmol / kg; (2) Water retention capacity index F2: （2）； In equation (2), θ max The maximum water holding capacity of the plant substrate is expressed in %; θ min The moisture content corresponding to the wilting coefficient of the plant substrate is expressed in %; θ avg The average moisture content of the plant substrate is expressed in % (t). s t0 represents the duration for which the moisture content of the plant substrate is maintained within the suitable range for crops, in hours; t0 represents the duration for which the standard plant substrate retains water, in hours. (3) Vegetation germination rate index : （3）； In equation (3), G act This represents the actual seed germination rate, expressed in %; G std Seed germination rate under standard conditions, in %; H act The actual average height of seedlings is given in cm; H std The average height of seedlings under standard conditions is expressed in cm. (4) Calculate the overall suitability score S1 for the vegetation substrate: S1 = F1×ω1 + F2×ω2 + F3×ω3. When S1 ≥ 0.85, it is determined to be the optimal formula. If S1 < 0.85, the proportion of each component is adjusted by particle swarm optimization algorithm until the score requirement is met. The expression for the adaptive spray pressure algorithm in step S4 is: （4）； In equation (4), P(x,y) is the spray pressure at the slope coordinates (x,y), in MPa; P0 is the reference spray pressure, ranging from 0.8 to 1.2 MPa; k1 is the slope correction coefficient, k1=0.15 when α≤30°; k1=0.3 when 30°<α≤60°; k1=0.5 when α>60°; k2 is the evaporation-to-precipitation ratio correction coefficient, ranging from 0.2 to 0.4; k3 is the initial moisture content correction coefficient, ranging from 0.1 to 0.25; ω opt The optimal moisture content for vegetation growth is 20%-35%; x represents the horizontal coordinate value of the slope. The spray flow rate Q and the spray pressure P(x,y) satisfy the following relationship: （5）； In equation (5), k is the flow coefficient, with a value of 0.85-0.95, A is the cross-sectional area of ​​the spray gun nozzle outlet, in square meters, and ρ is the density of the plant substrate mixture, in kilograms per cubic meter.

2. The integrated method for vegetation substrate spraying and water retention in ecological restoration of open-pit mine slopes according to claim 1, characterized in that: The slope stability assessment in step S1 uses the limit equilibrium method, and the specific assessment formula is as follows: （6）； In equation (6), F s For the slope stability safety factor, when F s When the slope is ≥1.2, it is considered a stable slope and spraying can be carried out directly; when 1.0≤F s When the value is less than 1.2, anchor bolts must be installed for reinforcement before construction; when F s When the value is less than 1.0, slope reduction and load reduction treatment must be carried out first; c i L represents the cohesion of the i-th sliding surface, in kPa. i Let be the length of the i-th sliding surface, in meters; W i Let be the weight of the i-th slider, in kN. i Let be the internal friction angle of the i-th sliding surface, in degrees; The spacing d of the anchor bolt reinforcement is determined by the stability compensation formula: （7）； In equation (7), F starget β is the target stability safety factor, with a value of 1.3; β is the anchor bolt safety factor, with a value of 1.5; and τ is the anchor bolt tensile strength, in MPa.

3. The integrated method for vegetation substrate spraying and water retention in ecological restoration of open-pit mine slopes according to claim 1, characterized in that: The components of the plant substrate in step S3 are as follows by weight: 60-80 parts of main substrate, 5-12 parts of water-retaining agent, 3-8 parts of nutrient regulator, 0.5-2 parts of plant seeds, and 20-35 parts of water. The main matrix material is composed of humus, perlite and fly ash in a weight ratio of 5:3:

2. The fly ash needs to be activated. The activation method is as follows: mix fly ash with a sulfuric acid solution with a mass fraction of 10%-15% in a liquid-solid ratio of 3:1, stir and react at 60-80℃ for 2-3 hours, filter and wash until neutral, and then dry and pulverize. The preparation method of the water-retaining functional agent is as follows: polyacrylamide and humic acid are mixed at a weight ratio of 4:1 to form a mixture, and 3%-5% of silane coupling agent KH-550 is added to the total weight of the mixture. The mixture is melt-blended at 120-150℃ for 15-20 minutes, cooled, and then pulverized to a particle size of 50-100μm. The nutrient regulator is composed of slow-release nitrogen fertilizer, superphosphate, potassium chloride and calcium-magnesium-boron-zinc-iron compound trace element fertilizer in a weight ratio of 6:3:2:

1. The slow-release nitrogen fertilizer is urea coated with urea-formaldehyde resin with a coating thickness of 50-100μm. The selection of plant seeds must meet regional adaptability requirements, using a mixture of native herbaceous and shrub seeds, with the specific ratio determined through a niche complementarity algorithm: （8）； In equation (8), i is the species number of herbaceous seeds, and N i S represents the weight percentage of the i-th type of herbaceous seed. i G represents the drought resistance score of the i-th herbaceous seed. i R represents the growth rate of the i-th herbaceous seed, expressed in cm / month. i S represents the soil-binding capacity coefficient of the i-th herbaceous seed, ranging from 0.5 to 1.2; j represents the species number of the shrub seed. j G represents the drought resistance score of the j-th shrub seed. j R represents the growth rate of the j-th shrub seed, expressed in cm / month. j This represents the soil-binding capacity coefficient of the j-th shrub seed, with a value ranging from 0.5 to 1.

2.

4. The integrated method for vegetation substrate spraying and water retention in ecological restoration of open-pit mine slopes according to claim 1, characterized in that: The dual-pipeline synchronous spraying system in step S5 includes a plant substrate storage tank, a water-retaining and strengthening agent storage tank, a twin-screw pump, a flow sensor, a pressure sensor, and a mixing spray gun. The plant substrate storage tank is equipped with a stirring device. The stirring speed v is dynamically adjusted according to the viscosity μ of the plant substrate, and the adjustment formula is as follows: （9）； In equation (9), v0 is the reference stirring speed, which is 150-200 r / min, and μ0 is the reference viscosity, which is 500-800 mPa·s; The water-retaining and reinforcing agent is a composite solution of modified cellulose and polyethylene glycol, with a mass ratio of modified cellulose to polyethylene glycol of 1:

4. The mass concentration of the water-retaining and reinforcing agent is 8%-12%, and the mixing ratio η of the water-retaining and reinforcing agent with the vegetation substrate is dynamically adjusted according to the average annual evaporation E of the slope. （10）； In equation (10), the unit of η is mm, and the value range of η is 0.02-0.1; The mixing spray gun has a spiral mixer inside its nozzle. The pitch p of the spiral mixer is matched with the spray flow rate Q, and the matching relationship is as follows: Where Q is in L / min and p is in mm.

5. The integrated method for vegetation substrate spraying and water retention in ecological restoration of open-pit mine slopes according to claim 1, characterized in that: The biodegradable water-retaining membrane in step S6 is made by blending polylactic acid and chitosan in a weight ratio of 7:

3. The thickness h of the biodegradable water-retaining membrane is determined by a water retention requirement algorithm. （11）； In formula (11), h0 is the reference film thickness, which is 0.08-0.15 mm. When the calculated h < 0.05 mm, h = 0.05 mm is used; when h > 0.2 mm, h = 0.2 mm is used. The wireless sensor network adopts the ZigBee communication protocol. The spacing D between each sensor node in the soil sensor array is determined based on the slope length L and slope α. （12）； In equation (12), the unit of D is m, and its value ranges from 3 to 8 m. n max This represents the maximum number of soil sensor nodes that can be deployed. The water retention regulation algorithm adjusts the irrigation amount I in real time based on the monitored water content ω inside the spray layer. The specific formula is as follows: When ω ≤ ω low then, I = I max × (ω opt - ω) / (ω opt - ω low )(13); When ω high ≥ω>ω low When I=0 (14); When ω>ω high At that time, drainage measures should be initiated; In equations (13)-(14), ω low The lower limit threshold for soil moisture content is ω. opt ×0.6, ω high The upper limit threshold for soil moisture content is ω. opt ×1.2, I max The maximum single irrigation volume is 2-5 L / m².

6. The integrated method for vegetation substrate spraying and water retention in ecological restoration of open-pit mine slopes according to claim 1, characterized in that: The ecological effect assessment in step S7 adopts the comprehensive evaluation index method, with the comprehensive evaluation index E. val The calculation formula is: AND val =0.4×C+0.3×σ+0.3×S2(15); In formula (15), C is the vegetation coverage rate, % is the percentage of the vertical projection area of ​​the vegetation coverage area to the total area; σ is the species diversity index, calculated using the Shannon-Wiener index, with no unit; S2 is the comprehensive soil improvement index. The formula for calculating the comprehensive soil improvement index S2 is as follows: S2=0.3×(OM´ / OM0)+0.25×(n´ / n0)+0.2×(ω avg / h opt )+0.25×(pH´ / pH opt )(16); In formula (16), pH´ is the pH value of the remediated soil, pH opt The optimal pH value for vegetation is 6.5-7.

5. When E val When the value is ≥0.8, the repair is considered satisfactory; when the value is ≤0.6, the repair is considered satisfactory. val When the thickness is less than 0.8, localized touch-up spraying is required, with the touch-up area accounting for (0.8-E). val ) / 0.2; when E val If the concentration is less than 0.6, a complete overspray is required, and the process should be repeated in step S3 to re-optimize the plant substrate formula.

7. The integrated method for vegetation substrate spraying and water retention in ecological restoration of open-pit mine slopes according to claim 1, characterized in that: The UAV remote sensing technology in step S2 uses a multispectral camera with a resolution of not less than 0.1m, and the extraction accuracy of slope topographic parameters is controlled by an error correction algorithm. a corr =a meas +Da (17); In equation (17), α corr To correct the slope, α meas The slope is the measured slope, and Δα is the error correction value, Δα = 0.5 × sin(α). meas (All units are degrees;) The soil sensor array includes a moisture content sensor, a conductivity sensor, and a temperature sensor. The measurement data is processed using a Kalman filter algorithm for noise reduction. The Kalman filter algorithm formula is as follows: X q =A zy ·X q-1 +B·u q-1 +w q-1 (18); Z q =Y·X q +v q (19); V q =P q｜q-1 ·Y T ·(Y·P q｜q-1 ·Y T +R) -1 (20); X q｜q =X q｜q-1 +V q ·(Z q -Y·X q｜q-1 )(21); P q｜q =(ξ-V q ·Y)·P q｜q-1 (22); In equations (18)-(22), X q Let q be the system state vector, containing soil moisture content. A. Conductivity, temperature monitored by temperature sensors, and other parameters. zy Let B be the state transition matrix, and let U be the control input matrix. q-1 For the control input at time q-1, w q-1 For process noise, Z q Let Y be the observation value at time q, and Y be the observation matrix. T v is the transpose of matrix Y. q To observe the noise, V q For Kalman gain, P q｜q-1 Let X be the prior error covariance matrix at time q, R be the observation noise covariance matrix, ξ be the identity matrix, and X be the prior error covariance matrix at time q. q｜q Let P be the optimal state estimate at time q. q｜q Let X be the posterior error covariance matrix at time q. q-1 Let be the system state vector at time q-1.

8. The integrated method for vegetation substrate spraying and water retention in ecological restoration of open-pit mine slopes according to claim 1, characterized in that: The spraying process in step S4 adopts a layered spraying method, consisting of a base layer, a middle layer, and a surface layer. The thickness ratio of each layer is determined according to the slope angle α. When α≤30°, the ratio of bottom layer: middle layer: top layer is 3:4:3; When 30° < α ≤ 60°, the ratio of bottom layer: middle layer: top layer is 4:4:2; When α > 60°, the ratio of bottom layer: middle layer: top layer = 5:3:2; The spraying interval t between each layer is based on the solidification rate v of the plant substrate. s Sure: t=h layer / v s (23); In equation (23), h layer The thickness of a single layer, whether it is the bottom layer, middle layer, or top layer, is expressed in cm. s v represents the solidification rate of the plant substrate. s =0.12×(1+0.05×T 环 ), in mm / h, T 环 This refers to the ambient temperature, expressed in °C. During the application of the base layer, glass fiber reinforcement material is added at a rate of 1%-2% of the total weight of the plant substrate. The lengths of the glass fibers l and h are [not specified in the original text]. layer The relationship is l = 5 × h layer This ensures that the fibers form a three-dimensional support network at the bottom layer, improving the adhesion between the sprayed layer and the slope; adhesion F f The calculation formula is: （24）； In equation (24), F f The unit is MPa.

9. The integrated method for vegetation substrate spraying and water retention in ecological restoration of open-pit mine slopes according to claim 1, characterized in that: The particle swarm optimization algorithm in step S3 is used to adjust the proportions of each component of the plant substrate. The objective function of the algorithm is max(S1) = max(F1×ω1 + F2×ω2 + F3×ω3), where max(S1) represents maximizing the value of the objective function S1. The constraints are as follows: 0.6≤m1 / (m1+m2+m3+m4)≤0.8(25); 0.05≤m2 / (m1+m2+m3+m4)≤0.12(26); 0.03≤m3 / (m1+m2+m3+m4)≤0.08(27); 0.005≤m4 / (m1+m2+m3+m4)≤0.02(28); In formulas (25)-(28), m1 is the weight of the main substrate material in g; m2 is the weight of the water-retaining agent in g; m3 is the weight of the nutrient regulator in g; and m4 is the weight of the plant seed in g. The parameters of the particle swarm optimization algorithm are set as follows: number of particles N=30, inertia weight ω=0.729, cognitive coefficient c1=1.494, social coefficient c2=1.494, maximum number of iterations λ=50, and the objective function value changes by less than 10 after 5 consecutive iterations. -3 When the time is reached, stop the iteration and output the component ratio corresponding to the current particle as the optimal formula.

10. The integrated method for vegetation substrate spraying and water retention in ecological restoration of open-pit mine slopes according to claim 1, characterized in that: The method also includes winter insulation measures, when the monthly average temperature T collected in step S2... 均 At ≤0℃, an antifreeze agent is added to the plant substrate, and the amount of antifreeze agent added is m. antifreeze Determined through an antifreeze requirement algorithm: m antifreeze =m base ×(0-T min ) / 100(29); In equation (29), m base The total weight of the plant substrate is expressed in grams (g); m antifreeze The addition ratio shall not exceed 5% of the total weight of the plant substrate; The antifreeze agent is a mixture of propylene glycol and glycerin in a weight ratio of 2:1, and its freezing point depression ΔT is related to the amount added m. antifreeze The relationship is: ΔT=1.86×(m antifreeze / (M×m water ))×1000(30); In equation (30), M is the average molar mass of the antifreeze, taken as 76 g / mol, and m water The weight of water in the plant substrate is used to ensure the freezing point T of the plant substrate after the addition of antifreeze. min ≤-5℃ to prevent damage to the sprayed layer due to freeze-thaw cycles in winter.

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