Quantization method of highway engineering slope greening carbon sink

Abstract

The invention relates to the technical field of highway engineering, and discloses a highway engineering slope greening carbon sink quantification method comprising the following steps: 1, vegetation investigation: S1, vegetation type identification: comprehensively identifying vegetation types in a highway engineering slope greening area, and covering arbors, shrubs, herbaceous plants and possible vines; according to the highway engineering slope greening carbon sink quantification method, through detailed vegetation investigation, soil data acquisition and environmental factor recording, rich basic data is provided for accurately quantifying the carbon sink capacity, the defect that data acquisition is incomplete in a traditional method is overcome, and the vegetation carbon sink is calculated by adopting a biomass method, so that the carbon sink quality is improved. The soil carbon sink is calculated in combination with the soil organic carbon content and volume weight, the soil carbon sink and the volume weight are integrated to obtain the total carbon sink, the calculation method is scientific and reliable, the carbon sink contribution of slope greening can be evaluated more accurately, and compared with a traditional single calculation method, the method has higher accuracy and credibility.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of highway engineering, and particularly relates to a method for quantifying carbon sink of highway engineering slope greening. BACKGROUND

[0002] In recent years, with the rapid development of global economy and the continuous advancement of urbanization process, the scale of highway engineering construction continues to expand. As an important infrastructure, highways play an irreplaceable role in promoting regional economic development and personnel and material exchanges. However, highway construction inevitably causes certain impact on the ecological environment along the line, especially the destruction of the slope ecological system.

[0003] Under the background of increasing environmental awareness, slope greening technology emerges as the times require. Slope greening not only can restore the ecological function of the slope and prevent soil erosion, but also can beautify the environment and reduce the impact of highway construction on the surrounding ecological environment. Through planting various plants and using the functions of plant root system to fix soil and stem and leaf to reduce rainwater runoff, the slope greening technology realizes the ecological restoration and stability of the slope. At present, the slope greening technology has been widely used in many highway engineering projects and has achieved good ecological benefits. However, with the increasingly prominent problem of global climate change, carbon emission reduction and carbon sink increase have become the focus of international society. Under this background, people have new expectations for the function of highway engineering slope greening, that is, through the photosynthesis of slope vegetation to absorb and fix carbon dioxide in the atmosphere, so as to produce carbon sink benefits and make contributions to addressing climate change. Carbon sink refers to the ability of vegetation to absorb and store carbon dioxide, which is one of the important ecological service functions of the ecological system. Introducing the concept of carbon sink into the field of slope greening not only expands the ecological function of slope greening, but also provides a new way for the low-carbon development of highway engineering construction.

[0004] However, the prior art still has the following disadvantages:

[0005] 1) The quantification method is not comprehensive enough, and most of them only focus on vegetation coverage and landscape effect, lack comprehensive consideration of vegetation, soil and environmental factors, and it is difficult to accurately evaluate the carbon sink capacity.

[0006] 2) The data collection and monitoring means are relatively backward, mainly relying on manual field investigation, which is low in efficiency and easy to be disturbed by human factors, and the comprehensiveness, accuracy and dynamics of the data are difficult to guarantee, and there is a lack of long-term continuous monitoring mechanism. SUMMARY

[0007] In view of the problems of the prior art that the quantification method is not comprehensive enough and the data collection and monitoring means are relatively backward, the present application is proposed.

[0008] Therefore, the present application aims to provide a highway engineering slope greening carbon sink quantification method, which aims to: through detailed vegetation investigation, soil data collection and environmental factor recording, provide rich basic data for accurate quantification of carbon sink capacity, make up for the defects of incomplete data collection of traditional methods, and calculate vegetation carbon sink by using the biomass method, calculate soil carbon sink by combining soil organic carbon content and soil bulk density, and obtain total carbon sink by comprehensively combining the two, and the calculation method is scientific and reliable.

[0009] To solve the above technical problems, the present application provides the following technical solutions: a highway engineering slope greening carbon sink quantification method, comprising the following steps:

[0010] Step one, vegetation investigation

[0011] S1: vegetation type identification, comprehensively identify the vegetation types in the highway engineering slope greening area, including trees, shrubs, herbaceous plants and possible liana plants;

[0012] S2: planting density determination, using the quadrat investigation method, setting representative quadrats in different areas of the slope;

[0013] S3: coverage measurement, using the method combining field measurement and image analysis, first in the quadrat, by measuring the proportion of the projection area of the plant to the quadrat volume, the vegetation coverage is preliminarily determined;

[0014] S4: growth condition evaluation, comprehensively evaluating the growth condition of vegetation from multiple dimensions;

[0015] Step two, soil data collection

[0016] S1: soil sample collection point layout, according to the topography, vegetation type distribution, soil type difference and human activity interference degree of the slope, and other factors, reasonable setting soil sample collection points in the slope greening area according to the principle of stratified random sampling;

[0017] S2: soil sampling method, at each collection point, using professional tools such as soil drill or soil drill, soil samples are collected according to the predetermined sampling depth interval;

[0018] S3: soil organic carbon content analysis, taking the collected soil samples back to the laboratory, and accurately analyzing the organic carbon content of each level of soil sample according to the standard soil organic carbon determination method;

[0019] S4: soil bulk density determination, using the cutting ring method to determine the soil bulk density, i.e. in each level of soil at each collection point, using the cutting ring to vertically cut the undisturbed soil sample, scraping the excess soil at both ends of the cutting ring, weighing the total mass of the cutting ring and the soil sample, and then calculating the soil bulk density;

[0020] S5: Soil depth measurement, at each soil sample collection point, use a measuring scale or depth probe instrument and other tools to accurately measure the depth of the soil profile, record the starting depth and ending depth of each level of soil, and the total depth of the entire soil profile;

[0021] Step three, environmental factor recording

[0022] S1: Climate condition monitoring, set up a small weather observation station in the highway engineering slope greening area and the surrounding area, or use the existing regional meteorological monitoring data, long-term continuous monitoring of climate condition indicators;

[0023] S2: Topographic feature recording: adopt topographic surveying instruments combined with field investigation method to record the topographic features of the slope in detail;

[0024] S3: Soil type division and property description, according to the soil classification system and field soil profile investigation, the soil of the slope is divided into types;

[0025] Step four, carbon sink calculation

[0026] S1: Vegetation carbon sink calculation;

[0027] S2: Soil carbon sink calculation, using soil organic carbon content, soil bulk density and soil depth data to calculate soil carbon storage;

[0028] S3: Total carbon sink determination, the calculated vegetation carbon storage and soil carbon storage are added to obtain the total carbon sink of the slope greening.

[0029] As a preferred scheme of the highway engineering slope greening carbon sink quantification method, the vegetation growth condition evaluation further includes using vegetation index image analysis technology, calculating common vegetation indexes such as normalized vegetation index and ratio vegetation index through the obtained high-spectrum remote sensing image, quantitatively evaluating the advantages and disadvantages of the vegetation growth state, further improving the growth condition evaluation accuracy and efficiency, and providing a more reliable basis for carbon sink calculation.

[0030] As a preferred scheme of the highway engineering slope greening carbon sink quantification method, the growth condition evaluation includes plant height measurement, tree or shrub measurement and growth trend observation.

[0031] As a preferred scheme of the highway engineering slope greening carbon sink quantification method, when the soil sample is collected, the soil texture sample is collected synchronously, the composition ratio of sand particles, silt particles and clay particles in the soil is analyzed, the air permeability, water permeability and water and fertilizer retention of the soil are evaluated according to the composition ratio, comprehensive analysis is conducted combined with the soil organic carbon content, bulk density and depth data, the soil carbon storage is more comprehensively determined, and the accuracy of the soil carbon sink calculation is enhanced.

[0032] As a preferred scheme of the highway engineering slope greening carbon sink quantification method, the climate condition record further comprises statistics of extreme climate event frequency and intensity, short-term impact and long-term influence of the extreme climate event on slope vegetation growth, soil erosion and carbon sink function, and a coping strategy is formulated in advance to ensure stability of the slope greening carbon sink benefit.

[0033] As a preferred scheme of the highway engineering slope greening carbon sink quantification method, after the carbon sink calculation, an uncertainty analysis method such as Monte Carlo simulation is used to quantitatively evaluate the influence range of uncertainty of input parameters (vegetation biomass, soil properties, etc.) on the carbon sink calculation result, to clearly quantitatively determine the confidence interval of the method, and to improve the reliability of the carbon sink evaluation result, thereby providing a more scientific reference for relevant decision-making.

[0034] As a preferred scheme of the highway engineering slope greening carbon sink quantification method, in the vegetation carbon sink calculation, a corresponding relationship model of biomass and carbon content is established for vegetation in different growth stages, so that the actual influence of vegetation growth dynamics on carbon storage change is more accurately reflected, the vegetation carbon sink estimation process is optimized, and the timeliness and accuracy of the calculation result are improved.

[0035] As a preferred scheme of the highway engineering slope greening carbon sink quantification method, the vegetation carbon sink calculation comprises vegetation biomass per unit area measurement, vegetation carbon storage calculation and dynamic carbon sink amount estimation.

[0036] As a preferred scheme of the highway engineering slope greening carbon sink quantification method, the soil carbon sink calculation formula is: soil carbon storage = soil organic carbon content x soil bulk density x soil thickness x soil area, wherein the soil thickness should be calculated layer by layer according to the starting and ending values of the soil depth of each layer, and then the soil carbon storages of the layers are added to obtain the total soil carbon storage.

[0037] Compared with the prior art, the present application has at least the following beneficial effects:

[0038] 1、The present application provides rich basic data for accurately quantifying carbon sink capacity through detailed vegetation investigation, soil data collection and environmental factor recording, which makes up for the defect of incomplete data collection of the traditional method, and the vegetation carbon sink is calculated by using the biomass method, the soil carbon sink is calculated by combining the soil organic carbon content and the bulk density, and the total carbon sink is obtained by comprehensively combining the two, the calculation method is scientific and reliable, the carbon sink contribution of slope greening can be more accurately evaluated, and compared with the traditional single calculation method, the present application has higher accuracy and reliability.

[0039] 2、The present application realizes long-term dynamic updating of carbon sink data by establishing slope greening carbon sink monitoring points, measuring vegetation growth indicators and soil organic carbon changes regularly every year, which helps to understand the changes of slope greening carbon sink benefits in a timely manner, provides real-time data support for subsequent management decisions, and not only pays attention to carbon sink data, but also combines ecological benefits and economic benefits for comprehensive evaluation, such as exploring carbon trading potential, and optimizing greening design by comparing the carbon sink capacity of different greening modes, which provides a scientific basis for the selection of greening scheme in highway engineering construction, and is beneficial to realize the win-win of ecological benefits and economic benefits.

[0040] 3、The present application also improves the data collection efficiency by introducing remote sensing technology for auxiliary monitoring, and establishes a slope greening carbon sink database, which accumulates systematic data for subsequent research and policy making, and promotes the technological progress and industry development of highway engineering slope greening carbon sink quantification. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 The present application is a whole process schematic diagram of the quantification method of highway engineering slope greening carbon sink. DETAILED DESCRIPTION

[0042] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings of the specification.

[0043] REFERENCE Figure 1 For the embodiments of the present application, a quantification method of highway engineering slope greening carbon sink is provided, which comprises:

[0044] Step one, vegetation investigation

[0045] S1: vegetation type identification, comprehensively identify the vegetation types in the highway engineering slope greening area, including trees, shrubs, herbaceous plants and possible liana plants, accurately record the name, family, genus and other information of each plant through field investigation and combined with botanical classification method, and draw a vegetation type distribution map, mark the specific distribution position and range of each vegetation on the slope, so as to clearly understand the spatial distribution characteristics of different vegetation types, and lay a foundation for subsequent targeted analysis of the contribution of each vegetation type to carbon sink;

[0046] S2: Planting density measurement, using quadrat investigation method, set representative quadrats in different areas of the slope, calculate the planting density per unit area by counting the number of individuals of each plant in the quadrat, for trees and shrubs, determine the size of the quadrat according to their growth habit and crown size, generally the size of the tree quadrat can be set to [specific area], the size of the shrub quadrat can be set to [specific area], and the size of the herb quadrat can be set to [specific area], in each quadrat, carefully count the number of each plant to ensure the accuracy of the statistical data, and calculate the average planting density of each plant, and record the geographical position coordinates (longitude, latitude, altitude) and other information of the quadrat, so as to analyze the differences of vegetation density in different areas and its influence on carbon sink;

[0047] S3: Coverage measurement, using the combination of field measurement and image analysis method, first measure the proportion of plant projection area in the size of the quadrat to preliminarily determine the vegetation coverage, then use unmanned aerial vehicle to obtain high-resolution images of the slope, use image processing software to analyze the images, identify the vegetation coverage area and non-vegetation area such as bare soil and rock, calculate the proportion of vegetation coverage area in the whole slope area to further accurately determine the vegetation coverage, compare the results of field measurement and image analysis to verify and calibrate the data, improve the reliability of the measurement results, in addition, analyze the contribution of different vegetation types to the coverage rate and the distribution difference of vegetation coverage rate in different slope sections and different directions of the slope, provide basis for optimizing the slope greening design;

[0048] S4: Growth condition evaluation, comprehensive evaluation of vegetation growth condition from multiple dimensions;

[0049] Step two, soil data collection

[0050] S1: Soil sample collection point layout, according to the topography, vegetation type distribution, soil type difference and human activity interference degree of the slope, reasonably set soil sample collection points in the slope greening area according to the principle of stratified random sampling, ensure that the collected soil samples can fully represent the characteristics of the soil of the whole slope, the number of collection points should not be less than [specific number], and a certain number of collection points should be set in different height, slope direction, slope degree zones and different vegetation coverage areas of the slope, to fully obtain the soil information of the slope, at the same time, record the geographical position coordinates (longitude, latitude, altitude), surrounding vegetation type, topographic features and other basic information of each collection point, provide spatial reference for subsequent data analysis;

[0051] S2: Soil sampling method, at each collection point, using soil drill or soil drill and other professional tools, according to the predetermined sampling depth interval, the soil sample collection, generally the soil profile is divided into [specific depth interval] levels, respectively, the soil sample of each level is collected, the sampling depth should reach at least [specific depth] to cover the main area of carbon storage in soil, the soil sample should be avoided to be contaminated and disturbed during collection, to ensure the authenticity and representativeness of the sample, when collecting the surface soil, the surface litter, stones and other sundries should be removed first, then the soil sample is drilled vertically; for deep soil sample collection, stratified continuous sampling method should be used to ensure that each level of soil sample can be obtained completely, the weight of soil sample collected in each level should not be less than [specific weight] to meet the needs of laboratory analysis;

[0052] S3: Soil organic carbon content analysis, the collected soil samples are taken back to the laboratory, the organic carbon content of each level of soil sample is accurately analyzed according to the standard soil organic carbon determination method, each soil sample should be determined in parallel, and the average value is taken as the final soil organic carbon content determination result, and the determination data is recorded, at the same time, the determination result is quality controlled to ensure the accuracy and reliability of the data, through analyzing the organic carbon content of soil in different levels and different collection points;

[0053] S4: Soil bulk density determination, the soil bulk density is determined by using the cutting ring method, that is, in each level of soil at each collection point, the undisturbed soil sample is cut vertically using the cutting ring, the excess soil at both ends of the cutting ring is scraped off, the total mass of the cutting ring and the soil sample is weighed, and then the soil bulk density is calculated;

[0054] S5: Soil depth measurement, at each soil sample collection point, the depth of the soil profile is accurately measured using a measuring ruler or depth probe and other tools, the starting depth and ending depth of each level of soil are recorded, and the total depth of the whole soil profile is recorded;

[0055] Step three, environmental factor recording

[0056] S1: Climate Condition Monitoring, Set up small weather observation stations in the highway engineering slope greening area and its surroundings, or use the existing weather monitoring data in the region, long-term continuous monitoring of climate condition indicators, including but not limited to annual average rainfall, annual rainfall distribution pattern (monthly rainfall and seasonal variation), annual average temperature, annual temperature difference, sunshine hours, relative humidity, wind speed, wind direction and other meteorological elements, the equipment of weather observation station should be maintained and calibrated regularly to ensure the accuracy and continuity of monitoring data, the time interval of recording data should not be less than [specific time interval] to obtain detailed climate data, at the same time analyze the relationship between climate factors and slope vegetation growth and soil carbon cycle, such as the influence of rainfall on water supply of vegetation growth and processes such as leaching and mineralization of soil carbon, the influence of temperature on plant photosynthesis, respiration and soil microbial activity, etc., through the establishment of quantitative relationship model between climate factors and carbon sink process, provide scientific basis for predicting the influence of climate change on slope greening carbon sink benefit;

[0057] S2: Topographic Features Recording: Use topographic surveying instruments combined with field investigation methods to record the topographic features of the slope in detail, including slope gradient, slope direction, slope length, slope height, terrain relief, etc. Draw the slope topographic profile and mark the key position of topographic feature points such as slope top, slope shoulder, slope foot, etc. Analyze the influence of topographic factors on vegetation growth, soil erosion and carbon sink distribution;

[0058] S3: Soil Type Classification and Characteristic Description, according to soil classification system and field soil profile investigation, classify the slope soil, determine the classification unit of soil class, sub-class, soil genus, soil species, etc. And describe the basic characteristics of each soil type in detail, including soil color, texture, structure, pH value, gravel content, organic matter content, nutrient status (nitrogen, phosphorus, potassium content) and other physical and chemical properties. Record the information of soil parent material, soil development degree and soil erosion condition, etc. Different soil types have significant differences in carbon storage capacity and carbon cycle process;

[0059] Step four, carbon sink calculation

[0060] S1: Vegetation Carbon Sink Calculation;

[0061] S2: Soil Carbon Sink Calculation, calculate the soil carbon storage using soil organic carbon content, soil bulk density and soil depth data;

[0062] S3: Total carbon sink determination, the calculated vegetation carbon storage and soil carbon storage are accumulated to obtain the total carbon sink of slope greening, the calculation result of total carbon sink should be kept to two decimal places, and the unit conversion and display are carried out according to the actual needs, and the composition of total carbon sink is analyzed in detail, the proportion of vegetation carbon sink and soil carbon sink in total carbon sink and their mutual relationship, as well as the contribution rate of different vegetation types and soil types to total carbon sink are clarified, which provides quantitative basis for optimizing slope greening design and improving carbon sink benefit, in addition, the correlation analysis model of total carbon sink and other ecological service functions (such as water and soil conservation capacity, biodiversity protection index, etc.) should be established, and the multiple ecological value and comprehensive benefit of slope greening ecosystem are comprehensively evaluated, which provides comprehensive decision support for the sustainable development of highway engineering construction.

[0063] The vegetation growth condition evaluation also includes using vegetation index image analysis technology to calculate normalized vegetation index, ratio vegetation index and other common vegetation indexes through the obtained hyperspectral remote sensing image, to quantitatively evaluate the advantages and disadvantages of vegetation growth state, and further improve the growth condition evaluation accuracy and efficiency, to provide more reliable basis for carbon sink calculation.

[0064] The growth condition evaluation includes plant height measurement: using measuring ruler or laser range finder and other tools to accurately measure the height of various plants, for trees and shrubs, measuring the vertical height from the root neck to the top of the crown; for herbaceous plants, measuring the average height of the plant, selecting a certain number of plants in each sample plot for measurement, recording the measurement data and calculating the average height, analyzing the height growth law of different plant species and different growth environments and the correlation with carbon sink capacity;

[0065] Tree or shrub measurement: for trees, using a diameter at breast height (DBH) measuring device to measure the DBH at the breast height position (generally at [specific height] above ground level) of the tree, recording the DBH value and calculating the average DBH of the trees in the sample plot; for shrubs, measuring the length and width of the crown, calculating the average crown area, DBH and crown width are important indicators reflecting the growth condition and biomass of trees and shrubs, and are closely related to the carbon absorption and fixation capacity of plants, through the measurement of these indicators, key data support can be provided for accurate estimation of vegetation biomass and carbon sink;

[0066] Growth trend observation: By observing the color, thickness, luster, yellowing, wilting, and other phenomena of plant leaves, as well as the growth trend of stems, the presence or absence of pest damage, the number of branches, and other characteristics, the growth trend of plants is qualitatively evaluated. The growth trend is divided into different levels such as excellent, good, medium, and poor, and the corresponding proportion is recorded. Vegetation with good growth trend usually has higher photosynthetic efficiency and biomass accumulation speed, so it can more effectively absorb and fix carbon dioxide. Therefore, growth trend evaluation helps to understand the internal relationship between vegetation growth condition and carbon sink function, and provides more targeted guidance for subsequent carbon sink calculation and greening maintenance management.

[0067] When collecting the soil samples, soil texture samples are collected synchronously to analyze the composition ratio of sand particles, silt particles, and clay particles in the soil, thereby evaluating the aeration, water permeability, and water and fertilizer retention of the soil. Combined with the comprehensive analysis of soil organic carbon content, bulk density, and depth data, the soil carbon storage is determined more comprehensively, and the accuracy of soil carbon sink calculation is enhanced.

[0068] The climate condition record also includes statistics of the frequency and intensity of extreme climate events to study their short-term impact and long-term influence on slope vegetation growth, soil erosion, and carbon sink function, so as to develop countermeasures in advance and ensure the stability of slope greening carbon sink benefits.

[0069] After the carbon sink calculation, uncertainty analysis methods such as Monte Carlo simulation are used to quantify the influence range of the uncertainty of input parameters (vegetation biomass, soil properties, etc.) on the carbon sink calculation results, and to clearly quantify the confidence interval of the method, thereby improving the credibility of the carbon sink evaluation results and providing a more scientific reference for related decisions.

[0070] In the vegetation carbon sink calculation, corresponding relationship models between biomass and carbon content are established for vegetation at different growth stages to more accurately reflect the actual influence of vegetation growth dynamics on carbon storage changes, optimize the estimation process of vegetation carbon sink, and improve the timeliness and accuracy of the calculation results.

[0071] The vegetation carbon sink calculation includes unit area vegetation biomass measurement: according to different vegetation types, corresponding biomass measurement methods are adopted. For trees, the biomass of single tree can be estimated by establishing the regression equation of diameter at breast height and biomass, combined with the measured diameter at breast height data, and then the unit area tree biomass is calculated according to the planting density of trees; for shrubs, the conversion relationship between crown area and biomass can be used to determine the unit area shrub biomass combined with crown measurement data and planting density; for herbaceous plants, the quadrat harvesting method can be used, that is, all herbaceous plants in the quadrat are harvested, weighed and dried to determine the dry weight biomass, and then the unit area biomass is calculated according to the coverage rate and quadrat area of herbaceous plants. The biomass measurement of each vegetation type should be repeated multiple times, and the average value is taken as the final unit area biomass result. The related data and parameters in the measurement process are recorded, and the uncertainty and error sources of the biomass measurement method are analyzed and evaluated to ensure the reliability of the biomass data.

[0072] Vegetation carbon storage calculation: the vegetation carbon storage is calculated by multiplying the unit area vegetation biomass (including aboveground biomass and underground biomass) by the corresponding plant carbon content coefficient (generally taken as 0.5, but can be adjusted appropriately according to different plant species and growth environment, the adjustment range should be between [specific range], and the adjustment basis should be explained). The carbon storage of different vegetation types is calculated respectively, and then the total vegetation carbon storage of the slope greening area is obtained by adding the carbon storage of each type of vegetation. The calculation unit of carbon storage should be unified as tons of carbon per hectare (tC / hm 2 ) or tons of carbon dioxide per hectare (tCO2 / hm 2 ), and the conversion relationship should be clearly explained (1tC is equivalent to 3.666tCO2). At the same time, the key links such as unit conversion and coefficient selection in the carbon storage calculation process are explained and verified in detail to ensure the scientificity and accuracy of the calculation results.

[0073] Dynamic carbon sink estimation: through long-term continuous vegetation growth monitoring, the annual growth (biomass increment) data of vegetation are obtained, and combined with the vegetation carbon storage calculation method, the annual new carbon sink of slope vegetation, i.e. dynamic carbon sink, is estimated. The seasonal variation and interannual fluctuation of vegetation growth should be considered in the estimation of dynamic carbon sink, and the moving average method or time series analysis method is used to smooth the data to more accurately reflect the dynamic change trend of vegetation carbon sink. At the same time, the influence of vegetation growth stage (such as young forest, middle-aged forest, mature forest, etc.) on dynamic carbon sink and the carbon sink contribution difference of different vegetation types in different growth stages are analyzed to provide dynamic data support for long-term evaluation and management decision of slope greening carbon sink benefit.

[0074] The soil carbon sink calculation formula is: soil carbon storage = soil organic carbon content x soil bulk density x soil thickness x soil area, wherein the soil thickness should be calculated layer by layer according to the starting and ending values of the soil depth of each layer, and then the soil carbon storage of each layer is added to obtain the total soil carbon storage, the soil area can be calculated by measuring the actual area of the slope or using geographic information system (GIS) technology combined with the slope topographic map, and the unit is also unified as tons of carbon per hectare (tC / hm 2 ) or tons of carbon dioxide per hectare (tCO2 / hm 2 ), in the calculation process, spatial interpolation analysis should be performed on the soil data of different collection points to generate the spatial distribution map of the properties such as soil organic carbon content and soil bulk density, so as to more accurately estimate the soil carbon storage of the entire slope, and the rationality and accuracy of the interpolation method should be evaluated, at the same time, the depth distribution characteristics of soil carbon storage and the contribution difference of different soil types to soil carbon storage should be considered, and the calculation results should be layering and classified statistical analysis, so as to provide data support for in-depth understanding of the formation mechanism and distribution rule of soil carbon sink.

[0075] It should be noted that the above examples are only used to illustrate the technical solutions of the present application and are not limiting, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application, and all should be covered in the scope of the claims of the present application.

Claims

1. A method for quantifying carbon sequestration of highway engineering slope greening, characterized in that, Comprising the following steps: Step one, vegetation investigation S1: Vegetation type identification, comprehensively identify the vegetation species in the highway engineering slope greening area, including trees, shrubs, herbaceous plants and possible liana plants; S2: Planting density determination, using quadrat survey method, set representative quadrats in different areas of the slope; S3: Coverage measurement, using the method of combining field measurement with image analysis, first in the quadrat, by measuring the proportion of the projection area of the plant to the volume of the quadrat, the vegetation coverage is preliminarily determined; S4: Growth condition evaluation, comprehensive evaluation of vegetation growth condition from multiple dimensions; Step two, soil data collection S1: Soil sample collection point layout, according to the topography, vegetation type distribution, soil type difference and human activity interference degree of the slope, reasonable set soil sample collection point in the slope greening area according to the principle of stratified random sampling; S2: Soil sampling method, at each collection point, using professional tools such as soil drill or soil drill, soil samples are collected according to the predetermined sampling depth interval; S3: Soil organic carbon content analysis, the collected soil samples are taken back to the laboratory, and the organic carbon content of each level of soil sample is accurately analyzed according to the standard soil organic carbon determination method; S4: Soil bulk density determination, using cutting ring method to determine soil bulk density, that is, in each level of soil at each collection point, using cutting ring to vertically cut original soil sample, scraping the excess soil at both ends of the cutting ring, weighing the total mass of the cutting ring and the soil sample, and then calculating the soil bulk density; S5: Soil depth measurement, at each soil sample collection point, using measuring ruler or depth probe instrument, accurately measure the depth of soil profile, record the starting depth and ending depth of each level of soil, and the total depth of the whole soil profile; Step three, environmental factor recording S1: Climate condition monitoring, set up small weather observation station in the highway engineering slope greening area and the surrounding area, or use the existing regional weather monitoring data, long-term continuous monitoring of climate condition index; S2: Topographic features record: using topographic surveying instruments combined with field investigation method, detailed record the topographic features of the slope; S3: Soil type division and property description, according to soil classification system and field soil profile investigation, divide the soil types of the slope; Step four, carbon sink calculation S1: Vegetation carbon sink calculation; S2: Soil carbon sink calculation, using soil organic carbon content, soil bulk density and soil depth data to calculate soil carbon storage; S3: Total carbon sink determination, add the calculated vegetation carbon storage and soil carbon storage to get the total carbon sink of the slope greening.

2. The method for quantifying carbon sink of highway engineering slope greening according to claim 1, characterized in that: The vegetation growth condition evaluation also includes using vegetation index image analysis technology, calculating normalized vegetation index, ratio vegetation index and other common vegetation indexes from the obtained hyperspectral remote sensing image, quantitatively evaluating the advantages and disadvantages of vegetation growth state, further improving the accuracy and efficiency of growth condition evaluation, and providing more reliable basis for carbon sink calculation.

3. The method for quantifying the carbon sink of highway engineering slope greening according to claim 2, characterized in that: The growth condition evaluation includes plant height measurement, tree or shrub measurement and growth trend observation.

4. The method for quantifying carbon sink of highway engineering slope greening according to claim 3, characterized in that: The soil sample is collected, and a soil texture sample is collected synchronously to analyze the composition ratio of sand particles, silt particles and clay particles in the soil, so as to evaluate the air permeability, water permeability and water and fertilizer retention of the soil, and comprehensively analyze the soil organic carbon content, bulk density and depth data, so as to more comprehensively determine the soil carbon storage and enhance the accuracy of the calculation of the soil carbon sink.

5. The method for quantifying carbon sink of highway engineering slope greening according to claim 4, characterized in that: The climate condition record also includes statistics of the frequency and intensity of extreme climate events, researches the short-term impact and long-term influence of the extreme climate events on the growth of slope vegetation, soil erosion and carbon sink function, formulates a response strategy in advance, and guarantees the stability of the carbon sink benefit of slope greening. 6.The method for quantifying carbon sink of highway engineering slope greening according to claim 5, characterized in that: After the calculation of the carbon sink, an uncertainty analysis method such as Monte Carlo simulation is used to quantitatively evaluate the influence range of the uncertainty of input parameters (vegetation biomass, soil properties, etc.) on the calculation result of the carbon sink, to clearly quantify the confidence interval of the method, and to improve the reliability of the carbon sink evaluation result, so as to provide a more scientific reference for related decision-making.

7. The method for quantifying carbon sequestration of highway engineering slope greening according to claim 6, characterized in that: In the calculation of the vegetation carbon sink, a corresponding relationship model of biomass and carbon content is established for vegetation in different growth stages, so as to more accurately reflect the actual influence of the growth dynamics of vegetation on the change of carbon storage, optimize the estimation process of the vegetation carbon sink, and improve the timeliness and accuracy of the calculation result. 8.The method for quantifying carbon sink of highway engineering slope greening according to claim 7, characterized in that: The vegetation carbon sink calculation includes unit area vegetation biomass measurement, vegetation carbon storage calculation and dynamic carbon sink estimation. 9.The method for quantifying carbon sink of highway engineering slope greening according to claim 8, characterized in that: The soil carbon sink calculation formula is: soil carbon storage = soil organic carbon content x soil bulk density x soil thickness x soil area, wherein the soil thickness should be calculated layer by layer according to the starting and ending values of the soil depth of each layer, and then the soil carbon storages of each layer are added to obtain the total soil carbon storage.

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