Carbon sequestration service flow path description method based on wind direction

Abstract

The invention discloses a carbon sequestration service flow path description method based on a wind direction, belongs to the technical field of carbon sequestration services, and solves the problems that an existing carbon sequestration service flow is not visualized and the influence of the wind direction is not considered. According to the method, the research area is divided into a plurality of space units, the supply quantity and the demand quantity of each unit are obtained, and the carbon sequestration service flow path is determined in combination with the annual prevailing wind direction, so that the carbon sequestration service flow path can be evaluated and depicted more finely, the network model and Gephi software are utilized to carry out visualization processing on the carbon sequestration service flow, and the accuracy of the carbon sequestration service flow path is improved. The spatial flow path of the carbon sequestration service is more intuitive, the spatial flow rule of the carbon sequestration service between the supply area and the demand area is intuitively revealed, and managers and researchers can conveniently carry out analysis and decision making to achieve reasonable matching of supply and demand.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon fixation services, and in particular to a method for characterizing a carbon fixation service flow path based on wind direction. Background Art

[0002] Carbon sequestration service is an important regulatory ecosystem service that plays an important role in mitigating the rise in atmospheric CO2 concentration and maintaining global carbon balance. It captures carbon in the atmosphere through the carbon sequestration function of the ecosystem and fixes the captured carbon to offset part of the CO2 emitted into the atmosphere by humans, thereby regulating the climate. The carbon sequestration service flow is the connection process of the flow of carbon sequestration services from the supply area generated by the ecosystem to the demand area consumed by human society. It is a description of the path of the flow of this service. Its flow direction, flow speed, and flow are attributes worthy of exploration and research.

[0003] For example, the invention patent with announcement number CN118115174A in the prior art provides a method for simulating the flow path of carbon sequestration services, including data collection, including statistical data, vector data and raster data; the collected data is divided into natural ecosystem carbon sequestration factors and human social carbon emissions, wherein the natural ecological carbon sequestration factors represent positive carbon sequestration services, and the human social carbon emissions represent negative carbon sequestration services; the natural ecological carbon sequestration factors and human social carbon emissions and the results of their interaction are localized using the SPANs conceptual framework to obtain "source areas", "sink areas", "use areas" and corresponding ecosystem service flows; the service flows are input into the BBN model for simulation, and finally the probability distribution of carbon sequestration service flows is obtained.

[0004] Although the invention can obtain the probability distribution of carbon sequestration service flow, it is not visualized, which makes it difficult to understand the path of carbon sequestration service flow, and the invention does not consider the impact of wind direction on carbon sequestration services. Wind direction affects the carbon sequestration capacity of ecosystems indirectly or directly by affecting the gas exchange between plants and the atmosphere, regulating microclimate, changing soil erosion and improvement, affecting biodiversity and habitat composition, and affecting the efficiency of artificial carbon sequestration technology. Appropriate wind direction and wind speed can promote the carbon capture efficiency and stability of the ecosystem, thereby enhancing carbon sequestration services; conversely, extreme wind direction or strong winds may cause soil erosion, restrict plant growth, and even affect the operation of carbon capture technology, reducing the carbon sequestration effect. Summary of the invention

[0005] In view of the above problems in the prior art, the present invention provides a method for characterizing the path of a carbon fixation service flow based on wind direction, which solves the problem that the existing carbon fixation service flow is not visualized and the influence of wind direction is not considered.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A method for characterizing a carbon sequestration service flow path based on wind direction is provided, comprising the steps of:

[0008] S1. Divide the study area into multiple spatial units, use primary productivity NPP as the supply of carbon sequestration services for each unit, and calculate the demand for carbon sequestration services for each unit.

[0009] S2. Calculate the difference between supply and demand of carbon sequestration services for each unit, DSDCS i =CS i -CD i , among which, DSDCS i , CS i and CD i are the difference between supply and demand of carbon sequestration service, supply and demand of the i-th unit respectively.

[0010] S3. Use ArcGIS's center point tool to extract the geographic coordinates of the center point of each unit as a node, and use the difference between the supply and demand of carbon sequestration services in each unit as the weight of each node. i If it is greater than 0, the i-th node is a surplus node, otherwise it is a deficit node. The number of surplus nodes and deficit nodes facilitates the analysis of the spatial matching status of supply and demand of carbon sequestration services.

[0011] S4. Obtain the annual dominant wind direction in each unit, determine the flow paths between all nodes according to the annual dominant wind direction and use it as the edge between the nodes.

[0012] S5. Construct a carbon sequestration service flow network model based on all nodes and edges, and use Gephi to visualize the carbon sequestration service flow network model.

[0013] In this plan, considering that within the scale of the study area, there is often a spatial mismatch between the supply and demand of carbon sequestration services, but it is impossible to intuitively understand the path of the study area, this plan divides the study area into multiple spatial units, obtains the supply and demand of each unit, and determines the carbon sequestration service flow path in combination with the annual dominant wind direction. It can not only more finely evaluate and characterize the carbon sequestration service flow path, but also use network models and Gephi software to visualize the carbon sequestration service flow, making the spatial flow path of carbon sequestration services more intuitive, and intuitively revealing the spatial flow law of carbon sequestration services between supply areas and demand areas, which is convenient for managers and researchers to analyze and make decisions to achieve a reasonable match between supply and demand.

[0014] Furthermore, the calculation method for the demand for carbon sequestration services is:

[0015]

[0016] C pop =p×l×365;

[0017] C agri =N f ×EF f +N P ×EF P +N m ×EF m +N e ×EF e +N a ×EF a +N ir ×EF ir ;

[0018]

[0019] C elec =N elec ×EF elec ;

[0020] C heat =N heat ×EF heat ;

[0021] Among them, C pop , C agri , C anim , C elec and C heat are the carbon emissions from residents’ breathing, agriculture, animal husbandry, electricity and heat in the ith unit; p and l are the number of people in the ith unit and the carbon dioxide emissions per person per day; N f 、N P 、N m 、N e 、N a and N ir are the amount of fertilizer used, the amount of pesticide used, the amount of agricultural plastic film used, the crop planting area, the power of agricultural machinery and the irrigation area in the i-th unit; EF f EF P EF m EF e EF a and EF ir are the carbon emission factors of fertilizers, pesticides, agricultural plastic films, crops, agricultural machinery and irrigation in the ith unit, respectively; and are the CH4 emission factors for animal enteric fermentation and manure management in the i-th unit, N i is the annual number of livestock and poultry of the i-th type, N elec 、N heat EF elec and EF heatare the electricity consumption, total steam and hot water, electricity emission coefficient and emission factor in the i-th unit respectively. By calculating the demand for carbon sequestration services in detail, carbon emissions from multiple aspects such as residents' breathing, agriculture, animal husbandry, electricity and heat are taken into account, making the estimation of demand more comprehensive and accurate. This helps to more accurately evaluate the difference in supply and demand of carbon sequestration services in each unit, thereby optimizing resource allocation.

[0022] Furthermore, Gephi's visualization of the carbon sequestration service flow network model includes: judging whether each red-chip node can be satisfied by the surplus node supplementation, if so, the edge between the red-chip node and the corresponding surplus node is a black solid line representing the flow edge, otherwise it is a red dotted line representing the interrupted edge. Through Gephi's visualization of the carbon sequestration service flow network model, it can intuitively show whether each red-chip node can be satisfied by the surplus node supplementation, which helps to quickly identify key nodes and paths and improve decision-making efficiency.

[0023] Furthermore, the units corresponding to the surplus nodes are ecological surplus areas, and the units corresponding to the deficit nodes are ecological deficit areas. Clearly dividing ecological surplus areas and ecological deficit areas will help identify which areas need to be protected and which areas need to increase the supply of carbon sequestration services.

[0024] Furthermore, step S6 of evaluating the carbon sequestration service flow in the study area includes calculating the network density of the carbon sequestration service flow network model. The greater the network density, the better the overall connectivity of the carbon sequestration service flow network model.

[0025] Furthermore, the calculation method of the dominant wind direction per unit year is:

[0026]

[0027] Among them, d dom is the annual dominant wind direction of the unit, f(d j ) is the wind frequency distribution in the unit, n is the wind direction d j The number of times, m is the total number of wind direction measurements, d j is the jth wind direction in wind direction d, and d includes at least 16 wind directions. The annual dominant wind direction is determined by wind frequency distribution, which ensures the accuracy and reliability of the data and helps to more accurately simulate the impact of wind direction on the carbon sequestration service flow path.

[0028] Furthermore, wind direction d = [0°, 22.5°, 45°, 67.5°, 90°, 112.5°, 135°, 157.5°, 180°,

[0029] 202.5°, 225°, 247.5°, 270°, 292.5°, 315°, 337.5°]. The wind directions are divided into 16 directions, which provides a more detailed classification of wind directions, helps to more accurately analyze the impact of wind directions on the carbon sequestration service flow path, and improves the accuracy of the carbon sequestration service flow network model.

[0030] Furthermore, there is loss in the process of supplementary transfer of carbon sequestration service flow between the red node and the surplus node. The calculation method of the total loss factor in the carbon sequestration service flow path in the unit is:

[0031] R total =W d ×R t ×R v ×R b

[0032]

[0033] R v =exp(-k×NDVI)

[0034] R b =exp(-c×ρ)

[0035] Among them, R total is the total loss factor in the carbon fixation service flow path in the unit, W d is the weight factor of the annual dominant wind direction, R t , R v and R b They are terrain resistance factor, vegetation resistance factor and building resistance factor, is the average wind direction in unit d, d dom is the annual dominant wind direction in the unit, σ is the smoothing parameter, θ is the angle between the annual dominant wind direction and the slope in that direction, NDVI is the normalized vegetation index, k and c are constants for the degree of influence of vegetation and buildings on wind speed, and ρ is the building density in the annual dominant wind direction. By introducing terrain resistance factor, vegetation resistance factor and building resistance factor, the influence of multiple factors on the carbon sequestration service flow path is comprehensively considered, making the loss calculation more comprehensive and accurate. This helps to simulate the actual transmission of carbon sequestration service flow more realistically.

[0036] The present invention discloses a method for characterizing a carbon fixation service flow path based on wind direction, which has the following beneficial effects:

[0037] 1. The present invention divides the study area into multiple spatial units, obtains the supply and demand of each unit, and determines the carbon sequestration service flow path in combination with the annual dominant wind direction. It can not only evaluate and characterize the carbon sequestration service flow path more finely, but also use network models and Gephi software to visualize the carbon sequestration service flow, making the spatial flow path of the carbon sequestration service more intuitive, and intuitively reveals the spatial flow law of carbon sequestration services between the supply area and the demand area, which is convenient for managers and researchers to analyze and make decisions to achieve a reasonable match between supply and demand.

[0038] 2. The present invention improves the accuracy of matching the supply and demand of carbon sequestration services. By collecting regional characteristic data, the present invention can accurately calculate the supply and demand of carbon sequestration services for each unit, and then determine the difference between supply and demand of carbon sequestration services. Based on the scientific calculation of net primary productivity (NPP) and carbon emissions, it provides accurate data support for matching the supply and demand of carbon sequestration services.

[0039] 3. The present invention enhances the visualization of carbon sequestration service flow paths: Using Gephi software and geographic coordinate data extracted from ArcGIS, the present invention constructs a carbon sequestration service flow network model, and achieves intuitive display of spatial flow paths between nodes through Geo layout. This visualization process not only makes the path of carbon sequestration service flow clearly visible, but also further enhances the intuitiveness and comprehensibility of information by indicating surplus or deficit states through nodes of different sizes and colors.

[0040] 4. The present invention provides a theoretical basis and tools for regional carbon management. The network model of the present invention provides a theoretical basis and visualization support for regional carbon management. By analyzing the relevant parameters of the carbon sequestration service flow network model, such as the number of surplus nodes and red-end nodes, the number of flow edges and interruption edges, and the network density, the overall state of the regional carbon sequestration service flow can be evaluated, thereby providing scientific guidance for the formulation and implementation of carbon management measures.

[0041] 5. The present invention simulates the dynamic changes of regional carbon sequestration service flows from the perspective of carbon sequestration service supply and demand, which plays an important role in the formation, delivery, transformation and maintenance of carbon sequestration services, and builds a bridge between the supply and demand of carbon sequestration services. The quantification and mapping of ecosystem service flows are the key points and difficulties of ecosystem service research. The present invention visualizes the carbon sequestration service flow path based on wind direction, which is largely an attempt and exploration, providing data and analysis support for local carbon management measures, and providing reference for regional carbon-related research, which is of great significance for achieving low-carbon city goals and mitigating global warming. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A schematic diagram of the components of the carbon sequestration service flow network model;

[0043] Figure 2A visual diagram of the carbon sequestration service flow network model; DETAILED DESCRIPTION

[0044] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0045] Example 1

[0046] This example uses a certain plateau city as the research area. Figure 1 , a method for characterizing a carbon sequestration service flow path based on wind direction is provided, comprising the steps of:

[0047] S1. Divide a plateau city into multiple spatial units, use primary productivity NPP as the supply of carbon sequestration services for each unit, and calculate the demand for carbon sequestration services for each unit. NPP can not only reflect the productivity of vegetation communities in the natural environment, but also reflect the surface carbon fixation capacity. Therefore, the present invention uses NPP to characterize the supply of carbon sequestration services at the plateau city level. The NPP data used in the embodiment is derived from the MODIS data of the National Aeronautics and Space Administration (NASA) (https: / / search.earthdata.nasa.gov / search / ), with a spatial resolution of 500m. Use ArcGIS for zoning statistics to obtain the carbon sequestration service supply reference table 1 for each prefecture-level city.

[0048] Table 1 Carbon sequestration service supply in 2019

[0049]

[0050]

[0051] Please refer to Table 2 for the demand for carbon sequestration services.

[0052] Table 2 Demand for carbon sequestration services in 2019

[0053]

[0054]

[0055] S2. Calculate the difference between supply and demand of carbon sequestration services for each unit, DSDCS i =CS i -CD i , among which, DSDCS i , CS iand CD i are the difference between supply and demand of carbon sequestration service, supply and demand of the i-th unit respectively.

[0056] S3. Use ArcGIS's center point tool to extract the geographic coordinates of the center point of each unit as a node, and use the difference between the supply and demand of carbon sequestration services in each unit as the weight of each node. i If it is greater than 0, the i-th node is a surplus node, otherwise it is a deficit node; the number of surplus nodes and deficit nodes facilitates the analysis of the spatial matching status of carbon sequestration service supply and demand. i If the value is greater than 0, the i-th unit is an ecological surplus area, otherwise it is an ecological deficit area. That is, the unit corresponding to the surplus node is an ecological surplus area, and the unit corresponding to the deficit node is an ecological deficit area. Clearly dividing the ecological surplus area and the ecological deficit area will help identify which areas need to be protected and which areas need to increase the supply of carbon sequestration services.

[0057] In this embodiment, there are 37 nodes representing the surplus or loss status of the carbon sequestration service, and the nodes are numbered from 1 to 37.

[0058] S4. Obtain the annual dominant wind direction in each unit, determine the flow paths between all nodes according to the annual dominant wind direction and use it as the edge between the nodes.

[0059] S5. Reference Figure 2 , a carbon sequestration service flow network model was constructed based on all nodes and edges, and Gephi was used to visualize the carbon sequestration service flow network model. Gephi's visualization of the carbon sequestration service flow network model includes: judging whether each red node can be satisfied by the surplus node supplementation, if so, the edge between the red node and the corresponding surplus node is a black solid line representing the flow edge, otherwise it is a red dotted line representing the interruption edge.

[0060] The 37 nodes in this embodiment are shown in Table 3.

[0061] Table 3

[0062]

[0063]

[0064] S6. Evaluate the carbon sequestration service flow in the study area based on the visualized carbon sequestration service flow network model, including calculating the network density of the carbon sequestration service flow network model. The greater the network density, the better the overall connectivity of the carbon sequestration service flow network model.

[0065] Table 4

[0066]

[0067] As shown in Table 4, in 2019, there were 18 carbon surplus nodes, 19 red-chip nodes, 29 flow edges, 11 interruption edges, and the network density of the service flow network was only 0.022. Compared with previous years, the shortage of carbon sequestration services in a certain plateau continued to intensify, and the connectivity of the service flow network remained at a low level.

[0068] Specifically, the calculation method for the demand for carbon sequestration services is:

[0069]

[0070] In the formula, C pop , C agri , C anim , C elec and C heat are the carbon emissions from residents’ breathing, agriculture, animal husbandry, electricity and heat in the i-th unit respectively.

[0071] Among them, C pop =p×l×365; p and l are the number of people in the ith unit and the daily carbon dioxide emissions per person respectively, l=0.75kg.

[0072] C agri =N f ×EF f +N P ×EF P +N m ×EF m +N e ×EF e +N a ×EF a +N ir ×EF ir Where N f 、N P 、N m 、N e 、N a and N ir are the amount of fertilizer used (kg), pesticide used (kg), agricultural plastic film used (kg), crop planting area (hm2) in the i-th unit. 2 ), agricultural machinery power (kW) and irrigation area (hm 2 );EF f EF P EF m EF e EF a and EF irThe carbon emission factors of fertilizers, pesticides, agricultural plastic films, crops, agricultural machinery and irrigation are 0.8956kg / kg, 4.934kg / kg, 5.180kg / kg and 16.47kg / hm 2 , 0.1800kg / kW and 20.476kg / hm 2 .

[0073] In the formula, and They are the CH4 emission factors for animal enteric fermentation and manure management, respectively, in kg / head / year. is the N2O emission factor from animal manure management, in kg / head / year; N i is the annual number of livestock and poultry of the i-th type, in units of head / year. 28 and 265 are the global warming potential factors of CH4 and N2O on a 100-year time scale.

[0074] C elec =N elec ×EF elec ; N elec and EF elec are the electricity consumption and electricity emission coefficient in the i-th unit respectively.

[0075] C heat =N heat ×EF heat ; C heat The total amount of steam and hot water N heat and emission factor EF heat Calculation, in this embodiment, C heat The value is 0.11.

[0076] As a further solution of this embodiment, the calculation method of the dominant wind direction per unit year is:

[0077]

[0078] Among them, d dom is the annual dominant wind direction of the unit, f(d j ) is the wind frequency distribution in the unit, n is the wind direction d j The number of times, m is the total number of wind direction measurements, d j is the jth wind direction among the wind directions.

[0079] Wind direction d = [0°, 22.5°, 45°, 67.5°, 90°, 112.5°, 135°, 157.5°, 180°,

[0080] 202.5°,225°,247.5°,270°,292.5°,315°,337.5°].

[0081] Dividing wind directions into 16 directions provides a more detailed classification of wind directions, which helps to more accurately analyze the impact of wind direction on the carbon sequestration service flow path and improves the accuracy of the carbon sequestration service flow network model.

[0082] As a further solution of this embodiment, in order to make the loss calculation more comprehensive and accurate, and to help simulate the actual transmission of the carbon sequestration service flow more realistically, a variety of factors are comprehensively considered, and in the judgment of whether each red-element node can be satisfied by the surplus node supplement, the total loss factor in the carbon sequestration service flow path in the unit is introduced, and the calculation method is:

[0083] R total =W d ×R t ×R v ×R b

[0084]

[0085] R v =exp(-k×NDVI)

[0086] R b =exp(-c×ρ)

[0087] Among them, R total is the total loss factor in the carbon fixation service flow path in the unit, W d is the weight factor of the annual dominant wind direction, R t , R v and R b They are terrain resistance factor, vegetation resistance factor and building resistance factor, is the average wind direction in unit d, d dom is the annual dominant wind direction in the unit, σ is the smoothing parameter, θ is the angle between the annual dominant wind direction and the slope in that direction, NDVI is the normalized vegetation index, k and c are constants for the degree of influence of vegetation and buildings on wind speed, and ρ is the building density in the annual dominant wind direction. By introducing terrain resistance factor, vegetation resistance factor and building resistance factor, the influence of multiple factors on the carbon sequestration service flow path is comprehensively considered, making the loss calculation more comprehensive and accurate. This helps to simulate the actual transmission of carbon sequestration service flow more realistically.

[0088] In this embodiment, it is convenient and more accurate to judge whether each red-element node can be satisfied by the surplus node according to the total loss factor.

[0089] Although the specific implementation of the invention is described in detail in conjunction with the drawings, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A method for characterizing carbon sequestration service flow paths based on wind direction, characterized in that: Includes steps: S1. Divide the study area into multiple spatial units, use primary productivity NPP as the supply of carbon sequestration services for each unit, and calculate the demand for carbon sequestration services for each unit; S2. Calculate the difference between supply and demand of carbon sequestration services for each unit, DSDCS i =CS i -CD i , among which, DSDCS i , CS i and CD i are the difference between supply and demand of carbon sequestration service, supply and demand of the i-th unit respectively; S3. Use ArcGIS's center point tool to extract the geographic coordinates of the center point of each unit as a node, and use the difference between the supply and demand of carbon sequestration services in each unit as the weight of each node. i If it is greater than 0, the i-th node is a surplus node, otherwise it is a deficit node; S4, obtaining the annual dominant wind direction in each unit, determining the flow paths between all nodes according to the annual dominant wind direction and using them as the edges between the nodes; S5. Construct a carbon sequestration service flow network model based on all nodes and edges, and use Gephi to visualize the carbon sequestration service flow network model.

2. The carbon fixation service flow path characterization method according to claim 1, characterized in that: The demand for carbon sequestration services is calculated as follows: C pop =p×l×365; C agri =N f ×EF f +N P ×EF P +N m ×EF m +N e ×EF e +N a ×EF a +N ir ×EF ir ; C elec =N elec ×EF elec ; C heat =N heat ×EF heat ; Among them, C pop , C agri , C anim , C elec and C heat are the carbon emissions from residents’ breathing, agriculture, animal husbandry, electricity and heat in the ith unit; p and l are the number of people in the ith unit and the carbon dioxide emissions per person per day; N f 、N P 、N m 、N e 、N a and N ir are the amount of fertilizer used, the amount of pesticide used, the amount of agricultural plastic film used, the crop planting area, the power of agricultural machinery and the irrigation area in the i-th unit; EF f EF P EF m EF e EF a and EF ir are the carbon emission factors of fertilizers, pesticides, agricultural plastic films, crops, agricultural machinery and irrigation in the ith unit, respectively; and are the CH4 emission factors for animal enteric fermentation and manure management in the i-th unit, N i is the annual number of livestock and poultry of the i-th type, N elec 、N heat EF elec and EF heat are the electricity consumption, total steam and hot water, electricity emission coefficient and emission factor in the i-th unit respectively.

3. The carbon fixation service flow path characterization method according to claim 1, characterized in that: Gephi's visualization of the carbon sequestration service flow network model includes: judging whether each red-chip node can be satisfied by the surplus node supplementation. If so, the edge between the red-chip node and the corresponding surplus node is a black solid line representing the flow edge, otherwise it is a red dotted line representing the interrupted edge.

4. The carbon fixation service flow path characterization method according to claim 1, characterized in that: The cells corresponding to the surplus nodes are ecological surplus areas, and the cells corresponding to the deficit nodes are ecological deficit areas.

5. The carbon fixation service flow path characterization method according to claim 1, characterized in that: Step S6 evaluates the carbon sequestration service flow in the study area, including calculating the network density of the carbon sequestration service flow network model.

6. The carbon fixation service flow path characterization method according to claim 1, characterized in that: The calculation method of the dominant wind direction per year is: Among them, d dom is the annual dominant wind direction of the unit, f(d j ) is the wind frequency distribution in the unit, n is the wind direction d j The number of times, m is the total number of wind direction measurements, d j is the jth wind direction among the wind directions, which includes at least 16 wind directions.

7. The carbon fixation service flow path characterization method according to claim 6, characterized in that: Wind direction d = [0°, 22.5°, 45°, 67.5°, 90°, 112.5°, 135°, 157.5°, 180°, 202.5°, 225°, 247.5°, 270°, 292.5°, 315°, 337.5°].

8. The carbon fixation service flow path characterization method according to claim 3, characterized in that: There is loss in the process of supplementary transfer of carbon sequestration service flow between the red node and the surplus node. The calculation method of the total loss factor in the carbon sequestration service flow path in the unit is: R total =W d ×R t ×R v ×R b R v =exp(-k×NDVI) R b =exp(-c×p) Among them, R total is the total loss factor in the carbon fixation service flow path in the unit, W d is the weight factor of the annual dominant wind direction, R t , R v and R b They are terrain resistance factor, vegetation resistance factor and building resistance factor, is the average wind direction in unit d, d dom is the annual dominant wind direction in the unit, σ is a smoothing parameter, α is the angle between the annual dominant wind direction and the slope direction in this direction, σ is a smoothing parameter, NDVI is the normalized difference vegetation index, k and c are constants of the influence of vegetation and buildings on wind speed, respectively, and p is the building density in the annual dominant wind direction.

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