Lake methane emission flux estimation method and device

Abstract

The application provides a lake methane emission flux estimation method and device, the estimation method comprises: for a target lake to be estimated for methane emission flux, obtaining the lake water temperature value, lake water depth value, total organic carbon concentration, lake trophic state index and environmental wind speed value of the target lake; based on the lake trophic state index, total organic carbon concentration and lake water temperature value, the methane production potential index of the target lake is determined; based on the methane production potential index, the lake water temperature value, the lake water depth value and the environmental wind speed value, the bubble flux and the methane diffusion flux corresponding to the target lake are determined respectively; the sum of the bubble flux and the methane diffusion flux is determined as the target methane emission flux corresponding to the target lake estimated. Through the above method, the accuracy and stability of estimating the lake methane emission flux are improved, the application difficulty in the actual application process is reduced, and the balance between the complexity and practicality of estimating the lake methane emission is realized.

Description

Technical Field

[0001] This application relates to the field of lake methane emission technology, and in particular to a method and apparatus for estimating lake methane emission flux. Background Technology

[0002] Methane is the world's second largest greenhouse gas and plays a key role in global climate change. Inland water bodies such as lakes and reservoirs are important natural sources of atmospheric methane emissions, and their emissions account for a significant portion of the global methane balance. Methane in lakes is mainly released into the atmosphere through two pathways: diffusion at the water-air interface and bubbles. Among these, the bubbling flux is highly spatiotemporally heterogeneous and sporadic, which increases the difficulty of accurately monitoring and estimating methane emissions.

[0003] Currently, the main method for estimating methane emissions from lakes is to collect existing methane emission data and use a pure data-driven model to estimate the total methane emissions. This method has difficulty distinguishing between diffusion flux and bubbling flux of methane emissions from lakes, and it lacks an understanding of the methane generation and emission process, which reduces the accuracy and stability of estimating methane emission flux from lakes.

[0004] In addition, there is a method to estimate lake methane emission flux through process mechanism models. However, this method involves complex data and a complicated measurement process, which is not conducive to its widespread application in practice. Summary of the Invention

[0005] In view of this, the purpose of this application is to provide a method and apparatus for estimating methane emission flux in lakes. By obtaining the environmental parameters corresponding to the target lake for which the methane emission flux to be estimated is to be determined, the methane production potential index corresponding to the target lake is determined. Based on the methane production potential index and the environmental parameters, the bubbling flux and methane diffusion flux corresponding to the target lake are determined respectively. Then, the sum of the bubbling flux and the methane diffusion flux is determined as the estimated target methane emission flux of the target lake. This improves the accuracy and stability of estimating methane emission flux in lakes, has lower computational resource requirements, and reduces the application difficulty in practical applications while ensuring the scientific validity of the core mechanism. It achieves a balance between the complexity and practicality of estimating methane emissions in lakes.

[0006] This application provides a method for estimating methane emission flux in lakes, the estimation method comprising:

[0007] For a target lake where the methane emission flux is to be estimated, the corresponding environmental parameters of the target lake are obtained; wherein, the environmental parameters include at least the lake water temperature, lake water depth, total organic carbon concentration, lake trophic state index, and environmental wind speed.

[0008] Based on the lake's trophic status index, total organic carbon concentration, and lake water temperature, the methanogenic potential index corresponding to the target lake is determined.

[0009] Based on the methanogenic potential index, the lake water temperature, the lake water depth, and the ambient wind speed, the bubbling flux and methane diffusion flux corresponding to the target lake are determined respectively.

[0010] The sum of the bubbling flux and the methane diffusion flux is determined as the estimated target methane emission flux for the target lake.

[0011] Furthermore, the trophic status index of the lake is obtained through the following steps:

[0012] Collect the chlorophyll content values ​​of the target water body in the target lake;

[0013] Based on the content value, the trophic state index of the lake is determined using a preset formula for calculating the trophic state index.

[0014] Furthermore, determining the methanogenic potential index corresponding to the target lake based on the lake's trophic status index, total organic carbon concentration, and lake water temperature includes:

[0015] Based on the lake trophic state index, determine the ratio parameter corresponding to the organic matter decomposed when the target lake produces methane;

[0016] Based on the ratio parameter, the total organic carbon concentration, the lake water temperature, and the preset organic carbon decomposition rate coefficient, methanogenesis temperature sensitivity coefficient, and methanogenesis reference temperature corresponding to the target lake, the methanogenesis potential index corresponding to the target lake is determined.

[0017] Furthermore, determining the bubbling flux and methane diffusion flux corresponding to the target lake based on the methanogenic potential index, the lake water temperature, the lake water depth, and the ambient wind speed includes:

[0018] Based on the methanogenic potential index, the lake water temperature, and the lake water depth, the bubble flux corresponding to the target lake is determined.

[0019] Based on the methanogenic potential index, the lake water temperature, the lake water depth, and the ambient wind speed, the methane diffusion flux corresponding to the target lake is determined.

[0020] Furthermore, determining the methane diffusion flux corresponding to the target lake based on the methanogenic potential index, the lake water temperature, the lake water depth, and the ambient wind speed includes:

[0021] Based on the methanogenic potential index and the lake depth value, the dissolved concentration of methane in the surface water of the target lake is determined.

[0022] Based on the ambient wind speed and the lake water temperature, the gas transport rate of methane in the target lake is determined.

[0023] Based on the dissolved concentration value, the gas transport rate value, and the preset theoretical methane equilibrium concentration value, the methane diffusion flux corresponding to the target lake is determined.

[0024] Furthermore, determining the gas transport velocity of methane in the target lake based on the ambient wind speed and the lake water temperature includes:

[0025] Based on the environmental wind speed value, determine the standard gas transport velocity value corresponding to the target lake;

[0026] Based on the lake water temperature value, determine the Schmidt number corresponding to methane in the target lake;

[0027] Based on the standard gas transport rate value and the Schmitt number, the gas transport rate value corresponding to methane in the target lake is determined.

[0028] Furthermore, the estimation method also includes:

[0029] The target lake is divided into multiple grid unit water areas according to a preset grid size, and the grid methane emission flux corresponding to each grid unit water area is determined.

[0030] Based on the methane emission flux corresponding to each grid cell water area, the spatial distribution relationship of emission flux corresponding to the target lake is generated.

[0031] This application embodiment also provides a device for estimating lake methane emission flux, the device comprising:

[0032] The data acquisition module is used to acquire environmental parameters corresponding to the target lake for which the methane emission flux is to be estimated; wherein, the environmental parameters include at least the lake water temperature, lake water depth, total organic carbon concentration, lake trophic state index and environmental wind speed.

[0033] The potential calculation module is used to determine the methanogenic potential index of the target lake based on the lake's trophic status index, total organic carbon concentration, and lake water temperature.

[0034] The flux calculation module is used to determine the bubbling flux and methane diffusion flux corresponding to the target lake based on the methanogenic potential index, the lake water temperature value, the lake water depth value, and the ambient wind speed value, respectively.

[0035] An emission estimation module is used to determine the sum of the bubbling flux and the methane diffusion flux as the estimated target methane emission flux for the target lake.

[0036] Furthermore, when the data acquisition module is used to acquire the lake's trophic state index, the data acquisition module is used to:

[0037] Collect the chlorophyll content values ​​of the target water body in the target lake;

[0038] Based on the content value, the trophic state index of the lake is determined using a preset formula for calculating the trophic state index.

[0039] Furthermore, when the potential calculation module is used to determine the methanogenesis potential index corresponding to the target lake based on the lake's trophic state index, total organic carbon concentration, and lake water temperature, the potential calculation module is used to:

[0040] Based on the lake trophic state index, determine the ratio parameter corresponding to the organic matter decomposed when the target lake produces methane;

[0041] Based on the ratio parameter, the total organic carbon concentration, the lake water temperature, and the preset organic carbon decomposition rate coefficient, methanogenesis temperature sensitivity coefficient, and methanogenesis reference temperature corresponding to the target lake, the methanogenesis potential index corresponding to the target lake is determined.

[0042] Furthermore, when the flux calculation module is used to determine the bubbling flux and methane diffusion flux corresponding to the target lake based on the methanogenic potential index, the lake water temperature, the lake water depth, and the ambient wind speed, the flux calculation module is used to:

[0043] Based on the methanogenic potential index, the lake water temperature, and the lake water depth, the bubble flux corresponding to the target lake is determined.

[0044] Based on the methanogenic potential index, the lake water temperature, the lake water depth, and the ambient wind speed, the methane diffusion flux corresponding to the target lake is determined.

[0045] Furthermore, when the flux calculation module is used to determine the methane diffusion flux corresponding to the target lake based on the methanogenic potential index, the lake water temperature, the lake water depth, and the ambient wind speed, the flux calculation module is used to:

[0046] Based on the methanogenic potential index and the lake depth value, the dissolved concentration of methane in the surface water of the target lake is determined.

[0047] Based on the ambient wind speed and the lake water temperature, the gas transport rate of methane in the target lake is determined.

[0048] Based on the dissolved concentration value, the gas transport rate value, and the preset theoretical methane equilibrium concentration value, the methane diffusion flux corresponding to the target lake is determined.

[0049] Furthermore, when the flux calculation module is used to determine the gas transport velocity of methane in the target lake based on the ambient wind speed and the lake water temperature, the flux calculation module is used to:

[0050] Based on the environmental wind speed value, determine the standard gas transport velocity value corresponding to the target lake;

[0051] Based on the lake water temperature value, determine the Schmidt number corresponding to methane in the target lake;

[0052] Based on the standard gas transport rate value and the Schmitt number, the gas transport rate value corresponding to methane in the target lake is determined.

[0053] Furthermore, the estimation device also includes a raster analysis module, which is used for:

[0054] The target lake is divided into multiple grid unit water areas according to a preset grid size, and the grid methane emission flux corresponding to each grid unit water area is determined.

[0055] Based on the methane emission flux corresponding to each grid cell water area, the spatial distribution relationship of emission flux corresponding to the target lake is generated.

[0056] This application embodiment also provides an electronic device, including: a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the memory via the bus. When the machine-readable instructions are executed by the processor, the steps of the lake methane emission flux estimation method described above are performed.

[0057] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, performs the steps of the method for estimating lake methane emission flux as described above.

[0058] The present application provides a method and apparatus for estimating methane emission flux in lakes. The estimation method includes: acquiring environmental parameters corresponding to a target lake for which the methane emission flux to be estimated; wherein the environmental parameters include at least lake water temperature, lake water depth, total organic carbon concentration, lake trophic state index, and ambient wind speed; determining a methanogenic potential index corresponding to the target lake based on the lake trophic state index, the total organic carbon concentration, and the lake water temperature; determining a bubbling flux and a methane diffusion flux corresponding to the target lake based on the methanogenic potential index, the lake water temperature, the lake water depth, and the ambient wind speed; and determining the sum of the bubbling flux and the methane diffusion flux as the estimated target methane emission flux corresponding to the target lake.

[0059] Compared with existing technologies that estimate total methane emissions by collecting existing methane emission data and using a purely data-driven model, and methods that estimate lake methane emission fluxes through process mechanism models, this method improves the accuracy and stability of estimating lake methane emission fluxes by obtaining environmental parameters corresponding to the target lake for which the methane emission flux to be estimated, determining the corresponding methanogenic potential index of the target lake, and determining the bubbling flux and methane diffusion flux of the target lake based on the methanogenic potential index and environmental parameters, and then using the sum of the bubbling flux and methane diffusion flux as the estimated target methane emission flux of the target lake. It also has lower computational resource requirements and reduces the application difficulty in practical applications while ensuring the scientific validity of the core mechanism, thus achieving a balance between the complexity and practicality of estimating lake methane emissions.

[0060] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0061] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0062] Figure 1 One of the flowcharts for a method of estimating methane emission flux in a lake provided in the embodiments of this application;

[0063] Figure 2 A second flowchart illustrating a method for estimating methane emission flux in lakes, provided as an embodiment of this application;

[0064] Figure 3This is one of the structural schematic diagrams of a device for estimating lake methane emission flux provided in an embodiment of this application;

[0065] Figure 4 This is a second schematic diagram of a device for estimating methane emission flux in a lake, provided in an embodiment of this application.

[0066] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0067] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. Based on the embodiments of this application, every other embodiment obtained by those skilled in the art without inventive effort falls within the scope of protection of this application.

[0068] Research has found that current methods for estimating methane emissions from lakes primarily rely on collecting existing methane emission data and using purely data-driven models to estimate total methane emissions. This method struggles to distinguish between diffusion and bubbling fluxes in lake methane emissions and lacks a comprehensive understanding of the methane generation and emission process, thus reducing the accuracy and stability of estimated lake methane emission fluxes. Furthermore, methods that estimate lake methane emission fluxes using process mechanism models present complex data and measurement processes, hindering their widespread application and hindering the establishment of greenhouse gas inventories and the implementation of emission reduction efforts.

[0069] Based on this, this application provides a method for estimating methane emission flux in lakes. By obtaining the environmental parameters corresponding to the target lake whose methane emission flux is to be estimated, the methanogenic potential index corresponding to the target lake is determined. Based on the methanogenic potential index and environmental parameters, the bubbling flux and methane diffusion flux corresponding to the target lake are determined respectively. Then, the sum of the bubbling flux and the methane diffusion flux is determined as the estimated target methane emission flux of the target lake. This method improves the accuracy and stability of estimating methane emission flux in lakes, has lower computational resource requirements, and reduces the application difficulty in practical applications while ensuring the scientific validity of the core mechanism. It achieves a balance between the complexity and practicality of estimating methane emissions in lakes.

[0070] Please see Figure 1 , Figure 1 This is one of the flowcharts for a method of estimating lake methane emission flux provided in an embodiment of this application. Figure 1 As shown in the embodiments of this application, the method for estimating lake methane emission flux includes:

[0071] S101. For the target lake where the methane emission flux is to be estimated, obtain the corresponding environmental parameters of the target lake.

[0072] The environmental parameters include at least the lake water temperature, lake water depth, total organic carbon concentration, lake trophic state index, and ambient wind speed.

[0073] Here, organic carbon is the substrate for methanogenesis. When obtaining the total organic carbon concentration of the target lake, the total organic carbon content of the target lake is first obtained, and the total organic carbon concentration of the target lake is determined based on the total organic carbon and the preset water volume data of the target lake.

[0074] In the embodiments of this application, the lake trophic state index (TSI) is a numerical value that describes the trophic state of a lake. It is designed to include most lakes in a range of levels (e.g., 0 to 100) to quantify the degree of eutrophication of the lake. The higher the lake trophic state index, the more severe the eutrophication of the lake.

[0075] There are various methods for calculating the trophic state index of a lake, such as using transparency, chlorophyll a concentration, or total phosphorus concentration. However, this embodiment of the application chooses to use the chlorophyll content value of the target water body in the target lake for calculation, so as to better reflect the trophic state index of the lake.

[0076] In one possible implementation of this application, the step of obtaining the lake trophic status index in step S101 may include:

[0077] S1011. Collect the chlorophyll content value of the target water body in the target lake.

[0078] Here, the chlorophyll in the target water body may include chlorophyll a, which is one of the most important photosynthetic pigments in plants, algae and some bacteria. It is essential for photosynthesis and its main function is to capture light energy and transfer it to the photosynthetic reaction center to drive the photolysis of water and the production of adenosine triphosphate and reduced nicotinamide adenine dinucleotide phosphate.

[0079] S1012. Based on the content value, determine the trophic state index of the lake using a preset trophic state index calculation formula.

[0080] In this embodiment of the application, the preset formula for calculating the nutritional status index is as follows.

[0081] .

[0082] in, Indicates the trophic status index of a lake; This indicates the chlorophyll content value of the target water body in the target lake.

[0083] S102. Based on the lake's trophic status index, total organic carbon concentration, and lake water temperature, determine the methanogenic potential index corresponding to the target lake.

[0084] In the embodiments of this application, the methanogenic potential index (unit: mmol / m³) 2 / d) is a comprehensive index used to characterize the theoretical potential of a lake per unit area to generate and transport methane flux upwards under specific conditions.

[0085] Here, the fundamental reason for the high uncertainty of prediction results is that existing technologies mostly use purely data-driven "black box" models, which directly establish statistical relationships between environmental parameters and total emission fluxes, and lack an intrinsic mechanism description of the core process of methane "generation-release".

[0086] Thus, this application embodiment calculates the methanogenic potential index corresponding to the target lake, based on recognized biogeochemical principles, to demonstrate the driving role of the substrate for methane production, the temperature effect of the methanogenic microbial process, and nutrient status on methanogenic efficiency.

[0087] In one possible implementation of this application, step S102 may include:

[0088] S1021. Based on the lake trophic state index, determine the ratio parameter corresponding to the organic matter decomposed by the target lake when producing methane.

[0089] Here, the ratio parameter corresponding to the organic matter decomposed when the target lake produces methane represents the yield of the target lake to successfully convert a portion of organic carbon into methane when it is decomposed by microorganisms. This ratio parameter is a dimensionless proportionality coefficient.

[0090] Specifically, the efficiency of methanogenesis, i.e., the ratio parameter, changes with the trophic state of the lake. When the lake is oligotrophic, the efficiency of methanogenesis remains at a low level, and the ratio parameter decreases; as the trophic state of the lake improves, the efficiency of methanogenesis gradually increases, and the ratio parameter increases.

[0091] In this embodiment of the application, the ratio parameter corresponding to the organic matter decomposed when the target lake produces methane is determined by the following formula.

[0092] .

[0093] in, This parameter represents the ratio of organic matter produced by the decomposition of methane in the target lake. This indicates the trophic status index of a lake.

[0094] S1022. Based on the ratio parameter, the total organic carbon concentration, the lake water temperature value, and the preset organic carbon decomposition rate coefficient, methanogenic temperature sensitivity coefficient, and methanogenic reference temperature corresponding to the target lake, determine the methanogenic potential index corresponding to the target lake.

[0095] In this embodiment of the application, the methanogenic potential index corresponding to the target lake is determined by the following formula.

[0096] .

[0097] in, This represents the methanogenic potential index corresponding to the target lake; This parameter represents the ratio of organic matter produced by the decomposition of methane in the target lake. This indicates the total organic carbon concentration, expressed in mmol / m³. 3 ; This indicates the lake water temperature, expressed in °C. This represents the preset organic carbon decomposition rate coefficient corresponding to the target lake; This indicates the preset methanogenic temperature sensitivity coefficient for the target lake; This indicates the preset reference temperature for methanogenesis corresponding to the target lake.

[0098] Here, the preset organic carbon decomposition rate coefficient for the target lake can generally be set to 0.01; the preset methanogenesis temperature sensitivity coefficient for the target lake can generally be set to 3; and the preset methanogenesis reference temperature for the target lake can generally be set to 20℃.

[0099] S103. Based on the methanogenic potential index, the lake water temperature, the lake water depth, and the ambient wind speed, determine the bubbling flux and methane diffusion flux corresponding to the target lake, respectively.

[0100] Here, because existing technologies cannot distinguish between diffusion flux and bubbling flux of methane emissions from lakes, only a relatively general estimate of total emissions can usually be given, which greatly limits the in-depth understanding of the methane cycle process in lakes and the formulation of targeted emission reduction strategies.

[0101] To address the aforementioned issues, this application's embodiments determine the bubbling flux and methane diffusion flux corresponding to the target lake based on the methanogenic potential index, lake water temperature, lake water depth, and ambient wind speed, thereby determining the target methane emission flux corresponding to the target lake.

[0102] In the embodiments of this application, bubbling flux and methane diffusion flux are two main ways in which lakes emit methane into the atmosphere. Methane diffusion flux refers to the flux of methane dissolved in water that slowly diffuses from a high concentration of water to a low concentration of air through the water-air interface, which is a continuous and stable emission method. Bubbling flux refers to the flux of methane generated in lake bottom sediments that rises directly from the bottom of the lake in the form of bubbles and is released into the atmosphere.

[0103] In one possible implementation of this application, step S103 may include:

[0104] S1031. Based on the methanogenic potential index, the lake water temperature value, and the lake water depth value, determine the bubbling flux corresponding to the target lake.

[0105] Here, the bubbling flux in the lake water is obtained by fitting the methanogenic potential. Based on the methanogenic potential, it is affected by the lake water temperature and depth of the target lake. Specifically, as the lake water temperature increases, the bubbling flux increases, while as the lake water depth increases, the bubbling flux decreases.

[0106] In this embodiment of the application, the bubbling flux corresponding to the target lake is determined by the following formula.

[0107] .

[0108] in, This represents the bubbling flux corresponding to the target lake; This represents the methanogenic potential index corresponding to the target lake; This indicates the lake water temperature value; This indicates the depth of the lake.

[0109] S1032. Based on the methanogenic potential index, the lake water temperature, the lake water depth, and the ambient wind speed, determine the methane diffusion flux corresponding to the target lake.

[0110] In one possible implementation of this application, step S1032 may include:

[0111] S10321. Based on the methanogenic potential index and the lake depth value, determine the dissolved concentration of methane in the surface water of the target lake.

[0112] Here, the dissolved methane concentration in the surface water of the target lake is obtained by fitting the methanogenic potential, which is influenced by the lake water temperature and depth.

[0113] In this embodiment of the application, the dissolved concentration of methane in the surface water of the target lake is determined by the following formula.

[0114] .

[0115] in, This indicates the dissolved concentration of methane in the surface water of the target lake. This represents the methanogenic potential index corresponding to the target lake; This indicates the depth of the lake.

[0116] S10322. Based on the ambient wind speed value and the lake water temperature value, determine the gas transport rate value of methane in the target lake.

[0117] In one possible implementation of this application, step S10322 may include:

[0118] S103221. Based on the environmental wind speed value, determine the standard gas transport velocity value corresponding to the target lake.

[0119] Here, the standard gas transport velocity value corresponding to the target lake can be expressed as the gas transport velocity value of the freshwater in the target lake at 20°C, which is standardized.

[0120] In this embodiment of the application, the standard gas transport velocity value corresponding to the target lake is determined by the following formula.

[0121] .

[0122] in, This represents the standard gas transport velocity value corresponding to the target lake, in m / s. This indicates the ambient wind speed value, in m / s.

[0123] S103222. Based on the lake water temperature value, determine the Schmitt number corresponding to methane in the target lake.

[0124] In this embodiment of the application, the Schmidt number corresponding to methane in the target lake is determined by the following formula.

[0125] .

[0126] in, This represents the Schmidt number corresponding to methane in the target lake; This indicates the lake water temperature, expressed in °C.

[0127] S103223. Based on the standard gas transport rate value and the Schmitt number, determine the gas transport rate value corresponding to methane in the target lake.

[0128] In this embodiment of the application, the gas transport rate value of methane in the target lake is determined by the following formula.

[0129] .

[0130] in, This represents the gas transport velocity of methane in the target lake, expressed in m / s. This represents the standard gas transport velocity value corresponding to the target lake, in m / s. This represents the Schmidt number corresponding to methane in the target lake.

[0131] S10323. Based on the dissolved concentration value, the gas transport rate value, and the preset theoretical methane equilibrium concentration value, determine the methane diffusion flux corresponding to the target lake.

[0132] Here, the preset theoretical methane equilibrium concentration value represents the theoretical equilibrium concentration value of methane when the target lake's water and atmosphere are in equilibrium.

[0133] In this embodiment of the application, the methane diffusion flux corresponding to the target lake is determined by the following formula.

[0134] .

[0135] in, This represents the methane diffusion flux corresponding to the target lake; This indicates the dissolved concentration of methane in the surface water of the target lake. This represents the gas transport rate of methane in the target lake; This represents the preset theoretical equilibrium concentration of methane.

[0136] S104. The sum of the bubbling flux and the methane diffusion flux is determined as the estimated target methane emission flux corresponding to the target lake.

[0137] In this step, the determined bubbling flux is added to the determined methane diffusion flux to obtain the sum, and this sum is determined as the estimated target methane emission flux corresponding to the target lake, that is, the estimated total methane emission flux corresponding to the target lake.

[0138] Optional, please refer to Figure 2 , Figure 2This is a second flowchart illustrating a method for estimating methane emission flux in lakes, provided as an embodiment of this application. Figure 2 As shown in the embodiment of this application, the method for estimating lake methane emission flux includes steps S105 to S106 in addition to steps S101 to S104. Specifically, steps S105 to S106 are used to explain the method of dividing the target lake into grids to determine the total methane emission flux corresponding to each grid, and then generating the spatial distribution relationship of emission flux corresponding to the target lake.

[0139] In this way, by calculating the spatial distribution of emission fluxes in target lakes, we can understand the methane emission situation and fluctuations in local areas of the lakes. This is especially applicable to assessing methane emissions from shallow lakes in mid- and low-latitude regions of the world during non-ice-covered periods, thereby improving the precision of low-carbon work inventory establishment and emission reduction efforts.

[0140] S105. Divide the water area of ​​the target lake into multiple grid unit water areas according to the preset grid size, and determine the grid methane emission flux corresponding to each grid unit water area.

[0141] Here, the preset grid size can be specifically set according to actual needs and the actual characteristics of the target lake. For example, the grid size can be set to 1km×1km, 250m×250m, or 500m×500m, etc.

[0142] The description of determining the grid methane emission flux corresponding to each grid cell water area in S105 can refer to the descriptions in S101 to S104 and achieve the same technical effect, so it will not be elaborated further.

[0143] S106. Based on the methane emission flux corresponding to each grid cell water area, generate the spatial distribution relationship of emission flux corresponding to the target lake.

[0144] In this step, after preprocessing the grid methane emission flux corresponding to each grid cell water area, a preset spatial distribution processing tool is used to generate the spatial distribution relationship of emission flux corresponding to the target lake, including but not limited to an emission flux spatial distribution map.

[0145] Here, by generating the spatial distribution relationship of emission fluxes corresponding to the target lake, a high-resolution spatial distribution map of emission fluxes corresponding to the target lake is generated, which can intuitively identify which areas within the target lake are emission hotspots; in terms of time, by inputting environmental parameters of different time series, the seasonal and interannual fluctuations of emissions corresponding to the target lake can be simulated.

[0146] The method for estimating lake methane emission flux provided in this application obtains the environmental parameters corresponding to the target lake for which the methane emission flux to be estimated, determines the methanogenic potential index corresponding to the target lake, and determines the bubbling flux and methane diffusion flux corresponding to the target lake based on the methanogenic potential index and environmental parameters, respectively. Then, the sum of the bubbling flux and the methane diffusion flux is determined as the estimated target methane emission flux of the target lake. This method improves the accuracy and stability of estimating lake methane emission flux, has low computational resource requirements, and reduces the application difficulty in practical applications while ensuring the scientific validity of the core mechanism. It achieves a balance between the complexity and practicality of estimating lake methane emissions.

[0147] Please see Figure 3 , Figure 4 , Figure 3 This is one of the structural schematic diagrams of a lake methane emission flux estimation device provided in the embodiments of this application. Figure 4 This is a second schematic diagram of a device for estimating lake methane emission flux provided in an embodiment of this application. Figure 3 As shown, the estimation device 300 includes:

[0148] The data acquisition module 310 is used to acquire environmental parameters corresponding to the target lake for which the methane emission flux is to be estimated; wherein, the environmental parameters include at least the lake water temperature, lake water depth, total organic carbon concentration, lake trophic state index and environmental wind speed.

[0149] The potential calculation module 320 is used to determine the methanogenic potential index of the target lake based on the lake's trophic status index, total organic carbon concentration, and lake water temperature.

[0150] The flux calculation module 330 is used to determine the bubbling flux and methane diffusion flux corresponding to the target lake based on the methanogenic potential index, the lake water temperature value, the lake water depth value, and the ambient wind speed value, respectively.

[0151] The emission estimation module 340 is used to determine the sum of the bubbling flux and the methane diffusion flux as the estimated target methane emission flux corresponding to the target lake.

[0152] Furthermore, when the data acquisition module 310 is used to acquire the lake trophic state index, the data acquisition module 310 is used to:

[0153] Collect the chlorophyll content values ​​of the target water body in the target lake;

[0154] Based on the content value, the trophic state index of the lake is determined using a preset formula for calculating the trophic state index.

[0155] Furthermore, when determining the methanogenic potential index of the target lake based on the lake's trophic state index, total organic carbon concentration, and lake water temperature, the potential calculation module 320 is used to:

[0156] Based on the lake trophic state index, determine the ratio parameter corresponding to the organic matter decomposed when the target lake produces methane;

[0157] Based on the ratio parameter, the total organic carbon concentration, the lake water temperature, and the preset organic carbon decomposition rate coefficient, methanogenesis temperature sensitivity coefficient, and methanogenesis reference temperature corresponding to the target lake, the methanogenesis potential index corresponding to the target lake is determined.

[0158] Furthermore, when the flux calculation module 330 is used to determine the bubbling flux and methane diffusion flux corresponding to the target lake based on the methanogenic potential index, the lake water temperature, the lake water depth, and the ambient wind speed, the flux calculation module 330 is used to:

[0159] Based on the methanogenic potential index, the lake water temperature, and the lake water depth, the bubble flux corresponding to the target lake is determined.

[0160] Based on the methanogenic potential index, the lake water temperature, the lake water depth, and the ambient wind speed, the methane diffusion flux corresponding to the target lake is determined.

[0161] Furthermore, when the flux calculation module 330 is used to determine the methane diffusion flux corresponding to the target lake based on the methanogenic potential index, the lake water temperature value, the lake water depth value, and the ambient wind speed value, the flux calculation module 330 is used to:

[0162] Based on the methanogenic potential index and the lake depth value, the dissolved concentration of methane in the surface water of the target lake is determined.

[0163] Based on the ambient wind speed and the lake water temperature, the gas transport rate of methane in the target lake is determined.

[0164] Based on the dissolved concentration value, the gas transport rate value, and the preset theoretical methane equilibrium concentration value, the methane diffusion flux corresponding to the target lake is determined.

[0165] Furthermore, when the flux calculation module 330 determines the gas transport velocity value of methane in the target lake based on the ambient wind speed value and the lake water temperature value, the flux calculation module 330 is used to:

[0166] Based on the environmental wind speed value, determine the standard gas transport velocity value corresponding to the target lake;

[0167] Based on the lake water temperature value, determine the Schmidt number corresponding to methane in the target lake;

[0168] Based on the standard gas transport rate value and the Schmitt number, the gas transport rate value corresponding to methane in the target lake is determined.

[0169] Furthermore, such as Figure 4 As shown, the estimation device 300 further includes a raster analysis module 350, which is used for:

[0170] The target lake is divided into multiple grid unit water areas according to a preset grid size, and the grid methane emission flux corresponding to each grid unit water area is determined.

[0171] Based on the methane emission flux corresponding to each grid cell water area, the spatial distribution relationship of emission flux corresponding to the target lake is generated.

[0172] The lake methane emission flux estimation device provided in this application obtains the environmental parameters corresponding to the target lake for which the methane emission flux to be estimated, determines the methanogenic potential index corresponding to the target lake, and determines the bubbling flux and methane diffusion flux corresponding to the target lake based on the methanogenic potential index and environmental parameters, respectively. Then, the sum of the bubbling flux and the methane diffusion flux is determined as the estimated target methane emission flux of the target lake. This improves the accuracy and stability of estimating lake methane emission flux, has low computational resource requirements, and reduces the application difficulty in practical applications while ensuring the scientific nature of the core mechanism. It achieves a balance between the complexity and practicality of estimating lake methane emissions.

[0173] Please see Figure 5 , Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 5 As shown, the electronic device 500 includes a processor 510, a memory 520, and a bus 530.

[0174] The memory 520 stores machine-readable instructions executable by the processor 510. When the electronic device 500 is running, the processor 510 and the memory 520 communicate via the bus 530. When the machine-readable instructions are executed by the processor 510, they can perform the operations described above. Figure 1 as well as Figure 2 The steps of the method for estimating lake methane emission flux in the illustrated method embodiment can be found in the method embodiment for specific implementation, and will not be repeated here.

[0175] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, can perform the above-described actions. Figure 1 as well as Figure 2 The steps of the method for estimating lake methane emission flux in the illustrated method embodiment can be found in the method embodiment for specific implementation, and will not be repeated here.

[0176] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0177] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0178] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0179] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0180] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0181] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The scope of protection of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for estimating methane emission flux in lakes, characterized in that, The estimation method includes: For a target lake where the methane emission flux is to be estimated, the corresponding environmental parameters of the target lake are obtained; wherein, the environmental parameters include at least the lake water temperature, lake water depth, total organic carbon concentration, lake trophic state index, and environmental wind speed. Based on the lake trophic status index, the ratio parameter corresponding to the organic matter decomposed when the target lake produces methane is determined. Based on the ratio parameter, the total organic carbon concentration, the lake water temperature value, and the preset organic carbon decomposition rate coefficient, methanogenic temperature sensitivity coefficient, and methanogenic reference temperature corresponding to the target lake, the methanogenic potential index corresponding to the target lake is determined. The ratio parameter is determined using the following formula: ； in, This represents the ratio parameter; This represents the trophic status index of the lake; The methanogenesis potential index is determined using the following formula: ； in, This indicates the methanogenic potential index; This represents the ratio parameter; This indicates the total organic carbon concentration; This indicates the temperature value of the lake water; This represents the organic carbon decomposition rate coefficient; This represents the temperature sensitivity coefficient of methanogenesis; This indicates the methanogenesis reference temperature; Based on the methanogenic potential index, the lake water temperature, and the lake water depth, the bubbling flux corresponding to the target lake is determined, and based on the methanogenic potential index, the lake water temperature, the lake water depth, and the ambient wind speed, the methane diffusion flux corresponding to the target lake is determined. The bubbling flux is determined by the following formula: ； in, This represents the bubbling flux; This indicates the methanogenic potential index; This indicates the temperature value of the lake water; This indicates the depth of the lake water; The determination of the methane diffusion flux corresponding to the target lake based on the methane production potential index, the lake water temperature, the lake water depth, and the ambient wind speed includes: Based on the methanogenic potential index and the lake depth value, the dissolved concentration of methane in the surface water of the target lake is determined. The solution concentration value is determined using the following formula: ； in, This indicates the dissolved concentration value; This indicates the methanogenic potential index; This indicates the depth of the lake water; Based on the ambient wind speed and the lake water temperature, the gas transport rate of methane in the target lake is determined. Based on the dissolved concentration value, the gas transport rate value, and the preset theoretical methane equilibrium concentration value, the methane diffusion flux corresponding to the target lake is determined; The methane diffusion flux is determined using the following formula: ； in, This represents the methane diffusion flux; This indicates the dissolved concentration value; This represents the gas transport speed value; This represents the preset theoretical equilibrium concentration of methane; The sum of the bubbling flux and the methane diffusion flux is determined as the estimated target methane emission flux for the target lake.

2. The method according to claim 1, characterized in that, The trophic status index of the lake is obtained through the following steps: Collect the chlorophyll content values ​​of the target water body in the target lake; Based on the content value, the trophic state index of the lake is determined using a preset formula for calculating the trophic state index.

3. The method according to claim 1, characterized in that, Determining the gas transport velocity of methane in the target lake based on the ambient wind speed and the lake water temperature includes: Based on the environmental wind speed value, determine the standard gas transport velocity value corresponding to the target lake; Based on the lake water temperature value, determine the Schmidt number corresponding to methane in the target lake; Based on the standard gas transport rate value and the Schmitt number, the gas transport rate value corresponding to methane in the target lake is determined.

4. The method according to claim 1, characterized in that, The estimation method further includes: The target lake is divided into multiple grid unit water areas according to a preset grid size, and the grid methane emission flux corresponding to each grid unit water area is determined. Based on the methane emission flux corresponding to each grid cell water area, the spatial distribution relationship of emission flux corresponding to the target lake is generated.

5. A device for estimating methane emission flux in lakes, characterized in that, The estimation device includes: The data acquisition module is used to acquire environmental parameters corresponding to the target lake for which the methane emission flux is to be estimated; wherein, the environmental parameters include at least the lake water temperature, lake water depth, total organic carbon concentration, lake trophic state index and environmental wind speed. The potential calculation module is used to determine the ratio parameter corresponding to the organic matter decomposed by the target lake when producing methane based on the lake trophic state index, and to determine the methane production potential index corresponding to the target lake based on the ratio parameter, the total organic carbon concentration, the lake water temperature value, and the preset organic carbon decomposition rate coefficient, methanogenic temperature sensitivity coefficient and methanogenic reference temperature corresponding to the target lake. The potential calculation module is used to determine the ratio parameter using the following formula: ； in, This represents the ratio parameter; This represents the trophic status index of the lake; The potential calculation module is used to determine the methanogenesis potential index using the following formula: ； in, This indicates the methanogenic potential index; This represents the ratio parameter; This indicates the total organic carbon concentration; This indicates the temperature value of the lake water; This represents the organic carbon decomposition rate coefficient; This represents the temperature sensitivity coefficient of methanogenesis; This indicates the methanogenesis reference temperature; The flux calculation module is used to determine the bubbling flux corresponding to the target lake based on the methanogenic potential index, the lake water temperature value, and the lake water depth value, and to determine the methane diffusion flux corresponding to the target lake based on the methanogenic potential index, the lake water temperature value, the lake water depth value, and the ambient wind speed value. The flux calculation module is used to determine the bubbling flux using the following formula: ； in, This represents the bubbling flux; This indicates the methanogenic potential index; This indicates the temperature value of the lake water; This indicates the depth of the lake water; When the flux calculation module is used to determine the methane diffusion flux corresponding to the target lake based on the methane production potential index, the lake water temperature, the lake water depth, and the ambient wind speed, the flux calculation module is used to: Based on the methanogenic potential index and the lake depth value, the dissolved concentration of methane in the surface water of the target lake is determined. The solution concentration value is determined using the following formula: ； in, This indicates the dissolved concentration value; This indicates the methanogenic potential index; This indicates the depth of the lake water; Based on the ambient wind speed and the lake water temperature, the gas transport rate of methane in the target lake is determined. Based on the dissolved concentration value, the gas transport rate value, and the preset theoretical methane equilibrium concentration value, the methane diffusion flux corresponding to the target lake is determined; The methane diffusion flux is determined using the following formula: ； in, This represents the methane diffusion flux; This indicates the dissolved concentration value; This represents the gas transport speed value; This represents the preset theoretical equilibrium concentration of methane; An emission estimation module is used to determine the sum of the bubbling flux and the methane diffusion flux as the estimated target methane emission flux for the target lake.

6. An electronic device, characterized in that, include: The device includes a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the memory via the bus. The machine-readable instructions are executed by the processor to perform the steps of the method for estimating lake methane emission flux as described in any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, performs the steps of the method for estimating lake methane emission flux as described in any one of claims 1 to 4.

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