A method and system for calculating wetland net greenhouse gas budget NGB

Abstract

The present invention provides a method and system for calculating the net greenhouse gas balance NGB of a wetland, and its application belongs to the field of ecological accounting methods. The calculation method calculates the net greenhouse gas balance NGB of a wetland according to the following formula (1); NGB=WDCB+ER+ECD-CSRL (1); In formula (1), NGB is the net greenhouse gas budget; WDCB Changes in greenhouse gases for ecological water replenishment; IS The change in greenhouse gases for reclamation; ECD Changes in greenhouse gases for development and construction; CSRL The carbon sequestration amount of returning farmland to lakes. Based on the calculation method, the present invention also provides a computer-readable storage medium and a calculation system. The calculation method and system of the present invention comprehensively consider the impact of the wetland ecosystem itself and various management measures such as water replenishment, reclamation, development and construction, returning farmland to lakes, etc. on the greenhouse gas balance of wetlands, and can obtain a more accurate net greenhouse gas balance of the target wetland.

Description

Technical Field

[0001] The present invention relates to the field of ecological accounting methods, and in particular to a method and system for calculating the net greenhouse gas balance NGB of a wetland. Background Art

[0002] The greenhouse gas balance of wetland ecosystems plays a very important role in global climate change. Global wetland ecosystems account for only 5% to 8% of the land surface, but store 30% of the carbon in terrestrial ecosystems. At the same time, the decomposition of organic matter in wetlands can also emit CH4 and N2O, and its CH4 emissions account for about 30% of the global total emissions. The greenhouse gas balance of wetlands is strongly affected by human management measures such as changes in hydrological conditions caused by ecological water replenishment, reclamation and returning farmland to lakes, and changes in vegetation cover caused by them. About half of the world's wetlands are under the threat of drought degradation, and water level changes caused by drought or ecological water replenishment directly change the source / sink function of wetlands. In addition, agricultural reclamation and urban development and construction have put global wetlands under severe challenges. In the past 200 years, the global wetland area has decreased by 50%, resulting in a large amount of carbon emissions from wetlands; while regional protection measures such as returning farmland to lakes have increased wetland carbon fixation and changed the CH4 and N2O balance. Changes in the greenhouse gas balance process of wetlands caused by human management measures such as development, utilization and protection of wetlands have received increasing attention. A comprehensive understanding of the greenhouse gas balance of wetlands and their response to human management measures is also a prerequisite for implementing reasonable emission reduction and carbon sink control measures. Given the important role of wetland ecosystems in global climate change, we urgently need to study the impact of increasing human management measures on greenhouse gas balance and net source / sink effects. However, current research on greenhouse gas accounting of wetland ecosystems mainly considers the fixation and emission of CO2, CH4 and N2O by the ecosystem itself, and lacks a comprehensive greenhouse gas accounting method under human management.

[0003] At present, the existing technology needs to comprehensively calculate the wetland by combining the accounting methods reported in multiple literatures to obtain the exact data of the greenhouse gas balance of the wetland. It is unsystematic, time-consuming, labor-intensive, and costly. At the same time, there is a lack of a calculation method that comprehensively considers the greenhouse gas balance NGB (Net GHG Budget) under human management. Therefore, this field urgently needs to develop a calculation method that comprehensively considers the greenhouse gas balance NGB under human management, which can be used to study the impact of increasing human management measures on greenhouse gas balance and net source / sink effects, and provide scientific guidance for the implementation of effective wetland emission reduction and sink enhancement control measures. Summary of the invention

[0004] In order to solve the above-mentioned needs in the prior art of the present invention, the present invention provides a method, system and application for calculating the net greenhouse gas balance NGE of a wetland.

[0005] The technical solution of the present invention is as follows:

[0006] A method for calculating a wetland net greenhouse gas balance NGB, characterized in that the wetland net greenhouse gas balance NGB is calculated according to the following formula (1);

[0007] (1)

[0008] In formula (1), NGB is the net greenhouse gas budget; WDCB Changes in greenhouse gases for ecological water replenishment; ER The change in greenhouse gases for reclamation; ECD Changes in greenhouse gases for development and construction; CSRL To restore farmland to lakes and sequester carbon;

[0009] The change of greenhouse gas in ecological water replenishment WDCB Calculate according to formula (3):

[0010] Said (3)

[0011] In formula (3), CSB is the change in carbon fixation of vegetation before and after water replenishment, CSW The amount of carbon sequestration increased by the water body; CCS To carry more carbon into the sediment, EWC 1 is the change in greenhouse gas emissions of the vegetation-water-soil system before and after water replenishment;

[0012] Changes in carbon sequestration in vegetation before and after water replenishment CSB According to formula (4), we can calculate:

[0013] (4)

[0014] In formula (4), F i For the i Changes in vegetation CO2 fixation flux before and after water replenishment at the measurement point; A i is the area between two adjacent points; F (i+1) It is i+ 1. Changes in vegetation CO2 fixation flux before and after water replenishment at the measuring point;

[0015] Changes in greenhouse gas emissions from vegetation-water-soil system before and after water replenishment EWC 1 The relationship is as follows:

[0016] (5)

[0017] In formula (5), F ij For the i The measurement point before and after water replenishment j The average flux change of greenhouse gases; F （i+1）j For the i+ 1 The measurement point before and after water replenishment j The average flux change of greenhouse gases; A i is the area between two adjacent points;

[0018] Changes in greenhouse gases from reclamation ER It is calculated by the following formula (6):

[0019] (6)

[0020] In formula (6), CBB 围 is the amount of carbon loss from vegetation; SOC 30围 is the amount of soil organic carbon loss within 30 cm depth; CW 围 is the amount of carbon loss in water bodies; EAC is the greenhouse gas budget of the farmland after reclamation; EWC is the greenhouse gas budget of the wetland before reclamation;

[0021] The greenhouse gas balance in formula (6) can be measured by the greenhouse gas balance measurement method reported in the prior art, and the greenhouse gas balance that can be measured refers to the greenhouse gas balance of farmland after reclamation and wetland before reclamation, which is different from the calculation of the greenhouse gas balance of the NGB of the present invention. The measurement of greenhouse gas balance in the prior art is the greenhouse gas balance of one or several processes involved in the management of forests, farmland, wetlands or other ecosystems, and there is no calculation of the impact of various artificial processes on the greenhouse gas balance in the wetland ecosystem management process. Therefore, it cannot truly and objectively reflect the greenhouse gas balance of wetlands managed by the ecosystem. The NGB calculation method of the present invention just makes up for this defect and can comprehensively calculate the greenhouse gas balance and net change of multiple processes involved in the wetland ecosystem management process (including water replenishment, reclamation, development and construction, returning farmland to lakes, etc.). The NGB of the present invention is obtained by calculation through the greenhouse gas balance of farmland after reclamation, the greenhouse gas balance of wetlands before reclamation, and other processes involved in greenhouse gas balances. The data of the experimental examples of the present invention can well reflect the difference in the measurement or calculation results of the indoor gas budget of the same target wetland between the measurement method of the indoor gas budget of the prior art and the NGB calculation method of the present invention.

[0022] Changes in greenhouse gases from development and construction ECD It is calculated by the following formula (7):

[0023] (7)

[0024] In formula (7), CBB 开 is the amount of carbon loss from vegetation; SOC 30开 is the amount of soil organic carbon loss within 30 cm depth; CW 开 is the amount of carbon loss in water bodies; ECC Greenhouse gas emissions from construction land after development and construction; EWC is the greenhouse gas budget of the wetland before reclamation;

[0025] Carbon sequestration from returning farmland to lakes CSRL It is calculated by the following formula (8):

[0026] (8)

[0027] In formula (8), CBB 退 is the amount of carbon loss from vegetation; SOC 30退 is the amount of soil organic carbon loss within 30 cm depth; CW 退 is the amount of carbon loss in water bodies; EAC is the greenhouse gas budget of the farmland after reclamation; EWC is the greenhouse gas budget of the wetland before reclamation;

[0028] Carbon loss from vegetation CBB It is calculated by the following formula (9):

[0029] (9)

[0030] In formula (9), BCD After,k Land use type after conversion k vegetation carbon density; BCD Before,k Land use type before conversion k The vegetation carbon density; Area k Land use type k The conversion area, n is the time interval between two data periods;

[0031] Soil organic carbon loss within 30 cm depth SOC 30 It is calculated by the following formula (10):

[0032] (10)

[0033] In formula (10), SOC k Land use type within 0~30cm depth k Soil carbon density or sediment carbon density at a depth of 0-10 cm; IF k Land use type k The influencing factors of soil organic carbon conversion; Area k Land use type k The conversion area, n is the time interval between two data periods;

[0034] Carbon loss from water bodies CW It is calculated by the following formula (11):

[0035] (11)

[0036] In formula (11), CWD is the density of dissolved organic carbon in water; Area k Land use type k The conversion area, n is the time interval between two data periods.

[0037] The greenhouse gas is selected from: CO2, CH4, N2O;

[0038] The land use type k Selected from: water area, cultivated land, construction land; the land use type k For construction land BCD After,k is 0.

[0039] Land use type k The conversion area Area k It can be obtained using the transfer matrix of ArcGIS 10.2 software.

[0040] The carbon fixation change values ​​in formula (3) and formula (4) are measured by the carbon fixation determination method;

[0041] Preferably, the greenhouse gas emissions described in formula (3) and formula (7) are measured by a greenhouse gas emissions measurement method;

[0042] Preferably, the greenhouse gas change is measured by a greenhouse gas change measurement method;

[0043] Although the change in greenhouse gases can be measured, the measurement method in the prior art can only measure the change in greenhouse gases under certain fixed conditions. The calculation of the change in greenhouse gases in equations (3), (6) and (7) of the present invention reflects a change process, which cannot be measured directly and needs to be obtained through calculation.

[0044] Preferably, the CO2 fixation flux value of formula (4) is measured by a CO2 fixation flux value determination method;

[0045] Preferably, the areas of formula (4), formula (5) and formula (9) are measured by an area measurement method;

[0046] Preferably, the greenhouse gas flux value of formula (5) is measured by a greenhouse gas flux value determination method;

[0047] Preferably, the greenhouse gas balance in formula (6), formula (7) and formula (8) is measured by a greenhouse gas balance measurement method;

[0048] Preferably, the carbon loss amount in formula (6), formula (7) and formula (8) is measured by a carbon loss amount measurement method;

[0049] Preferably, the organic carbon loss amount in formula (6), formula (7) and formula (8) is measured by an organic carbon loss measurement method;

[0050] Preferably, the vegetation carbon density in formula (9) is measured by a vegetation carbon density measurement method;

[0051] Preferably, the soil carbon density of formula (10) is measured by a soil carbon density determination method;

[0052] Preferably, the sediment carbon density of formula (10) is measured by a sediment carbon density determination method;

[0053] Preferably, the organic carbon impact factor of the transformed soil in formula (10) is measured by a method for measuring the organic carbon impact factor of the transformed soil.

[0054] A computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the method for calculating the net greenhouse gas balance NGB of a wetland is implemented.

[0055] A system for calculating the net greenhouse gas balance NGB of a wetland, characterized by comprising: a calculation unit; the calculation unit comprises: the computer-readable storage medium.

[0056] The system for calculating the net greenhouse gas balance NGB of a wetland further includes: a carbon sequestration measurement unit; the carbon sequestration measurement unit includes a computer-readable storage medium on which a computer program is stored; when the computer program is executed by a processor, a carbon sequestration determination method is implemented;

[0057] Preferably, the system further comprises: a greenhouse gas emission measurement unit; the greenhouse gas emission measurement unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements the greenhouse gas emission measurement method when executed by the processor;

[0058] Preferably, the system further comprises: a greenhouse gas change amount measuring unit; the greenhouse gas change amount measuring unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements the greenhouse gas change amount measuring method when executed by the processor;

[0059] Preferably, the system further comprises: a CO2 fixation flux value measuring unit; the CO2 fixation flux value measuring unit comprises a computer-readable storage medium on which a computer program is stored; when the computer program is executed by the processor, the CO2 fixation flux value determination method is implemented;

[0060] Preferably, the system further comprises: an area measurement unit; the area measurement unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements the area measurement method when executed by the processor;

[0061] Preferably, the system further comprises: a greenhouse gas flux value measuring unit; the greenhouse gas flux value measuring unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements the greenhouse gas flux value determination method when executed by the processor;

[0062] Preferably, the system further comprises: a greenhouse gas balance measurement unit; the greenhouse gas balance measurement unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements the greenhouse gas balance determination method when executed by the processor;

[0063] Preferably, the system further comprises: a carbon loss amount measuring unit; the carbon loss amount measuring unit comprises a computer readable storage medium on which a computer program is stored; the computer program implements the carbon loss amount measuring method when executed by the processor;

[0064] Preferably, the system further comprises: an organic carbon loss measurement unit; the organic carbon loss measurement unit comprises a computer-readable storage medium on which a computer program is stored; when the computer program is executed by the processor, the method for determining the organic carbon loss is implemented;

[0065] Preferably, the system further comprises: a vegetation carbon density measuring unit; the vegetation carbon density measuring unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements the vegetation carbon density measuring method when executed by the processor;

[0066] Preferably, the system further comprises: a soil carbon density measuring unit; the soil carbon density measuring unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements the soil carbon density measuring method when executed by the processor;

[0067] Preferably, the system further comprises: a bottom mud carbon density measuring unit; the bottom mud carbon density measuring unit comprises a computer readable storage medium on which a computer program is stored; the computer program implements the bottom mud carbon density measuring method when executed by the processor;

[0068] Preferably, the system further comprises: a unit for measuring the organic carbon impact factor of the transformed soil; the unit for measuring the organic carbon impact factor of the transformed soil comprises a computer-readable storage medium on which a computer program is stored; when the computer program is executed by the processor, a method for determining the organic carbon impact factor of the transformed soil is implemented;

[0069] The carbon fixation measurement unit, greenhouse gas emission measurement unit, greenhouse gas change measurement unit, CO2 fixation flux value measurement unit, area measurement unit, greenhouse gas flux value measurement unit, greenhouse gas balance measurement unit, carbon loss measurement unit, organic carbon loss measurement unit, vegetation carbon density measurement unit, soil carbon density measurement unit, sediment carbon density measurement unit, and soil organic carbon impact factor measurement unit are respectively connected to the calculation unit via a data path.

[0070] The beneficial effects of the present invention are as follows:

[0071] Different from the existing greenhouse gas balance method based only on the wetland ecosystem itself, and without the need to refer to the accounting methods of multiple documents for comprehensive accounting of the target wetland, the present invention comprehensively considers the impact of the wetland ecosystem itself, water level changes before and after ecological water replenishment, reclamation, development and construction, and returning farmland to lakes and other management measures on the greenhouse gas balance of the wetland, and clarifies the net source / sink role of the wetland. It is of great significance to reveal the key management measures that affect the changes in the greenhouse gas balance of the wetland ecosystem and formulate reasonable emission reduction and sink control measures. At the same time, the method of the present invention forms a set of organic and integrated calculations that comprehensively consider the impact of multiple factors on the changes in greenhouse gas balance, avoiding the operation of using multiple documents for accounting, and taking into account cost saving, labor saving and high efficiency while ensuring accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1A schematic diagram of the principle of the net greenhouse gas balance calculation method provided for the experimental example of the present invention.

[0073] Figure 2 Schematic diagram of the process of wetland carbon fixation and greenhouse gas emissions under the management measures of the experimental example of the present invention. DETAILED DESCRIPTION

[0074] The specific contents of the present invention are further described in detail below in conjunction with specific embodiments and experimental examples, but the protection scope of the present invention is not limited thereto.

[0075] The first group of embodiments, the calculation method of NGB of the present invention

[0076] This group of embodiments provides a method for calculating the net greenhouse gas balance NGB of a wetland. All embodiments in this group have the following common features: the net greenhouse gas balance NGB of a wetland is calculated according to the following formula (1);

[0077] (1)

[0078] In formula (1), NGB is the net greenhouse gas budget; WDCB Changes in greenhouse gases for ecological water replenishment; ER The change in greenhouse gases for reclamation; ECD Changes in greenhouse gases for development and construction; CSRL To restore farmland to lakes and sequester carbon;

[0079] The change of greenhouse gas in ecological water replenishment WDCB Calculate according to formula (3):

[0080] Said (3)

[0081] In formula (3), CSB is the change in carbon sequestration of vegetation before and after water replenishment; CCS To carry more carbon into the sediment, EWC 1 is the change in greenhouse gas emissions of the vegetation-water-soil system before and after water replenishment;

[0082] In a specific embodiment, NGB , WDCB , ER , ECD , CSRL , CSAB , CSW , CCS , EAWC , EBWC The dimension of Tg Ce yr -1 .

[0083] The water replenishment has the conventional technical meaning commonly understood by those skilled in the art, and may be the meaning of the term "water replenishment" as described in the article "Ecological Service Value Tradeoffs: An Ecological Water Replenishment Model for the Jilin Momoge National Nature Reserve, China".

[0084] The carbon sequestration amount has the conventional technical meaning commonly understood by those skilled in the art, and may be the meaning of the term “carbon sequestration” as recorded in the article “Ecological Service Value Tradeoffs: An Ecological Water Replenishment Model for the Jilin Momoge National Nature Reserve, China”.

[0085] The determination of carbon fixation is a conventional technical means well known to those skilled in the art. For example, the determination of carbon fixation of plants can refer to the determination method described in the article "Study on methane and carbon dioxide emissions and their influencing factors in the Three Gorges Reservoir" to measure the carbon fixation of plants;

[0086] The "increased carbon fixation amount caused by water transfer" can be calculated based on the measurement method described in the article "Study on Methane and Carbon Dioxide Emissions from the Three Gorges Reservoir and Their Influencing Factors".

[0087] The water transfer refers to the amount of water added to the target wetland by the water replenishment operation; the amount of carbon fixation increased by the water transfer refers to the amount of carbon fixation brought about by the increased water volume in the template wetland.

[0088] The "carrying sediment amount" can be measured according to the measurement method recorded in the article "Research on the dynamic feedback effect of water and sediment in high turbidity estuaries".

[0089] Carried sediment refers to the sediment carried in the water volume added to the target wetland by the water replenishment operation. The amount of carbon fixation increased by carried sediment refers to the amount of carbon fixation and organic carbon content brought by the sediment carried in the water volume added to the target wetland.

[0090] The "carbon fixation amount after returning farmland to lake" can be measured according to the determination method described in the article "Study on the physical and chemical properties of soil and related enzyme activities in the Dongting Lake area after returning farmland to lake".

[0091] “Carbon sequestration from returning farmland to lake” refers to the carbon sequestration brought to the target wetland by the operation of returning farmland to lake. If the target wetland does not have the operation of returning farmland to lake, this independent variable is 0.

[0092] The term "returning farmland to lake" is a conventional technical term commonly understood by those skilled in the art, and may have the meaning of the term "returning farmland to lake" as recorded in the article "Dynamic Evolution of Wetland Landscape Pattern in Taihu Lake Basin and Analysis of Its Multi-level Driving Mechanism".

[0093] The vegetation-water-soil system has the conventional technical meaning commonly understood by those skilled in the art, and may be the vegetation-water-soil system described in the article “Study on Methane and Carbon Dioxide Emissions from the Three Gorges Reservoir and Their Influencing Factors”.

[0094] The greenhouse gas emissions have the conventional technical meaning commonly understood by those skilled in the art, and may be the greenhouse gas emissions recorded in the article “Agricultural greenhouse gas measurement and emission reduction potential assessment based on literature statistics and case observations”.

[0095] The greenhouse gas emissions of the vegetation-water-soil system before and after water replenishment can be measured by measurement methods familiar to those skilled in the art, for example, the measurement method described in the article "Study on Methane and Carbon Dioxide Emissions from the Three Gorges Reservoir and Their Influencing Factors".

[0096] The reclamation has the conventional technical meaning commonly understood by those skilled in the art, and may be the reclamation recorded in the article “The Impact of Conversion of Estuarine Swamp Wetlands into Aquaculture Ponds on the Content of Different Components of Organic Carbon in Wetland Soils”.

[0097] The development and construction has the conventional technical meaning commonly understood by those skilled in the art, and may be the development and construction recorded in the article “Research on Overall Optimization of Ecological Tourism in Wanshui Scenic Area, Songzi City”.

[0098] The greenhouse gas change has the conventional technical meaning commonly understood by those skilled in the art, and may be the greenhouse gas change recorded in the article “Study on the Impact of Water Pollution Prevention and Control Action Plan on Greenhouse Gases”.

[0099] Those skilled in the art can use conventional technical means in the field to measure the change in greenhouse gases. For example, the change in greenhouse gases caused by reclamation refers to the change in greenhouse gases caused by the reclamation operation to the target wetland. The determination of this indicator can refer to the determination method recorded in the article "The Impact of Agricultural Reclamation on Greenhouse Gas Emissions from Wetlands Surrounding Farmland in Sanjiang Plain" to measure the change in greenhouse gases caused by reclamation.

[0100] The greenhouse gas change from development and construction refers to the greenhouse gas change from development and construction to the target wetland. The determination of this indicator can refer to the determination method recorded in the article "Research on Carbon Emission Effect of Land Use in China" to measure the greenhouse gas change from development and construction;

[0101] Changes in vegetation carbon fixation before and after water replenishment CSB According to formula (4), we can calculate:

[0102] (4)

[0103] In formula (4), F i For the i Changes in vegetation CO2 fixation flux before and after water replenishment at the measurement point; A i is the area between two adjacent points; F (i+1) It is i+ 1. Changes in vegetation CO2 fixation flux before and after water replenishment at the measuring point;

[0104] No. i The vegetation CO2 fixation flux value before and after water replenishment at the measuring point refers to the value of the vegetation CO2 fixation flux value at a specific measuring point in the target wetland. i CO2 fixation flux value of vegetation at .

[0105] The CO2 fixation flux value has the conventional technical meaning commonly understood by those skilled in the art, and may be the CO2 fixation flux value recorded in the article “Study on Methane and Carbon Dioxide Emissions and Their Influencing Factors from the Three Gorges Reservoir”.

[0106] The measurement of CO2 fixation flux value can be achieved by those skilled in the art using conventional technical means in the art, and specifically, the measurement method described in the article "Study on Methane and Carbon Dioxide Emissions and Their Influencing Factors from the Three Gorges Reservoir" can be used.

[0107] CSB The dimension of Tg Ce yr -1 , F i or F (i+1) The dimension of the CO2 fixation flux change is mg Ce m -2 h -1 , A i The dimension is m 2 .

[0108] Two adjacent points refer to a specific measurement point in the target wetland. i Another adjacent point i +1 and determination point i .

[0109] The area between two adjacent points is the area between the measuring points. i With another point i The area between φ and φ is measured by conventional techniques known to those skilled in the art. For example, the measurement method described in the article “Study on Methane and Carbon Dioxide Emissions from the Three Gorges Reservoir and Their Influencing Factors” can be used.

[0110] Changes in greenhouse gas emissions from vegetation-water-soil systems before and after water replenishment EWC 1 The relationship is as follows:

[0111] (5)

[0112] In formula (5), F ij For the i The measurement point before and after water replenishment j The average flux change of greenhouse gases; F （i+1）j For the i+ 1 The measurement point before and after water replenishment j The average flux change of greenhouse gases; A i is the area between two adjacent points;

[0113] No. i The measurement point before and after water replenishment j The average flux value of a greenhouse gas refers to the average flux value of a greenhouse gas at a specific measurement point in the target wetland. i The first to the j The average value of greenhouse gas fluxes.

[0114] The greenhouse gas flux value has the conventional technical meaning commonly understood by those skilled in the art, and may be the greenhouse gas flux value recorded in the article “Study on Greenhouse Gas Flux and Influencing Factors at the Water-Air Interface of Major Rivers in Shanghai”.

[0115] The measurement of greenhouse gas flux values ​​can be achieved by those skilled in the art using conventional technical means in the art, and specifically, the measurement method described in the article “The primary drivers of greenhouse gas emissions along the watertable gradient in the Zoige Alpine peatland” can be used.

[0116] EWC The dimension is Tg Ce yr -1 , F i or F (i+1) The unit of the average flux change of greenhouse gases is mg Cem -2 h -1 , A i The dimension is m 2 .

[0117] Changes in greenhouse gases from reclamation ER It is calculated by the following formula (6):

[0118] (6)

[0119] In formula (6), CBB 围 is the amount of carbon loss from vegetation; SOC 30围 is the amount of soil organic carbon loss within 30 cm depth; CW 围 is the amount of carbon loss in water bodies; EAC is the greenhouse gas budget of the farmland after reclamation; EWC is the greenhouse gas budget of the wetland before reclamation;

[0120] The carbon loss amount has the conventional technical meaning commonly understood by those skilled in the art, and may be the carbon loss amount recorded in the article “Response of greenhouse gas exchange in Yancheng coastal wetlands to simulated warming and its significance”.

[0121] The measurement of carbon loss can be achieved by those skilled in the art using conventional technical means in the art. For example, the carbon loss of vegetation can be measured using the measurement method described in the article “Study on Methane and Carbon Dioxide Emissions from the Three Gorges Reservoir and Their Influencing Factors”, and the carbon loss of water bodies can be measured using the measurement method described in the article “Study on Methane and Carbon Dioxide Emissions from the Three Gorges Reservoir and Their Influencing Factors”.

[0122] The greenhouse gas balance has the conventional technical meaning commonly understood by those skilled in the art, and may be the greenhouse gas balance recorded in the article “Study on Methane and Carbon Dioxide Emissions from the Three Gorges Reservoir and Their Influencing Factors”.

[0123] The measurement of greenhouse gas balance can be achieved by those skilled in the art using conventional technical means in the art. For example, the greenhouse gas balance of farmland after reclamation can be measured by the measurement method described in the article “Carbon footprint of main crop production in China: magnitude, spatial-temporal pattern and attribution”, and the greenhouse gas balance of wetlands before reclamation can be measured by the measurement method described in the article “Research on methane and carbon dioxide emissions from the Three Gorges Reservoir and their influencing factors” or “The primary drivers of greenhouse gas emissions along the water table gradient in the Zoige Alpine peatland”.

[0124] ER , CBB 围 , SOC 30围 , CW 围 , EAC , EWC The dimension of Tg Ce yr -1 .

[0125] Changes in greenhouse gases from development and construction ECD It is calculated by the following formula (7):

[0126] (7)

[0127] In formula (7), CBB 开 is the amount of carbon loss from vegetation; SOC 30开 is the amount of soil organic carbon loss within 30 cm depth; CW 开 is the amount of carbon loss in water bodies; ECC Greenhouse gas emissions from construction land after development and construction; EWC is the greenhouse gas budget of the wetland before reclamation;

[0128] The amount of organic carbon loss has a conventional technical meaning that can be generally understood by those skilled in the art, and may be the “amount of organic carbon loss” recorded in the article “Research on Carbon Emission Effects of Land Use in China”.

[0129] The measurement of organic carbon loss can be achieved by those skilled in the art using conventional technical means in the art. For example, the soil organic carbon loss within a depth of 30 cm can be measured using the measurement method described in the article “Study on Dynamic Changes of Soil Organic Carbon Reserves and Reservoir Sediment Carbon Sediment Characteristics in the Sanjiang Plain from 1980 to 2010”.

[0130] The measurement of greenhouse gas emissions can be achieved by those skilled in the art using conventional technical means in the art. For example, the greenhouse gas emissions of construction land after development and construction can be measured using the measurement method described in the article "Research on Carbon Emission Effects of Land Use in China".

[0131] ECD , CBB 开 , SOC 30开 , CW 开 , ECC , EWC The dimension of Tg Ce yr -1 .

[0132] Carbon sequestration from returning farmland to lakes CSRL It is calculated by the following formula (8):

[0133] (8)

[0134] In formula (8), CBB 退 is the amount of carbon loss from vegetation; SOC 30退 is the amount of soil organic carbon loss within 30 cm depth; CW 退 is the amount of carbon loss in water bodies; EAC is the greenhouse gas budget of the farmland after reclamation; EWC is the greenhouse gas budget of the wetland before reclamation;

[0135] CSRL , CBB 退 , SOC 30退 , CW 退 , EAC , EWC The dimension of Tg Ce yr -1 ;

[0136] Carbon loss from vegetation CBB It is calculated by the following formula (9):

[0137] (9)

[0138] In formula (9), BCD After,k Land use type after conversion k vegetation carbon density; BCD Before,k Land use type before conversion k The vegetation carbon density; Area k Land use type k The conversion area, n is the time interval between two data periods;

[0139] The conversion means that the original wetland of the target wetland is converted into cultivated land or construction land, or cultivated land or construction land is converted into new wetland;

[0140] Vegetation carbon density is a conventional technical term well known to those skilled in the art, and has the meaning of vegetation carbon density as recorded in the article “Study on Methane and Carbon Dioxide Emissions and Their Influencing Factors from the Three Gorges Reservoir”.

[0141] The determination of vegetation carbon density can be achieved by those skilled in the art using conventional techniques in the art, for example, the land use type after conversionk The vegetation carbon density can be measured using the measurement method described in the article “Study on methane and carbon dioxide emissions from the Three Gorges Reservoir and their influencing factors and Carbon footprint of main crop production in China: magnitude, spatial-temporal pattern and attribution”; BCD After,k , BCD Before,k The dimensions are Mg Ce ha -1 .

[0142] Land use type before conversion k The vegetation carbon density can be measured using the measurement method described in the article “Study on methane and carbon dioxide emissions from the Three Gorges Reservoir and their influencing factors and Carbon footprint of main crop production in China: magnitude, spatial-temporal pattern and attribution”;

[0143] The interval time n between two periods of data refers to the interval time from before to after the transformation, and the unit is year.

[0144] △ Area k The dimension is ha, CBB The dimension is Tg Ce yr -1 .

[0145] Soil organic carbon loss within 30 cm depth SOC 30 It is calculated by the following formula (10):

[0146] (10)

[0147] In formula (10), SOC k Land use type within 0~30cm depth k Soil carbon density or sediment carbon density at a depth of 0-10 cm; IF k Land use type k The influencing factors of soil organic carbon conversion; Area k Land use type k The conversion area, n is the time interval between two data periods;

[0148] Soil carbon density and sediment carbon density both have conventional technical meanings commonly understood by those skilled in the art, and may be the soil carbon density and sediment carbon density recorded in the article “Study on Dynamic Changes of Soil Organic Carbon Reserves and Reservoir Sediment Carbon Sediment Characteristics in Sanjiang Plain from 1980 to 2010”.

[0149] The measurement of soil carbon density and sediment carbon density is a conventional technical means well known to those skilled in the art. For example, the land use type within a depth of 0 to 30 cm k The soil carbon density can be measured using the measurement method described in the article “Dynamic Changes of Soil Organic Carbon Storage in Sanjiang Plain from 1980 to 2010”; the sediment carbon density in waters with a depth of 0 to 10 cm can be measured using the measurement method described in the article “Study on Sediment Characteristics of Reservoir Sediment”; SOC k The dimensions of soil carbon density and sediment carbon density are Mg Ce ha -1 .

[0150] Land use type k The organic carbon impact factor of the converted soil has the conventional technical meaning commonly understood by those skilled in the art, and may be the organic carbon impact factor recorded in the article “Good practice guidance for land use, land use change and forestry and soil carbon and nitrogen storage and land use change in China from 1990 to 2000”; the organic carbon impact factor of the converted soil itself is expressed in numerical values ​​and may be directly substituted into formula (10) for calculation.

[0151] Land use type k The determination of the organic carbon conversion factor of the converted soil is a conventional technical means well known to those skilled in the art. For example, the measurement method described in the article "Good practice guidance for land use, land use change and forestry" can be used for measurement;

[0152] Land use type k The conversion area has a common technical meaning that can be conventionally understood by those skilled in the art. Its measurement is a conventional technical operation well known to those skilled in the art. It can be measured using the measurement method described in the article "Changes in the Soil Conservation Function of Ecosystems in China and Its Influencing Factors". Area k The dimension of is ha. The dimension of the interval between two periods of data is year (yr).

[0153] Carbon loss from water bodies CW It is calculated by the following formula (11):

[0154] (11)

[0155] In formula (11), CWD is the dissolved organic carbon density in water (Mg Ce ha -1 );△ Area k Land use type k Conversion area (ha), n is the time interval between two periods of data (yr).

[0156] The organic carbon density has the conventional technical meaning generally understood by those skilled in the art, and may be the organic carbon density recorded in the article “Study on Methane and Carbon Dioxide Emissions and Their Influencing Factors from the Three Gorges Reservoir”. CWD The dimension is Mg Ce ha -1 △ Area k The dimension of is ha. The dimension of the interval between two periods of data is year (yr).

[0157] In a specific embodiment, the greenhouse gas is selected from: CO2, CH4, N2O;

[0158] In some embodiments, the land use type k Selected from: water area, cultivated land, construction land; the land use type k For construction land BCD After,k is 0.

[0159] In other embodiments, land use type k The conversion area Area k It can be obtained using the transfer matrix of ArcGIS 10.2 software.

[0160] The transfer matrix has a common technical meaning that can be conventionally understood by those skilled in the art. Its measurement is a conventional technical operation well known to those skilled in the art, and can be calculated using the measurement method described in the article “Analysis of Spatiotemporal Evolution of Wetland Landscape in the Yellow River Basin”.

[0161] In a preferred embodiment, the carbon fixation amount in formula (3) and formula (4) is measured by a carbon fixation amount determination method; in some embodiments, the carbon fixation amount determination method is a carbon fixation amount determination method described in the article "Study on methane and carbon dioxide emissions and their influencing factors in the Three Gorges Reservoir";

[0162] Preferably, the greenhouse gas emissions described in formula (3) and formula (7) are measured by a greenhouse gas emissions determination method; in some embodiments, the greenhouse gas emissions determination method is the greenhouse gas emissions determination method described in the article “Research on methane and carbon dioxide emissions and their influencing factors in the Three Gorges Reservoir”;

[0163] Preferably, the greenhouse gas change is measured by a greenhouse gas change measurement method;

[0164] In some embodiments, the method for determining the change in greenhouse gases is the method for determining the change in greenhouse gases described in the article “The Impact of Agricultural Reclamation on Greenhouse Gas Emissions from Wetlands Surrounding Farmland in the Sanjiang Plain”; although the change in greenhouse gases can be measured, the determination method in the prior art can only measure the change in greenhouse gases under certain fixed conditions, while the calculation of the change in greenhouse gases in formulas (3), (6), and (7) of the present invention reflects a change process, which cannot be directly measured and needs to be obtained through calculation.

[0165] Preferably, the CO2 fixation flux value of formula (4) is measured by a CO2 fixation flux value determination method; in some embodiments, the CO2 fixation flux value determination method is the CO2 fixation flux value determination method described in the article "Study on methane and carbon dioxide emissions and their influencing factors in the Three Gorges Reservoir";

[0166] Preferably, the areas in formula (4), formula (5) and formula (9) are measured by an area measurement method; in some embodiments, the area measurement method is the area measurement method described in the article “Study on methane and carbon dioxide emissions from the Three Gorges Reservoir and their influencing factors”;

[0167] Preferably, the greenhouse gas flux value of formula (5) is measured by a greenhouse gas flux value determination method; in some embodiments, the greenhouse gas flux value determination method is the greenhouse gas flux value determination method described in the article “The primary drivers of greenhouse gas emissions along the water table gradient in the Zoige Alpine peatland”;

[0168] Preferably, the greenhouse gas balance in formula (6), formula (7) and formula (8) is measured by a greenhouse gas balance determination method; in some embodiments, the greenhouse gas balance determination method is the greenhouse gas balance determination method described in the article “Research on methane and carbon dioxide emissions and their influencing factors in the Three Gorges Reservoir”;

[0169] Preferably, the carbon loss amount in formula (6), formula (7) and formula (8) is measured by a carbon loss amount determination method; in some embodiments, the carbon loss amount determination method is the carbon loss amount determination method described in the article “Response of greenhouse gas exchange in Yancheng coastal wetlands to simulated warming and its significance”;

[0170] Preferably, the organic carbon loss in formula (6), formula (7) and formula (8) is measured by an organic carbon loss determination method; in some embodiments, the organic carbon loss determination method is the organic carbon loss determination method described in the article “Research on Carbon Emission Effect of Land Use in China”;

[0171] Preferably, the vegetation carbon density of formula (9) is measured by a vegetation carbon density determination method; in some embodiments, the vegetation carbon density determination method is a vegetation carbon density determination method described in the article “Study on methane and carbon dioxide emissions from the Three Gorges Reservoir and their influencing factors” or “Carbon footprint of main crop production in China: magnitude, spatial-temporal pattern and attribution”;

[0172] Preferably, the soil carbon density of formula (10) is measured by a soil carbon density determination method; in some embodiments, the soil carbon density determination method is the soil carbon density determination method described in the article “Dynamic Changes of Soil Organic Carbon Storage in Sanjiang Plain from 1980 to 2010”;

[0173] Preferably, the sediment carbon density of formula (10) is measured by a sediment carbon density determination method; in some embodiments, the sediment carbon density determination method is a sediment carbon density determination method described in the article “Study on Sedimentation Characteristics of Reservoir Sediments”;

[0174] Preferably, the organic carbon impact factor of the transformed soil in formula (10) is measured by a method for determining the organic carbon impact factor of the transformed soil; in some embodiments, the method for determining the sediment carbon density is the method for determining the organic carbon impact factor carbon density of the transformed soil described in the article “Good practice guidance for land use, land use change and forestry”.

[0175] Second group of embodiments, computer readable storage medium of the present invention

[0176] This group of embodiments provides a computer-readable storage medium. All embodiments in this group have the following common features: a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, a method for calculating a wetland net greenhouse gas balance NGB as described in any one of the first group of embodiments is implemented.

[0177] The third group of embodiments, NGB computing system of the present invention

[0178] This group of embodiments provides a system for calculating the net greenhouse gas balance NGB of wetlands. All embodiments in this group have the following common features: the system includes: a calculation unit; the calculation unit includes: the computer-readable storage medium described in any one of the second group of embodiments.

[0179] In a further embodiment, the system for calculating the net greenhouse gas balance NGB of a wetland further comprises: a carbon fixation measurement unit; the carbon fixation measurement unit comprises a computer-readable storage medium on which a computer program is stored; when the computer program is executed by a processor, a carbon fixation measurement method is implemented; in some embodiments, the carbon fixation measurement method is a carbon fixation measurement method described in the article "Research on methane and carbon dioxide emissions and their influencing factors in the Three Gorges Reservoir";

[0180] Preferably, the system further comprises: a greenhouse gas emission measurement unit; the greenhouse gas emission measurement unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements a greenhouse gas emission measurement method when executed by a processor; in some embodiments, the greenhouse gas emission measurement method is a greenhouse gas emission measurement method described in the article "Study on methane and carbon dioxide emissions and their influencing factors in the Three Gorges Reservoir";

[0181] Preferably, the system further comprises: a greenhouse gas change measurement unit; the greenhouse gas change measurement unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements a greenhouse gas change measurement method when executed by a processor; in some embodiments, the greenhouse gas change measurement method is a greenhouse gas change measurement method described in the article “The Impact of Agricultural Reclamation on Greenhouse Gas Emissions from Wetlands Surrounding Farmland in Sanjiang Plain”;

[0182] Preferably, the system further comprises: a CO2 fixation flux value measuring unit; the CO2 fixation flux value measuring unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements a CO2 fixation flux value determination method when executed by a processor; in some embodiments, the CO2 fixation flux value determination method is a CO2 fixation flux value determination method described in the article "Study on Methane and Carbon Dioxide Emissions and Their Influencing Factors in the Three Gorges Reservoir";

[0183] Preferably, the system further comprises: an area measurement unit; the area measurement unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements an area measurement method when executed by a processor; in some embodiments, the area measurement method is the area measurement method described in the article "Study on methane and carbon dioxide emissions and their influencing factors in the Three Gorges Reservoir";

[0184] Preferably, the system further comprises: a greenhouse gas flux value measuring unit; the greenhouse gas flux value measuring unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements a greenhouse gas flux value determination method when executed by a processor; in some embodiments, the greenhouse gas flux value determination method is a greenhouse gas flux value determination method recorded in the article "The primary drivers of greenhouse gas emissions along the water table gradient in the Zoige Alpine peatland";

[0185] Preferably, the system further comprises: a greenhouse gas balance measurement unit; the greenhouse gas balance measurement unit comprises a computer-readable storage medium on which a computer program is stored; the computer program, when executed by the processor, implements a greenhouse gas balance determination method; in some embodiments, the greenhouse gas balance determination method is a greenhouse gas balance determination method described in the article "Study on methane and carbon dioxide emissions and their influencing factors in the Three Gorges Reservoir";

[0186] Preferably, the system further comprises: a carbon loss measurement unit; the carbon loss measurement unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements a carbon loss measurement method when executed by a processor; in some embodiments, the carbon loss measurement method is the carbon loss measurement method described in the article “Response of greenhouse gas exchange in Yancheng coastal wetlands to simulated warming and its significance”;

[0187] Preferably, the system further comprises: an organic carbon loss measurement unit; the organic carbon loss measurement unit comprises a computer-readable storage medium on which a computer program is stored; when the computer program is executed by the processor, an organic carbon loss measurement method is implemented; in some embodiments, the organic carbon loss measurement method is the organic carbon loss measurement method described in the article "Research on Carbon Emission Effect of Land Use in China";

[0188] Preferably, the system further comprises: a vegetation carbon density measurement unit; the vegetation carbon density measurement unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements a vegetation carbon density measurement method when executed by a processor; in some embodiments, the vegetation carbon density measurement method is a vegetation carbon density measurement method described in the article “Study on methane and carbon dioxide emissions from the Three Gorges Reservoir and their influencing factors” or “Carbon footprint of main crop production in China: magnitude, spatial-temporal pattern and attribution”;

[0189] Preferably, the system further comprises: a soil carbon density measuring unit; the soil carbon density measuring unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements a soil carbon density determination method when executed by a processor; in some embodiments, the soil carbon density determination method is a soil carbon density determination method recorded in the article “Dynamic Changes of Soil Organic Carbon Storage in Sanjiang Plain from 1980 to 2010”;

[0190] Preferably, the system further comprises: a sediment carbon density measuring unit; the sediment carbon density measuring unit comprises a computer-readable storage medium on which a computer program is stored; when the computer program is executed by the processor, a sediment carbon density measuring method is implemented; in some embodiments, the sediment carbon density measuring method is a sediment carbon density measuring method described in the article "Study on Carbon Deposition Characteristics of Reservoir Sediment";

[0191] Preferably, the system further comprises: a unit for measuring an organic carbon impact factor of the transformed soil; the unit for measuring an organic carbon impact factor of the transformed soil comprises a computer-readable storage medium on which a computer program is stored; when the computer program is executed by a processor, a method for determining an organic carbon impact factor of the transformed soil is implemented; in some embodiments, the method for determining the carbon density of the sediment is a method for determining the carbon density of the organic carbon impact factor of the transformed soil recorded in the article “Good practice guidance for land use, land use change and forestry”.

[0192] The carbon fixation measurement unit, greenhouse gas emission measurement unit, greenhouse gas change measurement unit, CO2 fixation flux value measurement unit, area measurement unit, greenhouse gas flux value measurement unit, greenhouse gas balance measurement unit, carbon loss measurement unit, organic carbon loss measurement unit, vegetation carbon density measurement unit, soil carbon density measurement unit, sediment carbon density measurement unit, and soil organic carbon impact factor measurement unit are respectively connected to the calculation unit via a data path.

[0193] Example: Application of the NGB calculation method of the present invention in Hengshui Lake Wetland and Sanjiang Plain Wetland

[0194] The present invention provides a wetland greenhouse gas balance and net emission reduction accounting method for application in Hengshui Lake Wetland and Sanjiang Plain Wetland, including:

[0195] 1. Wetland greenhouse gas balance and net emission reduction accounting

[0196] The research boundary is 1 km outside the research wetland, and the greenhouse gas balance and net emission reduction within the research boundary are calculated to determine the impact of wetland management measures on greenhouse gas balance and net source / sink. The wetland vegetation-water-soil system is used as the system research unit, and carbon fixation and greenhouse gas emissions (CO2, CH4 and N2O) are used as the guidance. Typical human management measures such as wetland ecological water replenishment, reclamation, urban development and construction, and returning farmland to lakes are selected for research. The changes in greenhouse gases within the research boundary before and after the implementation of various management measures are comprehensively compared, and a method for wetland greenhouse gas measurement and net emission reduction accounting is constructed ( Figure 1 , Equation 1). This method includes carbon input and greenhouse gas output ( Figure 2 ). The net greenhouse gas balance is equal to the greenhouse gas change due to the management measure minus the carbon sequestration:

[0197] (1)

[0198] In the formula, NGB is the net greenhouse gas balance (Tg Ce yr -1 ); WDCB Changes in greenhouse gases for ecological water replenishment ( WDCB , Tg Ce yr -1 ); ER is the greenhouse gas change in reclamation (Tg Ce yr -1 ); ECD To develop and construct greenhouse gas change (Tg Ce yr -1 ); CSRL is the carbon sequestration amount from returning farmland to lake (Tg Ce yr -1 ).

[0199] (Note: Wetland vegetation fixes carbon through photosynthesis, while vegetation and soil respiration release greenhouse gases. Ecological water replenishment increases carbon fixation by transferring water and carrying sediment. At the same time, water level changes before and after ecological water replenishment lead to different greenhouse gas emissions. In addition, reclamation, development and construction, etc. lead to reduced wetland area and increased carbon emissions, while returning farmland to lakes increases carbon fixation by expanding wetland area. At the same time, greenhouse gas emissions within the study boundary before and after the implementation of reclamation, development and construction, and returning farmland to lakes management measures are also different: there are CO2, CH4 and N2O emissions in wetlands before reclamation and development and construction, and the use of fossil fuels (and related products) in farming management after reclamation releases CO2 and N2O; the consumption of fossil fuels in construction land after development and construction also releases CO2; returning farmland to lakes is the opposite of reclamation.)

[0200] The relative contribution of greenhouse gas changes or carbon fixation of various management measures to net greenhouse gas sources / sinks is estimated using Formula 2, and the main driving factors affecting net sources / sinks are analyzed to clarify the key regulatory pathways for mitigating greenhouse gas emissions.

[0201] (2)

[0202] In the formula, RC is the relative contribution rate (%); GHGB is the carbon fixation or greenhouse gas change (Tg Ce yr -1 ), that is, WDCB , ER, ECD and CSRL ; NGB Same as formula 1.

[0203] 2. Response of wetland greenhouse gas budget to ecological water replenishment

[0204] The greenhouse gas budget model of ecological water replenishment (Formula 3) was constructed to estimate the change in wetland greenhouse gas before and after ecological water replenishment ( WDCB , Tg Ce yr -1 ):

[0205] (3)

[0206] In the formula, CSB is the change in vegetation carbon fixation before and after water replenishment (Tg Ce yr -1 ); CSW The amount of carbon fixation increased by the water body (Tg Ce yr -1 ); CCS The amount of carbon sequestration increased by carrying sediment (Tg Ce yr -1 ); EWC 1 is the change in greenhouse gas emissions from the vegetation-water-soil system before and after water replenishment (Tg Ce yr-1 ).

[0207] According to the actual situation of the wetland under study and the needs of the experiment, the CO2, CH4 and N2O measurement points were arranged in a uniform manner. The static box method was used to connect the greenhouse gas analyzer (UGGA30p, LGR, USA) to measure the ecosystem gas exchange before and after ecological water replenishment (including vegetation CO2 fixation, ecosystem CO2, CH4 and N2O emission fluxes), and the change values ​​of vegetation carbon fixation before and after water replenishment were calculated using formulas 4 and 5 respectively ( CSB , Tg Ce yr -1 ) and changes in greenhouse gas emissions before and after water replenishment ( EWC ,TgCe -1 ):

[0208] (4)

[0209] In the formula, F i For the i Changes in vegetation CO2 fixation flux before and after water replenishment at the measuring point (mg Ce m -2 h -1 ); A i is the area between two adjacent points (m 2 ).

[0210] Taking Hengshui Lake Wetland as an example, the CSB The calculations are shown in Table 1 below:

[0211] Table 1

[0212]

[0213] (5)

[0214] In the formula, F ij For the i The measurement point before and after water replenishment j Greenhouse gases ( j The average flux change of CO2, CH4 and N2O (mg Ce m -2 h -1 ); A i is the area between two adjacent points (m 2 ).

[0215] At the same time, the sedimentation method was used to collect the amount of sediment carried by the unit water body, and its organic carbon content was measured to calculate the total organic carbon input carried by the supplementary sediment ( CCS , Tg Ce yr-1 ). The measured water body organic carbon density is used to calculate the total water body organic carbon input introduced by water replenishment ( CSW , Tg Ce yr -1 ).

[0216] Taking Hengshui Lake Wetland as an example, the EWC 1 The calculation is shown in Table 2 below:

[0217] Table 2

[0218]

[0219] The increased water volume in the Hengshui Lake wetland carries an increased amount of carbon sequestration in the sediment CCS The measured value is 0.51×10 -3 TgC -1 . Increased carbon fixation by water transfer CSW The measured value is 0.11×10 -2 TgCe -1 .

[0220] Therefore, the calculated WDCB value of Hengshui Lake wetland is -1.59×10 -3 The WDCB value of the Sanjiang Plain Wetland calculated by the same method is -4.92×10 -2 .

[0221] III. Response of greenhouse gas budget to reclamation, development and construction, and returning farmland to lakes

[0222] TM remote sensing images with a resolution of 30 m × 30 m in 2000, 2010 and 2020 within the study boundary were selected to extract three typical land use types: water area, cultivated land and construction land. The land use changes caused by reclamation, development and construction, and returning lakes to farmland were determined. The conversion between different land use types may lead to carbon emissions or carbon fixation (Table 6). At the same time, the greenhouse gas balance within the study boundary before and after the implementation of reclamation, development and construction, and returning lakes to farmland management measures was also different. The greenhouse gas change of each management measure is equal to the sum of the carbon change during the implementation of the measure and the greenhouse gas balance change before and after the implementation of the measure. The transfer matrix in ArcGIS was used to calculate the area change caused by the three phases of wetland conversion in 2000, 2010 and 2020. Combining the organic carbon density of vegetation, water bodies and soil (or sediment) and the greenhouse gas balance in the two scenarios before and after the conversion, the following formulas were used to calculate the reclamation ( ER , Tg Ce yr -1 )、Development and Construction( ECD , Tg Ce yr -1 ) and returning lakes to farmland ( CSRL, Tg Ce yr -1 ) caused by the change in greenhouse gases in the vegetation-water-soil system:

[0223] (6)

[0224] In the formula, CBB 围 is the carbon loss from vegetation (Tg Ce yr -1 ); SOC 30围 is the soil organic carbon loss within 30 cm depth (Tg Ce yr -1 ); CW 围 is the carbon loss in water (Tg Ce yr -1 ); EAC is the greenhouse gas budget of farmland after reclamation (TgCe yr -1 ); EWC is the greenhouse gas budget of wetlands before reclamation (Tg Ce yr -1 ).

[0225] Taking Hengshui Lake Wetland as an example, Hengshui Lake Wetland has been reclaimed and its EAC value is 2.84×10 -6 Tg -1 ; EWC value is 0.01 Tg Ce yr -1 .

[0226] Taking the Sanjiang Plain Wetland as an example, the Sanjiang Plain Wetland has been reclaimed and its EAC value is 29.73 Tg Ceyr -1 ; EWC value is 10.49 Tg Ce yr -1 .

[0227] (7)

[0228] In formula (7), CBB 开 is the amount of carbon loss from vegetation; SOC 30开 is the amount of soil organic carbon loss within 30 cm depth; CW 开 is the amount of carbon loss in water bodies; ECC Greenhouse gas emissions from construction land after development and construction (Tg Ce yr -1 ).

[0229] Taking Hengshui Lake Wetland as an example, Hengshui Lake Wetland has been developed and constructed, and its ECC value is 0 Tg Ce yr -1 ;

[0230] Taking the Sanjiang Plain Wetland as an example, the Sanjiang Plain Wetland has been developed and constructed, and its ECC value is 0 Tg Ceyr -1 ;

[0231] (8)

[0232] In formula (8), EWC is the greenhouse gas budget of wetlands after returning farmland to lake (Tg Ce yr -1 ); EAC is the greenhouse gas budget of farmland before returning farmland to lake (Tg Ce yr -1 ); CBB 退 is the amount of carbon loss from vegetation; SOC 30退 is the amount of soil organic carbon loss within 30 cm depth; CW 退 is the amount of carbon loss in water bodies; EAC is the greenhouse gas budget of the farmland after reclamation; EWC is the greenhouse gas budget of the wetland before reclamation.

[0233] Taking Hengshui Lake Wetland as an example, Hengshui Lake Wetland has carried out the operation of returning farmland to lake. EWC Value is 0.01 Tg Ce yr -1 , the EAC value is 2.84×10 -6 TgCe -1 .

[0234] Taking the Sanjiang Plain Wetland as an example, the Sanjiang Plain Wetland has carried out the operation of returning farmland to lake. EWC The value is 10.49 TgCe yr -1 , EAC value is 29.73 Tg Ce yr -1 .

[0235] CBB , SOC 30 and CW are the carbon increase of vegetation, soil and water (Tg Ce yr -1 ).

[0236] CBB , SOC 30 and CW The calculation formulas are shown in Formulas 9-11 respectively.

[0237] (9)

[0238] In the formula, BCD After,k Land use type after conversion kVegetation carbon density (Mg Ce ha -1 ) (the carbon density of vegetation in construction land is 0); BCD Before,k Land use type before conversion k Vegetation carbon density (Mg Ce ha -1 ). Area k For the k The conversion area of ​​each land use type (ha) can be obtained using the transfer matrix of ArcGIS 10.2 software. n is the time interval between two periods of data (yr).

[0239] Taking Hengshui Lake Wetland as an example, the land use types SOC k , IF k As shown in Table 3 below:

[0240] Table 3

[0241]

[0242] Taking the Sanjiang Plain wetland as an example, the SOC k , IF k As shown in Table 4 below:

[0243] Table 4

[0244]

[0245] (10)

[0246] In the formula, SOC k The depth is 0~30 cm. k Soil carbon density (Mg Ce ha) of different land use types -1 ), for water bodies, it is the carbon density of the bottom mud at a depth of 0 to 10 cm; IF k For the k Factors affecting soil organic carbon in land use transformation; Area k and n Same as formula 9.

[0247] Taking Hengshui Lake Wetland as an example, the land use types SOC k , IF k As shown in Table 5 below:

[0248] Table 5

[0249]

[0250] Taking the Sanjiang Plain wetland as an example, the SOC k , IF k As shown in Table 6 below:

[0251] Table 6

[0252]

[0253] (11)

[0254] In the formula, CWD is the dissolved organic carbon density in water (Mg Ce ha -1 );△ Area k and n Same as formula 9.

[0255] Taking Hengshui Lake Wetland as an example, the land use types CWD As shown in Table 7 below:

[0256] Table 7

[0257]

[0258] Taking the Sanjiang Plain wetland as an example, the CWD As shown in Table 8 below:

[0259] Table 8

[0260]

[0261] According to the values ​​of the intermediate parameters calculated above, the ER of Hengshui Lake Wetland can be calculated to be -1.30×10 -2 TgC -1 , ECD = -1.30 × 10 -2 TgCe -1 , CSLR=1.26×10 -2 TgCe -1 ; Combined with the WDCB of Hengshui Lake Wetland calculated above, the NGB of Hengshui Lake Wetland is -4.02×10 -2 TgCe -1 .

[0262] According to the values ​​of the intermediate parameters calculated above, the ER of the Sanjiang Plain wetland can be calculated to be 19.47 Tg Ceyr -1,ECD=-10.49 Tg Ce yr -1 ,CSLR=-19.32 Tg Ce yr -1 Combined with the WDCB of the Sanjiang Plain Wetland calculated above, the NGB of the Sanjiang Plain Wetland is 28.25 Tg Ce yr -1 .

[0263] Based on the existing technology, the literature such as "Effect of water table level on CO2, CH4 and N2O emissions in a freshwater marsh of Northeast China", "Effect of returning farmland to wetlands on soil organic carbon accumulation in Qixing River wetland in Sanjiang Plain", and "Effect of agricultural reclamation on greenhouse gas emissions from wetlands around farmland in Sanjiang Plain" respectively considers the greenhouse gas balance caused by water level changes, the greenhouse gas balance caused by returning farmland to wetlands measures, and the changes in greenhouse gas balance caused by agricultural reclamation. The greenhouse gas balance of the Sanjiang Plain wetland calculated from the data recorded in these three papers is 32.32 Tg Ce yr -1 .

[0264] Based on the existing technology "Study on the distribution characteristics of soil organic carbon composition under different vegetation around Hengshui Lake", considering the soil carbon density of different land use modes, combined with the conversion of farmland to wetland, agricultural reclamation area and wetland greenhouse gas balance, the calculated greenhouse gas balance of Hengshui Lake wetland is -4.21×10 -2 TgCe -1 .

[0265] The NGB of the Sanjiang Plain wetland calculated by the NGB calculation method of the present invention is 28.25 Tg Ce yr -1 , the NGB of Hengshui Lake Wetland is -4.02×10 -2 TgCe -1 .

[0266] The results of the difference significance analysis of the two groups of greenhouse gas balance data calculated by the prior art and the NGB data calculated by the calculation method of the present invention are not statistically significant, that is, the difference between the two groups of data is not significant. Compared with the calculation method of the prior art, the calculation method of the present invention is more accurate.

[0267] Carbon density data of vegetation, soil and water bodies were obtained by combining field sampling and indoor analysis. Sample plots were set up on the three typical land use types studied to collect vegetation, water and soil samples (water area and some coastal soil samples have been collected). The vegetation sample collection was designed to be a 1 m × 1 m sample plot, and the vegetation biomass was taken and brought back to the laboratory for drying to determine the organic carbon content of the plants. Soil samples were collected from 0 to 30 cm soil layer, 1 kg, and brought back to the laboratory to determine the soil organic carbon content and soil bulk density; water samples were collected from 0.5 m below the water surface by a sampler, and 1 kg of sediment was collected from 0 to 10 cm deep by a grab bucket sampler, and brought back to the laboratory to determine the total organic carbon content of the water body and the organic carbon content of the sediment. The organic carbon content was determined by the potassium dichromate volumetric method. In addition, a pixel-based unit grid was used to cover the spatial analysis of the study area, and the carbon density of each sampling point was interpolated to the unit grid using the spatial interpolation method. The inventors have estimated the greenhouse gas balance of farmland in previous studies (Liu et al., 2018). The greenhouse gas balance of wetlands has been calculated in the ecological water replenishment section. The greenhouse gas emissions of construction land are estimated using the greenhouse gas emission coefficient of construction land.

[0268] Table 6. Carbon budget of different land use conversions

[0269] .

Claims

1. A method for calculating the net greenhouse gas budget NGB of a wetland, characterized in that: The net greenhouse gas balance NGB of wetlands is calculated according to formula (1); （1） In formula (1), NGB is the net greenhouse gas budget; WDCB Changes in greenhouse gases for ecological water replenishment; ER The change in greenhouse gases for reclamation; ECD Changes in greenhouse gases for development and construction; CSRL To restore farmland to lakes and sequester carbon; The change of greenhouse gas in ecological water replenishment WDCB Calculate according to formula (3): Said (3) In formula (3), CSB is the change in carbon fixation of vegetation before and after water replenishment, CSW The amount of carbon sequestration increased by the water body; CCS To carry more carbon into the sediment, EWC 1 is the change in greenhouse gas emissions of the vegetation-water-soil system before and after water replenishment; Changes in carbon sequestration in vegetation before and after water replenishment CSB According to formula (4), we can calculate: （4） In formula (4), F i For the i Changes in vegetation CO2 fixation flux before and after water replenishment at the measurement point; A i is the area between two adjacent points; F (i+1) It is i+ 1. Changes in vegetation CO2 fixation flux before and after water replenishment at the measuring point; Changes in greenhouse gas emissions from vegetation-water-soil systems before and after water replenishment EWC 1 The relationship is as follows: （5） In formula (5), F ij For the i The measurement point before and after water replenishment j The average flux change of greenhouse gases; F （i+1）j For the i + 1 The measurement point before and after water replenishment j The average flux change of greenhouse gases; A i is the area between two adjacent points; Changes in greenhouse gases from reclamation ER It is calculated by the following formula (6): (6) In formula (6), CBB 围 is the amount of carbon loss from vegetation; SOC 30围 is the amount of soil organic carbon loss within 30 cm depth; CW 围 is the amount of carbon loss in water bodies; EAC is the greenhouse gas budget of the farmland after reclamation; EWC is the greenhouse gas budget of the wetland before reclamation; Changes in greenhouse gases from development and construction ECD It is calculated by the following formula (7): (7) In formula (7), CBB 开 is the amount of carbon loss from vegetation; SOC 30开 is the amount of soil organic carbon loss within 30 cm depth; CW 开 is the amount of carbon loss in water bodies; ECC Greenhouse gas emissions from construction land after development and construction; EWC is the greenhouse gas budget of the wetland before reclamation; Carbon sequestration from returning farmland to lakes CSRL It is calculated by the following formula (8): (8) In formula (8), CBB 退 is the amount of carbon loss from vegetation; SOC 30退 is the amount of soil organic carbon loss within 30 cm depth; CW 退 is the amount of carbon loss in water bodies; EAC is the greenhouse gas budget of the farmland after reclamation; EWC is the greenhouse gas budget of the wetland before reclamation; Carbon loss from vegetation CBB It is calculated by the following formula (9): (9) In formula (9), BCD After,k Land use type after conversion k vegetation carbon density; BCD Before,k Land use type before conversion k The vegetation carbon density; Area k Land use type k The conversion area, n is the interval between two data periods; Soil organic carbon loss within 30 cm depth SOC 30 It is calculated by the following formula (10): (10) In formula (10), SOC k Land use type within 0~30cm depth k Soil carbon density or sediment carbon density at a depth of 0-10 cm; IF k Land use type k The influencing factors of soil organic carbon conversion; Area k Land use type k The conversion area, n is the interval between two data periods; Carbon loss from water bodies CW It is calculated by the following formula (11): (11) In formula (11), CWD is the density of dissolved organic carbon in water; Area k Land use type k The conversion area, n is the time interval between two data periods.

2. The method for calculating the net greenhouse gas budget NGB of a wetland according to claim 1, characterized in that: The greenhouse gas is selected from: CO2, CH4, N2O.

3. The method for calculating the net greenhouse gas budget NGB of a wetland according to claim 1, characterized in that: The land use type k Selected from: water area, cultivated land, construction land; the land use type k For construction land BCD After,k is 0.

4. The method for calculating the net greenhouse gas budget NGB of a wetland according to claim 1, characterized in that: Land use type k The conversion area Area k It can be obtained using the transfer matrix of ArcGIS 10.2 software.

5. The method for calculating the net greenhouse gas budget NGB of a wetland according to claim 1, characterized in that: The carbon fixation change values ​​in formula (3) and formula (4) are measured by the carbon fixation determination method; and / or, the greenhouse gas emissions described in formula (3) and formula (7) are measured by a greenhouse gas emissions measurement method; and / or, the greenhouse gas change is measured by a greenhouse gas change measurement method; And / or, the CO2 fixation flux value of formula (4) is measured by a CO2 fixation flux value determination method; And / or, the areas of formula (4), formula (5) and formula (9) are measured by an area measurement method; And / or, the greenhouse gas flux value of formula (5) is measured by a greenhouse gas flux value determination method; and / or, the greenhouse gas balance in formula (6), formula (7), and formula (8) is measured by a greenhouse gas balance determination method; And / or, the carbon loss amount in formula (6), formula (7) and formula (8) is measured by a carbon loss amount measurement method; And / or, the organic carbon loss amount in formula (6), formula (7) and formula (8) is measured by an organic carbon loss measurement method; And / or, the vegetation carbon density in formula (9) is measured by a vegetation carbon density measurement method; And / or, the soil carbon density of formula (10) is measured by a soil carbon density measurement method; And / or, the sediment carbon density of formula (10) is measured by a sediment carbon density determination method; And / or, the organic carbon impact factor of the transformed soil in formula (10) is measured by a method for measuring the organic carbon impact factor of the transformed soil.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, a method for calculating a wetland net greenhouse gas balance NGB as described in any one of claims 1 to 4 is implemented.

7. A system for calculating the net greenhouse gas budget NGB of a wetland, characterized in that: include: Computational unit; The computing unit comprises: the computer-readable storage medium of claim 6.

8. A system for calculating wetland net greenhouse gas budget NGB according to claim 7, characterized in that: Also includes: A carbon fixation measurement unit; the carbon fixation measurement unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements a carbon fixation determination method when executed by a processor; And / or, the system further comprises: a greenhouse gas emission measurement unit; the greenhouse gas emission measurement unit comprises a computer-readable storage medium having a computer program stored thereon; the computer program implements the greenhouse gas emission measurement method when executed by the processor; And / or, the system further comprises: a greenhouse gas change amount measuring unit; the greenhouse gas change amount measuring unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements the greenhouse gas change amount measuring method when executed by the processor; And / or, the system further comprises: a CO2 fixation flux value measuring unit; the CO2 fixation flux value measuring unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements the CO2 fixation flux value determination method when executed by the processor; And / or, the system further comprises: an area measurement unit; the area measurement unit comprises a computer-readable storage medium having a computer program stored thereon; the computer program implements the area measurement method when executed by the processor; And / or, the system further comprises: a greenhouse gas flux value measuring unit; the greenhouse gas flux value measuring unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements the greenhouse gas flux value determination method when executed by the processor; And / or, the system further comprises: a greenhouse gas balance measurement unit; the greenhouse gas balance measurement unit comprises a computer-readable storage medium having a computer program stored thereon; the computer program, when executed by the processor, implements the greenhouse gas balance determination method; And / or, the system further comprises: a carbon loss amount measuring unit; the carbon loss amount measuring unit comprises a computer readable storage medium on which a computer program is stored; the computer program implements the carbon loss amount measuring method when executed by the processor; And / or, the system further comprises: an organic carbon loss amount measuring unit; the organic carbon loss amount measuring unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements the organic carbon loss amount measuring method when executed by the processor; And / or, the system further comprises: a vegetation carbon density measuring unit; the vegetation carbon density measuring unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements the vegetation carbon density measuring method when executed by the processor; And / or, the system further comprises: a soil carbon density measuring unit; the soil carbon density measuring unit comprises a computer-readable storage medium on which a computer program is stored; the computer program implements the soil carbon density measuring method when executed by the processor; And / or, the system further comprises: a bottom mud carbon density measuring unit; the bottom mud carbon density measuring unit comprises a computer readable storage medium on which a computer program is stored; the computer program implements the bottom mud carbon density measuring method when executed by the processor; And / or, the system also includes: a unit for measuring the impact factor of organic carbon in transformed soil; the unit for measuring the impact factor of organic carbon in transformed soil includes a computer-readable storage medium on which a computer program is stored; when the computer program is executed by a processor, a method for determining the impact factor of organic carbon in transformed soil is implemented.

9. A system for calculating wetland net greenhouse gas budget NGB according to claim 8, characterized in that: The carbon fixation measurement unit, greenhouse gas emission measurement unit, greenhouse gas change measurement unit, CO2 fixation flux value measurement unit, area measurement unit, greenhouse gas flux value measurement unit, greenhouse gas balance measurement unit, carbon loss measurement unit, organic carbon loss measurement unit, vegetation carbon density measurement unit, soil carbon density measurement unit, sediment carbon density measurement unit, and soil organic carbon impact factor measurement unit are respectively connected to the calculation unit via a data path.

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