A method for evaluating carbon sink capacity of a hydropower station construction project
By using a dual-baseline dynamic comparison and multi-step quantitative accounting method, the problem of accurately assessing the carbon sequestration capacity of hydropower stations during the construction period was solved, and the accurate assessment of vegetation, soil improvement and water and soil conservation measures was achieved, ensuring the ecological benefits of "zero-carbon construction sites".
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUADIAN JINSHAJIANG UPSTREAM HYDROPOWER DEV CO LTD
- Filing Date
- 2025-11-28
- Publication Date
- 2026-08-04
AI Technical Summary
Existing technologies lack accurate assessments of the carbon sequestration capacity during the construction period of hydropower stations, especially the assessments of vegetation restoration, soil improvement, and water and soil conservation measures are not precise enough, leading to an underestimation of carbon sequestration capacity and an inability to fully reflect ecological and environmental benefits.
The assessment boundary is defined by dynamic comparison of dual baselines. A multi-step quantitative accounting method is adopted for carbon sink pathways such as vegetation construction, soil improvement, soil and water conservation, and reservoir sediment retention. This includes carbon sink enhancement models for vegetation construction measures, carbon sink enhancement models for soil improvement measures, emission reduction models for soil and water conservation measures, and carbon sequestration models for reservoir sediment retention, forming a systematic carbon sink assessment system.
It has achieved a systematic and quantitative assessment of the carbon sequestration capacity of hydropower stations during the construction period through multiple approaches, accurately evaluated the carbon sequestration benefits of various measures, and formed a verifiable method for calculating soil carbon sequestration, thus ensuring the implementation of the vision of "zero-carbon construction site".
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Abstract
Description
Technical Field
[0001] This application belongs to the field of water conservancy engineering technology, specifically a method for assessing the carbon sequestration capacity of hydropower station construction projects. Background Technology
[0002] Guided by the principles of "carbon peaking and carbon neutrality," the energy industry is accelerating its transformation towards a green and low-carbon direction. Hydropower stations, as the main force in clean energy supply, play a crucial role in their low-carbon construction and operation. Against this backdrop, the construction concept of "zero-carbon construction sites" or "near-zero-carbon construction sites" is being vigorously promoted in the hydropower industry. Its core lies in accurately calculating and effectively managing carbon sources and sinks throughout the entire project construction cycle.
[0003] Currently, the practice of "zero-carbon construction sites" for hydropower stations generally focuses on carbon source reduction, mainly through technologies such as "electricity-for-oil," optimized construction processes, energy management, and waste reduction and resource utilization to reduce carbon emissions. Existing technologies and standards primarily focus on the equivalent coal substitution carbon reduction generated by hydropower generation during the operation period of the hydropower station, which is an indirect emission reduction benefit during the operational phase. However, there is a lack of specific assessment standards and methods for carbon sink pathways that directly generate carbon during the construction period and have immediate ecological value. In the limited carbon sink assessment during the construction period, current methods mainly and only roughly estimate the carbon sequestration of vegetation restoration measures, and mostly draw on relevant standards in the forestry or grassland fields, which do not align well with the actual situation of hydropower station construction projects and have limited accuracy. More importantly, it completely ignores the carbon sinks generated by soil and water conservation measures ("erosion reduction and emission reduction"), as well as the carbon sink enhancement capacity of the "soil-vegetation" system in soil improvement and ecological optimization zones. This one-sided assessment leads to a serious underestimation of the true carbon sink capacity of hydropower station construction projects, failing to fully reflect their positive ecological and environmental benefits.
[0004] There is an urgent need for a dedicated technical system that can scientifically assess the carbon sequestration capacity of hydropower stations during the construction period, so as to identify the carbon sources and carbon sequestration pathways in the construction process, achieve precise management and quantitative assessment of ecological benefits, and ensure the implementation of the vision of "zero-carbon construction site". Summary of the Invention
[0005] To address the aforementioned problems in existing technologies, this application provides a method for assessing the carbon sequestration capacity of hydropower station construction projects. The method defines the assessment boundary through dynamic comparison of dual baselines, and within the determined assessment boundary, it distinguishes different calculation items based on carbon sequestration functions. Finally, through multi-step quantitative accounting, it achieves accurate assessment and comprehensive evaluation of carbon sequestration pathways such as vegetation construction, soil improvement, soil and water conservation measures, and reservoir sediment retention.
[0006] To achieve the above objectives, this application adopts the following technical solution: a method for assessing the carbon sequestration capacity of hydropower station construction projects, comprising the following steps: Obtain the basic assessment data for the hydropower station construction project to be evaluated. The basic assessment data includes baseline scenario data, evaluation boundary data, vegetation construction data, soil improvement data, soil and water conservation data, and reservoir sedimentation and carbon sequestration data. The baseline scenario data includes ecological baseline data and baseline data for the scenario without measures. The assessment data are input into the sub-item carbon sink accounting models to obtain the sub-item carbon sink output of each model. The sub-item carbon sink accounting models include vegetation construction measures to increase carbon sink, soil improvement measures to increase carbon sink, water and soil conservation measures to reduce emissions, and reservoir sedimentation and carbon sequestration models. Input the individual carbon sequestration amounts into the comprehensive carbon sequestration evaluation model, and obtain the overall carbon sequestration capacity of the project through a summarization formula and convert it into carbon dioxide equivalent. Determine the evaluation level corresponding to the carbon dioxide equivalent within the target preset carbon sink range, and output the evaluation results of the hydropower station construction project to be evaluated.
[0007] The calculation formula for the carbon sequestration model based on vegetation construction measures is: C1 = C1 of newly added vegetation carbon storage. 11 +Vegetation management measures and carbon sequestration C 12 ;
[0008] Where M i C represents the biomass of the i-th planted vegetation in that year, calculated from the number of plants multiplied by the average plant weight, according to the greening project list. i The carbon content conversion coefficient of the i-th planted vegetation is generally taken as the measured value, and 0.5 is used as a substitute if the measured value is unavailable. C 12 =T csr ×A t +S csr ×A s +G csr ×A g ; Where T csr For forest vegetation sequestration rate, A t For the area of forest land under management measures, S csr A represents the rate of sequestration of shrubland vegetation. s For the area under forest land management measures, G csr A represents the grassland vegetation sequestration rate. g This refers to the area under forest land management measures.
[0009] The calculation formula for the carbon sequestration model based on soil improvement measures is: Soil improvement carbon sequestration C2 = Carbon sequestration from imported soil cultivation C 21 + Soil amendment carbon sequestration C 22 ; C 21 =S b×ρ b ×C b ; Among them, S b The amount of topsoil borrowed for the project; ρ b C is the soil bulk density of the borrowed soil. b The coefficient representing the average organic carbon content in the borrowed topsoil; C 22 =S af ×ρ af ×C af S pr ×ρ pr ×C pr ; Among them, S af ρ represents the amount of topsoil before soil improvement. af C represents the soil bulk density before soil improvement. af S represents the average organic carbon content coefficient of the soil before amendment. pr ρ represents the amount of topsoil after soil improvement. pr C represents the bulk density of the soil after soil improvement. pr This represents the average organic carbon content coefficient after soil improvement.
[0010] The calculation formula for the emission reduction model of soil and water conservation measures is as follows: C3=(M b M a )×A×C s ×T; Where C3 represents the emission reduction from soil and water conservation measures, and M... b M represents the baseline soil erosion pattern before engineering disturbance or the soil erosion pattern under no-measures scenario. a A represents the soil erosion modulus after the implementation of the measures; C represents the actual area disturbed during project construction; s is the soil organic carbon content coefficient; K is the organic carbon mineralization emission coefficient; and T is the project construction period.
[0011] The core formula of the reservoir sediment retention and carbon deposition model is: C4=(FPOCpr) FPOCaf)×(1-k); Where k represents the proportion of sedimentary organic carbon mineralization, an empirical value selected based on relevant studies on reservoir sedimentary environments, and represents the proportion of sedimentary carbon that may be released again through decomposition. FPOCpr and FPOCaf represent the particulate organic carbon flux at the upstream and downstream sections of the dam site, respectively. Measured data are preferred for POC flux calculation. When measured data is unavailable, the following empirical formula is used to estimate the flux from sediment concentration: FPOC = TSS × POC% POC% = -0.16(logCTSS) 3 +2.83(logCTSS) 2 -13.6(logCTSS)+20.3; Among them, TSS is the river sediment transport, which can be obtained from the observation data of the hydrological stations at the front and rear sections of the dam site; POC% is the suspended organic carbon content; and CTSS is the sediment content of the water body.
[0012] The summary formula is as follows: C = 44 / 12 (C1 + C2 + C3 + C4); Wherein C1 is the carbon sequestration amount obtained from the vegetation construction measures carbon sequestration model, C2 is the carbon sequestration amount obtained from the soil improvement measures carbon sequestration model, C3 is the emission reduction amount obtained from the soil and water conservation measures emission reduction model, and C4 is the amount of reservoir sedimentation carbon sequestration obtained from the reservoir sedimentation carbon sequestration model.
[0013] The preset carbon sink intervals are based on the additionality requirements of the project carbon sink calculation results under the baseline scenario I and the compliance requirements of the project's ecological protection and soil and water conservation measures under the baseline scenario II. The carbon sink assessment results during the construction period of the hydropower station are divided into four levels of threshold intervals.
[0014] The beneficial effects of this application are: This application provides a method for assessing the carbon sequestration capacity of hydropower station construction projects. It quantifies the effect of soil improvement on enhancing the soil organic carbon pool, forming a verifiable method for calculating soil carbon sequestration capacity. The physical soil-fixing function of soil and water conservation engineering measures is transformed into quantifiable carbon sequestration benefits. This accurately assesses the reduction in soil erosion after the implementation of these measures, establishing a scientific conversion relationship between "reduced erosion" and "avoided soil organic carbon loss and mineralization emissions," thereby calculating the "erosion reduction and emission reduction" carbon sequestration brought about by soil and water conservation measures. By treating the pre-construction baseline conditions, various measures during construction, and subsequent ecological optimization as a continuous whole, this method achieves a comprehensive and systematic quantitative assessment of the carbon sequestration capacity during the hydropower station construction period, solving the problem of "full-process, multi-pathway" systematic accounting of carbon sequestration capacity during the hydropower station construction period. Attached Figure Description
[0015] Figure 1 This is a flowchart illustrating the carbon sequestration capacity assessment method used in this application for hydropower station construction projects; Figure 2 This is another flowchart illustrating the carbon sequestration capacity assessment method used in this application for hydropower station construction projects. Detailed Implementation
[0016] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.
[0017] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0018] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0019] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0020] like Figure 1 , Figure 2 The method shown here for assessing the carbon sequestration capacity of hydropower station construction projects includes the following steps: S1. Obtain the basic assessment data for the hydropower station construction project to be evaluated.
[0021] The assessment data includes baseline scenario data, evaluation boundary data, vegetation establishment data, soil improvement data, soil and water conservation data, and reservoir sedimentation and carbon sequestration data. The baseline scenario data includes ecological baseline data and baseline data for a scenario without intervention measures. To accurately assess the net carbon sequestration benefits of hydropower station construction, this scheme uses a dual baseline for dynamic comparison: Baseline I (Ecological Baseline): Based on ecological and environmental survey data before project construction (or during the feasibility study phase), including but not limited to vegetation cover, soil organic carbon content, and land use type. This baseline is used to quantify the total change in carbon sink relative to the original state throughout the entire project construction cycle.
[0022] Baseline II (No-Measures Scenario Baseline): Based on project design data, construction planning, and empirical parameters from similar project areas, this baseline simulates and extrapolates the potential soil erosion modulus, vegetation destruction level, and soil carbon pool depletion under a scenario where no soil and water conservation, vegetation restoration, or soil improvement measures are implemented. This baseline is used to isolate and quantify the additional carbon sequestration benefits contributed purely by various ecological protection and restoration measures.
[0023] This step provides a comparative basis for quantifying all subsequent changes in carbon sequestration, ensuring that the assessment results reflect both the project's actual ecological impact and the additional carbon sequestration benefits brought about by the measures. Through the above dual-baseline comparison, the two key questions can be answered respectively: "To what extent has the project caused ecological impact?" and "How much incremental carbon sequestration has the measures taken brought about?"
[0024] This plan clearly defines the spatial boundary of the assessment as the scope of prevention and control responsibilities determined in the approved soil and water conservation plan. This scope typically includes all areas directly or potentially affected by project construction activities, such as reservoir inundation areas, key project construction areas, construction road areas, material yards, spoil disposal areas, and resettlement areas. Defining this boundary provides a unified spatial benchmark for data collection, monitoring deployment, and accounting for all subsequent calculations. This step defines a unified spatial scope for subsequent data collection, monitoring deployment, and all carbon sequestration accounting, ensuring the comprehensiveness and consistency of the assessment.
[0025] To prevent double counting or omission of carbon sequestration, this scheme divides the assessment system into two main categories of calculation items based on the carbon sequestration function: 1. Greening and Carbon Sequestration Enhancement Projects: The core mechanism is "green as a carbon sink," meaning that carbon dioxide in the atmosphere is directly fixed through photosynthesis. Specific accounting projects include: carbon sequestration enhancement through vegetation construction measures and carbon sequestration enhancement through soil improvement measures.
[0026] 2. Soil and Carbon Conservation and Erosion Reduction / Emission Reduction Functional Projects: The core mechanism is "soil is the foundation of carbon" and "erosion reduction equals emission reduction," that is, by reducing soil erosion and organic carbon loss, their mineralization and emission are avoided. Specific accounting items include: water and soil conservation measures for emission reduction and reservoir sedimentation for carbon retention.
[0027] This classification system provides a clear framework for subsequent itemized accounting, ensuring that each type of carbon sequestration pathway has a corresponding quantitative method.
[0028] Finally, the validity of the acquired raw data was verified and outliers were removed. For parameters lacking measured values, such as soil organic carbon content and vegetation sequestration rate, standard default values were used to supplement them. Data units were standardized, such as converting the number of planted vegetation into biomass (t / a) and converting the area into hectares (hm²) or square kilometers (km²).
[0029] S2. Input the assessment data into the sub-item carbon sequestration accounting models respectively, and obtain the sub-item carbon sequestration output by each model.
[0030] The sub-item carbon sequestration models include the vegetation construction measures carbon sequestration model, the soil improvement measures carbon sequestration model, the soil and water conservation measures emission reduction model, and the reservoir sedimentation carbon sequestration model.
[0031] The carbon sequestration model of vegetation construction measures is used to quantify the amount of carbon sequestration generated by vegetation construction and management measures such as afforestation and grass planting.
[0032] Calculation formula: Vegetation carbon sequestration (C1) = Newly added vegetation carbon storage (C) 11 ) + Carbon sequestration by vegetation management measures (C) 12 ).
[0033] New vegetation carbon storage (C 11 ): Where Mi is the biomass (t / a) of the i-th vegetation planted in the current year, obtained by multiplying the number of plants by the average weight of each plant according to the greening project list. Ci is the carbon content conversion coefficient of the i-th vegetation planted, generally based on measured values, with 0.5 used as a substitute if measured values are unavailable.
[0034] Carbon sequestration (C) of vegetation management measures 12 ): Through the rate of vegetation sequestration per unit area (tC / (hm) 2 a)) and vegetation area (hm 2 The calculation is obtained using the following formula: .in The rate of sequestration in forest vegetation. The area under forest land management measures; For the rate of sequestration of shrubland vegetation, The area under forest land management measures; The rate of grassland vegetation sequestration. The area under forest protection measures is used; the relevant vegetation sequestration rate is based on national or industry standard values. The area under vegetation protection measures is obtained from engineering data and UAV imagery data.
[0035] The soil improvement measures sink enhancement model is used to quantify the increase in soil organic carbon pool through soil improvement measures such as topsoil, application of organic fertilizer or biochar.
[0036] Calculation formula: Soil improvement carbon sequestration (C1) = Carbon sequestration from imported soil cultivation (C) 21 ) + Soil amendment carbon sequestration (C 22 ).
[0037] Carbon sequestration in topsoil cultivation (C 21 The calculation formula is: ;in, The amount of topsoil borrowed from outside the project (m3); The soil bulk density (t / m3) of the borrowed soil. This is the coefficient of average organic carbon content in the borrowed topsoil.
[0038] Soil-amended carbon sequestration (C 22 The calculation formula is: ;in, Topsoil volume before soil improvement (m³) 3 ); Soil bulk density before soil improvement (t / m³) 3 ), This represents the average organic carbon content coefficient before soil improvement. The amount of topsoil after soil improvement (m³) 3 ); The soil bulk density after soil improvement (t / m³) 3 ), This represents the average organic carbon content coefficient after soil improvement.
[0039] The soil and water conservation measures emission reduction model is used to quantify the amount of organic carbon loss avoided by engineering measures, vegetation measures, and temporary measures due to reduced soil erosion. The specific calculation formula is as follows: Water and soil conservation measures to reduce emissions (C3): .in, The soil erosion patterns are either the baseline soil erosion patterns before engineering disturbance (based on Scenario I) or the soil erosion patterns under the scenario without implemented measures (based on Scenario II). Soil erosion modulus (t / km²) after implementation of measures (based on monitoring) 2 •a); A represents the actual construction disturbance area of the project (km²) 2 ); C sis the soil organic carbon content coefficient; K is the organic carbon mineralization emission coefficient; and T is the project construction period (a).
[0040] The reservoir sedimentation and carbon sequestration model is used to quantify the long-term sedimentary carbon sink formed by intercepting upstream sediment and the particulate organic carbon it carries after the dam is built.
[0041] Core formula: ,;where k represents the proportion of sedimentary organic carbon mineralization, which is selected based on empirical values from relevant studies on reservoir sedimentary environments, representing the proportion of sedimentary carbon that may be decomposed and released again. and These represent the particulate organic carbon (POC) flux (unit: t / m³·a) at the upstream and downstream sections of the dam site, respectively. Measured data are preferred for POC flux calculation. When measured data are unavailable, the following empirical formula is used to estimate the flux from sediment concentration: FPOC = TSS × POC% POC% = -0.16(logCTSS) 3 +2.83(logCTSS) 2 -13.6(logCTSS)+20.3.
[0042] Where TSS represents river sediment transport, which can be obtained from observational data of hydrological stations at the upstream and downstream sections of the dam site. POC% represents suspended organic carbon content, and CTSS represents water sediment concentration (mg / L). Note: This empirical formula is applicable to rivers with sediment concentrations below 2250 mg / L.
[0043] S3. Input the individual carbon sequestration amounts into the comprehensive carbon sequestration evaluation model, and obtain the overall carbon sequestration capacity of the project through the summarization formula and convert it into carbon dioxide equivalent.
[0044] After quantifying the four types of carbon sink pathways in step S2, this step summarizes them into the overall carbon sink capacity of the project and converts them into carbon dioxide equivalent (CO2e) for the convenience of subsequent carbon management, trading or policy evaluation.
[0045] Summary formula:
[0046] Wherein C1 is the carbon sequestration amount obtained from the vegetation construction measures carbon sequestration model, C2 is the carbon sequestration amount obtained from the soil improvement measures carbon sequestration model, C3 is the emission reduction amount obtained from the soil and water conservation measures emission reduction model, and C4 is the amount of reservoir sedimentation carbon sequestration obtained from the reservoir sedimentation carbon sequestration model.
[0047] S4. Determine the evaluation level corresponding to the carbon dioxide equivalent within the target preset carbon sink range, and output the evaluation results of the hydropower station construction project to be evaluated.
[0048] Baseline I, the ecological baseline, reflects the project's overall carbon sequestration capacity relative to its original state, while Baseline II, the no-measures scenario baseline, reflects the additional contribution of ecological measures. Carbon sequestration monitoring data from hydropower stations of different scales in the same river basin across the country were referenced during their construction periods. Based on the additionality requirements of the project's carbon sink calculation results under Baseline I scenario and the compliance requirements of the project's ecological protection and soil and water conservation measures under Baseline II scenario, the carbon sink assessment results during the construction period of the hydropower station are divided into the following four levels, including: Excellent (C≥8000 t CO2e under Baseline Scenario I): The project has reached the top level in the industry in terms of ecological restoration investment (large-scale vegetation planting, high-standard soil improvement), water and soil conservation engineering (large-scale slag retaining dams, ecological slope protection), and reservoir ecological management. Its carbon sequestration capacity far exceeds that of projects of the same scale, making it a "high-quality supplier" in the carbon trading market.
[0049] Good (C≥0 t CO2e under Baseline Scenario I): The project has sound ecological measures, the project construction basically meets the requirements of "zero carbon construction site", the emission reduction of hydropower can stably meet the excess emission reduction needs of key emission units, the carbon sink performance meets the "additionality" requirements of carbon trading, and the carbon sink assessment results can be included in the carbon trading market.
[0050] Medium (C < 0 t CO2e under Baseline I scenario and C ≥ 2000 t CO2e under Baseline II scenario): This indicates that the project's ecological measures basically meet the standards, and the project's ecological protection and soil and water conservation measures largely satisfy the project's construction requirements. It is a basic manifestation of the project's "ecological compliance".
[0051] Poor (C < 2000 t CO2e under baseline scenario II): This indicates that the project may have shortcomings in ecological measures (such as insufficient investment in soil improvement, incomplete soil and water conservation projects, and limited vegetation restoration area), and the project's ecological protection and soil and water conservation measures may not meet the requirements of the project approval.
[0052] Finally, it should be noted that in this document, relationships such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "include," "contain," or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.
[0053] 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.
[0054] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.
Claims
1. A method for assessing the carbon sequestration capacity of hydropower station construction projects, characterized in that, Includes the following steps: Obtain the basic assessment data for the hydropower station construction project to be evaluated. The basic assessment data includes baseline scenario data, evaluation boundary data, vegetation construction data, soil improvement data, soil and water conservation data, and reservoir sedimentation and carbon sequestration data. The baseline scenario data includes ecological baseline data and baseline data for the scenario without measures. The assessment data are input into the sub-item carbon sink accounting models respectively to obtain the sub-item carbon sink output by each model. The sub-item carbon sink accounting models include vegetation construction measures to increase carbon sink, soil improvement measures to increase carbon sink, water and soil conservation measures to reduce emissions, and reservoir sedimentation and carbon sequestration models. The calculation formula for the carbon sequestration model of the vegetation construction measures is: C1 = C1 of newly added vegetation carbon storage 11 +Vegetation management measures and carbon sequestration C 12 ; ； Where M i C represents the biomass of the i-th planted vegetation in that year, calculated from the number of plants multiplied by the average plant weight, according to the greening project list. i The carbon content conversion coefficient of the i-th planted vegetation is taken as the measured value, and 0.5 is used as a substitute if the measured value is unavailable. ； Where Tcsr is the forest vegetation sequestration rate, At is the forest area under management measures, and Scsr is the shrubland vegetation sequestration rate. Gcsr represents the area under shrubland protection measures, Ag represents the grassland vegetation sequestration rate, and Ag represents the area under grassland protection measures. The calculation formula for the carbon sequestration model of the soil improvement measures is: C2 = C21 of carbon sequestration from imported soil cultivation + C22 of carbon sequestration from soil improvement. ； in, The amount of topsoil borrowed for the project; The bulk density of the borrowed soil, The coefficient representing the average organic carbon content in the borrowed topsoil; ； in, This represents the amount of topsoil before soil improvement. This refers to the soil bulk density before soil improvement. The coefficient representing the average organic carbon content of the soil before soil improvement. This refers to the amount of topsoil after soil improvement. This refers to the bulk density of the soil after soil improvement. The average organic carbon content coefficient after soil improvement; The calculation formula for the emission reduction model of the soil and water conservation measures is as follows: ； in, To reduce emissions through soil and water conservation measures, This refers to the baseline soil erosion modulus before engineering disturbance or the soil erosion modulus under the scenario where no measures were implemented. The soil erosion modulus after the implementation of the measures; A is the actual area disturbed by the project construction; Cs is the soil organic carbon content coefficient; K is the organic carbon mineralization emission coefficient; and T is the project construction period. The core formula of the reservoir sediment retention and carbon deposition model is: ; Where k represents the proportion of sedimentary organic carbon mineralization, an empirical value selected based on relevant studies of reservoir sedimentary environments, indicating the proportion of sedimentary carbon that is released again through decomposition. and These represent the particulate organic carbon flux at the upstream and downstream sections of the dam site, respectively. Measured data are preferred for calculating the particulate organic carbon flux. When measured data is unavailable, the following empirical formula is used to estimate the flux from the sediment concentration: FPOC = TSS × POC% POC%=-0.16(logCTSS)3+2.83(logCTSS)2-13.6(logCTSS)+20.3; Among them, TSS is the river sediment transport, which uses the observation data of the hydrological stations at the front and rear sections of the dam site; POC% is the suspended organic carbon content; and CTSS is the sediment content of the water body. The individual carbon sequestration amounts are input into the comprehensive carbon sequestration evaluation model, and the overall carbon sequestration capacity of the project is obtained through a summarization formula and converted into carbon dioxide equivalent. The summarization formula is as follows: ； Wherein C1 is the amount of carbon sequestration by vegetation obtained based on the vegetation construction measures carbon sequestration model, C2 is the amount of carbon sequestration by soil improvement obtained based on the soil improvement measures carbon sequestration model, C3 is the amount of emission reduction by soil and water conservation measures obtained based on the water and soil conservation measures emission reduction model, and C4 is the amount of carbon sequestration by reservoirs obtained based on the reservoir sedimentation and carbon deposition model. Determine the evaluation level corresponding to the carbon dioxide equivalent within the target preset carbon sink range, and output the evaluation results of the hydropower station construction project to be evaluated.
2. The method for assessing the carbon sequestration capacity of hydropower station construction projects as described in claim 1, characterized in that, The preset carbon sink intervals are based on the additionality requirements of the project carbon sink calculation results under baseline scenario I and the compliance requirements of the project's ecological protection and soil and water conservation measures under baseline scenario II. The carbon sink assessment results during the construction period of the hydropower station are divided into four levels of threshold intervals.