Method, system, equipment and program for evaluating synergistic effect of pollution reduction, emission reduction and convergence increase of wetland

Abstract

The invention relates to a method, a system, equipment and a program for evaluating a synergistic effect of pollution reduction, emission reduction and convergence increase of a wetland. The method comprises the following steps: respectively acquiring quantized values of indexes for representing pollution reduction, emission reduction and convergence increase of the wetland; carrying out weighted calculation on the quantized value, and taking a calculation result as a comprehensive evaluation value of pollution reduction, emission reduction and convergence increase of the wetland; a coordinated development degree index is obtained based on the comprehensive evaluation values of pollution reduction, emission reduction and sink increase of the wetland; calculating a coupling degree index by adopting a coupling degree model by taking a comprehensive evaluation value of pollution reduction, emission reduction and convergence increase of the wetland as an independent variable; and calculating a coupling coordination degree index according to the coordination development degree index and the coupling degree index, and performing coupling coordination type division on the wetland based on the numerical value of the coupling coordination degree index. According to the method, the blank in the aspect of evaluating the synergistic effect of pollution reduction, emission reduction and convergence increase of the wetland in the prior art is filled up, important technical support is provided for scientific protection and repair and sustainable development and utilization of the wetland, and the method has important theoretical and practical significance in promoting the development of the wetland protection career.

Description

Technical Field

[0001] The present invention belongs to the field of data analysis technology, and specifically relates to a method, system, equipment and program for evaluating the synergistic effect of wetland pollution reduction, emission reduction and sink enhancement. Background Art

[0002] Wetlands are the kidneys of the earth. Along with forests and oceans, they are known as the three major ecosystems in the world. They have multiple functions, such as purifying water, fixing carbon sinks, and regulating climate. In view of the urgency and importance of ecological environmental protection and carbon neutrality goals, the role of wetlands in reducing pollution, reducing emissions, and increasing carbon sinks has received increasing attention. Wetlands have the dual characteristics of both terrestrial and aquatic ecosystems, showing the unique complexity and diversity of wetlands, making the evaluation of the synergistic effects of wetlands in reducing pollution, reducing emissions, and increasing carbon sinks a technical challenge.

[0003] In the past, studies on wetland pollution reduction, emission reduction and carbon sink enhancement were conducted relatively independently, ignoring the coupling effects of pollutant purification, greenhouse gas emissions and carbon storage, and lacking comprehensive and systematic evaluation methods. In particular, the evaluation methods are relatively single, and the data collection and processing capabilities are limited, making it difficult to accurately and comprehensively reflect the synergistic effects of wetlands in these three aspects. At the same time, due to the differences in environmental conditions, ecological characteristics and human activities in wetlands in different regions, the existing single evaluation methods are often not universal enough and cannot be well applied to various types of wetlands. In the relevant technical fields of wetland pollution reduction, emission reduction and carbon sink enhancement, there is a great lack of efficient evaluation systems and equipment to support large-scale, high-precision data processing and analysis, and there is also a lack of specialized computer programs to realize automated and intelligent evaluation processes. Therefore, in order to more scientifically and accurately evaluate the synergistic effects of wetland pollution reduction, emission reduction and carbon sink enhancement, it is necessary to develop a new comprehensive evaluation method, and to match it with corresponding systems, equipment and procedures, comprehensively consider the close coupling and synergistic relationship between pollution reduction, emission reduction and carbon sink enhancement indicators, and scientifically guide the synergistic enhancement of pollution reduction, emission reduction and carbon sink enhancement in wetland ecosystems. Summary of the invention

[0004] The first purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a method for evaluating the synergistic effect of wetland pollution reduction, emission reduction and sink enhancement.

[0005] To achieve the above object, the present invention adopts the following scheme:

[0006] A method for evaluating the synergistic effect of reducing pollution, reducing emissions and increasing sinks in wetlands, including:

[0007] Obtain the quantitative values ​​of indicators that characterize wetland pollution reduction, emission reduction and sink enhancement respectively;

[0008] Among them: the indicators that characterize wetland pollution reduction are the indicators that characterize the amount of nitrogen and phosphorus removed per unit area; the indicators that characterize wetland emission reduction are the indicators of different greenhouse gas emission fluxes; the indicators that characterize wetland carbon sink enhancement are the carbon storage indicators of different carbon pools in wetlands;

[0009] The quantitative values ​​of the indicators that characterize the pollution reduction, emission reduction and sink enhancement of wetlands are weighted and calculated respectively, and the calculation results are used as the comprehensive evaluation values ​​of the pollution reduction, emission reduction and sink enhancement of wetlands;

[0010] The coordinated development index is obtained based on the comprehensive evaluation value of wetland pollution reduction, emission reduction and sink enhancement; the coupling index is calculated using the coupling degree model, with the comprehensive evaluation value of wetland pollution reduction, emission reduction and sink enhancement as the independent variable;

[0011] The coupling coordination index is calculated according to the coordinated development index and the coupling index, and the coupling coordination types of wetlands are divided based on the value of the coupling coordination index.

[0012] As a preferred embodiment, the indicators corresponding to the wetland pollution reduction are: total nitrogen (TN) removal per unit area, nitrate nitrogen (NO3 - -N) removal amount, nitrite nitrogen (NO2 - -N) removal amount, ammonia nitrogen per unit area (NH4 + -N) removal, total phosphorus (TP) removal per unit area and phosphate (PO4 3- -P) removal amount;

[0013] The indicators characterizing wetland emission reduction are carbon dioxide (CO2) emission flux, methane (CH4) emission flux and nitrous oxide (N2O) emission flux;

[0014] The indicators characterizing wetland carbon sink are water carbon content, soil carbon density and aquatic plant carbon density.

[0015] As a preferred implementation, the quantitative value of the indicator is obtained as follows:

[0016] The nitrogen and phosphorus removal per unit area is calculated based on the following formula:

[0017]

[0018] Where, MRR is the removal per unit area, C in and C out The nitrogen / phosphorus concentrations at the wetland inlet and outlet (mgL -1 );Q in and Q out are the inlet and outlet flow rates (m 3 d -1 ); A is the area of ​​each wetland system.

[0019] The greenhouse gas emission flux calculation method is based on Fick's law;

[0020] The carbon content of water bodies is characterized by the sum of organic and inorganic dissolved carbon and organic and inorganic particulate carbon content in water bodies;

[0021] Soil carbon density was calculated based on the following formula:

[0022] SoilC=SOC×γ×H×10 -1

[0023] γ=a×e -b×SOC

[0024] Where SoilC is soil carbon density, SOC is soil organic carbon content, which is measured by element analyzer; γ is soil bulk density; H is soil layer thickness; a and b are fitting coefficients.

[0025] The carbon density of aquatic plants is calculated based on the following formula:

[0026] Plant C = biomass × C p

[0027] Where PlantC is the carbon density of aquatic plants, biomass represents plant biomass (dry weight), including aboveground biomass and underground biomass, which is obtained by drying plant samples in an oven to a constant weight and then weighing them on a balance; C p Indicates the carbon content of plants.

[0028] As a preferred implementation, the indicator quantification value is standardized and data shifted;

[0029] The standardization process adopts the min-max method to standardize the positive indicators and negative indicators respectively;

[0030] The data translation refers to:

[0031] Add a constant to each normalized data to make the data non-zero.

[0032] As a preferred implementation, the weight of the indicator is determined based on an entropy method.

[0033] As a preferred implementation, the comprehensive evaluation values ​​of wetland pollution reduction, emission reduction and carbon sink enhancement are weightedly calculated by arithmetic weighted average method to obtain a coordinated development index.

[0034] As a preferred implementation, the coupling degree model is a modified coupling degree model, and the calculation formula is as follows:

[0035]

[0036] Where C is the coupling index; U1, U2, and U3 are the comprehensive evaluation values ​​of pollution reduction, emission reduction, and carbon sink enhancement indicators, respectively.

[0037] The second object of the present invention is to provide a wetland pollution reduction, emission reduction and sink enhancement synergistic effect evaluation system, comprising:

[0038] The indicator data acquisition module obtains the quantitative values ​​of indicators representing wetland pollution reduction, emission reduction and carbon sink enhancement, respectively, where: the indicator representing wetland pollution reduction is the indicator representing the nitrogen removal per unit area and the phosphorus removal per unit area; the indicator representing wetland emission reduction is the different greenhouse gas emission flux indicators; the indicator representing wetland carbon sink enhancement is the carbon storage indicator of different carbon pools in the wetland;

[0039] The comprehensive evaluation value calculation module performs weighted calculation on the quantitative values ​​of the indicators that characterize the pollution reduction, emission reduction and sink enhancement of the wetland, and the calculation results are used as the comprehensive evaluation values ​​of the pollution reduction, emission reduction and sink enhancement of the wetland;

[0040] The coordinated development index calculation module obtains the coordinated development index based on the comprehensive evaluation value of wetland pollution reduction, emission reduction and sink enhancement;

[0041] The coupling index calculation module uses the comprehensive evaluation value of wetland pollution reduction, emission reduction and sink enhancement as the independent variable, and uses the coupling model to calculate the coupling index;

[0042] The synergistic effect evaluation module calculates the coupling coordination index based on the coordinated development index and the coupling index, and divides the wetlands into coupling coordination types based on the value of the coupling coordination index.

[0043] A third object of the present invention is to provide a computer device, comprising a memory, a processor and a computer program stored in the memory, wherein the processor executes the computer program to perform the steps of the above method.

[0044] A fourth object of the present invention is to provide a computer-readable storage medium having a computer program / instruction stored thereon, which implements the steps of the above method when the computer program / instruction is executed by a processor.

[0045] A fifth object of the present invention is to provide a computer program product, comprising a computer program / instruction, which implements the steps of the above method when executed by a processor.

[0046] The present invention has the following beneficial effects:

[0047] (1) The solution of the present invention realizes an integrated evaluation of the synergistic effects of wetland pollution reduction, emission reduction and carbon sink enhancement, breaking through the limitations of previous single-aspect research, making the evaluation results more comprehensive and accurate, and being able to more realistically and clearly reveal the interrelationships and action mechanisms among the various functions in the wetland ecosystem, providing strong technical support for an in-depth understanding of the comprehensive ecological functions of wetlands. Based on the evaluation results, wetland protection and restoration can be guided more scientifically, key objects and key links can be identified, thereby providing guidance and countermeasures tailored to local conditions for wetland protection and restoration. For example, for areas with strong synergistic effects, protection is the main focus to ensure the stability and improvement of their ecological functions; for areas with weaker synergistic effects, restoration and improvement are the main focus to continuously improve the overall ecological environmental benefits.

[0048] (2) The present invention constructs a scientific, systematic and complete indicator evaluation system for the evaluation of the synergistic effects of pollution reduction, emission reduction and sink enhancement. The selected indicators are easy to measure and representative, which simplifies the calculation amount and improves the calculation efficiency while ensuring the accuracy of the evaluation results. It can more comprehensively and accurately evaluate the synergistic effects of wetland pollution reduction, emission reduction and sink enhancement.

[0049] (3) The present invention selects scientific indicators and constructs a comprehensive evaluation system for wetland pollution reduction, emission reduction and sink enhancement, combines the entropy weight method to quantitatively evaluate the pollution reduction, emission reduction and sink enhancement levels of different wetlands, and uses a coupling coordination degree model to analyze its coupling coordination effect. This can provide important technical method support for studying the multi-objective coordinated improvement of water quality purification and emission reduction and sink enhancement functions under the background of global change.

[0050] (4) The present invention fills the gap in the existing technology in the evaluation of the synergistic effect of wetland pollution reduction, emission reduction and sink enhancement, provides important technical support for the scientific protection and restoration of wetlands and their sustainable development, and has important theoretical and practical significance for promoting the development of wetland protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 These are the evaluation results of the pollution reduction (a), emission reduction (b), and sink enhancement (c) subsystems of different types of wetlands.

[0052] Figure 2 It is the changes in the characteristics of the coordinated state of pollution reduction, emission reduction and sink enhancement in different types of wetlands. DETAILED DESCRIPTION

[0053] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0054] Example 1

[0055] The wetland pollution reduction, emission reduction and sink enhancement synergistic effect evaluation method of the present invention comprises the following steps:

[0056] (1) Establish an indicator evaluation system for synergy effect assessment;

[0057] Based on the principles of scientificity, systematicity, representativeness and data availability, this paper constructs a comprehensive evaluation system for wetland pollution reduction, emission reduction and sink enhancement (Table 1). The system consists of three subsystems, namely, pollution reduction subsystem, emission reduction subsystem and sink enhancement subsystem, and each subsystem indicator is characterized by several indicators.

[0058] When selecting indicators, the characteristics of wetland environment and subsystems need to be considered. At present, wetland evaluation usually tends to be health evaluation, but greenhouse gas emissions and carbon sink indicators are rarely involved. This embodiment constructs an evaluation index system for the synergistic effect of pollution reduction, emission reduction and carbon sink increase based on three subsystems and 12 detailed indicators, as follows:

[0059] For the pollution reduction subsystem, nitrogen and phosphorus, the two most typical pollutants, are selected, and multiple specific removal indicators are used to comprehensively cover the removal of nitrogen and phosphorus in different forms, including TN removal per unit area, NO3 removal per unit area, and - -N removal amount, NO2 per unit area - -N removal, NH4 per unit area + -N removal, TP removal per unit area, PO4 per unit area 3- -P removal amount is characterized by six specific indicators. This can not only more finely evaluate the pollutant removal capacity of wetlands, but also effectively reveal the differences and synergies in the removal of pollutants of different forms, providing a more accurate basis for targeted pollution control measures. For the emission reduction subsystem, the emission fluxes of the three most important greenhouse gases are selected as evaluation indicators, including CO2 emission flux, CH4 emission flux, and N2O emission flux, avoiding the limitations of previous studies that mainly focus on a single type of greenhouse gas, and focusing on the interaction between global warming and wetland greenhouse gas emissions, making the evaluation focus more prominent, more directly reflecting the actual contribution of wetlands to greenhouse gas emissions, and helping to formulate efficient emission reduction strategies. For the carbon sink subsystem, water carbon content, soil carbon density, and aquatic plant carbon density are selected as evaluation indicators, comprehensively considering the carbon storage of different carbon pools in wetlands, breaking through the previous defects of simply using vegetation or soil carbon pools as ecosystem carbon pools. This comprehensive consideration can accurately reflect the overall carbon sink capacity of wetlands, as well as the relationship and dynamic changes between carbon pools, and provide a scientific basis for the formulation of carbon sink enhancement measures. The data for these indicators are highly available and can be easily obtained based on existing monitoring technologies and methods, thereby improving the practicality and operability of the assessment method and providing the possibility for its widespread application in wetland management and protection practices.

[0060] ① Calculation method of nitrogen and phosphorus removal per unit area

[0061] Nitrogen and phosphorus removal per unit area (MRR, mg m -2d -1 ) is calculated as follows:

[0062]

[0063] In the formula, C in and C out The nitrogen / phosphorus concentrations at the wetland inlet and outlet (mgL -1 );Q in and Q out are the inlet and outlet flow rates (m 3 d -1 ); A is the area of ​​each wetland system (m 2 ).

[0064] ② Calculation method of greenhouse gas emission flux

[0065] Greenhouse gas flux (Flux, mgm) is calculated based on Fick's law. -2 h -1 ), the calculation formula is as follows:

[0066] Flux = k x (C water -C air )

[0067]

[0068] In the formula, C water is the concentration of dissolved greenhouse gases in the original water sample, calculated by headspace equilibrium-gas chromatography analysis; C air is the concentration of greenhouse gases in the atmosphere; k x is the gas transmission rate at the water-air interface; x is the adjustment coefficient; S c is the Schmidt constant.

[0069] ③Calculation method of carbon content in water

[0070] The carbon content of water bodies mainly refers to the dissolved carbon and particulate carbon content in the water body. The calculation formula is:

[0071] WaterC=DOC+DIC+POC+PIC

[0072] Wherein, DOC and DIC represent the contents of dissolved organic carbon and dissolved inorganic carbon, respectively, which are determined by total organic carbon analyzer; POC and PIC represent the contents of particulate organic carbon and particulate inorganic carbon, respectively, which are determined by elemental analyzer.

[0073] ④ Calculation method of soil carbon density

[0074] The calculation formula of soil carbon density (SoilC) is as follows:

[0075] SoilC=SOC×γ×H×10 -1

[0076] γ=1.3565×e -0.0046×SOC

[0077] Wherein, SOC is the soil organic carbon content, which is measured using an element analyzer; γ is the soil bulk density; H is the soil layer thickness; in this embodiment, the fitting coefficients in the existing literature are used for calculation, a=1.3565, b=-0.0046.

[0078] ⑤ Calculation method of aquatic plant carbon density

[0079] The calculation formula of aquatic plant carbon density (PlantC) is as follows:

[0080] Plant C = biomass × C p

[0081] Where biomass represents plant biomass (dry weight), including plant aboveground biomass and underground biomass, which is obtained by drying plant samples in an oven to a constant weight and then weighing them on a balance; C p It represents the carbon content of plants, which can be obtained by referring to the carbon content of corresponding plants in the literature.

[0082] Table 1 Comprehensive evaluation index system and weights for pollution reduction, emission reduction and carbon sink enhancement

[0083]

[0084] Note: “+” indicates a positive indicator; “-” indicates a negative indicator.

[0085] (2) Data Standardization

[0086] In view of the differences in the order of magnitude and units of the original indicators, the range standard method is used to perform dimensionless processing on the data to eliminate the possible interference of different dimensions on the evaluation results. For positive indicators and negative indicators, the following standardized calculation formulas are used respectively:

[0087] Positive indicator: X ij =(x ij -x ij,min ) / (x ij,max -x ij,min )

[0088] Negative indicator: X ij =(x ij,max -x ij ) / (x ij,max -x ij,min )

[0089] In the formula, X ijis the value after normalization, x ij is the initial value (i=1, 2, ..., m, representing the month; j=1, 2, ..., n, representing the evaluation index); x ij,max 、x ij,min Represent the maximum and minimum values ​​of the evaluation indicators respectively.

[0090] Since logarithmic transformation is required in the data processing process, and the values ​​0 and 1 must appear in the data standardization process, a constant is added to the standardized data to avoid the situation of no solution by translating the data. The translation calculation formula is as follows:

[0091] X' ij =X ij +0.0001

[0092] Where, X ij ' is the value after the standardized data is shifted.

[0093] (3) Determination of indicator weights

[0094] The entropy method is used to determine the weight of indicators. Based on the objective information of the original data, the weight of the indicator is determined by analyzing the degree of correlation between the indicators and the amount of information provided by each indicator. The calculation formula for the entropy method weighting of each indicator is as follows:

[0095]

[0096] Where P ij is the proportion of the jth indicator in the i-th month; X ij ' is the data after translation; K is a constant, generally K = 1 / ln(m), ln is the natural logarithm; E ij is the indicator information entropy; W ij is the weight of the jth indicator.

[0097] (4) Calculation of comprehensive evaluation index

[0098] The comprehensive levels of the three subsystems of pollution reduction, emission reduction and sink enhancement are calculated by weighted summation of the standardized values ​​and weights of each indicator. The calculation formula is as follows:

[0099]

[0100] Where x = 1, 2, 3, U1, U2, U3 are the comprehensive evaluation values ​​of the pollution reduction, emission reduction and sink enhancement subsystems respectively.

[0101] (5) Calculation of coupling coordination

[0102] The essence of coupling is to measure the degree of interconnection, interaction and interdependence between the three systems of pollution reduction, emission reduction and sink enhancement. By constructing a coupling degree and coupling coordination degree model between the three subsystems of pollution reduction, emission reduction and sink enhancement in a typical wetland, it is used to describe the degree of interaction between the three subsystems of pollution reduction, emission reduction and sink enhancement, and to quantitatively measure the three-way coupling coordination effect of pollution reduction, emission reduction and sink enhancement. The specific calculation method is as follows:

[0103] ① Calculation method of coordinated development index

[0104] The arithmetic weighted average method is used to calculate the comprehensive evaluation index of pollution reduction, emission reduction and carbon sink enhancement. The result is the coordinated development index, and the calculation formula is as follows:

[0105]

[0106] Where T is the coordinated development index of the three subsystems of pollution reduction, emission reduction and sink enhancement, that is, the comprehensive evaluation index of pollution reduction, emission reduction and sink enhancement; ω x Represents the degree of importance. In existing research, it is generally assumed that the importance of each subsystem is consistent, that is, in this embodiment, ω1=ω2=ω3=1 / 3.

[0107] ② Calculation method of coupling index

[0108] The modified coupling model is used to calculate the coupling index of pollution reduction, emission reduction and sink enhancement. The specific calculation method is as follows:

[0109]

[0110] Where C is the coupling index of the three subsystems of wetland pollution reduction, emission reduction and sink enhancement; U1, U2 and U3 are the comprehensive evaluation values ​​of the pollution reduction, emission reduction and sink enhancement subsystems respectively.

[0111] When C = 0, the coupling degree is extremely low, and the subsystems are in a disordered state; when C = 1, the coupling degree is extremely high, and the subsystems reach a benign symbiotic coupling state, and the system will tend to a new ordered structure. The coupling degree evaluation level is shown in Table 2.

[0112] Table 2 Coupling degree and evaluation level

[0113]

[0114] ③ Calculation method of coupling coordination index

[0115] The coupling coordination index is used to quantitatively measure the three-way coupling coordination effect of wetland pollution reduction, emission reduction and sink enhancement. The specific calculation method is as follows:

[0116]

[0117] Where D is the coupling coordination index of wetland pollution reduction, emission reduction and sink enhancement; C is the coupling index of the three subsystems of wetland pollution reduction, emission reduction and sink enhancement; T is the coordinated development index of the three subsystems of pollution reduction, emission reduction and sink enhancement.

[0118] C∈[0,1], the closer the coupling coordination index is to 1, the better the coupling coordination is; conversely, the lower the C value is. The coupling coordination is generally divided into three stages, namely, the misaligned decay zone, the transitional coordination zone, and the coordinated development zone, and can be further subdivided into 10 types of coupling coordination, as shown in Table 3.

[0119] Table 3 Coupling coordination degree and coupling coordination type

[0120]

[0121] Example 2

[0122] This embodiment takes three typical wetlands in the Tianmu Lake Basin (river wetland W1, lake estuary wetland W2 and returning farmland to wetland W3) as examples to illustrate the evaluation effect of the method of the present invention.

[0123] The calculation results of the comprehensive evaluation index of each subsystem are as follows: Figure 1 As shown:

[0124] The pollution reduction subsystem evaluation indexes of river wetlands (W1), estuary wetlands (W2) and returning farmland to wetlands (W3) fluctuated in the range of 0.06-0.08, 0.04-0.20 and 0.02-0.30, respectively, with average values ​​of 0.10, 0.08 and 0.06, respectively. The three wetlands were ranked according to the evaluation index of their pollution reduction effect subsystems, as follows: returning farmland to wetlands (W3) > estuary wetlands (W2) > river wetlands (W1) ( Figure 1 (a). Overall, the pollution reduction effects of returning farmland to wetlands (W3) and estuary wetlands (W2) are better than those of river wetlands (W1), but the evaluation index fluctuates greatly within the year. The annual coefficient of variation of the comprehensive evaluation index of the pollution reduction subsystem of river wetlands (W1) is 7.6%, while the annual coefficients of variation of estuary wetlands (W2) and returning farmland to wetlands (W3) are as high as 50.9% and 83.3%. The relatively good removal effects of returning farmland to wetlands (W3) and estuary wetlands (W2) are mainly due to the longer hydraulic retention time and high coverage of aquatic plants. Such conditions are more conducive to the comprehensive effects of multiple purification mechanisms such as plant absorption, sediment adsorption and interception, microbial degradation, and root zone reaction, thereby achieving effective purification of N and P in water.

[0125] The emission reduction subsystem evaluation indexes of river wetlands (W1), estuary wetlands (W2) and returning farmland to wetlands (W3) fluctuated in the range of 0.72-0.99, 0.65-0.96 and 0.15-0.91, respectively, with average values ​​of 0.90, 0.86 and 0.69, respectively. The three wetlands were ranked according to the evaluation index of their emission reduction effect subsystems, as follows: river wetlands (W1) > estuary wetlands (W2) > returning farmland to wetlands (W3) ( Figure 1 b), the annual coefficients of variation were 9.5%, 11.4% and 31.0%, respectively. Low flow conditions have a positive effect on the generation of greenhouse gases. At the same time, the presence of plants and the increase in material richness will significantly increase the greenhouse gas emission flux of wetlands. Therefore, the relatively weak hydrodynamic conditions and large-scale growth of aquatic plants in the wetland conversion project (W3) and the estuary wetland (W2) may be the important reasons for reducing their emission reduction effects.

[0126] The evaluation index of the river wetland (W1), estuary wetland (W2) and returning farmland to wetland (W3) increased the sink subsystem, fluctuating in the range of 0.16-0.64, 0.32-0.73 and 0.33-0.72, respectively, with average values ​​of 0.35, 0.45 and 0.52, respectively. The three wetlands were ranked according to the evaluation index of their sink effect subsystem, as follows: returning farmland to wetland (W3) > estuary wetland (W2) > river wetland (W1) ( Figure 1 c), the annual coefficients of variation were 23.7%, 28.6% and 43.1% respectively. As the most important carbon storage unit in this study, the plant carbon pool, the type and coverage of vegetation directly affect the carbon sink function of the entire wetland ecosystem. The plants growing in the wetland conversion (W3) and the estuary wetland (W2) are more robust and cover a wider area, so the carbon sink effect is better.

[0127] The calculation results of coupling index and coupling coordination index of each subsystem are as follows: Figure 2 As shown:

[0128] Depend on Figure 2 As shown in Figure a, the coupling indexes of river wetlands (W1), estuary wetlands (W2) and returning farmland to wetlands (W3) fluctuated in the range of 0.20-0.36, 0.24-0.48 and 0.28-0.59, respectively, with average values ​​of 0.27, 0.32 and 0.38, respectively. The three wetlands were ranked according to the evaluation results of their coupling degree, as follows: returning farmland to wetlands (W3) > estuary wetlands (W2) > river wetlands (W1). The coupling index of pollution reduction, emission reduction and sink enhancement of river wetlands (W1) was generally low, and was in a low coupling state. The coupling state of pollution reduction, emission reduction and sink enhancement of estuary wetlands (W2) fluctuated greatly, and continuously switched between a low coupling state and an antagonistic coupling state. Returning farmland to wetlands (W3) transitioned from a growth coupling state to an antagonistic coupling state, and then remained in an antagonistic coupling state relatively stably.

[0129] Depend on Figure 2 As shown in Figure b, the changes in the coupling coordination degree of pollution reduction, emission reduction and sink enhancement of different types of wetlands are basically synchronized. The coupling coordination index of river wetlands (W1), estuary wetlands (W2) and returning farmland to wetlands (W3) fluctuated in the range of 0.28-0.40, 0.32-0.46 and 0.29-0.53, respectively, with average values ​​of 0.34, 0.38 and 0.41, respectively. The three wetlands were ranked according to the evaluation results of their coupling coordination degree, which was returning farmland to wetlands (W3) > estuary wetlands (W2) > river wetlands (W1). The coupling coordination index of pollution reduction, emission reduction and sink enhancement of river wetlands (W1) showed an "S"-shaped fluctuation trend, and was generally located in the imbalance decline zone, in a state of slight imbalance. The coupling coordination degree of pollution reduction, emission reduction and sink enhancement of estuary wetlands (W2) and returning farmland to wetlands (W3) fluctuates between the imbalance decline zone and the transition coordination zone. For returning farmland to wetlands (W3), it is in a barely coordinated state when the coupling coordination index reaches its peak, and is in a slightly imbalanced state in most other months.

[0130] The present invention believes that aquatic plants are an important factor affecting the synergistic effect between the various subsystems of wetland pollution reduction, emission reduction and sink enhancement. The growth of wetland plants is cyclical, and when they grow to a certain stage, they will enter the dead period. In this process, the dead plants will rot and decompose, and the released organic matter provides a carbon source for the denitrification of microorganisms. However, on the other hand, the nutrients released after the death of plants may also cause secondary pollution of water bodies. This phenomenon has been verified by some existing theoretical analyses. Therefore, in the evaluation results of the present invention, the release of nutrients by the death of large areas of submerged plants Myriophyllum in river wetlands (W1) may also be an important factor affecting its pollution reduction effect, while the relatively superior pollution reduction ability of estuary wetlands (W2) and returning farmland to wetlands (W3) may also benefit from the relatively strong carbon release ability of floating leaf plants during the growth process. In addition, aquatic plants in wetlands can also absorb nutrients through roots, stems, and leaves to maintain their growth and development while achieving the purpose of pollution reduction. At the same time, as the most important carbon fixation unit in the study area, the size of aquatic plants will directly affect the carbon storage function of the wetland. Therefore, the aquatic plant biomass in returning farmland to wetlands (W3) is the highest and has the best effect in removing pollutants. Among the three wetlands, returning farmland to wetlands (W3) shows the relatively best coupling coordination, which is mainly due to the synergy of pollution reduction and carbon sink enhancement effects.

[0131] In general, the coupling coordination between the pollution reduction, emission reduction and sink enhancement subsystems of returning farmland to wetlands (W3) and estuary wetlands (W2) is better than that of river wetlands (W1), but it has not reached the best coordinated development state, which may be mainly limited by its relatively poor emission reduction effect. The presence of wetland plants will also have an important impact on greenhouse gas emissions. The aquatic plant biomass of returning farmland to wetlands (W3) is the highest, while the greenhouse gas emissions are also the highest, while the river wetlands (W1) with the lowest greenhouse gas emissions have the lowest aquatic plant biomass. It can be inferred that the emission reduction effect and sink enhancement effect in the wetland ecosystem of the study area cannot be well coordinated.

Claims

1. A method for evaluating the synergistic effect of wetland pollution reduction, emission reduction and sink enhancement, characterized in that: include: Obtain the quantitative values ​​of indicators that characterize wetland pollution reduction, emission reduction and sink enhancement respectively; Among them: the indicators that characterize wetland pollution reduction are the indicators that characterize the amount of nitrogen and phosphorus removed per unit area; the indicators that characterize wetland emission reduction are the indicators of different greenhouse gas emission fluxes; the indicators that characterize wetland carbon sink enhancement are the carbon storage indicators of different carbon pools in wetlands; The quantitative values ​​of the indicators that characterize the pollution reduction, emission reduction and sink enhancement of wetlands are weighted and calculated respectively, and the calculation results are used as the comprehensive evaluation values ​​of the pollution reduction, emission reduction and sink enhancement of wetlands; The coordinated development index is obtained based on the comprehensive evaluation value of wetland pollution reduction, emission reduction and sink enhancement; the coupling index is calculated using the coupling degree model, with the comprehensive evaluation value of wetland pollution reduction, emission reduction and sink enhancement as the independent variable; The coupling coordination index is calculated according to the coordinated development index and the coupling index, and the coupling coordination types of wetlands are divided based on the value of the coupling coordination index.

2. The method according to claim 1, characterized in that: The indicators characterizing wetland pollution reduction are: total nitrogen removal per unit area, nitrate nitrogen removal per unit area, nitrite nitrogen removal per unit area, ammonia nitrogen removal per unit area, total phosphorus removal per unit area and phosphate removal per unit area; The indicators characterizing wetland emission reduction are carbon dioxide emission flux, methane emission flux and nitrous oxide emission flux; The indicators characterizing wetland carbon sink are water carbon content, soil carbon density and aquatic plant carbon density.

3. The method according to claim 1, characterized in that Standardize and shift the quantitative values ​​of indicators; The standardization process adopts the min-max method to standardize the positive indicators and negative indicators respectively; The data translation refers to: Add a constant to each normalized data to make the data non-zero.

4. The method according to claim 1, characterized in that The weights of the indicators are determined based on the entropy method.

5. The method according to claim 1, characterized in that The comprehensive evaluation values ​​of wetland pollution reduction, emission reduction and carbon sink enhancement were weighted and calculated by the arithmetic weighted average method to obtain the coordinated development index.

6. The method according to claim 1, characterized in that The coupling degree model is a modified coupling degree model, and the calculation formula is as follows: Where C is the coupling index; U1, U2, and U3 are the comprehensive evaluation values ​​of pollution reduction, emission reduction, and carbon sink enhancement indicators, respectively.

7. A wetland pollution reduction, emission reduction and sink enhancement synergistic effect evaluation system, characterized in that: include: The indicator data acquisition module obtains the quantitative values ​​of indicators representing wetland pollution reduction, emission reduction and carbon sink enhancement, respectively, where: the indicator representing wetland pollution reduction is the indicator representing the nitrogen removal per unit area and the phosphorus removal per unit area; the indicator representing wetland emission reduction is the different greenhouse gas emission flux indicators; the indicator representing wetland carbon sink enhancement is the carbon storage indicator of different carbon pools in the wetland; The comprehensive evaluation value calculation module performs weighted calculation on the quantitative values ​​of the indicators that characterize the pollution reduction, emission reduction and sink enhancement of the wetland, and the calculation results are used as the comprehensive evaluation values ​​of the pollution reduction, emission reduction and sink enhancement of the wetland; The coordinated development index calculation module obtains the coordinated development index based on the comprehensive evaluation value of wetland pollution reduction, emission reduction and sink enhancement; The coupling index calculation module uses the comprehensive evaluation value of wetland pollution reduction, emission reduction and sink enhancement as the independent variable, and uses the coupling model to calculate the coupling index; The synergistic effect evaluation module calculates the coupling coordination index based on the coordinated development index and the coupling index, and divides the wetlands into coupling coordination types based on the value of the coupling coordination index.

8. A computer device comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instruction is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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