Bay ecosystem safety evaluation method

Abstract

The invention relates to the technical field of ecological system evaluation, in particular to a bay ecological system safety evaluation method which comprises a DPSIR framework model part and an entropy weight method-TOPSIS calculation part. According to the bay ecological system safety evaluation method provided by the invention, an evaluation index system of bay ecological safety is constructed from five aspects of driving force, pressure, state, influence and response based on a DPSIR theoretical framework, index selection is screened and refined for multiple times, the effectiveness and reliability of index data selection are improved, and the method is suitable for large-scale popularization and application. According to the bay ecological safety state grading method, bay ecological safety state grading is carried out on obtained data through the setting, fitting processing is carried out on data of different years through a linear regression equation, and a bay ecological safety state grading result is obtained through calculation of the value assignment weight of a selected index through an entropy weight method and calculation of a final result through a TOPSIS method. And a visual and reliable bay ecological safety index evaluation method is formed.

Description

Technical Field

[0001] The invention relates to the technical field of ecosystem assessment, in particular to a method for assessing the safety of a bay ecosystem. Background Art

[0002] The valuation of the Gulf ecosystem involves a comprehensive consideration of the economic and non-economic values ​​of its various ecological services and resources. Changes in the Gulf ecosystem usually occur over long time scales, and the assessment of ecosystem services needs to take these changes into account, as well as social and economic factors that change over time.

[0003] When conducting security assessments on some bay ecosystems, the reliability of the indicators selected by the bay ecological security index evaluation method is poor, and the final display of the evaluation method is not intuitive enough. Therefore, a bay ecosystem security evaluation method is proposed to address the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a method for evaluating the safety of a bay ecosystem, which is used to solve the problem that when conducting safety assessments on some bay ecosystems, the reliability of the indicators selected by the bay ecological security index evaluation method is poor, and the final display of the evaluation method is not intuitive enough.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] An evaluation method for the safety of a bay ecosystem includes a DPSIR framework model part and an entropy weight method-TOPSIS calculation part. The DPSIR framework model is divided into five parts, namely, a driving force system, a pressure system, a state system, an impact system and a response system.

[0007] S1. Indicators are selected in each system category of driving force system, pressure system, state system, impact system and response system. Comprehensive evaluation is conducted based on relevant policy documents, scientific research literature and technical specifications, combined with the actual situation of the Gulf and the data acquisition situation. The selected indicators are then evaluated in the following steps;

[0008] S2. Conduct a preliminary selection of ecological security indicators, and select indicator categories with high relevance to the bay ecology from policy documents and scientific research literature;

[0009] S3. Screening quantifiable indicators, selecting quantifiable categories from each indicator category, and determining the quantitative parameters of each indicator category;

[0010] S4. Screening ecological safety parameters, matching the obtained monitoring and statistical data with the safety assessment data to determine the parameters used for ecological safety calculation;

[0011] S5. De-dimensionalize and standardize the indicator data obtained in step S4 so that the evaluation method is not affected by the data type, and the calculated ecological security index is a dimensionless value;

[0012] S6. Assign values ​​through the entropy weight method, using the characteristics of entropy to assign corresponding weights based on the amount of information feedback from each indicator. If the entropy value of an indicator is smaller, the amount of information it provides is greater, the weight assigned is greater, and the role it plays in the comprehensive performance evaluation is greater;

[0013] S7, calculate the ecological security index, and use the TOPSIS method to calculate the index of the final result after the data assigned in step S6;

[0014] S8. Set the system security level and analyze and evaluate the calculation results obtained in step S7.

[0015] Preferably, in the steps S1 and S2:

[0016] The selection of driving force system indicators includes: GDP, tourist arrivals, tourism output, fisheries, ship throughput, industrial output, and agricultural and animal husbandry output;

[0017] The selection of pressure system indicators includes: pollution of rivers entering the sea, outlets into the sea, pollutant reception from ships, green coverage of built-up areas, agricultural and rural pollution, marine aquaculture pollution, and biological invasion;

[0018] The selection of state system indicators includes: water quality, sediment, biological quality, amount of marine debris, length of natural coastline, and area of ​​coastal wetlands;

[0019] The selection of influencing system indicators includes: fishery resources, water quality of biodiversity index, proportion of water quality of the fifth worst category in rivers entering the sea, and habitat conditions;

[0020] The response system indicators are the relevant measures and standards for marine ecological environmental protection in the relevant documents of various ecological and environmental planning. They are divided into three parts: sewage treatment capacity, supervision capacity and scientific and technological support. The selection of response system indicators includes: protection of endangered marine species, important marine ecological areas, marine ecological disaster control, construction of emergency marine pollution treatment capacity, monitoring capacity building, information release, investigation of coastal risk sources, control of environmental risk hazards, construction of emergency supervision capacity for marine sudden environmental incidents, control and standardized supervision of sewage outlets into the sea, improvement of water quality of rivers entering the sea, control of total nitrogen in rivers entering the sea, construction of sewage treatment infrastructure, upgrading and transformation of urban sewage treatment plants to quasi-Class IV standards, rural domestic sewage treatment, prevention and control of agricultural non-point source pollution, treatment and resource utilization of livestock and poultry manure, construction of seawater aquaculture tailwater treatment facilities, construction of ship and port pollution prevention and control facilities, construction of fishing port pollution prevention and control facilities and environmental cleaning and remediation, marine ecological restoration, comprehensive improvement of shore environment, construction of emergency capacity for marine environmental incidents, bay demonstration construction, improvement of sewage treatment capacity, transformation of urban combined sewer network, comprehensive improvement of fishing port environment and scientific and technological support.

[0021] Preferably, in the steps S5 and S6, the calculation step of the entropy weight method is:

[0022] (1) Data standardization;

[0023] The standardized calculation formula for the positive indicator is:

[0024]

[0025] The standardized calculation formula for the negative indicator is:

[0026]

[0027] Among them, the positive index means that the larger the value of the index is, the more favorable it is to the evaluation result, and the negative index means that the smaller the value of the index is, the more favorable it is to the evaluation result. ij is a standardized index, x ij is the original value of the indicator, maxx j and minx j They represent the maximum and minimum values ​​of the j index data within the evaluation range, respectively. The standardized data is a dimensionless constant between 0 and 1;

[0028] (2) Calculation of indicator variability;

[0029] The coefficient of variation calculation formula is:

[0030]

[0031] In the formula, f ij is the coefficient of variation, e ij for standardized indicators;

[0032] (3) Information entropy calculation;

[0033] The calculation formula of information entropy is:

[0034]

[0035] In the formula, H j is the entropy value of the jth indicator, k = 1 / lnn, n is the year of evaluation, f ij is the coefficient of variation;

[0036] (4) Weight calculation;

[0037] The weight calculation formula is:

[0038]

[0039] Where W j is the weight of the jth indicator, H j is the information entropy value of the jth indicator.

[0040] Preferably, in step S7, the TOPSIS evaluation method is a ranking method that is close to an ideal solution, and reflects the quality of the evaluation object by quantitatively measuring the distance between the evaluation object and the positive and negative ideal solutions. The specific calculation steps of the TOPSIS method include:

[0041] (1) Data standardization;

[0042] The data normalization formula is:

[0043]

[0044] In the formula, x ij is the original value of the indicator, y ij is the standardized value of the indicator;

[0045] (2) Calculate the weighted matrix;

[0046] The formula for calculating the weighted matrix is:

[0047] T=(t ij ) m×n =Y ij ×W ij (07)

[0048] Where T is the indicator matrix after weighted standardization, Yij is the indicator matrix after indicator standardization, and W ij is the weight matrix;

[0049] (3) Determine the positive and negative ideal solutions;

[0050] The formula for determining the positive ideal solution is:

[0051] T + ={maxT ij ,j=1,2,3,...,n} (08)

[0052] The formula for determining the negative ideal solution is:

[0053] T - ={minT ij ,j=1,2,3,...,n} (09)

[0054] Where, T + is a positive ideal solution, T - is a negative ideal solution;

[0055] (3) Calculate the distance of each index to the positive ideal solution and the negative ideal solution;

[0056] The calculation formula of the positive ideal solution is:

[0057]

[0058] The calculation formula for the negative ideal solution is:

[0059]

[0060] In the formula, is the distance to the positive ideal solution, is the distance to the negative ideal solution.

[0061] Compared with the prior art, the present invention has the following beneficial effects:

[0062] In the present invention, the evaluation method for the safety of the bay ecosystem provided is based on the DPSIR theoretical framework to construct an evaluation index system for the bay ecological security from five levels: driving force, pressure, state, impact, and response. The index selection is screened and refined multiple times to improve the effectiveness and reliability of the indicator data selection. The assignment weights of the selected indicators are calculated by the entropy weight method. On this basis, the final results are calculated by the TOPSIS method. Through the above settings, the obtained data are divided into the levels of the bay ecological security status, and the data of different years are fitted by a linear regression equation to form an intuitive and relatively reliable bay ecological security index evaluation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 It is a schematic diagram of the technical roadmap of safety evaluation of the present invention;

[0064] Figure 2 This is a schematic diagram of the categories of the preliminary selected indicators of the present invention;

[0065] Figure 3 This is a schematic diagram of the indicator system framework for calculating ecological security in the present invention. DETAILED DESCRIPTION

[0066] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] See also Figure 1-3 , the present invention provides a technical solution:

[0068] An evaluation method for the safety of a bay ecosystem includes a DPSIR framework model part and an entropy weight method-TOPSIS calculation part. The DPSIR framework model is divided into five parts, namely, the driving force system, the pressure system, the state system, the impact system and the response system.

[0069] S1. Indicators are selected in each system category of driving force system, pressure system, state system, impact system and response system. Comprehensive evaluation is conducted based on relevant policy documents, scientific research literature and technical specifications, combined with the actual situation of the Gulf and the data acquisition situation. The selected indicators are then evaluated in the following steps;

[0070] S2. Conduct a preliminary selection of ecological security indicators, and select indicator categories with high relevance to the bay ecology from policy documents and scientific research literature;

[0071] S3. Screening quantifiable indicators, selecting quantifiable categories from each indicator category, and determining the quantitative parameters of each indicator category;

[0072] S4. Screening ecological safety parameters, matching the obtained monitoring and statistical data with the safety assessment data to determine the parameters used for ecological safety calculation;

[0073] This model is a widely used multi-factor comprehensive evaluation system, which organically links the five categories of elements together, and looks at the interaction between human and environmental systems from a system analysis perspective. It can better reveal the relationship and internal logic between social, economic, and environmental factors involved in complex ecosystems.

[0074] S5. De-dimensionalize and standardize the indicator data obtained in step S4 so that the evaluation method is not affected by the data type, and the calculated ecological security index is a dimensionless value;

[0075] S6. Assign values ​​through the entropy weight method, using the characteristics of entropy to assign corresponding weights based on the amount of information feedback from each indicator. If the entropy value of an indicator is smaller, the amount of information it provides is greater, the weight assigned is greater, and the role it plays in the comprehensive performance evaluation is greater;

[0076] S7, calculate the ecological security index, and use the TOPSIS method to calculate the index of the final result after the data assigned in step S6;

[0077] S8, setting the system security level, analyzing and evaluating the calculation results obtained in step S7;

[0078] The entropy weight method-TOPSIS calculation part converts the parameter data obtained in the S4 step of the DPSIR framework model into the final evaluation value. The entropy weight method is used to calculate the weighting of the ecological security index, and finally the index is calculated through the TOPSIS method.

[0079] Table 1 Index initial screening table

[0080]

[0081]

[0082]

[0083] As shown in Table 1, in steps S1 and S2:

[0084] The selection of driving force system indicators includes: GDP, tourist arrivals, tourism output, fisheries, ship throughput, industrial output, and agricultural and animal husbandry output;

[0085] The selection of pressure system indicators includes: pollution of rivers entering the sea, outlets into the sea, pollutant reception from ships, green coverage of built-up areas, agricultural and rural pollution, marine aquaculture pollution, and biological invasion;

[0086] The selection of state system indicators includes: water quality, sediment, biological quality, amount of marine debris, length of natural coastline, and area of ​​coastal wetlands;

[0087] The selection of influencing system indicators includes: fishery resources, water quality of biodiversity index, proportion of water quality of the fifth worst category in rivers entering the sea, and habitat conditions;

[0088] The response system indicators are the relevant measures and standards for marine ecological environmental protection in the relevant documents of various ecological and environmental planning. They are divided into three parts: sewage treatment capacity, supervision capacity and scientific and technological support. The selection of response system indicators includes: protection of endangered marine species, important marine ecological areas, marine ecological disaster control, construction of emergency marine pollution treatment capacity, monitoring capacity building, information release, investigation of coastal risk sources, control of environmental risk hazards, construction of emergency supervision capacity for marine sudden environmental incidents, control and standardized supervision of sewage outlets into the sea, improvement of water quality of rivers entering the sea, control of total nitrogen in rivers entering the sea, construction of sewage treatment infrastructure, upgrading and transformation of urban sewage treatment plants to quasi-Class IV standards, rural domestic sewage treatment, prevention and control of agricultural non-point source pollution, treatment and resource utilization of livestock and poultry manure, construction of seawater aquaculture tailwater treatment facilities, construction of ship and port pollution prevention and control facilities, construction of fishing port pollution prevention and control facilities and environmental cleaning and remediation, marine ecological restoration, comprehensive improvement of shore environment, construction of emergency capacity for marine environmental incidents, bay demonstration construction, improvement of sewage treatment capacity, transformation of urban combined sewer network, comprehensive improvement of fishing port environment and scientific and technological support.

[0089] Table 2 Quantifiable indicators

[0090]

[0091]

[0092] As shown in Table 2, in step S3: the above evaluation factors are selected as parameters, and quantifiable indicator data are set.

[0093] Table 3 Final indicators

[0094]

[0095]

[0096]

[0097] As shown in Table 3, in step S4: the above index data are selected as parameters for calculation, and the final index data are set.

[0098] Table 4 Weights of evaluation indicators for ecological security of Jiaozhou Bay

[0099]

[0100]

[0101]

[0102]

[0103] Note: P is a positive indicator (the larger the index value, the lower the pressure, the better the state, and the more obvious the response), and N is a negative indicator (the smaller the index value, the greater the pressure, the worse the state, and the more fragile the response).

[0104] As shown in Table 4, taking the entropy weight method of the weight of the Jiaozhou Bay ecological security evaluation index as an example, the greater the amount of information provided by the index in the comprehensive evaluation, the greater the corresponding weight, and vice versa. Table 4 shows that the weights of each part of the Jiaozhou Bay ecosystem security evaluation model are from large to small: state > response > pressure > impact > driving force, indicating that the importance of each part in the Jiaozhou Bay ecosystem security evaluation is state, response, pressure, impact and driving force.

[0105] In steps S5 and S6, the calculation steps of the entropy weight method are:

[0106] (1) Data standardization;

[0107] The standardized calculation formula for the positive indicator is:

[0108]

[0109] The standardized calculation formula for the negative indicator is:

[0110]

[0111] Among them, the positive index means that the larger the value of the index is, the more favorable it is to the evaluation result, and the negative index means that the smaller the value of the index is, the more favorable it is to the evaluation result. ij is a standardized index, x ij is the original value of the indicator, maxx j and minx j They represent the maximum and minimum values ​​of the j index data within the evaluation range, respectively. The standardized data is a dimensionless constant between 0 and 1;

[0112] (2) Calculation of indicator variability;

[0113] The coefficient of variation calculation formula is:

[0114]

[0115] In the formula, f ij is the coefficient of variation, e ij for standardized indicators;

[0116] (3) Information entropy calculation;

[0117] The calculation formula of information entropy is:

[0118]

[0119] In the formula, H j is the entropy value of the jth indicator, k = 1 / lnn, n is the year of evaluation, f ij is the coefficient of variation;

[0120] (4) Weight calculation;

[0121] The weight calculation formula is:

[0122]

[0123] Where W j is the weight of the jth indicator, H j is the information entropy value of the jth indicator.

[0124] In step S7, the TOPSIS evaluation method is a ranking method that is close to the ideal solution. It reflects the quality of the evaluation object by quantitatively measuring the distance between the evaluation object and the positive and negative ideal solutions. The specific calculation steps of the TOPSIS method include:

[0125] (1) Data standardization;

[0126] The data normalization formula is:

[0127]

[0128] In the formula, x ij is the original value of the indicator, y ij is the standardized value of the indicator;

[0129] (2) Calculate the weighted matrix;

[0130] The formula for calculating the weighted matrix is:

[0131] T=(t ij ) n×n =Y ij ×W ij (07)

[0132] In the formula, T is the weighted and standardized indicator matrix, Y ij is the indicator matrix after the indicators are standardized, W ij is the weight matrix;

[0133] (3) Determine the positive and negative ideal solutions;

[0134] The formula for determining the positive ideal solution is:

[0135] T + ={maxT ij ,j=1,2,3,...,n} (08)

[0136] The formula for determining the negative ideal solution is:

[0137] T - ={minT ij ,j=1,2,3,...,n} (09)

[0138] Where, T + is a positive ideal solution, T - is a negative ideal solution;

[0139] (3) Calculate the distance of each index to the positive ideal solution and the negative ideal solution;

[0140] The calculation formula of the positive ideal solution is:

[0141]

[0142] The calculation formula for the negative ideal solution is:

[0143]

[0144] In the formula, is the distance to the positive ideal solution, is the distance to the negative ideal solution.

[0145] Table 5 Classification standards for the ecological security status of the bay

[0146] grade Comprehensive index range Security / risk type I 0.8～1.0 Low risk II 0.6～0.8 General Risks III 0.4～0.6 Critical Risk IV 0.2～0.4 Greater risk V 0～0.2 Significant risks

[0147] As shown in Table 5, the level of the bay’s ecological security status is divided into five standards;

[0148] Low risk: The marine ecological environment is safe, the ecosystem is basically intact, the overall functions are complete, the self-repair and anti-interference capabilities are strong, the biodiversity is rich, and the seawater quality is good.

[0149] General risks: The marine ecological environment is relatively safe. The ecosystem has been slightly damaged but can maintain a balanced state. The overall functions are relatively complete, the self-repair and anti-interference capabilities are strong, the biodiversity is relatively rich, and the seawater quality is good.

[0150] Critical risk: The marine ecological environment is in a critical state between safety and risk. The ecosystem is damaged, the ecological balance is broken, the basic functions can be maintained, the self-repair ability is weak, it can resist some external interference, the biodiversity is reduced, and the seawater quality is degraded.

[0151] Major risks: There are major risks to the marine ecological environment. The ecosystem has been severely damaged, its overall functions have been seriously degraded, and its self-repair and resistance to external interference capabilities are very poor, threatening the living environment of marine life. The seawater quality has been seriously degraded.

[0152] Major risks: There are major risks to the marine ecological environment. The ecosystem has been severely damaged, its functions have been basically lost, and it has basically no self-repair and external interference capabilities. It is not suitable for the survival of marine life, the seawater quality is poor, and it is difficult to compensate and repair the ecosystem.

[0153]

[0154] Table 6 Comprehensive evaluation index of Jiaozhou Bay ecological security from 2013 to 2022

[0155] (The dotted line in the table is the linear regression equation, and the red line is the functional expression of the linear regression equation)

[0156] As shown in Table 6, the evaluation method of the bay ecosystem security of the present invention takes Jiaozhou Bay as an example. The comprehensive index of ecological security evaluation of Jiaozhou Bay is a measurement index of the ecological security of the Jiaozhou Bay area. The TOPSIS method is used to perform weighted summation of various evaluation indicators of the ecological security of Jiaozhou Bay, which can more accurately evaluate its comprehensive level. The ecological security level in the region can be judged by the size of the comprehensive index of ecological security evaluation. The larger the value, the higher the ecological security level; otherwise, the lower the ecological security level.

[0157] The linear regression equation of the comprehensive evaluation index of Jiaozhou Bay's ecological security from 2013 to 2022 was calculated using the linear regression analysis method. The equation result is y=0.0468x+0.1888. There is a significant linear regression relationship between the response y of the equation and the variable x. The slope of the equation is positive, indicating that the ecological security index of Jiaozhou Bay is on an upward trend, and the overall interannual changes in the safety level of the Jiaozhou Bay ecosystem show a positive trend.

[0158] The evaluation method for the safety of the bay ecosystem provided by the present invention is used to ensure the effectiveness and reliability of the evaluation method for the safety of the bay ecosystem by analyzing the parameter calculation results of the Jiaozhou Bay.

[0159] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An evaluation method for the safety of a bay ecosystem, including a DPSIR framework model part and an entropy weight method-TOPSIS calculation part, is characterized by: The DPSIR framework model is divided into five parts, namely, driving force system, pressure system, state system, impact system and response system; S1. Indicators are selected in each system category of driving force system, pressure system, state system, impact system and response system. Comprehensive evaluation is conducted based on relevant policy documents, scientific research literature and technical specifications, combined with the actual situation of the Gulf and the data acquisition situation. The selected indicators are then evaluated in the following steps; S2. Conduct a preliminary selection of ecological security indicators, and select indicator categories with high relevance to the bay ecology from policy documents and scientific research literature; S3. Screening quantifiable indicators, selecting quantifiable categories from each indicator category, and determining the quantitative parameters of each indicator category; S4. Screening ecological safety parameters, matching the obtained monitoring and statistical data with the safety assessment data to determine the parameters used for ecological safety calculation; S5. De-dimensionalize and standardize the indicator data obtained in step S4 so that the evaluation method is not affected by the data type, and the calculated ecological security index is a dimensionless value; S6. Assign values ​​through the entropy weight method, using the characteristics of entropy to assign corresponding weights based on the amount of information feedback from each indicator. If the entropy value of an indicator is smaller, the amount of information it provides is greater, the weight assigned is greater, and the role it plays in the comprehensive performance evaluation is greater; S7, calculate the ecological security index, and use the TOPSIS method to calculate the index of the final result after the data assigned in step S6; S8. Set the system security level and analyze and evaluate the calculation results obtained in step S7.

2. The method for evaluating the safety of a bay ecosystem according to claim 1, characterized in that: In the steps S1 and S2: The selection of driving force system indicators includes: GDP, tourist arrivals, tourism output, fisheries, ship throughput, industrial output, and agricultural and animal husbandry output; The selection of pressure system indicators includes: pollution of rivers entering the sea, outlets into the sea, pollutant reception from ships, green coverage of built-up areas, agricultural and rural pollution, marine aquaculture pollution, and biological invasion; The selection of state system indicators includes: water quality, sediment, biological quality, amount of marine debris, length of natural coastline, and area of ​​coastal wetlands; The selection of influencing system indicators includes: fishery resources, water quality of biodiversity index, proportion of water quality of the worst five categories of rivers entering the sea, and habitat conditions; The response system indicators are the relevant measures and standards for marine ecological environmental protection in the relevant documents of various ecological and environmental planning. They are divided into three parts: sewage treatment capacity, supervision capacity and scientific and technological support. The selection of response system indicators includes: protection of endangered marine species, important marine ecological areas, marine ecological disaster control, construction of emergency marine pollution treatment capacity, monitoring capacity building, information release, investigation of coastal risk sources, control of environmental risk hazards, construction of emergency supervision capacity for marine sudden environmental incidents, control and standardized supervision of sewage outlets into the sea, improvement of water quality of rivers entering the sea, control of total nitrogen in rivers entering the sea, construction of sewage treatment infrastructure, upgrading and transformation of urban sewage treatment plants to quasi-Class IV standards, rural domestic sewage treatment, prevention and control of agricultural non-point source pollution, treatment and resource utilization of livestock and poultry manure, construction of seawater aquaculture tailwater treatment facilities, construction of ship and port pollution prevention and control facilities, construction of fishing port pollution prevention and control facilities and environmental cleaning and remediation, marine ecological restoration, comprehensive improvement of shore environment, construction of emergency capacity for marine environmental incidents, bay demonstration construction, improvement of sewage treatment capacity, transformation of urban combined sewer network, comprehensive improvement of fishing port environment and scientific and technological support.

3. The method for evaluating the safety of a bay ecosystem according to claim 1, characterized in that: In the steps S5 and S6, the calculation steps of the entropy weight method are: (1) Data standardization; The standardized calculation formula for the positive indicator is: The standardized calculation formula for the negative indicator is: Among them, the positive index means that the larger the value of the index is, the more favorable it is to the evaluation result, and the negative index means that the smaller the value of the index is, the more favorable it is to the evaluation result. ij is a standardized index, x ij is the original value of the indicator, maxx j and minx j They represent the maximum and minimum values ​​of the j index data within the evaluation range, respectively. The standardized data is a dimensionless constant between 0 and 1; (2) Calculation of indicator variability; The coefficient of variation calculation formula is: In the formula, f ij is the coefficient of variation, e ij for standardized indicators; (3) Information entropy calculation; The calculation formula of information entropy is: In the formula, H j is the entropy value of the jth indicator, k = 1 / lnn, n is the year of evaluation, f ij is the coefficient of variation; (4) Weight calculation; The weight calculation formula is: Where W j is the weight of the jth indicator, H j is the information entropy value of the jth indicator.

4. The method for evaluating the safety of a bay ecosystem according to claim 1, characterized in that: In step S7, the TOPSIS evaluation method is a ranking method that is close to the ideal solution. It reflects the quality of the evaluation object by quantitatively measuring the distance between the evaluation object and the positive and negative ideal solutions. The specific calculation steps of the TOPSIS method include: (1) Data standardization; The data normalization formula is: In the formula, x ij is the original value of the indicator, y ij is the standardized value of the indicator; (2) Calculate the weighted matrix; The formula for calculating the weighted matrix is: T=(t ij ) m×n =Y ij ×W ij (07) In the formula, T is the weighted and standardized indicator matrix, Y ij is the indicator matrix after the indicators are standardized, W ij is the weight matrix; (3) Determine the positive and negative ideal solutions; The formula for determining the positive ideal solution is: T + ={maxT ij ,j=1,2,3,...,n} (08) The formula for determining the negative ideal solution is: T - ={minT ij ,j=1,2,3,...,n} (09) Where, T + is a positive ideal solution, T - is a negative ideal solution; (3) Calculate the distance of each index to the positive ideal solution and the negative ideal solution; The calculation formula of the positive ideal solution is: The calculation formula for the negative ideal solution is: In the formula, is the distance to the positive ideal solution, is the distance to the negative ideal solution.

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