An ecological integrity-based water ecological health evaluation method and application thereof

Abstract

The application discloses a water ecological health evaluation method based on ecological integrity and application thereof, divides an evaluation index system into a target layer, a criterion layer, a factor layer and an index layer, adopts a differentiated benchmark determination method for indexes of different types based on ecological integrity, adopts a method combining an entropy weight method and an analytic hierarchy process for core indexes, quantitatively and qualitatively analyzes problems, and finally displays the health status of a water ecological system in the form of graphic marking and color zoning which is easy to understand. In summary, the application can comprehensively, scientifically and accurately evaluate the health status of a water ecological system, and is helpful to promote water ecological examination and provide a scientific basis for water ecological management and restoration.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of water ecology, more particularly, to a water ecological health evaluation method based on ecological integrity and application thereof. BACKGROUND

[0002] Water ecological integrity refers to the integrity of the structure and function of the water ecosystem. The water ecosystem has important ecological functions such as power generation, transportation, purification and regulation, and maintenance of biodiversity, and supports and serves the development and progress of human society. Under the influence of extreme climate events and high-intensity human activities, the water ecosystem is facing a series of ecological problems such as habitat quality damage, excessive pollutants, and species extinction, and urgently needs a scientific and comprehensive water ecological evaluation method to guide the development of water ecological management and restoration work.

[0003] Therefore, the prior art still has problems to be further improved and developed. SUMMARY

[0004] (I) Invention purpose: in order to solve the above problems existing in the prior art, the purpose of the present application is to provide a water ecological health evaluation method based on ecological integrity and application thereof.

[0005] (II) Technical scheme: in order to solve the above technical problems, the present application provides a water ecological health evaluation method based on ecological integrity, the specific steps are as follows,

[0006] Step 1. Determine the system criteria, including physical habitat, physicochemical properties, and aquatic organisms, and use differentiated ecological criteria for the selected indicators;

[0007] Step 2. The selected indicators are successively verified for applicability, sensitivity and redundancy to screen the core indicators;

[0008] Step 3. The entropy weight method and the analytic hierarchy process are combined to weight and sum each criterion layer, and the comprehensive score of the water ecosystem is calculated;

[0009] Step 4. The evaluation standard grade is divided and the result is displayed.

[0010] Further, the differentiated ecological criteria refer to using the historical reference method to determine the ecological criteria for the indicators of the point with small fluctuation, strong continuity or fast response to external stress, and taking the historical state before human activity interference as the ecological criteria value;

[0011] For the indicators of the point with large fluctuation, poor continuity or fast response to external stress, the reference point method is used to determine the ecological criteria, and the condition of the point less disturbed by human activities is used to determine the ecological criteria.

[0012] Further, the suitability verification is by calculating the coefficient of variation of the alternative indicators: C υ = σ / μ, wherein μ is the standard deviation of the indicator, and σ is the average value of the indicator, removing weak variation indicators with coefficient of variation C υ ≤ 0.15;

[0013] The sensitivity verification is to compare the ecological benchmark value R and the sample value S by adopting a box plot for the alternative indicators that pass the suitability verification, and eliminating indicators with IQ < 2 that do not have sensitivity;

[0014] The redundancy verification is to perform Pearson correlation analysis on the alternative indicators that pass the sensitivity verification, and if the correlation |r| between two alternative indicators that pass the sensitivity verification is ≥ 0.95, only one of the indicators is retained.

[0015] Further, the step 3 specifically comprises:

[0016] Step 301. Normalizing the core indicator data;

[0017] Step 302. Assigning weights to the core indicators by adopting the entropy weight method, and calculating the scores of each criterion layer by weighted summation;

[0018] Step 303. Assigning weights to each criterion layer by adopting the analytic hierarchy process, and calculating the comprehensive score of the water ecosystem.

[0019] Further, the normalization refers to normalizing the core indicators of the larger-the-better type according to formula (a), and normalizing the core indicators of the smaller-the-better type according to formula (b):

[0020] s = (x - x min ) / (x max -x min ) (a)

[0021] s = (x max -x) / (x max -x min ) (b)

[0022] Wherein s is the normalized value of the indicator, x is the measured value of the indicator, x max is the maximum value of the measured value of the indicator, and x min is the minimum value of the measured value of the indicator.

[0023] Further, according to the method for water ecological health evaluation based on ecological integrity according to claim 4, the entropy weight method is adopted to assign weights to the core indicators of the same criterion layer, and the scores of each criterion layer are calculated according to formula (c), formula (d) and formula (e) respectively:

[0024] P = 100 * ∑(pi *w pi ) (c)

[0025] C=100*∑(c i *w ci ) (d)

[0026] B=100*∑(b i *w bi ) (e)

[0027] wherein, P is a physical habitat score, p i is a normalized value of the i th physical habitat index, w pi is a weight of the i th physical habitat index; C is a physicochemical property score, c i is a normalized value of the i th physicochemical property index, w ci is a weight of the i th physicochemical property index; B is an aquatic organism score, b i is a normalized value of the i th aquatic organism index, w bi is a weight of the i th aquatic organism index

[0028] Further, the ecosystem comprehensive score is calculated according to formula (f):

[0029] EHI=P*W P +C*W C +B*W B (f)

[0030] In the formula, EHI is an ecosystem comprehensive score, WP is a physical habitat weight, WC is a physicochemical property weight, and WB is an aquatic organism weight.

[0031] Further, the evaluation standard grade refers to dividing the water ecosystem health condition into five grades of very healthy, healthy, sub-healthy, unhealthy and poor.

[0032] Further, the display result refers to intuitively displaying the water ecosystem health condition in the form of graphical annotation and color zoning according to the division grade of the water ecosystem health condition.

[0033] The application of the water ecosystem health evaluation method based on ecological integrity is applied to the health rating and / or management restoration of river and / or lake water ecosystems.

[0034] (Three) beneficial effects: the present application provides a water ecosystem health evaluation method based on ecological integrity and its application, which can comprehensively, scientifically and accurately evaluate the health status of water ecosystems, and is helpful to promote water ecology examination and provide scientific basis for water ecology management and restoration. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a flow chart of a method of water ecological health assessment based on ecological integrity according to the present application;

[0036] Figure 2 is a flow chart of screening core indicators;

[0037] Figure 3 is a result schematic diagram of sensitivity verification;

[0038] Figure 4 is a flow chart of a method combining entropy weight method and analytic hierarchy process;

[0039] Figure 5 is a variation coefficient of each indicator in the embodiment;

[0040] Figure 6 is a box plot of the indicator reference value R and sample value S verified by sensitivity in the embodiment;

[0041] Figure 7 is a water ecological system health condition zoning definition diagram. DETAILED DESCRIPTION

[0042] The present application will be further described below in conjunction with preferred embodiments, and more details are set forth in the following description in order to fully understand the present application, however, the present application can be implemented in various other ways different from the description, and those skilled in the art can make similar generalization and deduction according to actual application without departing from the connotation of the present application, therefore, the protection scope of the present application should not be limited by the content of the specific embodiments.

[0043] A water ecological health assessment method based on ecological integrity, as shown in Figure 1 , the specific steps include the following:

[0044] Step 1. Determine system criteria, including physical habitat, physicochemical properties, aquatic organisms, and adopt differentiated ecological criteria for the alternative indicators;

[0045] Step 2. Perform applicability verification, sensitivity verification, and redundancy verification on the alternative indicators in turn to screen core indicators;

[0046] Step 3. Perform weighted summation on each criterion layer by a method combining entropy weight method and analytic hierarchy process to calculate the comprehensive score of the water ecological system;

[0047] Step 4. Divide the evaluation standard grade and display the results.

[0048] The step 1 specifically includes:

[0049] An evaluation framework of "target layer - criterion layer - element layer - indicator layer" is adopted. Based on the concept of the integrity of aquatic ecosystem, an indicator system of three criterion layers is constructed to reflect different aspects of the physical habitat, physicochemical properties and aquatic organisms of aquatic ecosystem.

[0050] Because different types of indicators differ in their continuity, volatility, and response mechanisms, adopting a differentiated ecological benchmark determination method can more comprehensively and accurately reflect the health of aquatic ecosystems.

[0051] The method for determining the differentiated ecological benchmarks is as follows:

[0052] For points with small fluctuations, strong continuity, or slow response to external stresses, the historical reference method is used to determine the ecological baseline, and the historical state before human activities are disturbed is used as the ecological baseline value.

[0053] For points with large fluctuations, poor continuity, or rapid response to external stresses, the reference point method is used to determine the ecological baseline, and the ecological baseline is determined based on the condition of the points least affected by human activities among the sampling points.

[0054] More specifically, when selecting alternative indicators, the alternative indicators are physical habitat indicators that reflect hydrological conditions, spatial morphology and shoreline conditions, physicochemical property indicators that reflect water pollution and sediment pollution, and aquatic biological indicators that reflect the integrity of phytoplankton, zooplankton, macrobenthic invertebrates and fish.

[0055] Among them, such as Figure 2 As shown, step 2 specifically includes:

[0056] The applicability verification is performed by calculating the coefficient of variation of the candidate indicators: C υ =σ / μ, where μ is the standard deviation of the indicator, σ is the mean of the indicator, and C is the coefficient of variation. υ A weak variability index of ≤0.15.

[0057] The sensitivity verification involves using a box plot to compare the ecological baseline value R with the sample value S of the candidate indicators that have passed the applicability verification, and eliminating indicators that lack sensitivity and have an IQ < 2.

[0058] The specific method is as follows: compare the box plot of the ecological baseline value R with the box plot of the sample value S, and assign IQ values ​​to each candidate indicator based on the overlap range between the two. Figure 3 As shown:

[0059] If the candidate indicators do not overlap within the quartile range of the ecological baseline value R and the sample value S, then IQ = 3;

[0060] If the alternative index only has a small range of overlap in the quartile range of the ecological benchmark value R and the sample value S, and the median of both is not in the quartile range of the other, IQ=2;

[0061] If the alternative index has a large range of overlap in the quartile range of the ecological benchmark value R and the sample value S, and the median of one is in the quartile range of the other, IQ=1;

[0062] If the alternative index has a large range of overlap in the quartile range of the ecological benchmark value R and the sample value S, and the median of one is in the quartile range of the other, IQ=1;

[0063] It should be noted that in the screening index, the index IQ<2 needs to be removed, because when IQ<2, the ecological benchmark value R and the sample value S are not distinguished, and have no sensitivity.

[0064] The redundancy verification is a Pearson correlation analysis on the alternative indexes passing the sensitivity verification, and if the correlation |r| between two alternative indexes passing the sensitivity verification is greater than or equal to 0.95, only one of the indexes is retained.

[0065] As shown in the formula (1), the step 3 specifically comprises: Figure 4

[0066] Step 301. Normalizing the core index data;

[0067] Because the types of aquatic ecological health evaluation indexes are different, some index data is better the larger, and some index data is better the smaller, so the index data needs to be normalized. After normalization, the data is in the same order of magnitude, which can eliminate the influence of the dimension and dimension unit between indexes, and improve the comparability between different data indexes.

[0068] The normalization refers to normalizing the more the better type index according to formula (a), and normalizing the less the better type index according to formula (b).

[0069] s=(x-x min ) / (x max -x min ) (a)

[0070] s=(x max -x) / (x max -x min ) (b)

[0071] Wherein, s is the normalized value of the index, x is the measured value of the index, x max is the maximum value of the measured value of the index, and x min is the minimum value of the measured value of the index. ​

[0072] Step 302. The core indicators are weighted using the entropy weight method, and the scores of each criterion layer are calculated by weighted summation;

[0073] Specifically, for the core indicators of the same criterion layer, the entropy weight method is used for weighting, and the physical habitat score, the physicochemical property score and the aquatic organism score are calculated according to formula (c), formula (d) and formula (e) respectively.

[0074] P = 100 *∑(p i *w pi ) (c)

[0075] C = 100 *∑(c i *w ci ) (d)

[0076] B = 100 *∑(b i *w bi ) (e)

[0077] Wherein, P is the physical habitat score, p i is the normalized value of the i th physical habitat indicator, w pi is the weight of the i th physical habitat indicator; C is the physicochemical property score, c i is the normalized value of the i th physicochemical property indicator, w ci is the weight of the i th physicochemical property indicator; B is the aquatic organism score, b i is the normalized value of the i th aquatic organism indicator, w bi is the weight of the i th aquatic organism indicator.

[0078] Step 303. The criterion layers are weighted using the analytic hierarchy process method, and the comprehensive score of the aquatic ecosystem is calculated.

[0079] Specifically, the comprehensive score of the ecosystem is calculated according to formula (f):

[0080] EHI = P * W P +C * W C +B * W B (f)

[0081] In the formula, EHI is the comprehensive score of the ecosystem, WP is the weight of the physical habitat, WC is the weight of the physicochemical property, and WB is the weight of the aquatic organism.

[0082] The step 4 specifically comprises:

[0083] The evaluation standard grade refers to dividing the health status of the aquatic ecosystem into five grades of very healthy, healthy, sub-healthy, unhealthy and poor.

[0084] The display result is to intuitively display the water ecosystem health condition in the form of graphical annotation and color zoning according to the division level of the water ecosystem health condition.

[0085] The application provides the water ecosystem health evaluation method based on ecological integrity and an application of the water ecosystem health evaluation method in water ecosystem evaluation.

[0086] One preferred embodiment of the water ecosystem health evaluation method based on ecological integrity is applied to:

[0087] Step 1: integrating system elements, including physical habitat, physicochemical properties and aquatic organisms, and adopting differentiated ecological benchmarks for alternative indexes;

[0088] Firstly, an evaluation framework of "target layer-criterion layer-element layer-index layer" is adopted to construct an index system of the three criterion layers of physical habitat, physicochemical properties and aquatic organisms;

[0089] The target layer is water ecosystem health evaluation, the criterion layer is physical habitat (P), physicochemical properties (C) and aquatic organisms (B), the element layer of the physical habitat (P) is hydrological regime, spatial form and shoreline state, the element layer of the physicochemical properties (C) is water quality pollution and sediment pollution, and the element layer of the aquatic organisms (B) is phytoplankton integrity, zooplankton integrity, macrobenthic invertebrate integrity and fish integrity.

[0090] Secondly, ecological benchmarks and alternative indexes are determined.

[0091] The physical habitat index (P) corresponds to the indexes of the index layer, and the fish integrity corresponds to the indexes of the index layer, and the history reference method is adopted; the physicochemical properties (C), the phytoplankton integrity, the zooplankton integrity and the macrobenthic invertebrate integrity correspond to the indexes of the index layer, and the reference point method is adopted.

[0092] When the history reference method is adopted, the historical state before human activity interference is taken as the ecological benchmark value; when the reference point method is adopted, S1-S16 are arranged from upstream to downstream, and S1, S2, S3, S5 and S8 are finally selected as the reference points to determine the ecological benchmark value from the aspects of human activity interference degree and shoreline vegetation coverage.

[0093] In the selection of alternative indexes, the physical habitat indexes, the physicochemical property indexes and the aquatic organism indexes reflecting the water ecosystem condition are selected based on the clear theoretical framework of ecological integrity, and finally 40 candidate indexes are obtained to comprehensively and accurately evaluate the health state of the water ecosystem.

[0094] The index of the hydrological regime corresponding index layer is ecological flow compliance rate (P1), the index of the spatial form corresponding index layer is water body connectivity (P2), and the index of the shoreline state corresponding index layer is natural shoreline rate (P3).

[0095] The index of the water quality pollution corresponding index layer is ammonia nitrogen (C1), total phosphorus (C2), and permanganate index (C3).

[0096] The index of the sediment pollution corresponding index layer is total phosphorus (C4), organic matter content ratio (C5), Cr (C6), Ni (C7), Cu (C8), Zn (C9), As (C 10 ), Cd (C 11 ), and Pb (C 12 ).

[0097] The index of the phytoplankton integrity corresponding index layer is total taxonomic units (B1), total density (B2), total biomass (B3), diatom density ratio (B4), cyanobacteria density ratio (B5), diatom biomass ratio (B6), green algae biomass ratio (B7), and Shannon-Wiener diversity index (B8).

[0098] The index of the zooplankton integrity corresponding index layer is total taxonomic units (B9), total abundance (B 10 ), total biomass (B 11 ), and Shannon-Wiener diversity index (B 12 ).

[0099] The index of the macrobenthic invertebrate integrity corresponding index layer is total taxonomic units (B 13 ), total abundance (B 14 ), total biomass (B 15 ), Biological Monitoring Working Party (BMWP) index (B 16 ), Family Biotic Index (B 17 ), and Shannon-Wiener diversity index (B 18 ).

[0100] The index of the fish integrity corresponding index layer is the number of indigenous fish species (B 19 ), the proportion of the number of invasive species (B 20 ), the proportion of the number of rare or endemic species (B 21 ), the proportion of the number of protected species (B 22 ), and the proportion of the number of fish that produce drift eggs (B23 ), the proportion of fish-eating fish (B 24 ), the proportion of omnivorous fish (B 25 ). (See Table 1 for details)

[0101] Table 1: Evaluation of aquatic ecological health based on ecological integrity

[0102]

[0103]

[0104] Step 2: The suitability verification, sensitivity verification, and redundancy verification of the selected indicators are carried out in turn to screen the core indicators;

[0105] 1) Suitability verification: Calculate the coefficient of variation of each indicator: C υ = σ / μ, μ is the standard deviation of the indicator, σ is the average value of the indicator, remove the weak variation indicators P2, C3, C7 with C υ ≤0.15. As shown in Table 1. Figure 5

[0106] 2) Sensitivity verification: Boxplot method is used to compare the baseline value R and sample value S of the remaining indicators, only keep the indicators with IQ≥2. Finally, the indicators P1, P3, C1, C5, B2, B4, B5, B6, B7, B8, B 11 , B 16 , B 17 , B 19 , B 21 , B 23 , B 25 are retained. As shown in Table 2. Figure 6

[0107] 3) Redundancy verification: Pearson correlation analysis is carried out by IBM SPSS Statistics 26 to verify the redundancy of the 17 indicators passed the sensitivity verification, as shown in Table 2. For two indicators with a correlation coefficient |r|≥0.95, the number of indicators with high correlation and the integrity of the evaluation index system rule layer are considered comprehensively, and the core indicators P1, P3, C1, B2, B4, B5, B8, B 11 , B 17 , B 19 , B 21 , B 23 , B 25 are finally retained.

[0108] Table 2: Correlation coefficients of 17 indicators

[0109] ​​

[0110]

[0111] Step 3. The weighted sum of each criterion layer is calculated by combining the entropy weight method and the analytic hierarchy process method to obtain the comprehensive score of the water ecosystem;

[0112] Step 301. Normalize the core index data;

[0113] According to the different types of indicators, the 13 core indicators screened are normalized, as shown in Table 3.

[0114] Table 3. Indicator type and normalization formula

[0115]

[0116] In the formula, s is the normalized value of the indicator, x is the measured value of the indicator, x max is the maximum value of the measured value of the indicator, and x min is the minimum value of the measured value of the indicator.

[0117] Step 302. Assign weights to the core indicators using the entropy weight method, and calculate the score of each criterion layer by weighted sum;

[0118] The entropy weight method determines the weight of an indicator according to the amount of information contained in the indicator. The calculation steps are as follows:

[0119] (1) Assume that there are m sample points and n indicators. Based on the index scoring, a matrix S is constructed:

[0120] S = (s ij ) m×n

[0121] (2) Calculate the characteristic proportion p ij of the jth indicator in the ith sample point to measure the amount of information contained:

[0122]

[0123] (3) Calculate the information entropy e j and the difference coefficient d j of the jth indicator. The greater the dispersion of an indicator, the more information it contains. Therefore, e j is smaller, d j is larger, and the corresponding weight value is also larger:

[0124]

[0125] d j = 1-e j

[0126] (4) Finally, the weight w of each index is calculated based on the above results j :

[0127]

[0128] (5) The physical habitat score, physico-chemical property score and aquatic organism score of the whole river section are calculated according to formula (c), (d) and (e) respectively. As shown in Table 4 below.

[0129] P = 100 *∑(p i *w pi ) (c)

[0130] C = 100 *∑(c i *w ci ) (d)

[0131] B = 100 *∑(b i *w bi ) (e)

[0132] In the formula, P is the physical habitat score, p i is the normalized value of the i-th physical habitat index, w pi is the weight of the i-th physical habitat index; C is the physico-chemical property score, c i is the normalized value of the i-th physico-chemical property index, w ci is the weight of the i-th physico-chemical property index; B is the aquatic organism score, b i is the normalized value of the i-th aquatic organism index, w bi is the weight of the i-th aquatic organism index.

[0133] Table 4 Weight of each index of each criterion layer and score of each criterion layer

[0134]

[0135] Step 303. The analytic hierarchy process is used to weight each of the criterion layers, and the comprehensive score of the aquatic ecosystem is calculated.

[0136] The analytic hierarchy process divides the problem structure into levels by combining qualitative and quantitative methods, compares the relative importance of each index quantitatively, constructs a matrix, calculates the index weight, and mainly has three steps:

[0137] (1) Construct a judgment matrix: compare two indexes to determine the relative importance of two indexes, and construct a judgment matrix X:

[0138]

[0139] In the formula, X i and X jrespectively represent the i-th and j-th indicators, X ij represents the importance of the i-th indicator relative to the j-th indicator. The analytic hierarchy process generally uses the nine-scale method for quantitative description, as shown in the following Table 5.

[0140] Table 5 Nine-scale method meaning table

[0141] χ ij assignment scale Meaning 1 Indicator i is equally important compared to indicator j 3 Indicator i is slightly more important compared to indicator j 5 Indicator i is significantly more important compared to indicator j 7 Indicator i is particularly more important compared to indicator j 9 Indicator i is extremely more important compared to indicator j 2，4，6，8 Indicator i is in the middle of the two above importance levels compared to indicator j reciprocal (χ ji = 1 / χ ij )]]> Importance of indicator j compared to indicator i

[0142] Table 6 Criterion layer weight matrix

[0143] Physical habitat Physico-chemical property Aquatic organism Physical habitat 1 1 0.2 Physico-chemical property 1 1 0.2 Aquatic organism 5 5 1

[0144] (2) Calculate the weight vector and the maximum eigenvalue

[0145] First, calculate the Nth root of the product of each element in each row of the judgment matrix X

[0146]

[0147] Normalize the above results to calculate the weight W of each indicator i , to obtain the weight vector W

[0148]

[0149] W = [w1, w2, …, w n ] T

[0150] Finally, according to the method of simplifying operation, the maximum eigenvalue λ of the judgment matrix X is obtained max :

[0151]

[0152] (3) Consistency verification

[0153] To ensure the scientificity and effectiveness of the weight assignment result and avoid judgment errors caused by incorrect weight assignment, the consistency of the judgment matrix needs to be verified, which is generally judged by calculating the index random consistency ratio C.R. First, calculate the negative average of the remaining eigenvalues C.I. except the maximum eigenvalue of the judgment matrix:

[0154]

[0155] To measure whether the consistency of the judgment matrix is within an acceptable error range, the average random consistency index R.I. is introduced. In this embodiment, the order of the judgment matrix is 3, and R.I. = 0.52. Calculate the index random consistency ratio C.R. If C.R. < 0.1, the verification is passed, otherwise the verification is failed, and the judgment matrix needs to be reconstructed until the consistency verification is passed.

[0156]

[0157] The weight matrix of the index system is shown in Table 6 above, and the weights of the physical habitat, physicochemical property and aquatic biological criterion layers are 14.29%, 14.29% and 71.43%, respectively, C.R. < 0.1, and the consistency test is passed. The comprehensive score of the ecosystem is calculated according to formula (f), and the comprehensive ecological score of the entire river section is 47.26.

[0158] EHI = P * W P + C * W C + B * W B (f)

[0159] In the formula, EHI is the comprehensive score of the ecosystem, WP is the weight of the physical habitat, WC is the weight of the physicochemical property, and WB is the weight of the aquatic organism.

[0160] Step 4, evaluation standard grade division and display results.

[0161] Step 401. The health status of the ecosystem is divided into five grades of very healthy, healthy, sub-healthy, unhealthy and poor state;

[0162] In this embodiment, the score in (80, 100] is set as very healthy, the score in (60, 80] is set as healthy, the score in (40, 60] is set as sub-healthy, the score in (20, 40] is set as unhealthy, and the score in [0, 20] is set as poor state.

[0163] The comprehensive score of the ecosystem calculated by formula (f) is 47.26, which belongs to the sub-healthy state. The specific display results are shown in Figure 7 , wherein brown is poor state, yellow is unhealthy, blue is sub-healthy, green is healthy, and dark green is very healthy.

[0164] The water ecological health evaluation method based on ecological integrity of the present application relies on ecological integrity to construct a comprehensive evaluation index system including three criteria of physical habitat, physicochemical property and aquatic organism, adopts different ecological benchmark determination methods for different types of indexes, and provides more scientific ecological benchmark values. The subjective weighting method and the objective weighting method are combined to weight and score each index and each criterion layer. For each criterion layer, the index data is large, the decision criteria are clear, and the entropy weight method is used for weighting. For calculating the comprehensive score of the ecosystem, the analytic hierarchy process is used for weighting based on the ecological management needs and the ecological regional characteristics, so that the weighting structure is more accurate. Finally, the health status of the ecosystem is represented in a graphical and intuitive manner by graphical annotation and color zoning.

[0165] The above is the description of the preferred embodiments of the present application, which can help the skilled in the art to more fully understand the technical solutions of the present application. However, these embodiments are only illustrative, and the specific implementation of the present application should not be limited to the description of these embodiments. For those skilled in the art to which the present application belongs, without departing from the concept of the present application, a number of simple deductions and transformations can be made, which should be considered as falling within the protection scope of the present application.

Claims

1. A method for water ecological health assessment based on ecological integrity, characterized in that, The specific steps are as follows, Step 1. Determine system criteria, including physical habitat, physicochemical properties, aquatic organisms, and adopt differentiated ecological benchmarks for the alternative indicators; Step 2. The applicability verification, sensitivity verification, and redundancy verification are sequentially performed on the alternative indicators to screen the core indicators; Step 3. The weighting sum of each criterion layer is calculated by combining the entropy weight method and the analytic hierarchy process method to calculate the comprehensive score of the water ecosystem; Step 4. The evaluation standard grade is divided and the results are displayed; Step 3 specifically includes: Step 301. Normalizing the core indicator data; Step 302. Assigning weights to the core indicators using the entropy weight method, and calculating the score of each criterion layer by weighted summation; Step 303. Assigning weights to each criterion layer using the analytic hierarchy process method to calculate the comprehensive score of the water ecosystem; The differentiated ecological benchmark refers to using the historical reference method to determine the ecological benchmark for the point with small fluctuations, strong continuity, or slow response to external stress, and taking the historical state before human activity interference as the ecological benchmark value; For the point with large fluctuations, poor continuity, or fast response to external stress, the reference point method is used to determine the ecological benchmark, and the condition of the point less disturbed by human activities is used to determine the ecological benchmark; In step 303, the analytic hierarchy process is used to assign weights to each criterion layer, specifically including the analytic hierarchy process, which divides the problem structure into hierarchical levels by combining qualitative and quantitative methods, quantitatively compares the relative importance of each indicator, constructs a matrix, and calculates the weight of the indicator.

2. The method for water ecological health assessment based on ecological integrity according to claim 1, characterized in that, The suitability verification is by calculating the coefficient of variation of the alternative indicator: wherein μ is the standard deviation of the indicator, σ is the mean value of the indicator, and the coefficient of variation C υ ≤ 0.15 is a weakly variable indicator; The sensitivity verification is to compare the ecological benchmark value R and the sample value S of the alternative indicators that pass the applicability verification using a box plot, and to remove the indicators with IQ < 2 that do not have sensitivity; The redundancy verification is to perform Pearson correlation analysis on the alternative indicators that pass the sensitivity verification, and if the correlation |r| between two alternative indicators that pass the sensitivity verification is ≥0.95, only one of the indicators is retained.

3. The method for water ecological health assessment based on ecological integrity according to claim 1, characterized in that, The analytic hierarchy process includes the following steps of combining qualitative and quantitative methods to divide the problem structure into hierarchical levels, quantitatively comparing the relative importance of each indicator, constructing a matrix, and calculating the weight of the indicator, (1) Construct a judgment matrix: compare two indicators to determine their relative importance, and construct a judgment matrix X: ， In the formula, X i and X j respectively represent the i-th and j-th indicators, X ij represents the importance of the i-th indicator relative to the j-th indicator; the weighting of the analytic hierarchy process is quantitatively described by the nine-scale method; (2) Calculate the weight vector and the maximum eigenvalue: first calculate the Nth root of the product of each element in each row of the judgment matrix X : and normalize the results to calculate the weight of each indicator , get the weight vector , finally, according to the method of simplifying operation, the maximum eigenvalue of the judgment matrix X is obtained ; (3) Consistency verification: verify the consistency of the judgment matrix by calculating the index random consistency ratio C.R. First, calculate the negative average of the remaining eigenvalues C.I. excluding the largest eigenvalue of the judgment matrix; Introduce the average random consistency index R.I. to measure whether the consistency of the judgment matrix is within an acceptable error range; calculate the index random consistency ratio C.R. If C.R. < 0.1, the verification is passed, otherwise the verification is not passed, and the judgment matrix is reconstructed until the consistency verification is passed.

4. The method for water ecological health assessment based on ecological integrity according to claim 3, characterized in that, The normalization refers to normalizing the core indicators of the more-is-better type according to formula (a), and normalizing the core indicators of the less-is-better type according to formula (b): s = (x - x min ) / (x max - x min ) (a) s = (x max -x) / (x max -x min ) (b) where s is the normalized value of the index, x is the measured value of the index, x max is the maximum value of the measured value of the index, x min is the minimum value of the measured value of the index.

5. The method for water ecological health assessment based on ecological integrity according to claim 3, characterized in that, The entropy weight method is used to weight the core indexes of the same criterion layer, and the score of each criterion layer is calculated according to formula (c), formula (d) and formula (e) respectively. P = 100 *∑(p i *w pi ) (c) C = 100 *∑(c i *w ci ) (d) B = 100 *∑(b i w bi ) (e) wherein P is the physical habitat score, p i is the normalized value of the i-th physical habitat indicator, w pi is the weight of the i-th physical habitat indicator; C is the chemical-physical property score, c i is the normalized value of the i-th chemical-physical property indicator, w ci is the weight of the i-th chemical-physical property indicator; B is the aquatic organism score, b i is the normalized value of the i-th aquatic organism indicator, w bi is the weight of the i-th aquatic organism indicator.

6. The method for water ecological health assessment based on ecological integrity according to claim 3, characterized in that, The comprehensive score of the ecosystem is calculated according to formula (f): EHI = P*W P +C*W C +B*W B (f) In the formula, EHI is the comprehensive score of the ecosystem, WP is the weight of physical habitat, WC is the weight of physicochemical properties, and WB is the weight of aquatic organisms.

7. The method for water ecological health assessment based on ecological integrity according to claim 1, characterized in that, The evaluation standard grade refers to dividing the health status of the water ecosystem into five grades of very healthy, healthy, sub-healthy, unhealthy and poor.

8. The method for water ecological health assessment based on ecological integrity according to claim 1, characterized in that, The display result refers to directly displaying the health status of the water ecosystem in the form of graphical annotation and color zoning according to the division grade of the health status of the water ecosystem.

9. Use of a method for assessing the ecological integrity-based water ecological health according to any one of claims 1 to 8, characterized in that, Health evaluation and / or management restoration for river and / or lake water ecosystems.

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