Method for comprehensive evaluation of river water ecology by fusing benthos and water physicochemical parameters

Abstract

The application discloses a river water ecological comprehensive evaluation method fusing benthos and water physical and chemical parameters, relates to the technical field of river water ecological environment evaluation, and comprises the following steps: constructing a comprehensive evaluation index system based on water physical and chemical parameters and benthic community parameters of a river to be evaluated; calculating water physical and chemical index weights and benthic index weights based on the comprehensive evaluation index system; inputting the comprehensive evaluation index system, the water physical and chemical index weights and the benthic index weights into a pre-constructed biological-physical coupling evaluation model to output a river water ecological comprehensive health index EHI; determining the ecological comprehensive health grade of the river to be evaluated from a pre-constructed ecological grade determination table based on the river water ecological comprehensive health index EHI; and generating and outputting an evaluation result. The application can fuse two types of monitoring data of water physical and chemical parameters and benthos to complete river water ecological comprehensive evaluation, output an evaluation result, and support fine management of a watershed water environment.

Description

Technical Field

[0001] This application relates to the field of river water ecological environment assessment technology, and in particular to a comprehensive river water ecological assessment method that integrates benthic organisms and water body physicochemical parameters. Background Technology

[0002] Current river aquatic ecosystem assessment methods are mainly divided into two categories: single-body physicochemical assessment and single-benthic organism assessment. Single-body physicochemical assessment focuses on indicators such as pH, dissolved oxygen (DO), chemical oxygen demand (COD), ammonia nitrogen (NH3-N), total phosphorus (TP), and total nitrogen (TN). It employs single-factor water quality assessment and the Nemerow pollution index method to classify water pollution levels. This method has the advantages of rapid detection and intuitive quantification, making it the mainstream approach for routine water environment monitoring. Single-benthic organism assessment selects macrobenthic invertebrates as indicator organisms and uses indicators such as the Shannon-Wiener diversity index, Margalef richness index, and Biotic index to reflect the integrity of the biological community structure, thus characterizing the long-term ecological stress state of the river.

[0003] The existing technology has the following drawbacks: (1) The evaluation dimension is singular and the results are one-sided: At present, the industry generally adopts a single dimension to carry out evaluation. For example, only a single water body physicochemical evaluation is used. Relying on the physicochemical parameters of the water body can only reflect the instantaneous water quality of the sample, and cannot reflect the continuous damage caused by long-term cumulative pollution to aquatic organisms. Only a single benthic organism is used, which is easily affected by seasonal and hydrological conditions, making it difficult to accurately identify the source of pollution and unable to distinguish the ecological impact of natural environmental fluctuations and human sewage discharge.

[0004] (2) The coupling and correlation of indicators are weak and the data utilization efficiency is low: A few comprehensive evaluation methods simply superimpose the physical and chemical monitoring data, without building a correlation model between physical and chemical indicators and benthic communities based on the habitat adaptation law of benthic organisms, ignoring the regulatory role of environmental factors such as dissolved oxygen, flow velocity, and riverbed matrix on the habitat and reproduction of benthic organisms, the integration logic of physical and chemical and biological data is rigid, and the evaluation system lacks biological support.

[0005] (3) Fixed weight assignment and poor method universality: Traditional weight assignment methods such as the analytic hierarchy process and conventional entropy weight method have fixed weights and do not differentiate the weights based on the river management level and watershed ecological function. They are poorly adapted to different types of water bodies such as mountain rivers, plain rivers and urban rivers, and the evaluation results are significantly biased. They are difficult to meet the needs of differentiated evaluation of rivers in different watersheds and different hydrological seasons.

[0006] (4) The grading standards are crude and have limited value in guiding restoration: The existing evaluation system only divides the river into rough grades such as excellent and polluted, with broad grading thresholds, making it difficult to accurately identify polluted river sections and core stress factors, and thus unable to provide quantitative support for targeted ecological restoration of rivers.

[0007] Therefore, there is an urgent need to provide a comprehensive evaluation method for river water ecology that integrates benthic organisms and water physicochemical parameters to address at least one of the aforementioned existing deficiencies. Summary of the Invention

[0008] The purpose of this application is to provide a comprehensive evaluation method for river water ecology that integrates benthic organisms and water physicochemical parameters. This method can integrate two types of monitoring data—water physicochemical parameters and benthic organisms—to complete a comprehensive evaluation of river water ecology and output standardized ecological health levels, indicator pollution contribution, and pollution source tracing results, thereby supporting the refined management of watershed water environment.

[0009] To achieve the above objectives, this application provides a comprehensive evaluation method for river aquatic ecology that integrates benthic organisms and water physicochemical parameters, comprising the following steps: S1: Obtaining the water physicochemical parameters and benthic community parameters of the river to be evaluated; S2: Constructing a comprehensive evaluation index system based on the water physicochemical parameters and benthic community parameters; the comprehensive evaluation index system includes a target layer, a criterion layer, and an indicator layer set from top to bottom, with the criterion layer belonging to the target layer and the indicator layer belonging to the corresponding criterion layer; S3: Calculating the weights of the water physicochemical indicators and the benthic indicators based on the comprehensive evaluation index system; S4: Integrating the water physicochemical indicators and benthic indicators, as well as the weights of the water physicochemical indicators and the benthic indicators in the comprehensive evaluation index system... The weighted inputs are fed into a pre-constructed biological-physicochemical coupled evaluation model, which outputs the river water ecological health index (EHI); S5: Based on the river water ecological health index (EHI), the ecological health level of the river to be evaluated is determined from a pre-constructed ecological level determination table; the pre-constructed ecological level determination table includes multiple ecological health levels, each corresponding to an EHI value range, ecological status description, and management recommendations; S6: The evaluation results are generated and output; the evaluation results include the ecological health level of the river to be evaluated, the weights of water physicochemical indicators, the weights of benthic organism indicators, the pollution contribution of each indicator, and the pollution types obtained from source tracing.

[0010] As described above, the sub-steps of S1 are as follows: S11: Divide the river to be evaluated into river sections based on the river basin topography, hydrological characteristics, and the distribution of sewage outlets along the riverbank, and determine multiple sampling sections; S12: Set up multiple sampling points at each sampling section, which are divided into water body physicochemical sampling points and benthic organism sampling points; configure water body physicochemical sampling devices at the water body physicochemical sampling points and benthic organism sampling devices at the benthic organism sampling points; S13: During the same collection period, collect water body physicochemical samples using the water body physicochemical sampling devices, and use detection equipment to detect the water body physicochemical samples to obtain water body physicochemical parameters; collect benthic organism samples using the benthic organism sampling devices, and use screening equipment to screen and sort the benthic organism samples to obtain benthic organism community parameters.

[0011] As above, the sub-step of S2 is as follows: S21: Construct an initial comprehensive evaluation index system based on water body physicochemical parameters and benthic community parameters; the initial comprehensive evaluation index system includes a target layer, a criterion layer, and an initial index layer set from top to bottom. The criterion layer belongs to the target layer, and the initial index layer belongs to the corresponding criterion layer; the target layer is set as the river water ecological comprehensive health index (EHI); the criterion layer is divided into three evaluation dimensions: water body physicochemical dimension, benthic organism dimension, and habitat auxiliary dimension; the initial index layer includes initial water body physicochemical indicators, initial benthic organism indicators, and initial habitat auxiliary indicators. The initial water body physicochemical indicators belong to the water body physicochemical dimension, the initial benthic organism indicators belong to the benthic organism dimension, and the initial habitat auxiliary indicators belong to the habitat auxiliary dimension; S22: Calculate the initial index within each evaluation dimension of the criterion layer. The Pearson correlation coefficients between each pair of indicators in the target layer are calculated. When the absolute value of the Pearson correlation coefficient between two indicators within the same evaluation dimension is greater than the preset correlation threshold, the two indicators are considered to have highly overlapping information. The indicator whose significance probability value in relation to the total phosphorus concentration response is less than the preset significance test threshold is retained, and the other indicator is removed. After completing the redundancy judgment of all indicators within each evaluation dimension, the set of effective indicators after screening is obtained. The set of effective indicators is divided according to the evaluation dimension to form an effective indicator layer including effective water body physicochemical indicators, effective benthic biological indicators, and effective habitat auxiliary indicators. S23: The effective water body physicochemical indicators, effective benthic biological indicators, and effective habitat auxiliary indicators in the effective indicator layer are preprocessed without dimensions to obtain an indicator layer including water body physicochemical indicators, benthic biological indicators, and habitat auxiliary indicators.

[0012] As described above, the sub-step of S23 is as follows: S231: Based on the ecological attributes of the indicators, the effective water body physicochemical indicators, effective benthic biological indicators, and effective habitat auxiliary indicators within the effective indicator layer are divided into positive indicators, negative indicators, and interval optimal indicators; S232: The positive range standardization algorithm is used to perform dimensionless preprocessing on the positive indicators to obtain normalized positive indicators; S233: The negative range standardization algorithm is used to perform dimensionless preprocessing on the negative indicators to obtain normalized negative indicators; S234: The interval standardization method is used to perform dimensionless preprocessing on the interval optimal indicators to obtain normalized interval indicators; S235: The normalized positive indicators, normalized negative indicators, and normalized interval indicators are divided according to their respective evaluation dimensions to form an indicator layer including water body physicochemical indicators, benthic biological indicators, and habitat auxiliary indicators.

[0013] As shown above, the expression for the positive range standardization algorithm is: ;in, For the first The first monitoring sample The normalized value of a positive indicator; For the first The first monitoring sample The original test value of the positive indicator; The first of all monitored samples The minimum value of a positive indicator; The first of all monitored samples The maximum value of a positive indicator.

[0014] As shown above, the expression for the negative range standardization algorithm is: ;in, For the first The first monitoring sample The normalized value of the negative indicator; For the first The first monitoring sample The original test value of the negative indicator; The first of all monitored samples The minimum value of a negative indicator; The first of all monitored samples The maximum value of a negative indicator.

[0015] As shown above, the sub-step of S3 is: S31: Set the correction coefficient according to the control type of the river to be evaluated. S32: Physicochemical indices and correction coefficients of water bodies based on the index layer Calculate the weights of each water body physicochemical index in the water body physicochemical index; S33: Benthic biological index and correction coefficient based on the index layer. Calculate the weight of each benthic organism index in the benthic organism index.

[0016] As shown above, the sub-step of S32 is: S321: Calculate the information entropy weight of each indicator in the physicochemical indicators of the water body using the entropy weight method. S322: Calculate the fluctuation weights of each indicator in the physicochemical properties of water bodies using the coefficient of variation method. S323: Weighting based on indicator information entropy Volatility weight and correction factor The first of the water body physicochemical indicators was obtained. The weight of the water body's physicochemical indicators Among them, the first of the water body physicochemical indicators The weight of the water body's physicochemical indicators The expression is .

[0017] As above, the sub-step of S33 is: S331: Calculate the information entropy weight of each indicator in the benthic organism indicators using the entropy weight method. S332: Calculate the fluctuation weights of each indicator in the benthic organism index using the coefficient of variation method. S333: Weights based on indicator information entropy Volatility weight and correction factor Obtained the first of the benthic biometrics Benthic organism index weights of the item Among them, the first of the benthic organism indicators Benthic organism index weights of the item The expression is .

[0018] As mentioned above, the pre-constructed bio-physicochemical coupled evaluation model is used to calculate the comprehensive health index of river water ecology. The expression for the pre-constructed bio-physicochemical coupling evaluation model is: ;in, The comprehensive health index of river water ecology. The value range is [0,1]; This is the benthic pollution tolerance correction factor. R represents the percentage of pollution-tolerant organisms; The first of the physicochemical indicators of water bodies The weights of the water body's physicochemical indicators for each item; The first of the physicochemical indicators of water bodies Items, , This represents the total number of indicators in the physicochemical properties of water bodies. The first of the benthic bioindicators The weight of the benthic organism indicator for each item; The first of the benthic bioindicators Items, , This represents the total number of indicators in the benthic organism indicators. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0020] Figure 1 A flowchart of one embodiment of a comprehensive evaluation method for river water ecology that integrates benthic organisms and water physicochemical parameters. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] like Figure 1 As shown, this application provides a comprehensive evaluation method for river aquatic ecology that integrates benthic organisms and water physicochemical parameters, including the following steps: S1: Obtain the water physicochemical parameters and benthic community parameters of the river to be evaluated.

[0023] Furthermore, the sub-steps of S1 are as follows: S11: Based on the river basin topography, hydrological characteristics, and the distribution of sewage outlets along the river, the river to be evaluated is divided into river sections, and multiple sampling sections are determined.

[0024] The sampling sections are arranged as follows: sampling sections are set up at locations where the river cross-section morphology changes abruptly, at tributary confluence areas, and in river bends; sampling sections are set up at intervals along the flow direction of the river; for sewage outlets along the riverbank, sampling sections are set up in the upstream area of ​​the sewage outlet and in the downstream area where the water is fully mixed; when there are multiple sewage outlets concentrated along the riverbank, the sampling sections are set up more densely.

[0025] S12: Multiple sampling points are set up at each sampling section. The sampling points are divided into water body physicochemical sampling points and benthic organism sampling points. Water body physicochemical sampling devices are configured at the water body physicochemical sampling points, and benthic organism sampling devices are configured at the benthic organism sampling points.

[0026] Furthermore, the specific number of sampling points is determined based on the river morphology and hydrological conditions. In this application, it is preferred that 3 to 5 sampling points be set up for each sampling section.

[0027] Furthermore, the specific locations of the sampling points are determined based on the river flow distribution and bottom sediment conditions. This application preferably includes both surface and bottom sampling points vertically; surface sampling points are located 0.5m below the free water surface, and bottom sampling points are located 1.5m above the riverbed surface; when the river depth is no more than 1.5m, only surface sampling points are used. Benthic organism sampling points are preferentially located at the riverbed positions corresponding to the vertical lines of the water body physicochemical sampling points; if the riverbed sediment conditions at these locations do not meet the sampling requirements, benthic organism sampling points can be located in the adjacent areas of the vertical lines of the water body physicochemical sampling points.

[0028] Furthermore, the specific model of the water physicochemical sampling device is selected based on the river depth and flow conditions; this application prefers a deep-water sampler.

[0029] Furthermore, the specific model of the benthic organism sampling device is selected based on the riverbed sediment conditions, and the Peterson mud sampler is preferred in this application.

[0030] S13: During the same collection period, water physicochemical samples are collected using a water physicochemical sampling device and tested using a detection device to obtain water physicochemical parameters; benthic organism samples are collected using a benthic organism sampling device and screened and sorted using a screening device to obtain benthic organism community parameters.

[0031] For example, after the water body physicochemical samples are collected, they are refrigerated and stored before testing is carried out; the testing equipment is used to determine the physicochemical indicators of the water body, and may include, but is not limited to, a multi-parameter water quality analyzer and a spectrophotometer; the physicochemical parameters of the water body include at least pH, dissolved oxygen (DO), chemical oxygen demand (COD), ammonia nitrogen (NH3-N), total phosphorus (TP) and total nitrogen (TN).

[0032] For example, the screening equipment uses, but is not limited to, a sieve with an aperture of 0.25 mm; after screening and sorting the benthic organism samples, species identification, individual number statistics are carried out, and habitat substrate type is recorded; the benthic community parameters include at least species composition, individual number of each species, and habitat substrate type.

[0033] Preferably, at least three sets of parallel monitoring units are set up at the same sampling section. Each set of parallel monitoring units simultaneously collects water physicochemical samples and benthic organism samples as monitoring samples. After detection and processing, the corresponding monitoring data (i.e., water physicochemical parameters and benthic community parameters) are obtained. After the detection is completed, the relative error of each indicator in the monitoring data collected by each set of parallel monitoring units is calculated. The monitoring data is considered valid only when the relative error of each indicator corresponding to the entire set of water physicochemical parameters and benthic community parameters is less than or equal to the preset indicator relative error threshold. If the relative error of any indicator is greater than the preset indicator relative error threshold, the monitoring data collected by the set of parallel monitoring units is removed as abnormal data to ensure the reliability of the data calculated from the input indicators.

[0034] Furthermore, the preset relative error threshold for the index can be flexibly selected based on the watershed monitoring conditions, index type, and monitoring instrument accuracy. In this application, the preset relative error threshold for the index is preferably 5%.

[0035] Furthermore, at least one data collection period should be set up during the high-water season, normal-water season, and low-water season respectively; conducting monitoring in different seasons can eliminate monitoring disturbance errors caused by seasonal changes in water temperature and hydrological conditions, and improve the representativeness of monitoring data throughout the year.

[0036] Specifically, step S1 simultaneously collects two types of monitoring data: water physicochemical properties and benthic organisms. This takes into account both instantaneous water quality and long-term ecological status, ensuring that subsequent evaluation data is comprehensive and reliable.

[0037] S2: Construct a comprehensive evaluation index system based on water body physicochemical parameters and benthic community parameters; the comprehensive evaluation index system includes a target layer, a criterion layer and an indicator layer set from top to bottom, with the criterion layer belonging to the target layer and the indicator layer belonging to the corresponding criterion layer.

[0038] Furthermore, the sub-steps of S2 are as follows: S21: Construct an initial comprehensive evaluation index system based on water body physicochemical parameters and benthic community parameters; the initial comprehensive evaluation index system includes a target layer, a criterion layer, and an initial index layer set from top to bottom. The criterion layer belongs to the target layer, and the initial index layer belongs to the corresponding criterion layer; among them, the target layer is set as the river water ecological health index (EHI); the criterion layer is divided into three major evaluation dimensions: water body physicochemical dimension, benthic organism dimension, and habitat auxiliary dimension; the initial index layer includes initial water body physicochemical indicators, initial benthic organism indicators, and initial habitat auxiliary indicators. The initial water body physicochemical indicators belong to the water body physicochemical dimension, the initial benthic organism indicators belong to the benthic organism dimension, and the initial habitat auxiliary indicators belong to the habitat auxiliary dimension.

[0039] Specifically, the initial physicochemical indicators of the water body are obtained directly from the physicochemical parameters of the water body. The initial physicochemical indicators of the water body include: pH, dissolved oxygen (DO), chemical oxygen demand (COD), ammonia nitrogen (NH3-N), total phosphorus (TP) and total nitrogen (TN).

[0040] Initial benthic biometrics were calculated based on benthic community parameters using existing ecological formulas. These initial biometrics included: the Shannon-Wiener diversity index H', the Margalef richness index d, the Pielou evenness index J, and the proportion of pollution-tolerant organisms R. When calculating the proportion of pollution-tolerant organisms R, the pollution tolerance attributes of each benthic species were pre-defined based on existing ecological data.

[0041] Initial habitat auxiliary indicators include: riverbed matrix stability and riparian vegetation coverage; riverbed matrix stability can be comprehensively determined based on the habitat matrix type in the benthic community parameters, while riparian vegetation coverage is obtained simultaneously through field surveys.

[0042] S22: Within each evaluation dimension of the criterion layer, calculate the Pearson correlation coefficient between each pair of indicators in the initial indicator layer; when the absolute value of the Pearson correlation coefficient between two indicators within the same evaluation dimension is greater than the preset correlation critical threshold, it is determined that the information of the two indicators is highly overlapping, and the indicator whose significance probability value in the response relationship with total phosphorus concentration is less than the preset significance test threshold is retained, while the other indicator is removed; after completing the redundancy judgment of all indicators within each evaluation dimension, the set of effective indicators after screening is obtained; the set of effective indicators is divided according to the evaluation dimension to form an effective indicator layer including effective water body physicochemical indicators, effective benthic biological indicators, and effective habitat auxiliary indicators.

[0043] It should be noted that Pearson correlation calculations are performed only for indicators within the same evaluation dimension; correlation assessments are not performed for indicators across different evaluation dimensions. For example, pH, dissolved oxygen (DO), chemical oxygen demand (COD), ammonia nitrogen (NH3-N), total phosphorus (TP), and total nitrogen (TN) within the initial indicator layer all belong to the water body physicochemical dimension; the Shannon-Wiener diversity index H', Margalef richness index d, Pielou evenness index J, and pollution-tolerant organism proportion R all belong to the benthic organism dimension; riverbed matrix stability and riparian vegetation coverage all belong to the habitat auxiliary dimension; correlation calculations are not performed for indicators between the water body physicochemical evaluation dimension, the benthic organism evaluation dimension, and the habitat auxiliary evaluation dimension.

[0044] The Pearson correlation coefficient is used to characterize the degree of linear correlation between two sets of continuous variables. The Pearson correlation coefficient between each pair of indicators in the initial indicator layer can be obtained using existing standard statistical formulas. The calculation of the Pearson correlation coefficient can be carried out directly using the original monitoring values ​​of the indicators, and the calculation process will automatically eliminate the influence of the indicator dimensions. Alternatively, the indicators can be standardized in advance before the correlation calculation is carried out. This application prefers to use the original monitoring values ​​directly for calculation, and the standard statistical formula calculation can be completed using conventional statistical software such as Python, R, and SPSS.

[0045] For each indicator in the initial indicator layer, a response relationship model between that indicator and total phosphorus concentration is constructed. A general linear regression significance test is used to obtain the significance probability value (p-value) corresponding to the response relationship between that indicator and total phosphorus concentration. The response relationship between each indicator and total phosphorus concentration can be represented by a univariate linear regression model, but it is not limited to univariate linear regression; logarithmic regression and exponential regression models can also be used. This application preferably uses a univariate linear regression model, the specific expression of which is as follows: ; in, For the first in the initial index layer The monitoring values ​​of each indicator; The intercept; These are the regression coefficients; This represents the total phosphorus concentration.

[0046] Specifically, the intercept and regression coefficients are solved using the least squares method by fitting the synchronous monitoring dataset. (Complete the first...) After fitting the model to the response relationship between the indicator and total phosphorus concentration, the significance test method of general linear regression was used to obtain the result. The significance probability value (p-value) corresponding to the relationship between the indicator and the total phosphorus concentration is given. The model fitting and significance test methods are all existing mature statistical methods, so they will not be described in detail here.

[0047] Furthermore, the specific values ​​of the correlation threshold and the significance test threshold can be flexibly set according to the watershed type of the river to be evaluated, the total number of monitoring samples, and the regional ecological background characteristics. This application preferably sets the correlation threshold to 0.8 and the significance test threshold to 0.05.

[0048] Preferably, the comprehensive evaluation index system can be adjusted according to the river type: for urban rivers, flow velocity-related indicators can be removed; for mountain rivers, the weight of the riverbed matrix stability index can be increased to adapt to different river habitat characteristics.

[0049] S23: Perform dimensionless preprocessing on the effective water body physicochemical indicators, effective benthic biological indicators, and effective habitat auxiliary indicators in the effective indicator layer to obtain an indicator layer including water body physicochemical indicators, benthic biological indicators, and habitat auxiliary indicators.

[0050] Furthermore, the sub-step of S23 is as follows: S231: Based on the ecological attributes of the indicators, the effective water body physicochemical indicators, effective benthic biological indicators, and effective habitat auxiliary indicators within the effective indicator layer are divided into positive indicators, negative indicators, and interval optimal indicators.

[0051] Specifically, positive indicators are those whose higher values ​​indicate a higher level of river ecological health; negative indicators are those whose higher values ​​indicate a lower level of river ecological health; and interval-optimal indicators are those whose ecological level is optimal when the indicator is within a preset value range, and whose ecological level declines when it deviates from the preset value range.

[0052] Among them, positive indicators include: dissolved oxygen (DO), Shannon-Wiener diversity index H', Margalef richness index d, Pielou evenness index J, benthic organism population, riverbed matrix stability, and riparian vegetation coverage.

[0053] Negative indicators include: chemical oxygen demand (COD), ammonia nitrogen (NH3-N), total phosphorus (TP), and total nitrogen (TN).

[0054] The optimal index for intervals includes pH.

[0055] S232: The positive index is preprocessed dimensionlessly using the positive range standardization algorithm to obtain the normalized positive index.

[0056] Furthermore, the expression for the positive range standardization algorithm is: ; in, For the first The first monitoring sample The normalized value of a positive indicator; For the first The first monitoring sample The original test value of the positive indicator; The first of all monitored samples The minimum value of a positive indicator; The first of all monitored samples The maximum value of a positive indicator.

[0057] Specifically, the normalized positive index is mapped to the interval [0,1].

[0058] S233: The negative range standardization algorithm is used to perform dimensionless preprocessing on the negative index to obtain the normalized negative index.

[0059] Furthermore, the expression for the negative range standardization algorithm is: ; in, For the first The first monitoring sample The normalized value of the negative indicator; For the first The first monitoring sample The original test value of the negative indicator; The first of all monitored samples The minimum value of a negative indicator; The first of all monitored samples The maximum value of a negative indicator.

[0060] Specifically, the normalized negative index is mapped to the interval [0,1].

[0061] S234: The interval standardization method is used to perform dimensionless preprocessing on the interval optimal index to obtain the normalized interval index.

[0062] Specifically, a suitable pH range is delineated based on the river management objectives. The specific calculation formula for the range standardization method can be flexibly selected according to the watershed management standards, and this application does not impose any limitations. For example, the piecewise linear range standardization method or the trapezoidal membership degree range standardization method can be used.

[0063] Among them, the normalized interval index is uniformly mapped to the interval [0,1].

[0064] S235: Normalized positive indicators, normalized negative indicators, and normalized interval indicators are divided according to their respective evaluation dimensions to form an indicator layer that includes water body physicochemical indicators, benthic organism indicators, and habitat auxiliary indicators.

[0065] Among them, habitat auxiliary indicators are used as reference data to assist technicians in comprehensively assessing the ecological status of rivers. For example, when the evaluation result of the river water ecological health index (EHI) is in the critical range of adjacent ecological health levels, the evaluation result can be reviewed in conjunction with habitat auxiliary indicators such as riverbed matrix stability and riparian vegetation coverage.

[0066] Specifically, step S2 improves the fusion effect and data utilization of multi-source data by building a three-dimensional coupled index system, eliminating redundant indicators, and standardizing by type to eliminate dimensional differences.

[0067] S3: Based on the comprehensive evaluation index system, calculate the weights of water body physicochemical indicators and benthic organism indicators respectively.

[0068] Furthermore, the sub-steps of S3 are as follows: S31: Set a correction coefficient based on the control type of the river to be evaluated. .

[0069] Furthermore, the river management type is classified according to the watershed water environment management objectives; the preferred management types in this application include drinking water source rivers, landscape and recreational rivers, and agricultural irrigation rivers.

[0070] Furthermore, the specific value of the correction coefficient is determined based on the control objectives of the river to be evaluated; this application prefers a correction coefficient. The value range is 0.4 to 0.6.

[0071] Furthermore, the logic for selecting the correction coefficient is as follows: the more the control objective emphasizes long-term stable water quality assurance, the larger the correction coefficient is selected to strengthen the contribution of information entropy weight; the more the control objective emphasizes the identification of fluctuations in water indicators, the smaller the correction coefficient is selected to increase the contribution of fluctuation weight. The preferred correction coefficient selection rule in this application is: if the river to be evaluated is a drinking water source river, the preferred correction coefficient is... The correction factor is 0.6; if the river to be evaluated is a scenic and recreational river, the preferred correction factor is... The correction factor is 0.4; if the river to be evaluated is an agricultural irrigation river, the preferred correction factor is 0.4. The value is 0.5; if the river to be evaluated is not a drinking water source river, a landscape and recreation river, or an agricultural irrigation river, a linear interpolation value in the range of 0.4 to 0.6 can be selected according to the focus of control.

[0072] S32: Physicochemical indices and correction coefficients of water bodies based on the index layer Calculate the weight of each water body physicochemical index in the water body physicochemical index.

[0073] Furthermore, the sub-steps of S32 are as follows: S321: Calculate the information entropy weight of each indicator in the physicochemical indicators of water bodies using the entropy weight method. .

[0074] Specifically, the calculation logic of the entropy weight method is as follows: Information entropy is calculated based on the numerical distribution of each indicator among the physicochemical indicators of the water body in all monitored samples; the higher the degree of dispersion of the indicator's values, the smaller the value of the information entropy, and the corresponding information entropy weight. The larger the value, the stronger the indicator's ability to distinguish the ecological state of the river.

[0075] S322: Calculate the fluctuation weight of each indicator in the physicochemical properties of water using the coefficient of variation method. .

[0076] Specifically, the calculation logic of the coefficient of variation method is as follows: For a single indicator among the physicochemical indicators of the water body, the ratio of the standard deviation to the mean is calculated using the values ​​of the indicator from all monitored samples to obtain the coefficient of variation; the coefficients of variation of all indicators among the physicochemical indicators of the water body are normalized to obtain the fluctuation weights corresponding to each indicator; the higher the degree of variation of the indicator value, the greater the corresponding fluctuation weight. The larger.

[0077] S323: Weighting Based on Indicator Information Entropy Fluctuation weight and correction factor To obtain the first of the physicochemical indicators of water bodies The weight of the water body's physicochemical indicators Among them, the first of the water body physicochemical indicators The weight of the water body's physicochemical indicators The expression is .

[0078] S33: Benthic biota indices and correction coefficients based on the indicator layer Calculate the weight of each benthic organism index in the benthic organism index.

[0079] Furthermore, the sub-steps of S33 are as follows: S331: Calculate the information entropy weight of each indicator in the benthic organism index using the entropy weight method. .

[0080] Specifically, the calculation logic of the entropy weight method is as follows: Information entropy is calculated based on the numerical distribution of each indicator among the benthic organism indicators in all monitored samples; the higher the degree of dispersion of the indicator's values, the smaller the value of the information entropy, and the corresponding information entropy weight. The larger the value, the stronger the indicator's ability to distinguish the ecological state of the river.

[0081] S332: Calculate the fluctuation weights of each indicator in the benthic organism index using the coefficient of variation method. .

[0082] Specifically, the calculation logic of the coefficient of variation method is as follows: For a single indicator among the benthic organism indicators, the ratio of the standard deviation to the mean is calculated using the values ​​of the indicator from all monitored samples to obtain the coefficient of variation; the coefficients of variation of all indicators among the benthic organism indicators are normalized to obtain the fluctuation weights corresponding to each indicator; the higher the degree of variation of the indicator value, the greater the corresponding fluctuation weight. The larger.

[0083] S333: Weighting Based on Indicator Information Entropy Fluctuation weight and correction factor Obtained the first of the benthic biometrics Benthic organism index weights of the item Among them, the first of the benthic organism indicators Benthic organism index weights of the item The expression is .

[0084] Specifically, step S3 uses the entropy weight method to calculate the information entropy weight of the indicators, the coefficient of variation method to calculate the fluctuation weight, and the correction coefficient to fuse the two types of weights, information entropy weight and fluctuation weight, to obtain the weights of the water body physicochemical indicators and the weights of the benthic organism indicators. This approach can take into account both the information capacity contained in the indicators and the sensitivity of the indicators to changes in the ecological environment, overcome the limitations of a single weighting method, reduce human interference caused by subjective weighting, and improve the objectivity and scientificity of the indicator weight allocation.

[0085] S4: Input the water body physicochemical indicators and benthic organism indicators, as well as the weights of the water body physicochemical indicators and benthic organism indicators, from the comprehensive evaluation index system into the pre-constructed biological-physicochemical coupled evaluation model. The pre-constructed biological-physicochemical coupled evaluation model outputs the comprehensive health index of river water ecology. .

[0086] Furthermore, a pre-constructed bio-physicochemical coupled evaluation model was used to calculate the comprehensive health index of river water ecology. The expression for the pre-constructed bio-physicochemical coupling evaluation model is: ; in, The comprehensive health index of river water ecology. The value range is [0,1]; This is the benthic pollution tolerance correction factor. R represents the percentage of pollution-tolerant organisms; The first of the physicochemical indicators of water bodies The weights of the water body's physicochemical indicators for each item; The first of the physicochemical indicators of water bodies Items, , This represents the total number of indicators in the physicochemical properties of water bodies. The first of the benthic bioindicators The weight of the benthic organism indicator for each item; The first of the benthic bioindicators Items, , This represents the total number of indicators in the benthic organism indicators.

[0087] Specifically, the pre-constructed biological-physicochemical coupled evaluation model in this application can realize the coupled calculation of water body physicochemical indicators and benthic biological indicators, integrate instantaneous water quality monitoring results with long-term benthic community stress information, and improve the one-sidedness of single-dimensional evaluation; relying on the benthic cleanliness coefficient to perform global correction on the weighted sum total score, avoid the evaluation result distortion problem that is easy to produce by traditional linear weighted models, and make the evaluation results more consistent with the actual ecological health status of the river.

[0088] S5: Based on the River Water Ecological Health Index (EHI), determine the comprehensive ecological health level of the river to be evaluated from a pre-constructed ecological level determination table. The pre-constructed ecological level determination table includes multiple ecological health levels, each of which corresponds to an EHI value range, an ecological status description, and management recommendations.

[0089] Specifically, the contents of the pre-constructed ecological level determination table can be comprehensively determined based on the watershed water body functional zoning, regional water ecological background conditions, and current water environment assessment industry standards; the number of ecological health levels can be flexibly set according to the assessment accuracy requirements. This application preferably uses a pre-constructed ecological level determination table that includes five ecological health levels, as shown in Table 1.

[0090] Table 1 is the ecological level determination table. The specific determination method is as follows: Based on the River Water Ecological Health Index (EHI), traverse each EHI value range in the pre-constructed ecological level determination table, and determine the River Water Ecological Health Index... The ecological health level corresponding to the EHI value range is determined as the comprehensive ecological health level of the river to be evaluated.

[0091] Step S5 relies on the ecological level determination table to complete the index classification determination. While classifying the ecological health level of the river, the corresponding ecological status description and management suggestions can be matched simultaneously, which can facilitate rapid support for watershed water environment management decisions.

[0092] S6: Generate and output evaluation results; the evaluation results include the comprehensive ecological health level of the river to be evaluated, the weight of water body physicochemical indicators, the weight of benthic organism indicators, the pollution contribution of each indicator, and the pollution type obtained from source tracing.

[0093] Furthermore, as an example, the expression for the pollution contribution of each indicator is as follows: ; in, For the first The contribution of each indicator to pollution. , , This represents the total number of indicators in the physicochemical properties of water bodies. This represents the total number of indicators in the benthic organism indicators; For the first The weight of the indicator, when the first indicator If the indicator is an indicator under the physicochemical category of water body, then For the first The weight of the water body's physicochemical indicators for the first item, when the... If the indicator is an indicator under the category of benthic organisms, then For the first The weight of the benthic organism indicator for each item; For the first Item 1, when the first If the indicator is an indicator under the physicochemical category of water body, then The first of the physicochemical indicators of water bodies Item 1, when the first If the indicator is an indicator under the category of benthic organisms, then The first of the benthic bioindicators Item; This is the weighted sum of scores for all indicators.

[0094] As another embodiment, the pollution contribution of each indicator includes: the pollution contribution of each indicator under the water body physicochemical category and the pollution contribution of each indicator under the benthic organism category.

[0095] The expressions for the pollution contribution of each indicator under the water body physicochemical category are as follows: ; The expressions for the pollution contribution of each indicator under the benthic organism category are as follows: ; ; ; in, The first under the water body physicochemical category The contribution of each indicator to pollution. , This represents the total number of indicators in the physicochemical properties of water bodies. This is the benthic pollution tolerance correction factor. R represents the percentage of pollution-tolerant organisms; The first of the physicochemical indicators of water bodies The weights of the water body's physicochemical indicators for each item; The first of the physicochemical indicators of water bodies Item; Weighted score for correcting water body physicochemical indicators; The original weighted score of the physicochemical indicators of the water body; Correct the weighted score for benthic organism indicators; The first of the benthic bioindicators The weight of the benthic organism indicator for each item; The first of the benthic bioindicators Items, , This represents the total number of indicators in the benthic organism indicators.

[0096] It should be noted that: water body physicochemical indicators are instantaneous monitoring data, which are easily affected by short-term hydrological conditions, while benthic biological indicators can characterize long-term ecological stress. Therefore, only the weighted scores of physicochemical indicators are corrected to avoid evaluation distortion caused by repeated correction of biological information. The sum of the pollution contribution of all indicators obtained by solving the expressions of the pollution contribution of each indicator under the water body physicochemical category and the expressions of the pollution contribution of each indicator under the benthic biological category is always equal to 100%, which is in line with the general definition of pollution contribution ratio in the field of water environment assessment.

[0097] As one example, the method for tracing the pollution type is as follows: Benthic community parameters are analyzed using species composition statistics, dominant species screening, and species survival status statistics to obtain the structural characteristics of the benthic community. Different pollution types selectively affect the survival of benthic species and community composition. The community structural characteristics can inversely indicate the type of water pollution. Based on this, pollution type tracing and identification are carried out: if the benthic community is dominated by chironomid larvae and tubifex worms, it is determined to be organic pollution; if a large number of mollusks die off, it is determined to be heavy metal pollution; if the activity of all benthic organisms is significantly reduced, it is determined to be hypoxic pollution.

[0098] Based on the pollution types identified through source tracing, we can provide supporting evidence for targeted ecological restoration of rivers.

[0099] Step S6 integrates multi-dimensional evaluation information to form a complete evaluation result; it introduces benthic organism cleanliness coefficients to correct physicochemical indicators, integrates long-term stress information of benthic communities, and realizes coupled analysis of instantaneous water quality monitoring data and biological community characteristics; it overcomes the judgment bias caused by traditional calculation of contribution based solely on physicochemical indicators, while ensuring that the total pollution contribution of all indicators is 100%, which is in line with the industry's common analysis habits, clearly locates the main stress factors of the river, and supports the refined ecological management and restoration of the watershed.

[0100] Furthermore, the biological-physicochemical coupling evaluation model and ecological level determination table can be updated periodically using newly added watershed monitoring samples. For example, when the number of newly added monitoring samples reaches a preset sample size threshold, the index weights are recalculated, model parameters are calibrated, and ecological level thresholds are adjusted to adapt to the long-term ecological evolution characteristics of the watershed. This updating method can continuously match the dynamic changes in watershed hydrology and habitat conditions, avoiding the evaluation results from gradually deviating from the actual ecological condition of the river due to long-term fixed evaluation models and level determination standards.

[0101] The beneficial effects achieved by this application are as follows: (1) The river water ecology comprehensive evaluation method integrating benthic organisms and water physicochemical parameters proposed in this application can realize the coupled evaluation of instantaneous water quality monitoring information and long-term ecological information of benthic organisms, effectively solving the problem of result bias caused by a single evaluation dimension. Specifically, this application simultaneously collects two types of basic data: water physicochemical and benthic community data. The comprehensive health index and the pollution contribution of physicochemical indicators are uniformly corrected by the benthic pollution tolerance correction coefficient. Short-term water quality fluctuations and long-term biological stress damage are included in the same calculation system, making up for the shortcomings of existing technologies that rely solely on physicochemical or biological data for evaluation and have one-sided conclusions.

[0102] (2) The river water ecology comprehensive evaluation method integrating benthic organisms and water body physicochemical parameters proposed in this application adopts a combined weighting method adapted to watershed management objectives, coupled with a coupled correction-type pollution contribution calculation model, which can accurately identify core pollution indicators and pollution types. Specifically, this application integrates the entropy weight method and the coefficient of variation method to calculate the weight of indicators, and sets differentiated correction coefficients according to the river function type to reduce the subjectivity of weighting; at the same time, it completes pollution source tracing based on the structural characteristics of benthic organism communities, which can quantify the actual ecological stress ratio of each indicator, and solve the problem that traditional evaluation and classification are rough and cannot provide quantitative support for targeted ecological restoration.

[0103] (3) The integrated river water ecology evaluation method of this application, which integrates benthic organisms and water body physicochemical parameters, forms a complete and standardized full-process evaluation system with unified algorithms that are adaptable to various river water bodies. Specifically, from on-site sampling, standardization of indicator selection, weight calculation, comprehensive index solution, health level classification to integrated output of evaluation results, the entire process has clear and executable operating rules and mathematical calculation models, eliminating the need for extensive subjective human judgment; the parameter thresholds within the system can be flexibly adjusted according to watershed characteristics, making it applicable to rivers with different functions such as drinking water sources, landscapes, and agricultural irrigation, with a wider range of applications.

[0104] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the scope of protection of this application is intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application. Obviously, those skilled in the art can make various alterations and variations to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of protection of this application and its equivalents, this application also intends to include these modifications and variations.

Claims

1. A comprehensive evaluation method for river aquatic ecology that integrates benthic organisms and water physicochemical parameters, characterized in that, Includes the following steps: S1: Obtain the water physicochemical parameters and benthic community parameters of the river to be evaluated; S2: Construct a comprehensive evaluation index system based on water body physicochemical parameters and benthic community parameters; the comprehensive evaluation index system includes a target layer, a criterion layer and an indicator layer set from top to bottom, with the criterion layer belonging to the target layer and the indicator layer belonging to the corresponding criterion layer; S3: Based on the comprehensive evaluation index system, calculate the weights of water body physicochemical indicators and benthic organism indicators respectively; S4: Input the water body physicochemical indicators and benthic biological indicators in the comprehensive evaluation index system, as well as the weights of the water body physicochemical indicators and benthic biological indicators, into the pre-constructed biological-physicochemical coupled evaluation model. The pre-constructed biological-physicochemical coupled evaluation model outputs the river water ecological comprehensive health index EHI. S5: Based on the River Water Ecological Health Index (EHI), determine the comprehensive ecological health level of the river to be evaluated from a pre-constructed ecological level determination table; the pre-constructed ecological level determination table includes multiple ecological health levels, each of which corresponds to an EHI value range, an ecological status description, and management recommendations. S6: Generate and output evaluation results; the evaluation results include the comprehensive ecological health level of the river to be evaluated, the weight of water body physicochemical indicators, the weight of benthic organism indicators, the pollution contribution of each indicator, and the pollution type obtained from source tracing.

2. The comprehensive evaluation method for river aquatic ecology integrating benthic organisms and water physicochemical parameters according to claim 1, characterized in that, The sub-steps of S1 are: S11: Based on the river basin topography, hydrological characteristics, and the distribution of sewage outlets along the river, the river to be evaluated is divided into river sections, and multiple sampling sections are determined; S12: Multiple sampling points are set up at each sampling section. The sampling points are divided into water body physicochemical sampling points and benthic organism sampling points. Water body physicochemical sampling devices are set up at the water body physicochemical sampling points, and benthic organism sampling devices are set up at the benthic organism sampling points. S13: During the same collection period, water physicochemical samples are collected using a water physicochemical sampling device and tested using a detection device to obtain water physicochemical parameters; benthic organism samples are collected using a benthic organism sampling device and screened and sorted using a screening device to obtain benthic organism community parameters.

3. The comprehensive evaluation method for river aquatic ecology integrating benthic organisms and water physicochemical parameters according to claim 1, characterized in that, The sub-steps of S2 are: S21: Construct an initial comprehensive evaluation index system based on water body physicochemical parameters and benthic community parameters; the initial comprehensive evaluation index system includes a target layer, a criterion layer, and an initial index layer set from top to bottom. The criterion layer belongs to the target layer, and the initial index layer belongs to the corresponding criterion layer; among them, the target layer is set as the river water ecological health index (EHI); the criterion layer is divided into three major evaluation dimensions: water body physicochemical dimension, benthic organism dimension, and habitat auxiliary dimension; the initial index layer includes initial water body physicochemical indicators, initial benthic organism indicators, and initial habitat auxiliary indicators. The initial water body physicochemical indicators belong to the water body physicochemical dimension, the initial benthic organism indicators belong to the benthic organism dimension, and the initial habitat auxiliary indicators belong to the habitat auxiliary dimension; S22: Within each evaluation dimension of the criterion layer, calculate the Pearson correlation coefficient between each pair of indicators in the initial indicator layer; when the absolute value of the Pearson correlation coefficient between two indicators within the same evaluation dimension is greater than the preset correlation critical threshold, it is determined that the information of the two indicators is highly overlapping, and the indicator whose significance probability value in the response relationship with total phosphorus concentration is less than the preset significance test threshold is retained, while the other indicator is removed; after completing the redundancy judgment of all indicators within each evaluation dimension, the set of effective indicators after screening is obtained; the set of effective indicators is divided according to the evaluation dimension to form an effective indicator layer including effective water body physicochemical indicators, effective benthic biological indicators, and effective habitat auxiliary indicators; S23: Perform dimensionless preprocessing on the effective water body physicochemical indicators, effective benthic biological indicators, and effective habitat auxiliary indicators in the effective indicator layer to obtain an indicator layer including water body physicochemical indicators, benthic biological indicators, and habitat auxiliary indicators.

4. The comprehensive evaluation method for river aquatic ecology integrating benthic organisms and water physicochemical parameters according to claim 3, characterized in that, The sub-steps of S23 are as follows: S231: Based on the ecological attributes of the indicators, the effective water body physicochemical indicators, effective benthic biological indicators, and effective habitat auxiliary indicators within the effective indicator layer are divided into positive indicators, negative indicators, and interval optimal indicators. S232: The positive index is preprocessed with a dimensionless algorithm using the positive range standardization algorithm to obtain the normalized positive index; S233: The negative range standardization algorithm is used to perform dimensionless preprocessing on the negative index to obtain the normalized negative index; S234: The interval-optimal index is preprocessed with dimensionless standardization to obtain the normalized interval index. S235: Normalized positive indicators, normalized negative indicators, and normalized interval indicators are divided according to their respective evaluation dimensions to form an indicator layer that includes water body physicochemical indicators, benthic organism indicators, and habitat auxiliary indicators.

5. The comprehensive evaluation method for river aquatic ecology integrating benthic organisms and water physicochemical parameters according to claim 4, characterized in that, The expression for the positive range standardization algorithm is: ； in, For the first The first monitoring sample The normalized value of a positive indicator; For the first The first monitoring sample The original test value of the positive indicator; The first of all monitored samples The minimum value of a positive indicator; The first of all monitored samples The maximum value of a positive indicator.

6. The comprehensive evaluation method for river aquatic ecology integrating benthic organisms and water physicochemical parameters according to claim 4, characterized in that, The expression for the negative range normalization algorithm is: ； in, For the first The first monitoring sample The normalized value of the negative indicator; For the first The first monitoring sample The original test value of the negative indicator; The first of all monitored samples The minimum value of a negative indicator; The first of all monitored samples The maximum value of a negative indicator.

7. The comprehensive evaluation method for river aquatic ecology integrating benthic organisms and water physicochemical parameters according to claim 1, characterized in that, The sub-steps of S3 are: S31: Set a correction coefficient based on the control type of the river to be evaluated. ; S32: Physicochemical indices and correction coefficients of water bodies based on the index layer Calculate the weight of each water body physicochemical index in the water body physicochemical index; S33: Benthic biota indices and correction coefficients based on the indicator layer Calculate the weight of each benthic organism index in the benthic organism index.

8. The comprehensive evaluation method for river aquatic ecology integrating benthic organisms and water physicochemical parameters according to claim 7, characterized in that, The sub-steps of S32 are as follows: S321: Calculate the information entropy weight of each indicator in the physicochemical indicators of water bodies using the entropy weight method. ; S322: Calculate the fluctuation weight of each indicator in the physicochemical properties of water using the coefficient of variation method. ; S323: Weighting Based on Indicator Information Entropy Fluctuation weight and correction factor To obtain the first of the physicochemical indicators of water bodies The weight of the water body's physicochemical indicators Among them, the first of the water body physicochemical indicators The weight of the water body's physicochemical indicators The expression is .

9. The comprehensive evaluation method for river aquatic ecology integrating benthic organisms and water physicochemical parameters according to claim 7, characterized in that, The sub-steps of S33 are: S331: Calculate the information entropy weight of each indicator in the benthic organism index using the entropy weight method. ; S332: Calculate the fluctuation weights of each indicator in the benthic organism index using the coefficient of variation method. ; S333: Weighting Based on Indicator Information Entropy Fluctuation weight and correction factor Obtained the first of the benthic biometrics Benthic organism index weights of the item Among them, the first of the benthic organism indicators Benthic organism index weights of the item The expression is .

10. The comprehensive evaluation method for river aquatic ecology integrating benthic organisms and water physicochemical parameters according to claim 1, characterized in that, A pre-constructed bio-physicochemical coupled evaluation model was used to calculate the comprehensive health index of river water ecology. The expression for the pre-constructed bio-physicochemical coupling evaluation model is: ； in, The comprehensive health index of river water ecology. The value range is [0,1]; This is the benthic pollution tolerance correction factor. R represents the percentage of pollution-tolerant organisms; The first of the physicochemical indicators of water bodies The weights of the water body's physicochemical indicators for each item; The first of the physicochemical indicators of water bodies Items, , This represents the total number of indicators in the physicochemical properties of water bodies. The first of the benthic bioindicators The weight of the benthic organism indicator for each item; The first of the benthic bioindicators Items, , This represents the total number of indicators in the benthic organism indicators.

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