Physical and chemical index water environment quality evaluation method based on CRITIC method

Abstract

The invention relates to the field of surface water quality safety evaluation, in particular to a CRITIC method-based physical and chemical index water environment quality evaluation method, which comprises the following steps of: determining a quality evaluation index based on a water body type; according to the selected quality evaluation index, calculating the condition of the quality evaluation index and then assigning a score; an original index data matrix is constructed to store assigned scores of the quality evaluation indexes, and nondimensionalization is carried out on data values in the original index data matrix; calculating the standard deviation of data values in the original index data matrix, and calculating the conflict of the evaluation indexes; calculating the information amount of the quality evaluation index, and calculating the weight of the quality evaluation index; and calculating a comprehensive index, and rating the water environment quality according to the comprehensive index. The method has the effects of improving the accuracy of a calculation result and improving the accuracy of a water environment quality evaluation result in the water environment quality evaluation process.

Description

Technical Field

[0001] The present invention relates to the field of surface water quality safety assessment, and in particular to a water environment quality assessment method based on CRITIC method using physical and chemical indicators. Background Art

[0002] Water quality assessment in water areas is the basic work of water environment management. Only by adopting scientific and reasonable water quality assessment methods can we accurately reflect the current water quality and pollution status, clarify the laws of water quality changes and developments, identify major pollution problems, and provide a basis for water pollution control, water function zoning, water environment planning and water environment management.

[0003] With the continuous emergence of new pollutants, they pose a threat to the survival of aquatic organisms, and the protection of surface water quality must be strengthened. Surface water quality evaluation is an important means to achieve surface water protection. When evaluating whether the water quality is safe, it is often necessary to determine whether the concentrations of various pollutants contained in the evaluated surface water are within the required maximum limits. The traditional methods used in surface water environmental quality evaluation mainly include single factor method. Generally, the excess index method is used according to national standards or background values. The evaluation results of the worst water quality factor among multiple evaluation factors that have been included in the management are selected as the comprehensive evaluation results. The method is simple and intuitive. However, the traditional single factor method does not consider the new pollutant indicators that pose a major risk to the aquatic environment and are not included in the management. At the same time, the evaluation results mainly depend on the most serious pollution factor, and the role of other factors is weakened, and the evaluation effect is poor. As a result, the existing water quality evaluation technology has problems such as the evaluation results and calculation results are prone to deviations, and the calculation process involves many parameters and indicators that are difficult to achieve, which is not conducive to the rapid and accurate evaluation of whether the water quality is safe. Summary of the invention

[0004] In order to solve the problem that in the process of water environment quality evaluation, the calculation results have obvious deviations, resulting in low accuracy of the water environment quality evaluation results, the present invention provides a water environment quality evaluation method based on physical and chemical indicators of the CRITIC method.

[0005] The present invention provides a water environment quality evaluation method based on the CRITIC method using physical and chemical indicators, which adopts the following technical scheme:

[0006] A water environment quality evaluation method based on physical and chemical indicators of CRITIC method, comprising the following steps:

[0007] Determine the quality evaluation indicators based on the water body type, including comprehensive pollution status, comprehensive nutrient status, heavy metal risk status and organic pollution risk status;

[0008] According to the selected quality evaluation index, calculate the status of the quality evaluation index and then assign points;

[0009] Construct the original indicator data matrix to save the scores of quality evaluation indicators, and make the data values ​​in the original indicator data matrix dimensionless;

[0010] Calculate the standard deviation of the data values ​​in the original indicator data matrix, and further calculate the conflict of the evaluation indicators through the standard deviation;

[0011] The information content of the quality evaluation index is calculated by standard deviation and conflict, and the weight of the quality evaluation index is calculated according to the information content;

[0012] The comprehensive index is calculated according to the weights of the quality evaluation indicators, and the water quality is rated according to the comprehensive index.

[0013] In a specific implementation scheme, the calculation method of the comprehensive pollution status is:

[0014] First calculate the exceeding range F1, exceeding frequency F2 and exceeding amplitude F3, and then use the formula:

[0015]

[0016] Calculate the comprehensive water quality index WQI.

[0017] In a specific implementation scheme, the calculation formula of the excess range F1 is:

[0018]

[0019] In the above formula, m is the number of pollution indicators that have exceeded the standard, and M is the number of all pollution indicators;

[0020] The calculation formula of the excess frequency F2 is:

[0021]

[0022] In the above formula, n is the number of times the pollution index has exceeded the standard, and N is the total number of monitoring times for all pollution indexes;

[0023] The calculation method of the excess amplitude F3 is:

[0024] First calculate the offset ei, calculate the indicator offset θ through the offset ei, normalize the indicator offset θ to get nse, and then use the formula:

[0025]

[0026] Calculate the excess margin F3.

[0027] In a specific implementation scheme, the calculation formula of the indicator deviation θ is:

[0028] In a specific embodiment, the method for calculating the comprehensive nutritional status is:

[0029] Calculate the nutritional status index of the nutritional indicators and then use the formula:

[0030]

[0031] Calculate the comprehensive nutritional status index TLI(∑), where TLI(j) is the nutritional status index of the jth nutritional indicator; X is the number of nutritional indicators; W j is the weight of the nutritional status index of the j-th nutritional indicator that is pre-assigned.

[0032] In a specific implementation scheme, the calculation method of heavy metal risk status is:

[0033] By formula:

[0034]

[0035] Calculation of heavy metal risk status index R in water bodies M , where Y is the total number of heavy metal types, C My is the concentration of the yth heavy metal in the water, S My is the maximum allowable concentration of the yth heavy metal in water.

[0036] In a specific embodiment, C is calculated My If multiple monitoring sections are involved, take the C of each monitoring section. My The average value of .

[0037] In a specific embodiment, the method for calculating the risk status of organic pollutants is:

[0038] By formula:

[0039]

[0040] Calculation of organic pollutant risk status index R o , where Z is the total number of organic pollutants, C oz is the concentration of the zth organic pollutant in the water body, S oz It is the maximum allowable concentration of the zth organic pollutant in water.

[0041] In a specific embodiment, C is calculated oz If multiple monitoring sections are involved, take the C of each monitoring section. oz The average value of .

[0042] In a specific implementation scheme, the method for calculating the comprehensive index is:

[0043] The sub-comprehensive index of each quality evaluation indicator is calculated according to the weight of the quality evaluation indicator, and all the sub-comprehensive indexes are added together to obtain the comprehensive index.

[0044] In summary, the present invention includes at least one of the following beneficial technical effects:

[0045] 1. By calculating the status of different quality evaluation indicators and assigning points, and then calculating the weights of different quality evaluation indicators, a comprehensive index is calculated to evaluate the water quality, thereby improving the comprehensiveness and accuracy of the calculation of water quality evaluation indicators and the accuracy of water quality evaluation.

[0046] 2. When calculating the comprehensive index, the data values ​​of each quality evaluation index are first dimensionless to facilitate the subsequent calculation of the comprehensive index and improve the accuracy of the calculation of the comprehensive index. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a flow chart of the evaluation method. DETAILED DESCRIPTION

[0048] The following is combined with Figure 1 The present invention is described in further detail.

[0049] Reference Figure 1 The physical and chemical indicators water environment quality evaluation method based on the CRITIC method includes the following steps:

[0050] S100, determining water environment quality evaluation indicators based on physical and chemical indicators based on different water body types.

[0051] Conduct water body type assessment and indicator survey on the water environment, and collect test data or conduct actual tests on the water environment.

[0052] The indicators that need to be tested in water environment quality evaluation are taken as necessary indicators, and the items in the entity pollution characteristics and management requirements are taken as reference indicators, so as to obtain the quality evaluation indicators of the water environment that need to be tested, as shown in Table 1.

[0053] Table 1

[0054]

[0055] S200, calculating the status of the water environment quality evaluation index and assigning points.

[0056] S210, calculating the comprehensive pollution status index and assigning points.

[0057] The pollution index of the comprehensive pollution status is obtained by evaluating the comprehensive water quality index of the monitoring section in each month, involving dissolved oxygen, pH, fluoride (in F - ), sulfate (as SO42- The monitoring sections include national control sections, provincial control sections and municipal control sections.

[0058] The water quality grade is evaluated using the Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) method, which takes into account the exceedance range F1, exceedance frequency F2 and exceedance amplitude F3.

[0059] The exceeding range F1 indicates the percentage of the number of pollution indicators that have exceeded the standard to the total number of pollution indicators. The calculation formula is as follows:

[0060]

[0061] In the formula, m is the number of pollution indicators that have exceeded the standard, and M is the total number of pollution indicators.

[0062] The frequency of exceeding the standard F2 indicates the number of times the pollution index exceeded the standard during the monitoring process, as a percentage of the total number of times all pollution indexes were monitored. The calculation formula is as follows:

[0063]

[0064] Where n is the number of times the pollution index exceeded the standard during the monitoring process, and N is the total number of monitoring times for all pollution indicators.

[0065] The excess range F3 indicates the extent to which the actual value of the pollution index in the water environment exceeds the standard value. When calculating the excess range F3, the number of times the pollution index exceeds the standard is counted, and then the offset ei is calculated. Exceeding the standard is divided into: the exceeding standard is that the standard value must not be exceeded, but the actual value exceeds the standard value; and the exceeding standard is that the standard value must not be less than the standard value, but the actual value does not reach the standard value. The actual value is the test data obtained by the test in the water environment, and the standard value is the preset threshold. Therefore, according to different exceeding conditions, two calculation forms are set:

[0066] When the exceeding standard is that the standard value must not be exceeded, the calculation formula of the offset ei is as follows:

[0067]

[0068] In the formula, C i is the actual value of the ith monitoring, that is, the value of the pollution index that exceeds the standard in the ith monitoring, C si is the standard value of the ith monitoring.

[0069] When the exceeding standard is not less than the standard value, the calculation formula of the offset ei is as follows:

[0070]

[0071] The standardized index deviation θ is calculated by adding the deviation ei of the pollution index in a single monitoring and dividing it by the total number of monitoring times for all pollution indexes. The calculation formula is as follows:

[0072]

[0073] The excess amplitude F3 is a progressive function, and the calculation formula is as follows:

[0074]

[0075] Where nse is the normalized value of the indicator offset θ.

[0076] The comprehensive water quality index WQI, that is, the value of the comprehensive pollution status index, can be obtained by the following formula:

[0077]

[0078] In the formula, 1.732 is the scaling factor, and the obtained water quality comprehensive index WQI is a value between [0,100], where 0 represents the worst water quality and 100 represents the best water quality.

[0079] The indicators are assigned points according to the comprehensive water quality index WQI, as shown in Table 2.

[0080] Table 2

[0081] Water quality comprehensive index (95,100] (80,95] (65,80] (45,65] (0,45] Index scoring 100 80 60 40 20

[0082] S220, calculating and scoring the comprehensive nutritional status index.

[0083] Before calculating the comprehensive nutritional status index, it is necessary to calculate the nutritional status index of multiple nutritional indicators. In this specific embodiment, the nutritional status index of chlorophyll TLI (chla), the nutritional status index of total phosphorus TLI (TP), the nutritional status index of total nitrogen TLI (TN), the nutritional status index of transparency TLI (SD) and the nutritional status index of permanganate index TLI (I Mn ) as an example, the calculation formula is as follows:

[0084]

[0085]

[0086]

[0087]

[0088]

[0089] In the formula,

[0090] ρchla is the chlorophyll concentration value, in mg / L;

[0091] ρ TN is the total nitrogen concentration value, in mg / L;

[0092] ρ TP is the total phosphorus concentration value, in mg / L;

[0093] D SD is the transparency, the unit is m;

[0094] ρI Mn It is the potassium permanganate index concentration value, the unit is mg / L.

[0095] The comprehensive nutritional status was further calculated by the following formula:

[0096]

[0097] In the formula, TLI (∑) is the comprehensive nutritional status index;

[0098] TLI(j) is the nutritional status index of the jth nutritional indicator;

[0099] X is the number of nutritional indicators, which is 5 in this embodiment;

[0100] W j is the weight of the nutritional status index of the jth nutritional indicator, specifically: W chla =0.5996,W TN =0.0718,W TP =0.137,W SD =0.0075,W IMn =0.1840.

[0101] According to the calculated comprehensive nutritional status index, points are assigned with reference to Table 3.

[0102] Table 3

[0103] Comprehensive nutritional status index TLI (∑) <40 [40，50) [50，60) [60，70) ≥70 Nutritional status Poor nutrition Medium Nutrition Mildly eutrophic Moderately eutrophic Severe eutrophication Points 100 75 50 25 0

[0104] S230, calculating the heavy metal risk status index and assigning a score.

[0105] The calculation formula of the heavy metal risk status index in water bodies is as follows:

[0106]

[0107] In the formula, R M is the risk status index of heavy metals in water; C My is the concentration of the yth heavy metal in the water, in mg / L; there are Y types of heavy metals, calculate CMy If multiple monitoring sections are involved, take the C of each monitoring section. My The average value of

[0108] S My It is the maximum allowable concentration of the yth heavy metal in water, in mg / L.

[0109] According to the calculated heavy metal risk status index in water bodies, points are assigned by referring to Table 4.

[0110] Table 4

[0111] Heavy Metal Risk Status Index ≥1.5 [1，1.5) [0.7，1) [0.3，0.7) <0.3 Index scoring 20 40 60 80 100

[0112] S240, calculate the risk status of organic pollutants and assign points.

[0113] The risk status index of organic pollutants in water bodies is calculated by the following formula.

[0114]

[0115] In the above formula, R o is the organic pollutant risk status index;

[0116] Co z is the concentration of the zth organic pollutant in the water, in mg / L; there are Z kinds of organic pollutants, calculate Co z If multiple monitoring sections are involved, take the C of each monitoring section. oz The average value of

[0117] S oz It is the maximum allowable concentration of the zth organic pollutant in water, in mg / L.

[0118] According to the calculated risk status index of organic pollutants in water bodies, points are assigned by referring to Table 5.

[0119] Table 5

[0120] Organic Pollutant Risk Status Index ≥1.5 [1，1.5) [0.7，1) [0.3，0.7) <0.3 Index scoring 20 40 60 80 100

[0121] It should be noted that there is no chronological order between steps S210 - S240 , and the step numbers are used to facilitate the distinction between different steps.

[0122] S300, weight calculation of quality evaluation indicators using the CRITIC method.

[0123] The original index data matrix R is constructed by assigning scores to the water samples and the quality evaluation indexes calculated in step S200.

[0124]

[0125] There are A water samples in total, B quality evaluation indicators in total, r ab Represents the data value of the bth quality evaluation indicator in the ath water body sample.

[0126] Due to different quality evaluation indicators, there are differences in the evaluation methods. For example, in the comprehensive pollution status of S200, the higher the index, the better the water quality evaluation, which is called a positive indicator; while the heavy metal risk status index is the opposite, the lower the index, the better the water quality evaluation, which is called a negative indicator. In some other quality evaluation indicators, the closer the index is to a fixed value, the better the water quality, which is called a fixed moderation index. Different calculation methods are set for positive indicators, negative indicators and fixed moderation indicators to make the quality evaluation indicators dimensionless.

[0127] For positive indicators:

[0128]

[0129] In the formula, r′ ab For r ab Normalized value after dimensionless transformation;

[0130] min(r ab ) is the minimum value in the original indicator data matrix R;

[0131] max(r ab ) is the maximum value in the original indicator data matrix R.

[0132] For negative indices:

[0133]

[0134] For fixed moderation indicators:

[0135]

[0136] In the formula, r a Is a constant.

[0137] Calculate the standard deviation of the quality evaluation index, and further calculate the conflict of the quality evaluation index through the correlation coefficient. The calculation formula of the standard deviation is as follows:

[0138]

[0139] In the above formula, is the average value of all data values ​​in the original indicator data matrix R, S b Represents the standard deviation of the bth quality evaluation index. The calculation formula for conflict is as follows:

[0140]

[0141] In the formula, τ ab Represents the correlation coefficient between the pth evaluation index of the qth water sample.

[0142] According to the obtained standard deviation S p and conflict R p Further calculation is performed to obtain the information content of the evaluation indicators in the original indicator data. The greater the information content of the evaluation indicator, the greater the role of the quality evaluation indicator in the overall quality evaluation system and the higher the weight. The calculation formula of the information content is as follows:

[0143]

[0144] In the above formula, D b That is the amount of information.

[0145] So further through the formula:

[0146]

[0147] Calculate the weight of the quality evaluation index, F b is the weight of the bth quality evaluation index.

[0148] S400, calculates a comprehensive index based on the weights of quality evaluation indicators and rates water quality based on the comprehensive index.

[0149] First, calculate the sub-comprehensive index of each quality evaluation index by weight, then add up all the sub-comprehensive indexes to get the comprehensive index. Finally, the quality of the water body is rated according to the comprehensive index and the pre-divided evaluation index rating. The evaluation index rating is shown in Table 6.

[0150] Table 6

[0151] Composite Index [80，100] [60，80) [40.60) [20，40) [0，20) Evaluation index rating excellent good generally Poor Difference

[0152] For ease of understanding, the following uses the data of 10 sampling points in a lake in the Yangtze River Basin as an example to evaluate the water quality of 10 sections using the above-mentioned physical and chemical indicator water environment quality evaluation method based on the CRITIC method. Sections correspond to sampling points one by one, that is, sampling point 1 corresponds to section 1, sampling point 2 corresponds to section 2, and so on.

[0153] S100, determining water environment quality evaluation indicators based on physical and chemical indicators based on water body types.

[0154] Based on the assessment and investigation of water body types, the comprehensive pollution status, comprehensive nutrient status, heavy metal risk status and organic pollutant risk status are determined as quality evaluation indicators, and water environment detection data are collected.

[0155] S200, calculate and score the comprehensive pollution status, comprehensive nutritional status, heavy metal risk status and organic pollutant risk status.

[0156] The calculation results and scores of the comprehensive pollution status are shown in Table 7, the calculation results and scores of the comprehensive nutritional status are shown in Table 8, the calculation results and scores of the heavy metal risk status are shown in Table 9, and the calculation results and scores of the organic pollutant risk status are shown in Table 10.

[0157] Table 7

[0158] serial number DO pH COD <![CDATA[ - ]]> <![CDATA[ - ]]> <![CDATA[SO4 2- ]]> Ammonia nitrogen WQ Points Section 1 8.93 8.44 6.43 0.20 8.48 10.20 0.044 100 100 Section 2 10.4 8.84 9.73 0.31 15.07 19.85 0.037 100 100 Section 3 8.79 6.81 4.08 0.29 14.50 16.75 0.009 100 100 Section 4 9.8 8.27 4.08 0.24 21.81 23.08 0.034 100 100 Section 5 9.48 8.1 3.77 0.26 16.21 18.43 0.015 100 100 Section 6 9.54 8.36 4.55 0.28 15.99 24.34 0.069 100 100 Section 7 9.37 8.18 5.96 0.22 12.19 10.06 0.037 100 100 Section 8 8.88 7.65 - 0.28 14.31 18.40 - 100 100 Section 9 8.48 8.31 4.71 0.19 9.46 10.84 0.110 100 100 Section 10 10.3 7.67 3.29 0.22 15.23 16.35 0.011 100 100

[0159] Table 8

[0160]

[0161] Table 9

[0162]

[0163]

[0164] Table 10

[0165] serial number TDCIPP <![CDATA[R o ]]> Points Section 1 646.18 1.56 20 Section 2 2505.3 6.07 20 Section 3 869.17 2.10 20 Section 4 1038.08 2.51 20 Section 5 194.94 0.47 80 Section 6 333.38 0.81 60 Section 7 273.71 0.66 60 Section 8 927.21 2.25 20 Section 9 727.92 1.76 20 Section 10 1351.98 3.27 20

[0166] The data in Table 7 are the concentrations of the corresponding pollutants. Except for chlorophyll, the units are all mg / L. In Table 7, DO is dissolved oxygen and COD is chemical oxygen demand. The data in Table 8 are the parameters of the corresponding nutritional indicators. Except for transparency in m and chlorophyll concentration in μg / L, the other units are all mg / L. The "-" in Tables 7 and 8 means that the corresponding parameters have not been measured.

[0167] Table 9 shows the concentration of heavy metal elements in water, in μg / L. Table 10 shows the concentration of TDCIPP in water, in μg / L.

[0168] S300, weight calculation of quality evaluation indicators using the CRITIC method.

[0169] First, calculate the standard deviation of the comprehensive pollution status index, comprehensive nutritional status index, heavy metal risk status index and organic pollutant risk status index. The calculation results are shown in Table 11.

[0170] Table 11

[0171] item Sample size average value Standard Deviation WQ 10 100.00 0.000 TLI(∑) 10 42.967 9.580 <![CDATA[R M ]]> 10 0.084 0.027 <![CDATA[R o ]]> 10 2.146 1.636

[0172] Calculate WQI, TLI(∑), R by correlation coefficient M and R oThe conflict of the two items is calculated, and the amount of information is further calculated, and the weight is assigned according to the amount of information. The calculation results of the conflict and weight are shown in Table 12.

[0173] Table 12

[0174] item Variability (standard deviation) Conflict Amount of information Weight WQ 0 3 0 0.00％ TLI(∑) 9.58 3.62 34.674 87.57％ <![CDATA[R M ]]> 0.027 3.107 0.085 0.21％ <![CDATA[R o ]]> 1.636 2.956 4.837 12.22％

[0175] S400, calculate the comprehensive index of each sampling point according to the calculated weight, and rate the water quality according to the comprehensive index. The comprehensive index of each sampling point is shown in Table 13.

[0176] Table 13

[0177]

[0178]

[0179] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A water environment quality evaluation method based on physicochemical indicators of CRITIC method, characterized by: The steps include: Determine the quality evaluation indicators based on the water body type, including comprehensive pollution status, comprehensive nutrient status, heavy metal risk status and organic pollution risk status; According to the selected quality evaluation index, calculate the status of the quality evaluation index and then assign points; Construct the original indicator data matrix to save the scores of quality evaluation indicators, and make the data values ​​in the original indicator data matrix dimensionless; Calculate the standard deviation of the data values ​​in the original indicator data matrix, and further calculate the conflict of the evaluation indicators through the standard deviation; The information content of the quality evaluation index is calculated by the standard deviation and the conflict, and the weight of the quality evaluation index is calculated according to the information content; The comprehensive index is calculated according to the weights of the quality evaluation indicators, and the water environment quality is rated according to the comprehensive index.

2. The method for evaluating water environment quality based on the CRITIC method according to claim 1 is characterized in that: The calculation method of comprehensive pollution status is: First calculate the exceeding range F1, exceeding frequency F2 and exceeding amplitude F3, and then use the formula: Calculate the comprehensive water quality index WQI.

3. The method for evaluating water environment quality based on the CRITIC method according to claim 2 is characterized in that: The calculation formula for the excess range F1 is: In the above formula, m is the number of pollution indicators that have exceeded the standard, and M is the number of all pollution indicators; The calculation formula of the excess frequency F2 is: In the above formula, n is the number of times the pollution index has exceeded the standard, and N is the total number of monitoring times for all pollution indexes; The calculation method of the excess amplitude F3 is: First calculate the offset ei, calculate the indicator offset θ through the offset ei, normalize the indicator offset θ to get nse, and then use the formula: Calculate the excess margin F3.

4. The method for evaluating water environment quality based on the CRITIC method according to claim 3 is characterized by: The calculation formula of indicator deviation θ is:

5. The method for evaluating water environment quality based on the CRITIC method according to claim 1 is characterized in that: The comprehensive nutritional status is calculated as follows: Calculate the nutritional status index of the nutritional indicators and then use the formula: Calculate the comprehensive nutritional status index TLI (∑), where YLI (j) is the nutritional status index of the jth nutritional indicator; X is the number of nutritional indicators; W j is the weight of the nutritional status index of the j-th nutritional indicator that is pre-assigned.

6. The method for evaluating water environment quality based on the CRITIC method according to claim 1, characterized in that: The calculation method for heavy metal risk status is: By formula: Calculation of heavy metal risk status index R in water bodies M , where Y is the total number of heavy metal types, C My is the concentration of the yth heavy metal in the water, S My is the maximum allowable concentration of the yth heavy metal in water.

7. The method for evaluating water environment quality based on the CRITIC method according to claim 6 is characterized by: Calculate C My If multiple monitoring sections are involved, take the C of each monitoring section. My The average value of .

8. The method for evaluating water environment quality based on physicochemical indicators of the CRITIC method according to claim 1 is characterized by: The calculation method for the risk status of organic pollutants is: By formula: Calculation of organic pollutant risk status index R o , where Z is the total number of organic pollutants, C oz is the concentration of the zth organic pollutant in the water body, S oz It is the maximum allowable concentration of the zth organic pollutant in water.

9. The method for evaluating water environment quality based on physicochemical indicators of the CRITIC method according to claim 8 is characterized by: Calculate C oz If multiple monitoring sections are involved, take the C of each monitoring section. oz The average value of .

10. The method for evaluating water environment quality based on physicochemical indicators of the CRITIC method according to claim 1 is characterized by: The method for calculating the composite index is: The sub-comprehensive index of each quality evaluation indicator is calculated according to the weight of the quality evaluation indicator, and all the sub-comprehensive indexes are added together to obtain the comprehensive index.

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