CN110187072A - A kind of methods of water environment quality assessment based on exchange premium degree model - Google Patents

Abstract

A water environment quality evaluation method based on a sticking schedule model relates to a water environment quality evaluation method. The present invention uses the water environment quality evaluation method based on the closeness model to determine the degree of membership for the first time, and fully considers the water environment in the area to be evaluated. Based on the status of the indicators, the weight of each evaluation indicator was calculated based on the water quality compliance. With reference to the basic items of the surface water environmental quality standard except pH, temperature and dissolved oxygen in the surface water environmental quality standard (GB3838‑2002) as evaluation indicators, the water environmental quality is divided into 5 grades according to the surface water environmental quality standard, and the evaluation standard The value selects the standard limit value of each index in the surface water environmental quality standard. This method considers the over-standard situation of the evaluation index, and comprehensively considers the water environment of each site to be evaluated. At the same time, the method has a reasonable structure, clear concept, flexibility and simplicity, which is beneficial to popularization.

Description

A water environment quality assessment method based on the sticking schedule model

technical field

The invention relates to a water environment quality evaluation method, in particular to a water environment quality evaluation method based on a sticking schedule model.

Background technique

Water resources are an indispensable natural resource for human production and development, and play an important role in people's daily life. As an important part of water resources, the status of rivers directly affects the water security of residents. However, with the development of the economy, people's demand for water has increased, and more and more industrial, agricultural and domestic waste water has been discharged into rivers, resulting in frequent occurrence of water pollution incidents, continuous decline in the quality of the water environment, and even harm to people. of physical health. Therefore, it is necessary to evaluate the water environment quality to accurately assess the water quality and its pollution degree, and to carry out research on countermeasures and improvement measures on the basis of the evaluation of water environment quality, so as to provide a basis for improving the water environment quality and environmental management level.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a water environment quality assessment method based on the sticking schedule model. The present invention refers to the surface water environmental quality standard (GB3838-2002), considers the current situation of water environment indicators in the area to be assessed, and avoids human interference factors. The scientific evaluation method of water environmental quality based on closeness.

The purpose of this invention is to realize through the following technical solutions:

A water environment quality evaluation method based on the sticking schedule model, the method includes taking 21 basic items in the surface water environmental quality standard (GB3838-2002) except pH, temperature and dissolved oxygen as the evaluation The standard limit of each index in the surface water environmental quality standard (GB3838-2002) is selected as the evaluation standard value of the water environment quality evaluation index system, and the surface water environmental quality standard is divided into 5 grades; The index weight is constructed based on the water quality exceeding the standard, and the water quality standard level for comparison is selected according to the actual situation of the area to be evaluated. Taking the third-level water quality standard as an example, the more points that exceed the third-level water quality standard, the greater the weight of the evaluation index;

Specific steps are as follows:

Step 1. Establishment of evaluation index system and determination of evaluation criteria:

Take the 21 basic items in the surface water environmental quality standard (GB3838-2002) except pH, temperature and dissolved oxygen as the evaluation indicators, and select the indicators in the surface water environmental quality standard (GB3838-2002) The standard limit is the evaluation standard value of the water environment quality evaluation index system, and the surface water environment quality standard divides the water environment quality into 5 grades;

Step 2: Determine the weight of the evaluation index:

The index weight is constructed based on the water quality exceeding the standard, and the water quality standard grade for comparison is selected according to the actual situation of the area to be evaluated; Step 3, using the method based on the sticking progress model to evaluate the water environment quality:

(1) Establish a sample matrix to construct a virtual "best point" or "worst point";

(2) Establish a sample matrix R;

(4) Calculate the distance between each sample point and the "best point" and "worst point";

(5) Calculate the closeness of each sample point to the standard value point;

(6) Evaluation of water environment quality.

In the water environment quality evaluation method based on the sticking schedule model, in the third step, the method based on the sticking schedule model is used to evaluate the water environment quality, and the distance between the "best point" and "the worst point" of each sample point is calculated. Distance, in order to calculate the distance between each sample point and standard value point and the constructed best point and worst point, and then calculate the closeness of each sample point and standard value point according to the result.

In the water environment quality evaluation method based on the sticking schedule model, in the third step, the method based on the sticking schedule model is used to evaluate the water environment quality, and the water environment quality evaluation is to determine the water environment quality level of the evaluation point.

The advantages and effects of the present invention are:

The invention uses the water environment quality evaluation method based on the closeness model to determine the membership degree for the first time, fully considers the current situation of the water environment indicators in the area to be evaluated, and calculates the weight of each evaluation indicator based on the water quality compliance. This evaluation method refers to the surface water environmental quality standard (GB3838-2002), determines the evaluation index system and evaluation standard, and the evaluation system is complete and scientific. This method considers the over-standard situation of the evaluation index, and comprehensively considers the water environment of each site to be evaluated. At the same time, the method has a reasonable structure, clear concept, flexible and simple, and can be popularized.

Description of drawings

Fig. 1 is a flow chart of the water environment quality evaluation method of the present invention.

Detailed ways

The present invention will be described in detail below with reference to the embodiments shown in the accompanying drawings.

The water environment quality evaluation method of the present invention comprises the following steps:

Step 1. Establishment of evaluation index system and determination of evaluation criteria:

Take the 21 basic items in the surface water environmental quality standard (GB3838-2002) except pH, temperature and dissolved oxygen as the evaluation indicators, and select the indicators in the surface water environmental quality standard (GB3838-2002) The standard limit is the evaluation standard value of the water environment quality evaluation index system. The surface water environment quality standard is divided into five grades. The water environment quality evaluation index and the standard value of each grade are shown in Table 1.

Table 1 Water environment quality evaluation index and standard value of each grade (mg/L)

Step 2: Determine the weight of the evaluation index:

The index weight is constructed based on the water quality exceeding the standard, and the water quality standard grade for comparison is selected according to the actual situation of the area to be evaluated. Taking the third-level water quality standard as an example, the more points that exceed the third-level water quality standard, the greater the weight of the evaluation index. The specific calculation process is as follows: First, count the number of points whose value of the evaluation index i exceeds the third-level standard value, which is recorded as ; secondly, take , the weight of the final evaluation index i .

Step 3. Use the method based on the sticking schedule model to evaluate the water environment quality:

(1) Establish a sample matrix and construct a virtual "best point" or "worst point"

Assuming that the number of water environmental quality monitoring points is m-1, for monitoring points, (m=1, 2, 3, 4, 5) is the standard value point of the five-level water environment quality level.

Will m-1 monitoring points and a standard value point 21 evaluation indicators of , forming the initial matrix :

in is the ith monitoring point The quantized value of the jth evaluation index of , i ∈ (1, 2, ... m-1), j ∈ (1, 2, ..., 21), is the jth index value of the standard value.

(2) Establish a sample matrix R

make

Normalize the matrix (1) to establish a sample matrix R:

In the formula, is the sample point to be optimized.

(3) Build the best and worst points

The evaluation index of this evaluation method is a negative index, that is, the larger the index value, the worse the water quality. Therefore, the best point after sample synthesis should be the minimum value set point of each index, and the worst point should be the maximum value set of each index. point, i.e.:

Best point:

Worst point:

The best part of the build , the worst point It is a virtual point for the extreme conditions (best and worst) of the water environment quality during the sampling period of the river to be evaluated.

(4) Calculate the distance between each sample point and the "best point" and "worst point"

Calculate the distance between each sample point and standard value point and the constructed best and worst points, and then calculate the closeness of each sample point and standard value point according to the result.

The distance between the i-th sample point and the "best point" is:

(4)

The distance between the i-th sample point and the worst point is:

(5)

The distance between the standard value point and the "best point" and "worst point" is:

(6)

(7)

in the formula is the weight of the jth index (that is, the jth pollutant factor) in the whole water quality evaluation.

(5) Calculate the closeness of each sample point to the standard value point

The closeness of the i-th sample point to the standard value point m is:

(6) Evaluation of water environment quality

According to the method described above, calculate the sticking progress between the i-th sample point and the five evaluation grade standard value points

, the membership degree of the i-th sample point and the five evaluation levels is defined as,

,Right now . Pick is the minimum value, if Then the water environment quality level of the i-th sample point is m at this time, otherwise, the water environment quality level of this point is m-1; if When the m value is 5 when it is the minimum value, the water environment quality level of this point is directly level 5.

Example 1:

Based on the water environment quality monitoring data of 8 monitoring points in the mainstream of the river, the water environment quality assessment was carried out.

(1) Establishment of the indicator system:

Take the 21 basic items in the surface water environmental quality standard (GB3838-2002) except pH, temperature and dissolved oxygen as the evaluation indicators, and select the indicators in the surface water environmental quality standard (GB3838-2002) The standard limit is the evaluation standard value of the water environment quality evaluation index system. The surface water environment quality standard is divided into five grades. The water environment quality evaluation index and the standard value of each grade are shown in Table 1.

(2) Determination of evaluation index weights:

According to the river pollution situation, the three-level water quality standard is selected, and the more points that exceed the three-level water quality standard, the greater the weight of the evaluation index. The specific calculation process is as follows: First, count the number of points whose value of the evaluation index i exceeds the third-level standard value, which is recorded as ; secondly, take , the weight of the final evaluation index i . After calculating the weight of each index (potassium permanganate index, chemical oxygen demand, BOD 5, ammonia nitrogen, total phosphorus, total nitrogen, copper, zinc, fluoride, selenium, arsenic, mercury, chromium, lead, Cyanide, volatile phenol, petroleum, anionic surfactant, sulfide, fecal coliform) were 0.0548, 0.0822, 0.1096, 0.1233, 0.0822, 0.1233, 0.0137, 0.0137, 0.0137, 0.0137, 0.0137, 0.0137, 0.0137, 0.0137, 0.0137, 0.0137, 0.0822, 0.1233, 0.0137, 0.0137, 0.0548.

(3) Use the method based on the sticking schedule model to evaluate the water environment quality:

According to the water environment quality assessment method, the initial matrix was constructed based on the monitoring data of 21 monitoring indicators at 8 monitoring points in the main river and the standard value points of 5 water environment quality grades. , calculate the sample matrix R involving different water environmental quality levels, and virtualize the "best point" or "worst point" involving different water environmental quality levels, and calculate the distance between each monitoring sample point according to formula (4) and formula (5). The distance between the best point" and the "worst point". The calculation results are as follows: for the first-level water environment quality standard, the distances of each monitoring point to the best point are 0.1871, 0.3567, 0.1763, 0.1912, 0.1996, 0.2642, 0.2825 and 0.1998, and the distances to the worst point are 0.3347, 0.2686, 0.3304, 0.3149, 0.2999, 0.2787, 0.2640 and 0.3243; for the second-level water environment quality standard, the distances of each monitoring point to the best point are 0.1590, 0.3287, 0.1494, 0.1660, 0.1768, 0.2429, 0.2584 and 0.1708. For the worst The distances of the points are 0.4041, 0.3489, 0.3981, 0.3878, 0.3746, 0.3552, 0.3426 and 0.3906; for the 3-level water environment quality standard, the distances of each monitoring point to the best point are 0.1330, 0.2911, 0.1200, 0.1478, 0.1513, and 0.2230. , 0.2357 and 0.1490, the distances to the worst point are 0.4226, 0.3717, 0.4169, 0.4058, 0.3943, 0.3779, 0.3663 and 0.4106; for the 4-level water environment quality standard, the distances of each monitoring point to the best point are 0.1176, 0.2657 , 0.1055, 0.1138, 0.1261, 0.1850, 0.2012 and 0.1172, the distances for the worst point are 0.4716, 0.4282, 0.4666, 0.4478, 0.4422, 0.4195, 0.4129 and 0.4535; The distances for the advantage are 0.0992, 0.2378, 0.0948, 0.0915, 0.1059, 0.1522, 0.1691 and 0.0850, and the distances for the worst point are 0.5907, 0.5539, 0.5869, 0.5713, 0.5671, 0.5434, 0.5377 and 0.5777.

According to formula (6), formula (7) and formula (8), calculate the sticking progress of the i-th sample point and the five evaluation grade standard value points

, the membership degree of the i-th sample point and the five evaluation levels is defined as, ,Right now . According to the above method, the progress of 5 water environment quality standards for 8 monitoring points in the mainstream of the river was calculated. The calculation result is that the membership degrees of monitoring point 1 for the five water environment quality standards are {0.0058, 0.5672, 1.0261, 2.1771, 3.8732}, and the membership degrees of monitoring point 2 are {-0.3541, -0.0289, 0.2232, 0.9706, 2.0085 }, the membership degree of monitoring point 3 is {0.0357, 0.6236, 1.1599, 2.3899, 3.9997}, the membership degree of monitoring point 4 is {-0.0319, 0.5021, 0.8655, 2.1813, 4.0650}, the membership degree of monitoring point 5 is {-0.0749, 0.4251, 0.8187, 1.9688, 3.6073}, the membership degree of monitoring point 6 is {-0.2347, 0.1518, 0.4178, 1.3278, 2.6782}, the membership degree of monitoring point 7 is {-0.2800, 0.0949, 0.3561 , 1.2099, 2.4659}, the membership degree of monitoring point 8 is {-0.0443, 0.4794, 0.8634, 2.1381, 4.3330}. like is the minimum value, if Then the water environment quality level of the i-th sample point is m at this time, otherwise, the water environment quality level of this point is m-1; if If the m value is 5 when it is the minimum value, the water environment quality level at this point is directly level 5. Therefore, the water environment quality of monitoring points 1 and 3 is grade 1, that of monitoring point 2 is grade 3, and that of monitoring points 4, 5, 6, 7, and 8 is grade 2.

Claims (3)

1. a kind of methods of water environment quality assessment based on exchange premium degree model, which is characterized in that the method includes with surface water 21 kinds of elementary items in surface water environment matter standard in environmental quality standards (GB3838-2002) in addition to pH, temperature and dissolved oxygen Mesh is evaluation index, and the standard limited value for choosing each index in water environment quality standard (GB3838-2002) is water environment Quality of water environment is divided into 5 grades by water environment quality standard by the evaluation criterion value of quality evaluation system；With water Index weights are constructed based on the exceeded situation of matter, select the water standard grade compared according to regional actual conditions to be evaluated, with For three-level water standard, the weight of the evaluation index more more than the point of three-level water standard is bigger；

Specific step is as follows:

Step 1: the foundation of assessment indicator system and the determination of evaluation criterion:

With the surface water environment matter standard in water environment quality standard (GB3838-2002) in addition to pH, temperature and dissolved oxygen In 21 kinds of elementary items be evaluation index, and choose the standard of each index in water environment quality standard (GB3838-2002) Limit value is the evaluation criterion value of water quality evaluation index system, and quality of water environment is divided by water environment quality standard 5 grades；

Step 2: the determination of evaluation criterion weight:

Index weights are constructed based on overproof water quality situation, select the water standard compared according to regional actual conditions to be evaluated Grade；Step 3: carrying out water quality evaluation using the method based on exchange premium degree model:

(1) sample matrix is established, virtual " optimum point " or " most not good enough " is constructed；

(2) sample matrix R is established；

(4) each distance of the sample point away from " optimum point ", " most bad point " is calculated；

(5) approach degree of each sample point and standard value point is calculated；

(6) water quality evaluation.

2. a kind of methods of water environment quality assessment based on exchange premium degree model according to claim 1, which is characterized in that institute State in step 3 using based on exchange premium degree model method carry out water quality evaluation, calculate each sample point away from " optimum point ", The distance of " most bad point ", to calculate each sample point and the distance between standard value point and the optimum point of building, most bad point, then root The approach degree of each sample point Yu standard value point is calculated according to the result.

3. a kind of methods of water environment quality assessment based on exchange premium degree model according to claim 1, which is characterized in that institute It states in step 3 and carries out water quality evaluation using the method based on exchange premium degree model, water quality evaluation is commented for determination The quality of water environment grade of valence point.