Method for measuring and calculating water environment capacity equivalent

Abstract

The method provides a water environment capacity equivalent calculation method, comprising the following steps: through hydrology and water quality monitoring of the target water body such as river, lake and reservoir, the water environment capacity of the main evaluation index is calculated; through analysis of the pollution control key points of the target water body, the core index of the water environment capacity calculation is selected, and the order conversion coefficient of the water environment capacity of other non-core indexes is determined based on the water environment capacity of the core index; through analysis of the historical monitoring data, the exceeding frequency of each water quality index is calculated, and then the capacity scarcity coefficient of each index is obtained; finally, the water environment capacity equivalent of the target water body is comprehensively calculated through the capacity equivalent calculation formula. The method can be widely applied to the comprehensive calculation and tracking evaluation of the water environment capacity of different target water bodies, can provide simple and effective decision information for water environment management, and has universality and high popularization value.

Description

Technical Field

[0001] This invention belongs to the field of environmental protection and water environment management, and specifically relates to a method for calculating water environment capacity equivalent. Background Technology

[0002] Water environmental capacity refers to the maximum amount of pollutants a water body can accommodate under designed hydrological conditions and specified environmental objectives. Theoretically, water environmental capacity reflects the migration, transformation, and accumulation patterns of pollutants in water bodies, as well as the water body's capacity to receive pollutants under specific functional conditions. In practice, water environmental capacity is the fundamental basis for environmental protection departments' assessment of water quality compliance and for water resources departments' river chief system management. It is a major constraint in water pollution control planning and a key parameter for total pollutant control.

[0003] In terms of its composition, water environmental capacity is generally composed of the environmental capacity of specific pollution indicators, such as total nitrogen, total phosphorus, permanganate index, and ammonia nitrogen. However, the environmental capacities of these pollution indicators generally vary greatly in magnitude, lack comparability, and are complex to quantify. Furthermore, the current water environmental capacity measurement system involves numerous indicators, making it difficult to directly align with actual management needs, and lacks a comprehensive indicator to systematically characterize the environmental capacity of a target water body. Therefore, there is an urgent need for a simplified, accurate, and unified water environmental capacity indicator to quantitatively describe the pollution carrying capacity of a target water body, in order to better serve application decision-making. Summary of the Invention

[0004] The purpose of this invention is to provide a method for calculating the equivalent of water environmental capacity.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for calculating water environmental capacity equivalent includes:

[0007] The water environment capacity of the assessment indicators is calculated based on the hydrological and water quality monitoring results of the target water body assessment section.

[0008] Based on the nature of the target water body and the key points of pollution control for the target water body, core indicators are selected from the assessment indicators, and the remaining assessment indicators are non-core indicators.

[0009] Using the water environment capacity occupancy of the core indicator as a reference value, calculate the corresponding order of magnitude conversion coefficient for each non-core indicator;

[0010] The frequency of exceeding the standard for each assessment indicator is calculated based on historical monitoring data of the target water body in order to obtain the capacity scarcity coefficient of each assessment indicator.

[0011] The equivalent water environmental capacity is calculated based on the following formula:

[0012]

[0013] In the formula, R d R represents the water environmental capacity equivalent. h R represents the water environment capacity of the core indicator, n represents the total number of non-core indicators, and R represents the total number of non-core indicators. i Let α represent the water environment capacity of the i-th non-core indicator. i w represents the magnitude conversion coefficient of the i-th non-core indicator, water environment capacity. i This represents the capacity scarcity coefficient of the i-th non-core indicator.

[0014] As a preferred embodiment, the assessment indicators include total nitrogen, total phosphorus, permanganate index, and ammonia nitrogen.

[0015] As a preferred implementation method, the core indicators of the target water body are determined based on the actual pollution situation and management needs of the target water body. Specifically, based on a comprehensive analysis of the characteristics of the target water body and the focus of pollution control, for example, for important water bodies such as lakes and reservoirs that are prone to cyanobacterial blooms, it is recommended to set total phosphorus as the core indicator.

[0016] In a preferred embodiment, the magnitude conversion coefficient is the ratio of the core indicator water environment capacity occupancy to the currently calculated non-core indicator water environment capacity occupancy, and the specific calculation formula is as follows:

[0017]

[0018] In the formula: α i This represents the magnitude conversion coefficient of the i-th non-core indicator. This indicates the occupancy of the core indicator, water environment capacity. This represents the water environment capacity utilization of the i-th non-core indicator.

[0019] In a preferred embodiment, the water environment capacity occupancy is the multi-year average of the water environment capacity occupancy of the target water body for the assessment indicators to be calculated. Specifically, it includes:

[0020] (1) Calculate the water environment capacity occupancy of target water bodies for different indicators in multiple years;

[0021] (2) Statistical analysis of the multi-year average of the water environment capacity occupancy of each pollution indicator;

[0022] (3) Perform magnitude conversion to obtain the magnitude conversion coefficient of the non-core indicator, water environment capacity.

[0023] In a preferred embodiment, the capacity scarcity coefficient of the non-core indicator is the ratio of the frequency of exceeding the standard of the core indicator to the frequency of exceeding the standard of the currently calculated non-core indicator.

[0024] As a preferred embodiment, the exceedance frequency is the frequency at which the concentration of each assessment indicator of the target water body exceeds the water quality assessment standard of the water body within a certain time period.

[0025] Specifically, the determination of the capacity scarcity coefficient adopts the following steps:

[0026] Statistically determine the frequency P of the concentration of core water quality indicators in a target water body exceeding the water quality assessment standard for that water body within a certain time period. h ;

[0027] Statistically determine the frequency P of non-core water quality indicators exceeding the water quality assessment standard of a target water body within a certain time period. i Assuming the scarcity coefficient of the core indicator is 1, the capacity scarcity coefficients of other non-core indicators are derived from the following equation:

[0028]

[0029] In the formula, w i P represents the capacity scarcity coefficient of the i-th non-core indicator. i P represents the frequency of exceeding the standard for the i-th non-core indicator. h This indicates the frequency of exceeding the standard for core indicators.

[0030] In a preferred embodiment, the method further includes calculating the monthly / annual water environment capacity equivalent of the target water body and monitoring the changes in the water environment capacity equivalent of the target water body.

[0031] Furthermore, the target capacity equivalent, capacity equivalent occupancy, and capacity equivalent warning line are used as monitoring indicators to monitor changes in the water environment capacity equivalent of the target water body.

[0032] Furthermore, the target capacity equivalent is the maximum amount of pollutants that can be accommodated under the constraint of water quality targets;

[0033] The capacity equivalent occupancy refers to the water environment capacity equivalent of the target water body occupied by various sewage discharge activities over a period of time;

[0034] The capacity equivalent warning line is a water quality warning and control target delineated based on the historical water quality of the target water body and water environment management requirements, and the water environment capacity equivalent is calculated accordingly.

[0035] The water environment capacity equivalent described in this invention is mainly used to quantitatively describe the comprehensive pollution carrying capacity of a target water body, reflecting the total amount of major pollutants such as total nitrogen, total phosphorus, permanganate index and ammonia nitrogen that water bodies such as rivers and lakes can accommodate under designed hydrological conditions and specified environmental targets.

[0036] This invention, based on the current system for calculating water environmental capacity, provides a method for calculating water environmental capacity equivalent. This method offers crucial evidence and reference for systematically characterizing the pollution-carrying capacity of target water bodies, quantitatively assessing the changing patterns of water quality, and making management decisions. It better aligns with real-world management needs. The method can be directly applied to the comprehensive calculation and tracking assessment of water environmental capacity for different target water bodies, providing simple and effective decision-making information for water environment management. It possesses universality and high potential for wider application. Attached Figure Description

[0037] Figure 1 This is a flowchart of the method of the present invention.

[0038] Figure 2 It is the result of the water environment capacity calculation under the constraints of water quality targets for various water quality indicators.

[0039] Figure 3 It is the result of monthly and annual water environment capacity equivalent calculations for the target water body. Detailed Implementation

[0040] To make the technical problems to be solved, the technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0041] In this embodiment, the environmental capacity of key water quality indicators should be calculated using standard methods or regionally constructed model tools. Specific details are provided in relevant publicly available technical guidelines, such as the "National Water Environmental Capacity Determination Technical Guidelines" compiled by the Chinese Academy of Environmental Planning, and will not be elaborated further in this application.

[0042] Example 1

[0043] The target water body in this embodiment is a reservoir, whose main function is to provide drinking water for the region. The target water quality is Class III surface water, and the data statistics period is from 2011 to 2020.

[0044] like Figure 1 As shown, the method of the present invention includes the following steps:

[0045] (1) Calculate the water environment capacity of the main assessment indicators.

[0046] The main assessment indicators in this embodiment are water quality indicators such as total nitrogen, total phosphorus, permanganate index, and ammonia nitrogen.

[0047] Based on existing methods for calculating water environmental capacity, the environmental capacity of various water quality indicators for the target water body since 2010 was calculated.

[0048] In this embodiment, the water environment capacity is further refined according to work requirements. Following standard methods, the target water quality capacity, capacity occupancy, and capacity warning line are calculated separately. The target capacity refers to the maximum amount of pollutants that can be accommodated under the constraints of the water quality target. The capacity occupancy refers to the water environment capacity of the target water body occupied by various sewage discharge activities over a period of time. The capacity warning line is a water quality warning and control target established based on the historical water quality of the target water body and water environment management requirements, and is thus calculated to determine the water environment capacity. The remaining environmental capacity for each water quality indicator can be obtained by subtracting the capacity occupancy from the target water quality capacity (or capacity warning line). When the capacity occupancy exceeds the capacity warning line, it is recommended to take early warning and control measures to prevent further deterioration of the water environment. The calculation of indicators such as the target water quality capacity, capacity occupancy, and capacity warning line can be carried out with reference to the water environment capacity calculation methods in the "National Technical Guidelines for Water Environment Capacity Determination".

[0049] Figure 2 The results of water environment capacity calculation for the period from 2011 to 2020 under the constraints of water quality targets for various water quality indicators are presented.

[0050] (2) Determine the magnitude conversion coefficient of the environmental capacity of each water quality indicator.

[0051] The target water body is a reservoir, and phosphorus is a significant limiting factor for algal proliferation in reservoirs. Therefore, total phosphorus was identified as the core indicator, while total nitrogen, permanganate, and ammonia nitrogen were identified as non-core indicators.

[0052] Based on the calculation results in this embodiment (1), the average annual environmental capacity occupancy of total phosphorus in the target water body during the period from 2011 to 2020 was determined to be 2.5 tons, and the environmental capacity occupancy of nitrogen, permanganate and ammonia nitrogen was 88.2 tons, 300.5 tons and 10.1 tons, respectively.

[0053] Based on the water environment capacity occupancy of each indicator, the magnitude conversion coefficients of the environmental capacity of non-core indicators are calculated, and the magnitude conversion coefficients of total nitrogen, permanganate index, and ammonia nitrogen are obtained as follows: and

[0054] (3) Statistically analyze the frequency of exceeding the standards of various water quality indicators to obtain the capacity scarcity coefficient.

[0055] Monthly water quality data from target water body assessment sections over the past 10 years were analyzed. The frequency of various water quality indicators exceeding the Class III surface water quality standard was statistically analyzed, and the percentage of exceedances was calculated. The results showed that the percentages of total nitrogen, total phosphorus, permanganate index, and ammonia nitrogen exceeding the Class III water quality standard were 36.74%, 54.92%, 14.39%, and 2.27%, respectively.

[0056] Furthermore, according to the scarcity coefficient equation, the environmental capacity scarcity coefficients were calculated to be 66.90%, 100%, 26.21%, and 4.14%, respectively.

[0057] (4) The water environment capacity equivalent of the target water body is calculated by using the formula for capacity equivalent.

[0058] Based on the above steps and the equation for equivalent calculation, the final formula for calculating the environmental capacity equivalent of the target water body is as follows:

[0059]

[0060] In the formula, R d R represents the capacity equivalent. TP R TN R COD and R AN The environmental capacity of total phosphorus, total nitrogen, permanganate index, and ammonia nitrogen, in that order; and The order of magnitude conversion factors are total nitrogen, permanganate index, and ammonia nitrogen, respectively; 0.67, 0.26, and 0.04 are capacity scarcity coefficients, respectively.

[0061] The capacity equivalent calculation method of this invention, combined with real-time acquired automatic observation data of the target water body, and compiled through background code, can quantitatively describe the dynamic changes of water environment capacity on a monthly and yearly basis, comprehensively indicating the comprehensive pollution carrying capacity of the target water body, and providing real-time and dynamic information for management decisions. Figure 3 It is the result of monthly and annual water environment capacity equivalent calculations for the target water body.

[0062] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for calculating the equivalent of water environmental capacity, characterized in that, include: The water environment capacity of the assessment indicators is calculated based on the hydrological and water quality monitoring results of the target water body assessment section. Based on the nature of the target water body and the key points of pollution control for the target water body, core indicators are selected from the assessment indicators, and the remaining assessment indicators are non-core indicators. Using the water environment capacity occupancy of the core indicator as a reference value, the ratio of the reference value to the water environment capacity occupancy of the non-core indicator is calculated and used as the order of magnitude conversion coefficient of the non-core indicator; the water environment capacity occupancy is the multi-year average of the water environment capacity occupancy of the target water body to be assessed. The frequency of exceeding the standard for each assessment indicator is calculated based on historical monitoring data of the target water body. The ratio of the frequency of exceeding the standard for non-core indicators to the frequency of exceeding the standard for core indicators is calculated as the capacity scarcity coefficient for non-core indicators. The frequency of exceeding the standard is the frequency at which the concentration of each assessment indicator of the target water body exceeds the water quality assessment standard of the water body within a certain period of time. The equivalent water environmental capacity is calculated based on the following formula: ； In the formula, Indicates water environmental capacity equivalent. represents the water environment capacity of the core indicator, and n represents the total number of non-core indicators. This represents the water environment capacity of the i-th non-core indicator. This represents the magnitude conversion coefficient of the i-th non-core indicator, water environment capacity. This represents the capacity scarcity coefficient of the i-th non-core indicator.

2. The calculation method according to claim 1, characterized in that, The assessment indicators include total nitrogen, total phosphorus, permanganate index, and ammonia nitrogen.

3. The calculation method according to claim 1, characterized in that, The core indicators of the target water body are determined based on the actual pollution situation and management needs of the target water body.

4. The calculation method according to claim 1, characterized in that, It also includes calculating the monthly / annual water environment capacity equivalent of the target water body and monitoring the changes in the water environment capacity equivalent of the target water body.

5. The calculation method according to claim 4, characterized in that, The target capacity equivalent, capacity equivalent occupancy, and capacity equivalent warning line are used as monitoring indicators to monitor changes in the water environment capacity equivalent of the target water body.

6. The calculation method according to claim 5, characterized in that, The target capacity equivalent is the maximum amount of pollutants that can be accommodated under the constraint of water quality targets; The capacity equivalent occupancy refers to the water environment capacity equivalent of the target water body occupied by various sewage discharge activities over a period of time; The capacity equivalent warning line is a water quality warning and control target delineated based on the historical water quality of the target water body and water environment management requirements, and the water environment capacity equivalent is calculated accordingly.

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