A method for analyzing intensity of total nitrogen pollution of area non-point source

Abstract

The application discloses a regional total nitrogen surface source pollution intensity analysis method, and belongs to the technical field of environmental monitoring. The method is characterized in that by analyzing river total nitrogen monitoring data and regional economic and social related data, the total nitrogen increment generated by regional economic and social activities and the total nitrogen change in the river water are calculated, and the river coefficient of the regional surface source pollution is further calculated, and the weak areas of the surface source pollution prevention and control are identified through the river coefficient. The data required by the method is derived from the publicly queryable ways such as national water quality monitoring, hydrological monitoring and statistical yearbook, so that a large amount of data difficult to obtain required by the establishment of a mechanism model is avoided, and the setting of the river coefficient of the surface source pollution is avoided. The total nitrogen change in the water body is directly calculated by using the actually measured water quality and hydrological data, and the river coefficient of the surface source pollution is indirectly calculated. The key areas of the surface source pollution prevention and control are identified through the analysis and calculation results, and the method has important significance for supporting the decision of the river total nitrogen pollution prevention and control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of environmental monitoring, in particular to a regional total nitrogen non-point source pollution intensity analysis method. BACKGROUND

[0002] Total nitrogen is the sum of various forms of nitrogen (such as ammonia nitrogen, nitrate nitrogen, organic nitrogen, etc.) in water bodies, and is one of the key pollutants leading to water eutrophication. Excessive nitrogen input into lakes, reservoirs or coastal waters through rivers can cause a large number of algae and other plankton to reproduce, reduce water dissolved oxygen, and deteriorate water quality, thereby affecting the survival and reproduction of aquatic organisms and disrupting the balance of the water ecosystem. Controlling river total nitrogen can effectively reduce the risk of water eutrophication and maintain the diversity of aquatic organisms and the stability of the ecosystem.

[0003] The main source of total nitrogen in water bodies is agricultural non-point source pollution, including rural domestic sewage discharge, planting non-point source pollution, aquaculture non-point source pollution, etc. These pollution sources are widely distributed in agricultural areas in river basins and have great dispersion, randomness and hysteresis, making it difficult to monitor and warn using point source (i.e. river discharge) monitoring methods, which has caused difficulties in preventing and controlling river total nitrogen pollution. Therefore, it is necessary to scientifically calculate the total nitrogen load caused by non-point source pollution to rivers based on river total nitrogen monitoring data and regional economic and social conditions to protect the water environment of the river basin and prevent water pollution.

[0004] The widely used mathematical models based on mechanism and machine learning methods based on data mining have high requirements for data and computing power, which makes it difficult to be widely applied. SUMMARY

[0005] In view of the above problems in the prior art, the present application provides a regional total nitrogen non-point source pollution intensity analysis method, which solves the problem that the prior art has high requirements for data and computing power and is difficult to be widely applied.

[0006] In order to achieve the above-mentioned purpose of the application, the technical solution adopted by the present application is as follows:

[0007] The present application provides a regional total nitrogen non-point source pollution intensity analysis method, comprising:

[0008] S1: obtaining and organizing total nitrogen monitoring data of river inflow section, total nitrogen monitoring data of river outflow section, daily average flow data, regional economic and social related data and total nitrogen atmospheric deposition coefficient in the study area;

[0009] S2: based on the organized data, calculating the annual increment of regional total nitrogen, the change amount of total nitrogen in the river and the total nitrogen discharge amount of the river discharge outlet;

[0010] S3: Based on the total nitrogen annual increment of the region, the total nitrogen variation in the river and the total nitrogen discharge of the river sewage outlet, the non-point source pollution into river coefficient is constructed, and the total nitrogen non-point source pollution intensity in the region is analyzed based on the non-point source pollution into river coefficient.

[0011] Further, the total nitrogen monitoring data of the river inflow section, the total nitrogen monitoring data of the outflow section, the daily average flow data, the regional economic and social related data in the research region are sorted, including:

[0012] The obtained total nitrogen monitoring data of the river inflow section, the total nitrogen monitoring data of the outflow section, the daily average flow data and the regional economic and social related data in the research region are respectively counted according to the administrative regions, and the total nitrogen monitoring data of each section in each administrative region after counting is sorted into monthly average value, the daily average flow data of each section is sorted into monthly runoff, and the regional economic and social related data is sorted into annual value.

[0013] Further, the calculation formula of the total nitrogen annual increment of the region is:

[0014]

[0015] Among them, TN is the total nitrogen annual increment in the research region, TN is the total nitrogen increment generated by population food consumption in the regional economic and social related data, TN is the total nitrogen increment generated by livestock breeding in the regional economic and social related data, TN is the total nitrogen increment generated by crop planting in the regional economic and social related data, TN is the total nitrogen increment generated by atmospheric deposition obtained by multiplying the atmospheric deposition coefficient by the area of the research region.

[0016] Further, the calculation of the total nitrogen variation in the river includes:

[0017] The inflow section and the outflow section of all rivers and tributaries in the research region are determined, numbered one by one, and the total nitrogen variation in the river water is calculated according to the hydrological and water quality monitoring data of each section, and the calculation formula is:

[0018]

[0019] Among them, TN is the total nitrogen variation in the water of all rivers in the research region, M is the month, N is the number of river inflow or outflow sections, N is the total number of river inflow or outflow sections, TN is the total nitrogen concentration of the first outflow section M is the month, TN is the total nitrogen concentration of the first outbound section monthly runoff, the first inbound section monthly total nitrogen concentration, the first inbound section monthly runoff.

[0020] Further, the total nitrogen discharge of the river outlet is calculated, comprising:

[0021] According to the monitoring data of the river outlet, the total nitrogen flux through the river outlet into the river water body in a year is calculated through monthly sewage discharge and total nitrogen concentration, and the total nitrogen discharge of the river outlet is obtained, and the calculation formula is:

[0022]

[0023] wherein, the total nitrogen discharge of the river outlet, the number of river outlets, the total number of river outlets, the first river outlet monthly total nitrogen concentration, the first river outlet monthly sewage discharge.

[0024] Further, the river outlet coefficient of non-point source pollution is constructed based on the annual increment of regional total nitrogen, the change amount of total nitrogen in the river and the total nitrogen discharge of the river outlet, comprising:

[0025] Based on the change amount of total nitrogen in the river, the total nitrogen discharge of the river outlet is deducted as the non-point source total nitrogen inflow, and the ratio of the non-point source total nitrogen inflow to the annual increment of regional total nitrogen is taken as the non-point source pollution inflow coefficient, and the expression of the non-point source pollution inflow coefficient is:

[0026]

[0027] wherein, the non-point source pollution inflow coefficient.

[0028] Further, the total nitrogen non-point source pollution intensity in the region is analyzed based on the non-point source pollution inflow coefficient, comprising:

[0029] If the change amount of total nitrogen in the river is less than zero, the non-point source pollution inflow coefficient is less than zero, indicating that the prevention and control of non-point source pollution in the research region is good, and the total nitrogen in the river is reduced;

[0030] If the total nitrogen change in the river is greater than zero and less than the total nitrogen discharge of the river pollution outlet, the non-point source pollution into river coefficient is greater than zero, indicating that the total nitrogen source of the research region is mainly point source;

[0031] If the total nitrogen change in the river is greater than zero and greater than the total nitrogen discharge of the river pollution outlet, the non-point source pollution into river coefficient is greater than zero, indicating that the total nitrogen source of the research region is mainly non-point source. The higher the non-point source pollution into river coefficient of the region, the greater the influence of non-point source pollution, which is the key area of non-point source pollution prevention and control.

[0032] The beneficial effects of the present application are:

[0033] The method provided by the present application for analyzing the intensity of non-point source pollution of total nitrogen in a region is calculated from data sources such as national water quality monitoring, hydrological monitoring, statistical yearbook, etc. which can be publicly queried, avoiding the need for a large amount of data that is not easy to obtain for establishing a mechanism model. At present, the research on non-point source pollution into river water all needs to give the non-point source pollution into river coefficient in advance, which is very difficult to set accurately. The present application avoids the setting of the non-point source pollution into river coefficient, and directly calculates the total nitrogen change in the water body by using the measured water quality and hydrological data to indirectly calculate the non-point source into river coefficient. The key areas of non-point source pollution prevention and control are identified by analyzing and calculating the results, which is of great significance for supporting the decision-making of total nitrogen pollution prevention and control of rivers. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other embodiments can also be obtained by those skilled in the art based on these drawings.

[0035] Figure 1 A flowchart of a method for analyzing the intensity of non-point source pollution of total nitrogen in a region is provided.

[0036] Figure 2 A schematic diagram of a research region of total nitrogen non-point source pollution is provided. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art based on the present application belong to the scope of protection of the present application.

[0038] The method for analyzing the intensity of non-point source pollution of total nitrogen in a region provided by the present application can be seen from Figure 1, Figure 1 The diagram shown is a flowchart illustrating a method for analyzing the intensity of regional total nitrogen non-point source pollution provided in an embodiment of this application, including:

[0039] S1: Data collection and processing.

[0040] In one embodiment of this application, such as Figure 2 As shown, Figure 2 This application provides a schematic diagram of a total nitrogen non-point source pollution research area. Gray lines represent area boundaries, blue lines represent rivers and their flow directions, gray dots represent sewage outlets into the river, green dots represent river inflow sections, and red dots represent river outflow sections. Through field surveys and hydrological data collection, total nitrogen monitoring data and daily average flow data for river inflow and outflow sections within the research area are obtained. By consulting statistical yearbooks for the research area, relevant regional economic and social data, such as regional population, livestock and poultry farming volume, major crop yields, and fertilizer application, are obtained. The atmospheric deposition coefficient of total nitrogen in the research area is determined by reviewing relevant research literature. The various data obtained in the previous step are statistically analyzed according to administrative divisions, and subsequent calculations and analyses are performed according to administrative divisions. Total nitrogen monitoring data for each section are compiled into monthly averages, and daily average flow data for each section are compiled into monthly runoff. The total nitrogen monitoring data and river runoff data should be consistent in time. Relevant economic and social data for each administrative region are compiled into annual values.

[0041] S2: Based on the processed data, calculate the annual increase in total nitrogen in the region, the change in total nitrogen in rivers, and the total nitrogen discharge from sewage outlets into rivers.

[0042] In one embodiment of this application, the annual increase in regional total nitrogen is mainly generated by the consumption of food (feed) by the population and livestock in the region, the application of chemical fertilizers during agricultural production, and atmospheric deposition. Therefore, the formula for calculating the annual increase in regional total nitrogen is:

[0043]

[0044] in, To represent the annual increase in total nitrogen within the study area, The total nitrogen increment generated by population food consumption in regional economic and social data is obtained by multiplying factors such as population size, per capita protein consumption, and total nitrogen content in protein within the region. The total nitrogen increment from livestock and poultry farming in the relevant regional economic and social data is obtained by multiplying factors such as the number of livestock and poultry farms in the region and the nitrogen excretion of individual animals. The total nitrogen increment generated by crop planting in regional economic and social data is calculated based on factors such as crop yield, nitrogen content of various crops, and nitrogen fertilizer application rate within the region. The total nitrogen increment generated by atmospheric deposition is obtained by multiplying the atmospheric deposition coefficient of total nitrogen by the area of the study area. The total nitrogen increment generated by atmospheric deposition can be estimated according to the relevant research literature of the study area.

[0045] The entry section and exit section of all rivers and tributaries in the study area are determined, numbered one by one, and the change amount of total nitrogen in the river water is calculated according to the hydrological and water quality monitoring data of each section. The calculation formula is:

[0046]

[0047] Among them, is the change amount of total nitrogen in the water of all rivers in the study area, is the month, is the number of river entry or exit sections, is the total number of river entry or exit sections, is the exit section month total nitrogen concentration, is the exit section month runoff, is the entry section month total nitrogen concentration, is the entry section month runoff.

[0048] According to the monitoring data of the river sewage outlet, the total nitrogen flux entering the river water through the river sewage outlet is calculated by the monthly sewage discharge and total nitrogen concentration, and the total nitrogen emission of the point source (river sewage outlet) is obtained. The calculation formula is:

[0049]

[0050] Among them, is the total nitrogen emission of the river sewage outlet, is the number of sewage outlets, is the total number of sewage outlets, is the sewage outlet month total nitrogen concentration, is the sewage outlet month sewage discharge.

[0051] S3: Based on the annual increment of total nitrogen in the region, the change amount of total nitrogen in the river, and the total nitrogen emission of the river sewage outlet, the area source pollution into river coefficient is constructed, and the total nitrogen area source pollution intensity in the region is analyzed based on the area source pollution into river coefficient.

[0052] In an embodiment of the present application, the total nitrogen variation in the regional water body is used, and the total nitrogen emission of point source is deducted as the non-point source total nitrogen into river, and the ratio of the non-point source total nitrogen into river to the annual increment of total nitrogen in the region is the non-point source pollution into river coefficient proposed in the present application, which is used to measure the non-point source pollution intensity in a region, and the expression of the non-point source pollution into river coefficient is:

[0053]

[0054] wherein, The non-point source pollution into river coefficient.

[0055] When the total nitrogen variation of the river is negative ( ), that is, the total nitrogen flux of the outflow section is less than the total nitrogen flux of the inflow section, the non-point source pollution into river coefficient , which indicates that the non-point source pollution prevention and control in the research region is good, and the total nitrogen of the river is reduced;

[0056] When the total nitrogen variation of the river is positive ( ), but less than the total nitrogen emission of point source ( ), the non-point source pollution into river coefficient , which indicates that the total nitrogen source in the research region is mainly point source, that is, the river discharge outlet;

[0057] When the total nitrogen variation of the river is positive ( ), and greater than the total nitrogen emission of point source ( ), the non-point source pollution into river coefficient , which indicates that the total nitrogen source in the research region is mainly non-point source, and the higher the coefficient, the greater the influence of non-point source pollution, which is the key region of non-point source pollution prevention and control.

[0058] The method for analyzing the non-point source pollution intensity of total nitrogen in a region provided in the present application calculates the total nitrogen increment generated by economic and social activities in the region and the total nitrogen variation in the river water body by analyzing the total nitrogen monitoring data of the river and the relevant data of economic and social activities in the region, and further calculates the non-point source pollution into river coefficient of the region, identifies the weak regions of non-point source pollution prevention and control through the into river coefficient, and has important significance for supporting the decision of total nitrogen pollution prevention and control of the river. In this process, the data required for calculation is derived from the publicly available ways such as national water quality monitoring, hydrological monitoring, statistical yearbook, etc., avoiding the large amount of data difficult to obtain required for establishing mechanism model; and at present, the research on non-point source pollution into river water body needs to give the non-point source pollution into river coefficient in advance, and it is very difficult to accurately set the coefficient, the present application avoids the setting of the non-point source pollution into river coefficient, directly calculates the total nitrogen variation in the water body by using the measured water quality and hydrological data, indirectly calculates the non-point source into river coefficient, and identifies the key regions of non-point source pollution prevention and control through the analysis and calculation results.

[0059] It should be noted that those skilled in the art will appreciate that the embodiments described herein are presented for the purpose of understanding the principles of the present application and should be understood as not limiting the scope of protection of the present application to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations according to the technical inspiration of the present application disclosed, which do not deviate from the essence of the present application, and these modifications and combinations are still within the scope of protection of the present application.

Claims

1. A method for analyzing the intensity of regional total nitrogen non-point source pollution, characterized in that, include: S1: Acquire and organize total nitrogen monitoring data at river inflow sections, total nitrogen monitoring data at river outflow sections, daily average flow data, regional economic and social data, and total nitrogen atmospheric deposition coefficient within the study area; The relevant regional economic and social data include regional population, livestock and poultry breeding volume, major crop yield, and fertilizer application volume. S2: Based on the processed data, calculate the annual increase in total nitrogen in the region, the change in total nitrogen in rivers, and the total nitrogen discharge from sewage outlets into rivers; The calculation of the total nitrogen change in the river includes: Identify and number the inflow and outflow sections of all rivers and tributaries within the study area. Calculate the total nitrogen change in the river water based on hydrological and water quality monitoring data for each section. The calculation formula is as follows: in, To determine the total nitrogen variation in all river bodies within the study area, For months, The number of river sections at or outside the river's border. The total number of river inflow or outflow sections. For the first Each exit section Monthly total nitrogen concentration For the first Each exit section Monthly runoff, For the first One inbound section Monthly total nitrogen concentration For the first One inbound section Monthly runoff; S3: Based on the annual increase in total nitrogen in the region, the change in total nitrogen in rivers, and the total nitrogen discharge from sewage outlets into rivers, construct the non-point source pollution into river coefficient, and analyze the intensity of total nitrogen non-point source pollution in the region based on the non-point source pollution into river coefficient. The non-point source pollution discharge coefficient is constructed based on the annual increase in regional total nitrogen, the change in total nitrogen in rivers, and the total nitrogen discharge from sewage outlets into rivers, including: Based on the change in total nitrogen in the river, the total nitrogen discharge from sewage outlets into the river is deducted to obtain the non-point source total nitrogen inflow. The ratio of the non-point source total nitrogen inflow to the annual increase in regional total nitrogen is used as the non-point source pollution inflow coefficient. The expression for the non-point source pollution inflow coefficient is as follows: in, Non-point source pollution discharge coefficient into rivers To represent the annual increase in total nitrogen within the study area, To determine the total nitrogen variation in all river bodies within the study area, This refers to the total nitrogen emissions from sewage outlets into the river.

2. The method for analyzing the intensity of regional total nitrogen non-point source pollution according to claim 1, characterized in that, The collected data include total nitrogen monitoring data at river inflow sections, total nitrogen monitoring data at river outflow sections, daily average flow data, and relevant regional economic and social data within the research area. The total nitrogen monitoring data at the river inflow sections, total nitrogen monitoring data at the river outflow sections, daily average flow data, and regional economic and social data within the research area were collected and statistically analyzed according to administrative regions. The total nitrogen monitoring data at each section within each administrative region was then compiled into monthly averages, the daily average flow data at each section was compiled into monthly runoff, and the regional economic and social data was compiled into annual values.

3. The method for analyzing the intensity of regional total nitrogen non-point source pollution according to claim 1, characterized in that, The formula for calculating the annual increase in total nitrogen in the region is as follows: in, To represent the annual increase in total nitrogen within the study area, This refers to the total nitrogen increase generated by population food consumption in regional economic and social data. This refers to the increase in total nitrogen from livestock and poultry farming in regional economic and social data. This refers to the increase in total nitrogen generated by crop cultivation in regional economic and social data. The total nitrogen increase resulting from atmospheric deposition is obtained by multiplying the total nitrogen atmospheric deposition coefficient by the area of ​​the study region.

4. The method for analyzing the intensity of regional total nitrogen non-point source pollution according to claim 3, characterized in that, The calculation of the total nitrogen emissions from the aforementioned sewage outfalls into the river includes: Based on monitoring data of sewage discharge outlets into rivers, the total nitrogen flux entering the river body through these outlets within the year is calculated using monthly sewage discharge volume and total nitrogen concentration. The total nitrogen discharge from these outlets is obtained using the following formula: in, This refers to the total nitrogen emissions from sewage outlets into the river. The number of sewage outlets This represents the total number of sewage outlets. For the first One sewage outlet Monthly total nitrogen concentration For the first One sewage outlet Monthly wastewater discharge.

5. The method for analyzing the intensity of regional total nitrogen non-point source pollution according to claim 4, characterized in that, The total nitrogen non-point source pollution intensity in the region analyzed based on the non-point source pollution inflow coefficient includes: If the change in total nitrogen in the river is less than zero, then the non-point source pollution inflow coefficient is less than zero, indicating that the non-point source pollution control in the study area is good and the total nitrogen in the river has been reduced. If the change in total nitrogen in the river is greater than zero and less than the total nitrogen discharge from the sewage outlets into the river, then the non-point source pollution discharge coefficient into the river is less than zero, indicating that the main source of total nitrogen in the study area is point source. If the change in total nitrogen in the river is greater than zero and greater than the total nitrogen discharge from the sewage outlets into the river, then the non-point source pollution inflow coefficient is greater than zero, indicating that the main source of total nitrogen in the study area is non-point source pollution. The higher the non-point source pollution inflow coefficient, the greater the impact of non-point source pollution, and the more important the area is for non-point source pollution prevention and control.

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