A method to quantify the contribution of different azimuthal sources to pollutant concentrations at monitoring sites

Abstract

The present invention discloses a method for quantifying the contribution of different azimuth sources to pollutant concentrations at monitoring sites, which relates to the field of atmospheric pollution prevention and control technology. The method comprises the following steps: obtaining meteorological data of a target area and pollutant concentration data of each monitoring site, and dividing the data into arrays according to a time series; filtering the lowest value of the pollutant concentration data of each site moment by moment, and using it as the background value of the pollutant concentration at the current moment; subtracting the pollutant concentration data of each site at each moment from the background value at the corresponding moment to obtain the contribution concentration of the pollution source at each moment to the current site; dividing the wind direction data of the target period into intervals, calculating the mean contribution concentration within the same wind direction interval, and obtaining the average contribution concentration of pollutants from different azimuths to the current site within the target period. Through the technical solution of the present invention, the contribution of pollution sources from various directions to the target site can be quantified in a timely manner without being affected by the uncertainty of the emission inventory.

Description

Technical Field

[0001] The present invention relates to the technical field of air pollution prevention and control, and in particular to a method for quantifying contributions of different azimuthal sources to pollutant concentrations at a monitoring station. Background Art

[0002] Air pollution poses serious hazards to human health and social development. In recent years, refined atmospheric control has been a new trend in the development of air pollution prevention and control. Against this background, tracing the source of atmospheric pollutants at the local scale for monitoring stations has become an urgent problem to be solved. However, in the tracing process at the local scale, there are obvious differences in the pollutant emissions from various directions of the monitoring stations, resulting in obvious differences in the contribution of pollutant emissions from various directions to the atmospheric pollutants at the monitoring stations. At the same time, changes in wind direction have a significant impact on the concentration of atmospheric pollutants at the monitoring stations. Therefore, it is difficult to directly determine the specific location of the pollution source at the local scale. Therefore, when facing control needs, quantifying the contribution of different directions of pollutant concentration at the monitoring stations is of great significance to determining the location of the pollution source.

[0003] Currently, the primary method for quantifying the contribution of pollutant emissions to atmospheric pollutant concentrations at monitoring sites relies on numerical simulation. This method can simulate and predict the transport and diffusion of atmospheric pollutants. Furthermore, gridded emission inventories are used to simulate and estimate the contribution of pollutant emissions from various directions to atmospheric pollutant concentrations at monitoring sites. However, due to the low temporal resolution of emission inventories, this method cannot accurately quantify the contribution of various pollution sources to recently polluted sites. Furthermore, due to the uncertainty of emission inventories, the contribution of potential emission sources to monitoring sites is often overlooked during the estimation process. Therefore, these methods cannot meet the current needs of atmospheric pollution control. Summary of the Invention

[0004] In response to the above problems, the present invention provides a method for quantifying the contribution of different directional sources to the pollutant concentration at the monitoring site. It can quickly quantify the contribution of pollutant emissions from various directions to the atmospheric pollutant concentration at the monitoring site through simple mathematical methods, and can also obtain the main contribution direction to the monitoring site by statistically analyzing the contribution of pollutants from various directions to the monitoring site over a long period of time. It can make a fast and accurate analysis of sites that have recently experienced pollution, will not be affected by the uncertainty of the emission inventory, and can timely quantify the contribution of pollution sources from various directions to the target site, providing technical support for the refined control of atmospheric pollution, and providing a certain theoretical basis for formulating the priority control order of atmospheric pollution.

[0005] To achieve the above objectives, the present invention provides a method for quantifying the contribution of different azimuthal sources to pollutant concentrations at a monitoring station, comprising:

[0006] Obtain meteorological data of the target area and pollutant concentration data collected by each monitoring station in the target area, correspond one to one according to the time series, and divide them into data arrays at preset times;

[0007] The lowest value of the pollutant concentration data corresponding to each monitoring station in the target area is obtained by screening at each moment as the background value of the pollutant concentration at the current moment;

[0008] The pollutant concentration data of each monitoring station in the target area at each moment are calculated by subtracting the background value of the pollutant concentration at the corresponding moment to obtain the contribution concentration of the pollution source to the current monitoring station at each moment;

[0009] The wind direction data in the meteorological data within the target period is divided into intervals, and the mean contribution concentration within the same wind direction interval is calculated to obtain the average contribution concentration of pollutants from different directions to the current monitoring site within the target period.

[0010] In the above technical solution, preferably, the meteorological data includes wind direction data and wind speed data, and the pollutants include PM 2.5 、PM 10 and NO2, the time resolution of the meteorological data is the same as that of the pollutant concentration data, which is daily or hourly.

[0011] In the above technical solution, preferably, the method of screening moment by moment to obtain the lowest value of the pollutant concentration data corresponding to each monitoring station in the target area as the background value of the pollutant concentration at the current moment includes:

[0012] In the target area, the lowest value of the pollutant concentration data of all monitoring stations is screened moment by moment and used as the background value of the pollutant concentration at the current moment. The calculation formula is:

[0013]

[0014] in, is the lowest value of the pollutant concentration data at each monitoring station at time t, is the pollutant concentration data collected by monitoring station n at time t.

[0015] In the above technical solution, preferably, the pollutant concentration data of each monitoring station in the target area at each moment is calculated by subtracting the pollutant concentration data from the background value of the pollutant concentration at the corresponding moment to obtain the contribution concentration of the pollution source to the current monitoring station at each moment. The specific method includes:

[0016] Based on the background value of pollutant concentration at each moment, the pollutant concentration data of each monitoring station at each moment is calculated by subtracting the background value to obtain the contribution concentration of pollutants to the current monitoring station at all moments. The calculation formula is:

[0017]

[0018] in, is the lowest value of the pollutant concentration data at each monitoring station at time t, is the pollutant concentration at station n at time t, is the contribution concentration of the pollutant to site n at time t.

[0019] In the above technical solution, preferably, the wind direction data in the meteorological data within the target period is divided into intervals, and the mean contribution concentration within the same wind direction interval is calculated to obtain the average contribution concentration of pollutants from different directions to the current monitoring site within the target period. The specific method includes:

[0020] Divide the wind direction data within the target period into different wind direction intervals according to national standards or preset methods, calculate the average value of the contribution concentration within the same wind direction interval, and obtain the contribution of pollutants from the corresponding direction sources to the pollutant concentration of the corresponding monitoring station within the target period;

[0021] Calculations are performed for all wind direction intervals to obtain the average contribution concentration of pollutants from various directional sources to each monitoring station.

[0022] Compared with the existing technology, the beneficial effects of the present invention are: it can quickly quantify the contribution of pollutant emissions from various directions to the concentration of atmospheric pollutants at monitoring stations through simple mathematical methods, and it can also obtain the main contribution direction to the monitoring station by statistically analyzing the contribution of pollutants from various directions to the monitoring station over a long period of time. It can make a fast and accurate analysis of stations that have recently experienced pollution, will not be affected by the uncertainty of the emission inventory, and can timely quantify the contribution of pollution sources from various directions to the target station, providing technical support for the refined control of atmospheric pollution, and providing a certain theoretical basis for formulating the priority control order of atmospheric pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A flow chart of a method for quantifying the contribution of different azimuth sources to pollutant concentrations at a monitoring site disclosed in one embodiment of the present invention;

[0024] Figure 2 A schematic diagram of the distribution of monitoring stations and meteorological stations within a target area disclosed in one embodiment of the present invention;

[0025] Figure 3 PM in different directions disclosed in one embodiment of the present invention10 Schematic diagram of emission contribution to monitoring site A. DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0027] The present invention is described in further detail below with reference to the accompanying drawings:

[0028] like Figure 1 As shown, a method for quantifying the contribution of different azimuth sources to pollutant concentrations at a monitoring site provided by the present invention includes:

[0029] Obtain meteorological data of the target area and pollutant concentration data collected by each monitoring station in the target area, correspond one to one according to the time series, and divide them into data arrays at preset times;

[0030] The lowest value of the pollutant concentration data corresponding to each monitoring station in the target area is obtained by screening at each moment and used as the background value of the pollutant concentration at the current moment;

[0031] The pollutant concentration data of each monitoring station in the target area at each moment is calculated by subtracting the background value of the pollutant concentration at the corresponding moment to obtain the contribution concentration of the pollution source to the current monitoring station at each moment;

[0032] The wind direction data in the meteorological data during the target period are divided into intervals, and the mean contribution concentration within the same wind direction interval is calculated to obtain the average contribution concentration of pollutants from different directions to the current monitoring station during the target period.

[0033] In this implementation, simple mathematical methods are used to quickly quantify the contribution of pollutant emissions from all directions to the concentration of atmospheric pollutants at monitoring sites. The main contribution directions to the monitoring sites can also be obtained by statistically analyzing the contribution of pollutants from all directions to the monitoring sites over a long period of time. This allows for a rapid and accurate analysis of sites that have recently experienced pollution, without being affected by the uncertainty of the emission inventory. It can timely quantify the contribution of pollution sources from all directions to the target site, providing technical support for the refined control of atmospheric pollution and a certain theoretical basis for formulating a priority control order for atmospheric pollution.

[0034] Specifically, during implementation, the following steps are used to quantify the concentration contribution of pollutants:

[0035] Step 1: Determine the target time period and target area, obtain meteorological data for the target area and pollutant concentration data for each station, and match wind direction data with pollutant concentration data based on the time series to obtain arrays of wind direction data and pollutant concentration data at each moment.

[0036] Step 2: Based on the pollutant concentration data of each station in the target area obtained in step 1, the lowest pollutant concentration value of each station in the target area is screened at each moment and used as the background value of the pollutant at that moment.

[0037] Step 3: Based on the background value at each moment obtained in step 2, the pollutant concentration at each station is subtracted from the background value to obtain the contribution concentration of the pollution source to the station at each moment.

[0038] Step 4: Based on the wind direction data and pollutant concentration data arrays obtained in step 1, divide the wind direction data of the target period into intervals, average the contribution concentrations within the same wind direction interval, and obtain the average contribution concentration of pollutants in different directions to the station during the target period.

[0039] In the above embodiment, preferably, the meteorological data includes wind direction data and wind speed data, and the pollutants include PM 2.5 、PM 10 and NO2, and may also include other atmospheric pollutants. The time resolution of meteorological data is the same as that of pollutant concentration data, which is daily, hourly, etc.

[0040] In the above embodiment, preferably, the lowest value of the pollutant concentration data corresponding to each monitoring station in the target area is screened moment by moment and used as the background value of the pollutant concentration at the current moment. The specific method includes:

[0041] In the target area, the lowest value of the pollutant concentration data of all monitoring stations is screened at each moment and used as the background value of the pollutant concentration at the current moment. The calculation formula is:

[0042]

[0043] in, is the lowest value of the pollutant concentration data at each monitoring station at time t, is the pollutant concentration data collected by monitoring station n at time t.

[0044] In the above embodiment, preferably, the pollutant concentration data of each monitoring station in the target area at each moment is calculated by subtracting the background value of the pollutant concentration at the corresponding moment to obtain the contribution concentration of the pollution source to the current monitoring station at each moment. The specific method includes:

[0045] Based on the background value of pollutant concentration at each moment, the pollutant concentration data of each monitoring station at each moment is calculated by subtracting the background value to obtain the contribution concentration of pollutants to the current monitoring station at all moments. The calculation formula is:

[0046]

[0047] in, is the lowest value of the pollutant concentration data at each monitoring station at time t, is the pollutant concentration at station n at time t, is the contribution concentration of the pollutant to site n at time t.

[0048] In the above embodiment, preferably, the wind direction data in the meteorological data within the target period is divided into intervals, and the mean contribution concentration within the same wind direction interval is calculated to obtain the average contribution concentration of pollutants from different directions to the current monitoring station within the target period. The specific method includes:

[0049] Divide the wind direction data within the target period into different wind direction intervals according to national standards or preset methods, calculate the average value of the contribution concentration within the same wind direction interval, and obtain the contribution of pollutants from the corresponding direction sources to the pollutant concentration of the corresponding monitoring station within the target period;

[0050] Calculations are performed for all wind direction intervals to obtain the average contribution concentration of pollutants from various directional sources to each monitoring station.

[0051] In this embodiment, the wind direction intervals are divided, for example, the wind direction data within the target time period is divided into intervals (north (0°~22.5°, 337.5°~360°), northeast (22.5°~67.5°), east (67.5°~112.5°), southeast (112.5°~157.5°), south (157.5°~202.5°), southwest (202.5°~247.5°), west (247.5°~292.5°), northwest (292.5°~337.5°)).

[0052] During implementation, the method for quantifying the contribution of different directional sources to the pollutant concentration at a monitoring station disclosed in the above embodiment is specifically described through the following examples.

[0053] Example 1

[0054] Taking a city as the target area, PM 10 For the target pollutants, site A is taken as the target site and the implementation case is as follows:

[0055] S1. Determine site A as the target site and set the target period from 0:00 on January 6, 2022 to 23:00 on January 9, 2022. Figure 2 As shown, get the PM data of sites A, B, C, D, E, F, and G from 0:00 on January 6, 2022 to 23:00 on January 9, 2022. 10 Concentration data, and obtain meteorological station data from 0:00 on January 6, 2022 to 23:00 on January 9, 2022, and sort the PM 10 Concentration data corresponds to meteorological data to form PM 10 Concentration data and meteorological data arrays. In this embodiment, the time resolution of the monitoring station and the meteorological station is 1 hour.

[0056] S2, based on the PM data of site A and other sites in the target area obtained in S1 from 0:00 on January 6, 2022 to 23:00 on January 9, 2022 10 Concentration data: filter out the lowest value of the pollutant concentration data of each station at each moment and use it as the background value at that moment.

[0057] S3, the PM of site A at the corresponding time 10 The concentration was subtracted from the background value obtained in S2 to obtain the contribution concentration of site A at each moment from 0:00 on January 6, 2022 to 23:00 on January 9, 2022.

[0058] Table 1 PM at each time 10 Contribution value (μg / m 3 )

[0059]

[0060]

[0061] S4. Divide the wind direction data from 0:00 on January 6, 2022 to 23:00 on January 9, 2022 into north (0°~22.5°, 337.5°~360°), northeast (22.5°~67.5°), east (67.5°~112.5°), southeast (112.5°~157.5°), south (157.5°~202.5°), southwest (202.5°~247.5°), west (247.5°~292.5°), and northwest (292.5°~337.5°). Average the contribution concentrations within the same wind direction interval to obtain the average contribution concentration of each direction to the target site A during this period. The results are shown in Table 2 below. Figure 3 As shown:

[0062] Table 2 PM in each wind direction range 10 Contribution value to site A

[0063] Wind direction range north northeast East southeast South southwest West northwest <![CDATA[PM 10 Concentration (μg / m 3 )]]> 17.7 16.3 15.2 19.2 - 18.2 23.4 21.6

[0064] Note: - indicates that the wind direction does not exist during the target period

[0065] Based on the above conclusions, we can conclude that during the target period, the west contributed the most to the target site, followed by the northwest, with the east and northeast contributing less. This provides a plan and evidence for prioritizing pollution control when Site A is polluted. (The above examples only use Site A as an example; the same applies to other monitoring sites.)

[0066] According to the above examples, the method proposed by the present invention for quantifying the contribution of different directional sources to the concentration of pollutants at monitoring stations is not affected by the uncertainty of the emission inventory. It can quickly quantify the contribution of pollutant emissions from various directions to the concentration of atmospheric pollutants at monitoring stations through simple mathematical methods. It can also calculate the contribution of pollution sources from various directions to monitoring stations over a long period of time to derive the main contribution direction to the monitoring station. This method provides technical support for the refined control of atmospheric pollution and provides a certain theoretical basis for formulating a priority control order for atmospheric pollution.

[0067] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for quantifying the contribution of different azimuthal sources to pollutant concentrations at a monitoring site, characterized in that: include: Obtain meteorological data of the target area and pollutant concentration data collected by each monitoring station in the target area, correspond one to one according to the time series, and divide them into data arrays at preset times; The meteorological data includes wind direction data and wind speed data, the pollutants include PM2.5, PM10 and NO2, and the time resolution of the meteorological data is the same as the time resolution of the pollutant concentration data, which is daily or hourly; The data arrays are the wind direction data and pollutant concentration data arrays at each moment. By determining the target period and target area, obtaining the meteorological data of the target area and the pollutant concentration data of each station, and matching the wind direction data with the pollutant concentration data according to the time series, the wind direction data and pollutant concentration data arrays at each moment are obtained. The lowest value of the pollutant concentration data corresponding to each monitoring station in the target area is screened moment by moment and used as the background value of the pollutant concentration at the current moment. The specific method includes: In the target area, the lowest value of the pollutant concentration data of all monitoring stations is screened moment by moment and used as the background value of the pollutant concentration at the current moment. The calculation formula is: in, is the lowest value of the pollutant concentration data at each monitoring station at time t, is the pollutant concentration data collected by monitoring station n at time t; The pollutant concentration data of each monitoring station in the target area at each moment is calculated by subtracting the background value of the pollutant concentration at the corresponding moment to obtain the contribution concentration of the pollution source to the current monitoring station at each moment. The specific method includes: Based on the background value of pollutant concentration at each moment, the pollutant concentration data of each monitoring station at each moment is calculated by subtracting the background value to obtain the contribution concentration of pollutants to the current monitoring station at all moments. The calculation formula is: in, is the lowest value of the pollutant concentration data at each monitoring station at time t, is the pollutant concentration at station n at time t, is the contribution concentration of the pollutant to site n at time t; Divide the wind direction data in the meteorological data within the target period into intervals, calculate the average contribution concentration within the same wind direction interval, and obtain the average contribution concentration of pollutants from different directions to the current monitoring station within the target period; The specific method for obtaining the average contribution concentration of pollutants from different directions to the current monitoring site during the target period includes: Divide the wind direction data within the target period into different wind direction intervals according to national standards or preset methods, calculate the average value of the contribution concentration within the same wind direction interval, and obtain the contribution of pollutants from the corresponding direction sources to the pollutant concentration of the corresponding monitoring station within the target period; Calculations are performed for all wind direction intervals to obtain the average contribution concentration of pollutants from various directional sources to each monitoring station.

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