Blue sky and white clouds Ningbo enter the best time slot a year in air quality
- Details
- Category: Ningbo News
- Published: Tuesday, 24 July 2012 15:49
Source 2012-7-24 11:09:04 South East Business News
Yesterday afternoon, the blue sky and white clouds on the lake like a painting. Reporter Bo photo
Yesterday, friends visited Lhasa "Huang said in microblogging, this two-day Ningbo air is really clean, exceptionally bright blue sky, she thought back to Lhasa. There are many like her post praised the air quality of the users.
According to information released yesterday by the portal of the Municipal Environmental Protection Bureau, July 22, the city's five points are measured daily average PM2.5 concentration per cubic meter of 9-11 micrograms, July 21 five points of the PM2. 5 concentration per cubic meter of 7-13 micrograms, record the lowest value since the detection of this year. These two days the city's air quality as a priority.
"Due to weather conditions, every summer, are the city air quality the best period." Municipal Environmental Monitoring Center expert told a reporter, now the city has entered the best period of the year in air quality, and generally can be maintained to 9 mid-March.
Sustainable good air to mid-September
However, the reporter also noted that the July 20, the city's air quality and PM2.5 concentrations are not very satisfactory. July 18, 5 point PM2.5 concentration is 55-75 micrograms per cubic meter, July 19, is 55-81 micrograms, fell down on July 20, 20-41 micrograms. Three days of air quality are two good.
Why the PM2.5 concentration values of these two days the city is suddenly reduced, air quality, converted to a superior? The expert explained, mainly because of the weather conditions changed. In general, Ningbo summer blowing southeast wind or south wind, making the sea a lot of fresh and pollution-free air into Ningbo. In addition, the control of the city of subtropical high pressure, which is also conducive to the diffusion of pollutants in the air.
The next few days if weather conditions in the city has not changed, so good air quality will be maintained. "Experts say, in general, every summer is the best time of the city air quality, has been continued until September in mid.
Reporters learned from the portal of the Department of Environmental Protection, July 22, the province's daily average PM2.5 concentration is very low per cubic meter of 7-16 micrograms.
Why choose a school park for the monitoring points
So far, the city has Taikoo Primary School, Three Rivers Middle School, the Municipal Environmental Monitoring Center, Long Race hospital, Beilun environmental building five point announcement of PM2.5 daily average concentration. Under the plan, the city will be announced during the year the control points of the three countries of the High-tech Zone Business Park, East Lake money lake plant and is located in Yinzhou Zhejiang Wanli College's PM2.5 monitoring data.
In response to these points, there are many people asks: choose whether the scientific basis of these monitoring points? Why schools and parks as monitoring points?
The air quality of the environment monitoring is a technical work, the countries have in the distribution, instrumentation, test standards. "Municipal Environmental Protection Bureau experts told reporters, different monitoring sites, constitute the ambient air quality monitoring network. Monitoring network design, we must first consider the established representative monitoring point.
Routine ambient air quality monitoring sites can be divided into four categories: pollution monitoring points, the air quality assessment point, air quality control point and air quality background point. Four types of monitoring points, the air quality evaluation point is the most talked about it for the different functional areas of the evaluation of urban air quality status and trends, reflecting the overall air quality levels within a radius of 500-4 m.
China's "ambient air quality monitoring standards" requirement, to protect against local human disturbance and to ensure that the evaluation of the representativeness of point evaluation point around 50 meters, there should be no sources of pollution; sampling around the mouth, air circulation, within a certain distance without obstacles and so on.
Both the primary and secondary schools and parks near densely populated areas, children and adolescents and the elderly are sensitive groups of contaminants, in this regional distribution is in line with regulatory requirements. "The experts said, the layout of monitoring points to take into account various factors OK, the point does not exist in the selection of clean surveillance. Yesterday's monitoring data also confirms this point: PM2.5 concentration values in the the Sanjiang secondary schools and the surrounding Pacific Primary School ranked first and second in the five monitoring sites.
