Czech Hydrometeorological Institute - Air Quality Protection Division


II.1 Networks of Ambient Air Quality Monitoring Stations

The ambient air pollution situation has been assessed based on the data archived in the ISKO air pollution database. In addition to the data from CHMI networks, several other organisations that play an important role in air pollution monitoring in the Czech Republic have also been contributing to the ISKO database for a number of years. As it was stated in the Preface, since 1996, the data for the German part of the Black Triangle has been included and presented in the air pollution ISKO database, and the data for the Polish border area has been included since 1997 likewise.

In early 2000 there emerged the need to optimize the air pollution network in order to provide the state bodies with the necessary information for the whole Czech Republic territory and the tools for fulfilling the tasks set by the respective EU directives and by the obligations ensuing from international agreements adopted by the Czech Republic in the field of air quality protection and to site the monitoring stations pursuant to the requirements of EU directives. Simultaneously the urgent need emerged to innovate the instruments worn down by continuous operation which resulted in ever increasing failure rate. Within the R&D project the Draft of the optimalized network of air quality monitoring was presented followed up in 2002 by the Implementation project of the National air pollution network (SIS) including the AIM network and the supplementary network with manual sampling. The SIS project, pursuant to 6, Art. 8 and 7, Art.. 5 of the Clean Air Act No. 86/2002 Coll., aimed at ambient air quality monitoring in the whole territory of the Czech Republic, and namely in the areas with deteriorated air quality. The project also considered new knowledge and requirements concerning the monitored pollutants, as well as the change in the emission situation in the Czech Republic. Pollutants monitoring within the national air pollution network was aimed mainly at the pollutants with the set limit values. It was supposed that the proposed SIS, operated by one authorized organization, is the basic component of air quality monitoring in the Czech Republic. If necessary it can be combined with and use the data from the specialized networks of other organizations or the monitoring stations operated at a lower level (regions and selected basic administrative units). This network, established with the PHARE project contribution, was launched on 1 January 2004.

Tables II.1.1–II.1.5 present the oveviews of the numbers of localities in the respective zones and agglomerations from which the measured data were supplied to the Air Quality Information System (ISKO) database.

Table II.1.1 provides the overview of the number of localities, broken down by the owners operating the respective monitoring network. Usually only one measuring programme is installed per the respective locality. Several localities, particularly the CHMI ones, operate more than one measuring programme, for example the stations Prague 4-Libuš, Košetice, Ústí n. L.-Kočkov, Bílý Kříž and some others at which automatic, manual and semiautomatic measuring programmes have been installed, as also those intended for the monitoring of PAHs and heavy metals.
Table II.1.2 lists the number of air pollution monitoring localities at which basic pollutants are monitored automatically. At AIM stations the pollutants are measured by continual analysers and the measured concentrations are as 1 hour averages transmitted in real time via switched lines or via radio transmission for further processing.
Table II.1.3 shows the number of localities in individual regions at which further pollutants, incl. supplementary meteorological parameters are monitored automatically.
Table II.1.4 lists the number of localities in individual regions at which the listed pollutants are monitored by manual methods.
Table II.1.5 presents the total numbers of localities in individual regions with special measurements using manual methods.
Network density in each of the Czech Republics regions and monitoring organisations involvement are illustrated in Fig. II.1.1.
The graphs in Fig. II.1.2 illustrate how the measurement of principal air pollutants has developed since 1971 for the organisations and network types listed; the measured data are archived in the ISKO database.
The production of maps of air pollution characteristics presented in this Yearbook is guided by the classification of the measuring stations carried out within the research project VaV740/2/00 Evaluation of the Czech Republic Readiness to Meet Air Quality Requirements of EU Directives and the LRTAP Convention [3] and further developed.
This classification is based on the Council Decision 97/101/EC on exchange of information (EoI) [4] and Criteria for EUROAIRNET [5]. The requirements of the Council Decision 97/101/EC are obligatory for the EU Member States.
Due to the fact that this is the only official European classification it has been applied to all air pollution stations in the Czech Republic registered in the ISKO database.
The classification of the SIS monitoring stations in the Czech Republic is described in Sládeček, J., Blažek, Z. (2000): Application of criteria for the classification of stations and station networks pursuant to the EoI Decision 97/101/EC and Criteria for EUROAIRNET to the stations included in the air quality assessment process. The Report on the task DU01-1.E1 of the R&D Project VaV/740/2/00, CHMI, Prague.
The EoI classification was simplified by the Decision of the European Commission 2001/752/EC. The character of the location of some monitoring stations in the Czech Republic, however, corresponds rather with the classification in the original version of 1997 and thus it continues to be used in the ISKO database. The Yearbook uses the term type of area instead of type of zone in accordance with the Council Decision 2001/752/EC.
The complete EoI classification (Table II.1.6) consisting of 3 fundamental letters divided by strokes is presented only in those stations at which it was officially affirmed by an expert team in accordance with local criteria. In some cases incomplete classification is presented (1–2 letters only) derived from the purpose of the station establishment.
The third column of the table II.1.6 shows only the examples of the combinations of zone characterisation. Any logical combination is possible and the order of letters in the abbreviation is meaningful – the first position is always of the highest priority.
The legends in maps of fields of pollutants concentrations the EoI classification is used in a simplified form based mainly on the type of area according to the Decision 2001/752/EC. The correct application of this classification during the production of maps of fields of pollutants is bound to the recommended area of representativeness (radius of area) for the various station types:

  • traffic – station directly influenced by traffic, located within 50 m from the communication with high traffic intensity; the station should cover the longest part of the road/street, the area of representativeness is not applicable here appropriately (mentioned in the Criteria for EUROAIRNET (Draft 98) less than 10–15 m). The area of representativeness can be defined in terms of length of road: city centre more than 100 m, suburban areas more than 1000 m.
  • industrial – station directly influenced by industry, located on the premises of a factory or at sites of potential influence of the smoke plume from the sources in the prevailing wind direction. The area of representativeness of the station is 10–100 m.
  • background – station in unafflicted localities, measuring the background of regions, cities and industrial areas. The station should not be directly afflicted by any source. The area of representativeness of the station differs as follows:
    • in urban and suburban stations more than 1–1.5 km,
    • in rural stations from more than 5 to cca 60 km (in the Czech Republic usually between 10 and 20 km).

In 2005 three specialized stations marked as traffic hot spot were in operation, and namely Prague 2-Legerova, Ústí n.L.-Všebořická and Ostrava-Českobratrská. These measuring sites are exclusively traffic oriented and their air pollution loads result from this. These stations meet the criteria for traffic-oriented samplers pursuant to the Government Order No. 350/2002 Coll. (For the measuring of all pollutants at least 25 meters from the edge of big crossroads and at least 4 meters from the centre of the nearest traffic lane.)
More detailed overview of background rural stations into subcategories pursuant to the Decision 2001/752/EC and Criteria for EUROAIRNET, Technical Report no. 12, EEA have been presented in the tables since 2004.

  • near-city, code NCI, located in rural/agricultural areas, with a distance of 3–10 km from built-up areas and other major sources, radius larger than about 5 km.
  • regional, code REG, located in rural/agricultural areas, with a distance of 10–50 km from built-up areas and other major sources, radius larger than about 20 km.
  • remote, code REM, located in rural/natural areas, with a minimum distance of 50 km to built-up areas and other major sources, radius larger than about 60 km.

Further details on station networks, the measurement methods used, on the detection limits of different methods used, and the detailed updated list of stations broken by territorial units and further specific data can be found in the summary Tabular Survey [2].
The degree of usability of the data supplied by the institutions that contributed to the ISKO database in the year under review (i.e. data capture) is listed in Tables II.1.7–II.1.10. For the parameters assessed these tables compare the number of those monitoring stations in the networks reviewed, which meet the criteria for the validity of annual air pollution characteristics (see the numerator), and the total number of stations of the given network measuring the respective parameter (see the denominator). This proportion of valid data from the annual file of the measured and verified data, submitted for the given parameter by the respective organization/network, is expressed as percentage (see the number below the fraction). Data validity is based on the longest-lasting continuous measurement failure in a year (NSV) and the minimum required percentage (MP) of valid data within the annual data file. Being the basic parameters of the criterion of comprehensiveness and uniformity of the data entered into the annual air pollution characteristics computations, the longest-lasting continuous failure in a year – expressed as a certain number of days – and the required minimum percentage of valid data are evaluated during the annual data processing, and stored as part of the annual data file for each station and for each parameter.

The criterion of the minimum percentage of valid data MP≥66 % and the longest-lasting continuous failure NSV≤40 is used for setting the valid annual arithmetic average of concentrations of the given substance as well as for the data capture (see Tables II.1.7–II.1.10). During 2003 and 2004 the CHMI measuring network changed significantly. The measuring sites were located with regard to the monitoring aims set in the respective EU directives, the Clean Air Act No. 86/2002 Coll. and the Government Order No. 350/2002 Coll. The changes were finished in 2004 and the measuring programmes and types of pollutants measurement ensure the ambient air quality monitoring in the whole territory of the Czech Republic and mainly in the areas with deteriorated air quality.

Tab. II.1.1 Air pollution monitoring localities, based on the owner, Czech Republic, 2005

Tab. II.1.2 Air pollution monitoring localities measuring basic pollutants, AMS, based on the owner, Czech Republic, 2005

Tab. II.1.3 Air pollution monitoring localities measuring other pollutants and supplementary quantities, AMS, based on the owner, Czech Republic, 2005

Tab. II.1.4 Air pollution monitoring localities measuring basic pollutants, manual methods, based on the owner, Czech Republic, 2005

Tab. II.1.5 Total number of monitoring localities with special measurements, manual methods, based on the owner, Czech Republic, 2005

Tab. II.1.6 Exchange of Information (EoI) station classification

Tab. II.1.7 Percentage of valid data from the stations with continuous measurement, 2005

Tab. II.1.8 Percentage of valid data from the stations with manual measurement, 2005

Tab. II.1.9 Percentage of valid data from the stations measuring meteorological parameters, 2005

Tab. II.1.10 Percentage of data from other measurements, 2005

Fig. II.1.1 Major station networks of ambient air quality monitoring, 2005

Fig. II.1.2 Monitoring of principal pollutants in selected organisations – development