Pursuant to the current legislation air pollution sources are divided into four categories. Complying with this categorisation, the ISKO system operated by CHMI includes REZZO 1–4 databases (Register of Emissions and Air Pollution Sources) which serve for archiving and presenting data on stationary and mobile air pollution sources. Large and medium-sized sources are monitored individually (point-source pollution), small sources at local level (area sources) and mobile sources at national level (line sources).

I. Large pollution sources - REZZO 1
II. Medium-sized pollution sources - REZZO 2
III. Small pollution sources - REZZO 3
IV. Mobile emission sources - REZZO 4

The category of large sources included about 2,200 sources. The data used in the 2000 emission inventory of air pollutants from large sources was extracted from the Operational Inventory of Large Pollution Sources submitted by source operators to the Czech Environmental Inspection Office (ČIŽP) which is in charge of data collection and verification. The REZZO 1 database has been updated, i.e. additional operating technical data on sources (information on boilers, fuel consumption and quality and technologies), using the form sheets submitted by operators as Summary Evaluation of Data from the Operational Inventory under Decree No. 117/1997 of the Ministry of the Environment, in cooperation with ČIŽP.

The medium-sized sources category includes data on more than 30,000 medium-sized sources. The 2000 results are based on the Operational Inventory of Medium-sized Pollution Sources, as verified by the district and municipal authorities� environment departments. The REZZO 2 database has been updated, i.e. additional operating technical data on sources (information on boilers, fuels, technologies and emissions), using the supplementary data from the Summary Evaluation of Data from the Operational Inventory under Decree No. 117/1997 in cooperation of the Emission and Sources Department of CHMI in Milevsko with the relevant district and municipal authorities� environment departments.

Emissions from small sources (local heating units) have been inventoried based on the 1991 General Census; its output includes information on the consumption of principal fossil fuels in households. Emission was calculated from updated figures on fuels consumption based on data on the way of household heating, on specific heat consumption and climatic conditions in 2000.

Pollutant emissions from mobile sources falling within the competency of the Ministry of Transport and Communications (road, rail, water and air transport) have been processed by the Transport Research Centre (CDV) Brno. Other mobile sources (agricultural and forest machines, building machines, in-plant transport and army vehicles) have been inventoried from calculations of fuel consumption levels and the respective emission factors.

Table 1-1 documents total emissions of principal air pollutants in 2000, and namely, solid particles SO₂, NO_x, CO and shares contributed by each of the emission source categories monitored to total air pollutant emissions.

International emission inventories (EMEP/CLRTAP, CORINAIR, EUROSTAT/OECD) require balances of volatile organic compounds (VOC). Pollutants presented as hydrocarbon emission (C_xH_y) shown in the Table 1-1 in previous years, do not correspond with pollutants presented as VOC. VOC emission balance is recorded differently and it includes also emission from the solvent use and paint application in sources not registered in REZZO database – outdoor and domestic paint and solvent use. Therefore data on total VOC emission and re-calculated VOC emission values for previous years are presented (see Fig. 1-1). This change corresponds also to the modification of the list of pollutants in the Supplement No. 1 to the Decree No. 117/97 under the Decree issued by the Ministry of the Environment No. 97/2000 of 10 April 2000.

The development of total emission of principal pollutants in 1990–2000 shown in Fig. 1-1 demonstrates their further drop in 2000 as compared to 1999, with the exception of NO_x. This trend was expected in connection with the fact that the majority of air pollution sources were meeting the required emission limits in the course of the whole year 2000. The increase of SO₂ and NO_x from large sources caused by higher production of electric energy followed by higher fuel consumption, was to a certain extent compensated by further decrease of emissions from medium-sized and small sources, contributed to by favourable climatic conditions and the introduction of gas heating.

Table 1-2 presents emissions of carbon dioxide and other greenhouse gases observed by the UN Framework Convention on Climate Change. The REZZO system does not include these values; the stated values are assessed according to the IPCC (Intergovernmental Panel on Climate Change) methodology. Nitrous oxide (N₂O) values of 1990–1995 will be re-calculated according to the recent revision of this method.

Table 1-3 covers heavy metal and POPs emission recorded within international co-operation in 1990–2000 with the use of capacity data (fuel consumption, heat supplied, statistical data on selected production technologies) and of the respective emission factors.

Table 1-4 demonstrates the consumption development of principal fuels in the period 1990–2000. A trend of marked decrease in brown coal and residual oil consumption by large emission sources has contributed to a long-term decline in SO₂ and particulates, mainly in the 1990–1996 period. The development of consumption of principal fuels of REZZO 3 sources between 1990 (data based on the inventory carried out by TECO Milevsko) and 2000 is shown in Fig. 1-2. Changes in residential heating in 1991 (data provided by General Census) and 2000 (updated situation) are shown in Fig. 1-3.

Emission data processed into emission density charts with the help of GIS is shown in Figs. 1-4, 1-5, 1-6 and 1-7, in which emission densities for solid particles, SO₂, NO_x and VOC are plotted in 5 x 5-km grid-squares. The charts are based on current emissions from stationary sources (REZZO 1 to 3) and line sources (REZZO 4) for 1999, with regional disaggregation of emissions from line sources according to the 1995 vehicle census.

Among the most polluted regions of the Czech Republic with regard to emissions of principal air pollutants are counted continuously the region of the Capital City of Prague, Northern Bohemia and Northern Moravia. Comparison of the specific emissions from stationary sources data in 1995 and 2000 (Table 1-5 and Table 1-6) shows that also in case of this coefficient expressive improvements occurred, especially reduction of SO₂ and particulate emission. Development of emissions from large sources in the regions mentioned above in 1990–2000 is shown in Figs. 1-8, 1-9 and 1-10.

Tab. 1-1 Total emissions of principal air pollutants from REZZO 1–4 sources in 2000

^a) including emissions from transport and emissions from other mobile sources

Tab. 1-2 Total emissions of principal greenhouse gases, 1990 to 1999

Comments: Presented values estimated by course of the IPCC methodology (including uptake from forestry). Emission recalculated to CO₂ equivalent using GWP coefficients 21 and 310 for methane and nitrous oxide respectively.

Tab. 1-3 Total emissions of HMs and POPs between 1990 and 2000

^a)preliminary data

Tab. 1-4 Fuel consumption in REZZO 1 sources between 1990 and 2000

Tab. 1-5 Specific emissions from stationary sources in 1995 (REZZO 1–3)

Tab. 1-6 Specific emissions from stationary sources in 2000 (REZZO 1–3)