Since the mid-1990s, the IPR has been updating the Air Pollution Source Register (REZZO) database annually.

Sources of pollution

Records of stationary and area sources of air pollution include:

1. listed stationary sources of pollution
   REZZO 1 (extra large and large sources)
   REZZO 2 (medium sources)
   Emissions are monitored for individual sources of pollution.

2. unlisted stationary sources of pollution
   REZZO 3 (small, mass monitored sources, including local heating stations)
   Emissions are monitored in total for the basic settlement units.

The database contains the annual fuel consumption of the source, the installed capacity of the source and the emissions of these substances: SO2, CO, NOx, particulate matter, suspended dust fractions PM10 and PM2.5, BaP, greenhouse gases (CO2, CH4, N2O, CO2ekv). The specific emissions are calculated for stationary sources in total for the area of the urban district.

This information is shown in Emissions from stationary sources and Listed sources of air pollution.

Example of pollution sources in the Environmental Atlas

Sources of background data

• Listed stationary sources of pollution REZZO 1 and REZZO 2

  • CHMI
  • operators of selected stationary sources of air pollution with full reporting obligations (TPPO3 and TPPO5) provide extracts from continuous emission measurements (hourly or ½ hourly intervals) or, for gas block boilers, hourly consumption of natural gas. These are Veolia Energie Praha, a.s., Pražská teplárenská a.s., Českomoravský cement, Radotín plant, Pražské služby, a.s.

• Unlisted stationary sources of pollution REZZO 3

  • CSO data from the Census of Population, Houses and Apartments
  • data on annual deliveries of natural gas from Pražská plynárenská Distribuce, a.s.
  • data on annual heat supplies from Pražská teplárenská, a.s. and Veolia Energie Praha, a.s.
  • data on annual electricity supplies from PRE distribuce, a.s.
  • the nature of the heating season (number of degree days).

Calculation of emissions

The group of monitored stationary sources in REZZO 3 includes mainly model-calculated emissions from the local heating of households, as well as emissions from livestock farming, field work, construction activities, landfills and coal mining, emissions from the area use of solvents, landfills and coal mining, livestock farming and the use of mineral fertilizers. Emissions of pollutants that operators are not obliged to detect are calculated in the emissions database on the basis of reported activity data and emission factors. Emission factors for stationary combustion sources are differentiated according to the type of combustion chamber and heat output.

Greenhouse gases were calculated in accordance with the IPCC (Intergovernmental Panel on Climate Change) methodology. The calculation is performed separately for each relevant greenhouse gas in the first stage. These emissions are then converted according to their contribution to global climate change into equivalent carbon dioxide emissions.

Air pollution model

In connection with the REZZO database update, the IPR makes regular updates of air pollution modeling in the territory of the capital city in two-year cycles. For Prague it was prepared by the company ATEM s.r.o. in cooperation with the Czech Hydrometeorological Institute (last update 2022). In 2016, the calculation procedure was substantially upgraded to include the effects of the timing of emission inputs and meteorological parameters over the course of the assessment year. It is a combination of a Eulerian chemical transport model, which includes the chemical reactions of pollutants in the air, and a modified Gaussian ATEM model, which was used to calculate concentrations at different hours of the year. Both models are based on actual meteorological parameters. The results from both models are combined with each other in order to correctly represent the background level of immissions at each point in the area and at the same time to affect elevated concentrations in the close vicinity of emission significant sources (high-capacity roads, major stationary sources). The following pollutants are monitored: CO, SO2, NO2, NOx, PM10, PM2.5, benzene, B[a]P, O3.The outputs are displayed in layers: Immission maps and Immissions at reference points.

Sample of an immission map in the Environmental Atlas

The following sources of pollution enter the model:

• point stationary sources, area stationary sources (including resuspension), the basis for these data is the REZZO database update
• car traffic: 4,660 linear sections in Prague, 488 major intersections, special sources (stationary area sources with increased traffic-related emissions): 26 bus stations and public transport terminals, 30 point and area sources representing tunnel portals and ventilation outlets, 976 large car parks and garages)
• emissions from uncounted traffic
• air transport
• transfers

Example of transport emissions in the Environmental Atlas

The shares of source groups (point, area, line and airport) in the annual averages of individual pollutants are shown in the Environmental Atlas layer Immissions at reference points.

Air pollution information is supplemented by the map layer Five-year immission averages. These data are published annually by the Czech Hydrometeorological Institute. Within the five-year averages of immission concentrations in the 1 x 1km network, pollution of PM10, PM2.5, NO2, benzene, arsenic, benzo(a)pyrene, SO2, lead, nickel and cadmium are mapped.