The diagnostic and prognostic assessment of changes in the chemical composition of air and water essentially depends upon the conditions for admixture transport in the atmosphere and water basins. Therefore, the ecological aspect of the problems related to the air and water composition essentially depends on the physical state of the atmosphere and hydrosphere. This defines the substantial relation with the national and international priorities of the activities carried out in the National Institute of Meteorology and Hydrology (NIMH), the department "Atmosphere and Hydrosphere Composition" in particular. The department consists of four sections :
  • Measurements and laboratory analyses;
  • Databases and information services;
  • Theoretical studies;
  • Experimental studies;


Specific operational activity

  • Obtaining, processing and storing of data from the NIMH air and water radioactivity monitoring network; preparation of information for the NIMH monthly bulletin and of specialized information for the Executive Agency on Environment.
  • Sampling and laboratory control of the total beta activity of the air, atmospheric depositions, precipitation, river and reservoir water, urban water supply system, based on the data from the stations of the NIMH atmosphere and water radioactivity network in South-West Bulgaria.
  • Control of the monthly gamma radiation background data from the NIMH monitoring network.
  • Gathering of precipitation chemistry data from 20 synoptic stations in the country.
    Updated guidelines for all types of sampling, measurements and analyses carried out in the NIMH network are prepared for printing.
  • Measurement of air pollution with sulfur dioxide (SO2), nitrous dioxide (NO2), hydrogen sulfide (H2S), phenol and dust in five points in the country; part of the data are sent to the World Greenhouse Gases Data Center, Japan.
  • Measurement of the total ozone in Sofia; data are sent to the World Ozone Center in Canada and are used for public information.
  • Study of the river and ground water quality in Southwest Bulgaria (the catchment area of rivers Struma, Mesta, Iskar and Nishava) by field samplings; (O2), BPK5, pH, air and water temperature as well as 20 characteristics of water quality are determined on site.


Specific operational activity

     In 2000, 19 projects were in hand at the Department. Most of these projects originated from the needs of different sectors in the country or were required by international cooperation. The main results obtained are:

  • Study of the pollution exchange between Bulgaria and Northern Greece - project funded by NATO and accomplished by Greek and Bulgarian scientists. A great number of atmospheric pollution simulations were carried out within this project. The sulfur deposition in Southeast Europe for 1995 was estimated using the Bulgarian dispersion EMEP model, the input data being prepared at NIMH. Different scenarios with reduction of the emissions of atmospheric pollutants in both countries ware constructed.
  • On the basis of developed theoretical grounds of a method for restoration of background values of dynamic air parameters in the lower atmosphere (planetary boundary layer), a computer system is established for restoration (in diagnostic and forecasting aspect) of the radioactive gamma background parameters, using measured or predicted surface values. Thus, an estimation of the radioactive gamma background values with height was obtained, as its direct measurement is practically impossible because of the high cost.
  • Within the project “General schemes for water use in regions with basin management”, assessment of the water quality at characteristic points of the river network in the river valleys was made, the tendencies for changes were established and categories of river flow for each river's catchment area were selected. The assessments of water quality are of extreme importance for the water use.
  • Comparative analysis of scenarios for sustainable development of the electricity sector in Bulgaria is carried out. The emissions and deposition of SO2 and NOx from Bulgarian thermal power plants as well as of the respective fields of deposition are assessed. The emissions and prices of cleaning technologies and the SO2 deposition fields obtained by two methods are compared. Four scenarios for development of the electricity sector in Bulgaria till 2020 are developed and strategy for its sustainable development till 2015 is outlined.
  • A method for categorization of river flow was proposed, related to the average minimum monthly water discharge. In 2000, the dependency between the water discharge and the basic water quality parameters was studied by this method. Such studies are performed in 65 characteristic points on the country territory, comprising all main Bulgarian rivers of water economy significance.
  • The regular completion of the databases for total ozone content and solar radiation components continues.
  • The archiving of data from the network for chemical composition of precipitation (functioning since 1987) on technical carrier continues.
  • Testing of the technique for measurement of short-living beta radionuclides in the atmospheric samples continues. The purpose is to assess the concentration of 222Rn and 220Rn daughter beta radionuclides in the atmospheric aerosol.
  • Archive of the information for the surface temperature and wind field, as well as these for the 850 hPa level, in the period after November 1999, provided by the German Meteorological Center in Offenbach (DWD) is established. The new-coming information is entered operationally. The earlier numerical model for prediction of meteorological elements in the planetary boundary layer was modified to allow the choice of different points and periods of simulation, as well as different types of input data. This model was used as a meteorological pre-processor of a model for estimation of local scale transport of air pollutants.
  • The microclimate and comfort conditions for the Northern slope of Vitosha mountain in the cold and warm half of the year were analyzed using data from the 1990 – 1995 period. Model estimation of the surface fields of the main air.
  • pollutants (SO2, NO2 and dust) on the territory of Sofia in 1995 was made.
  • The NIMH' system for early warning in case of severe nuclear accident has been improved. Surface orography was constructed and the choice of numerical grid was performed. Trajectory model was also developed.
  • The distribution of pollutants from different sources in the Black Sea was numerically studied using the Modular Ocean Model (MOM). The sensitivity of the ecosystem in different parts of the sea in respect to the river's run-off, gelatin organisms' decrease, fish catchment influence, and input of coastal pollutants was studied. New-generation three-dimensional circulation model for the Black Sea (MOM3) was configured.
  • In 2000, cooperation in the framework of COST 715 is realized through boundary layer modelling and parameterization of the turbulent characteristics of this layer as well as by providing data for the turbulence in urban environment. Studies have been carried out to search for statistical relations using the NIMH' multiannual data for chemical pollution, and surface meteorological and aerological data for urban environment.

     In addition, research on the following tasks or projects is carried out:

  • Study of local climatic conditions and air pollution in the region of eco-zone “Sofia-East”;
  • Study of radiation and humidity characteristics in forest areas;
  • Implementation of the German numerical model HRW for regional forecasts in the operational practice;
  • Pre-operational meteo-monitoring of the nuclear power plant "Belene";
  • Estimation of the radionuclides distribution along the Bulgarian Black Sea coastal zone and the role of the hydrophysical processes in its formation – participation at the International Monitoring Program of IAEA for the Black sea, Project RER2003. Participation in the international expedition of IAEA 'Cruise 2000' for the Black Sea;
  • Taking samples of glaciers and glaciological studies in Livingston island, Antarctica;
  • Editorial work for the newsletter of the European Association for the Science of Air Pollution;
  • Participation in UNESCO Project to publish Encyclopedia of Life Support Systems by editorial work on Theme "Natural Resources System Challenge: Climate Change, Human Systems and Policy".