Determination of regional influences on the deposition of Pb, Cd and H+ ion in a network of rain samplers

In order to determine the wet deposition rates of Pb, Cd and acid constituents, represented by pH, in industrial, urban, rural and maritime areas in Germany since 1979, a network of precipitation samplers has been established. Sampler positions are described and classified geographically and assumptions on pollutant sources effective at the sampler positions are made. These geographical expectations are verified by statistical analyses. Discriminant analysis of the total average values of the wet deposition rates regarding the complete network, permitted the classifications of industry, town and country for the sampler locations. The industry group is characterized by high wet deposition rates of Pb and Cd, the town group by enhanced wet deposition rates of acid constituents, whilst the country group in comparison with the town group showed altogether lower wet deposition rates for Pb, Cd and acid constituents. Factor analysis of the local time series of pollutant wet deposition rates including the precipitation rate shows the direct influence of strong pollutant sources at a number of sampler positions, especially for locations in the industry group. The town and country groups are characterized by non-individual wet depositions, depending preferentially on general local atmospheric conditions.