U S A G E O F M A S S E L E M E N T F L U X E S F R O M S M A L L C A T C H M E N T S I N T H E A S S E S S M E N T O F C R I T I C A L L O A D S O F H E A V Y M E T A L S

I r e n a S k ore p o v á ( C z e c h E n v i r o n m e n t a l I n s t i t u t e , V r ao v i c k á 6 5 , 1 0 0 1 0 P r a g u e 1 0 , C z e c h R e p u b l i c ) ; D a n i e l a F o t t o v á ( C z e c h G e o l o g i c a l S u r v e y , K l á r o v 3 , 1 1 8 21 Prague 1, Czech Republic)

Bulk deposition, throughfall and runoff data on Cd, Pb and Cu obtained from 14 small forest catchments of the GEOMON network in the Czech Republic were used in the assessment of their critical loads. From 1996 up to now the input / output fluxes of Cd and Pb have shown a decrease, similar to the development of sulphur deposition due to desulphurization measures. On the contrary the fluxes observed in the Northern part of the Czech Republic, the so called “black triangle”, remain at the same level.

Using heavy metal fluxes measured at the GEOMON sites critical loads were calculated on the base equilibrium processes including adsorption and complexation influenced by soil properties such as carbon contents, soil texture, pH and base cation contents. In the evaluation of critical loads maximum permissible concentrations of Cd, Pb and Cu for drinking water were applied as environmental quality criteria. The results gained from the observations assist in the verification of the mathematical model which is used in mapping critical loads for the whole territory of the Czech Republic.