Naslov
Calculating and mapping of critical loads on surface waters for selected sites in Republic of Croatia

Autori
Hudina, Sandra ; Jelavić, Vladimir ; Šaša, Duska ; Klobučar, Goran

Izvornik
Balance of Nutrients in Rural Areas BALNUTRA - Book of Abstracts

Vrsta, podvrsta
Ostale vrste radova, ostalo

Godina
2009

Ključne riječi
critical loads; surface waters

Sažetak
Project Calculating and mapping of critical loads on surface waters for selected sites in Republic of Croatia started in late July 2007 and was finished in July 2008. The main objective was to assess the impact of deposition of acidifying and nutritive compounds on freshwater ecosystems in selected areas in Croatia. Research consisted of selection of undisturbed sites, chemical and biological monitoring and modelling of critical loads in selected sites. Chemical monitoring results indicated that parameters related to acidification (especially pH with lower alkalinity levels) are in excellent condition regarding the research of acidification effects. The results showed elevated concentrations of certain nitrogen compounds (nitrates and total nitrogen) for certain period of time (winter). The overall water quality status, on the basis of biological monitoring, indicated clean waters and undisturbed communities. Only diatom indicator species composition and their population densities, saprobic index (SWegl) classified examined sites as class II water quality or ß- mesosaprobic waters, indicating slight organic burdening. Increased nutrient concentrations at all three locations were confirmed using Trophic Diatom Index (TDI) while Generic Diatom Index (GDI) indicated higher eutrophication status for Sutla, minimal eutrophication at Veličanka and no eutrophication at Bukovska Dobra. Calculated critical loads of acidity (CL(A)) for all three selected sites were high and there was no exceedance of critical loads for acidity. Simple mass balance calculation for nitrogen indicated that transboundary flux may cause classification to class II according the Croatian regulation, in extreme situation even class III. Transboundary nitrogen deposition was defined as a potential problem for Croatian freshwater ecosystems. The exceedance of critical loads for nitrogen deposition in terrestrial ecosystems has already been confirmed throughout European Union, but models for calculation of critical loads for eutrophication have not been developed yet.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA