Relationships between precipitation chemistry, hydrology, and runoff acidity [ionic composition, sea-spray, Cl, SO4, NO3, Ca, fish, Norway]
1981
Skartveit, A. (Bergen Univ. (Norway). Inst. of Geophysics)
High precipitation amounts of strongly varying ionic composition make the western parts of southern Norway well-suited for studies of certain relationships between precipitation chemistry, hydrology, and runoff acidity. Ions from sea-spray are the predominant ions in precipitaion in these areas. The remaining ions are almost exclusively acidifying compounds (H('+), NH('+)(,4), SO('2-)(,4), NO('-)(,3)), negatively correlated to the sea-spray ions. Hydrochemical observations during 5 years confirm that Cl('-) and, to a considerable extent, also SO('2-)(,4) move rather easily through the catchments, while, NO('-)(,3) is strongly adsorbed. The acid top soil tends to lead to acid surface runoff, while water penetrating deeper mineral soils becomes enriched in Ca('2+) and depleted in H('+), resulting in a high correlation between runoff acidity and runoff rate. The short-term variations in runoff acidity are thus governed largely by runoff rate and by atmospheric deposits of Cl('-) and SO('2-)(,4). In this particular precipitation climate this yields in fact a negative short-term correlation between precipitation acidity and runoff acidity. A long-term acidification, indicated by declining fish populations, does probably arise from a SO('2-)(,4) -increase in runoff (caused by increased atmospheric deposition), and from a change in soil properties (caused by acid precipitation, and possibly also by changed vegetation).
显示更多 [+] 显示较少 [-]