The Analysis of the Chemical Composition of Precipitation During the Driest Year from the Last Decade

Abstract

Abstract In order to investigate the precipitation chemistry, studies were carried out from January 2013 to December 2013 in Odorheiu Secuiesc and Miercurea Ciuc, Eastern Carpathians, Romania. During a period of eleven years (2006 – 2016), 2013 was the driest year. The rainwater samples were analyzed for pH, major anions and cations. HCO3− concentrations were calculated based on the empirical relationship between pH and HCO3−. NH4+, Ca2+, SO42− were the dominant ions in precipitation at both sites. The pH values varied from 6.75 to 7.46 Miercurea Ciuc, and from 6.69 to 7.67 in Odorheiu Secuiesc. The neutralization was mainly brought by Ca2+ and NH4+. Estimated ratios of sea-salt fraction (SSF), non-sea-salt fraction (NSSF), and results from Spearman’s rank correlation and Principal Component Analysis (PCA), showed that the acidic ions (SO42−, NO3−) were derived from anthropogenic activities, NH4+ from soil fertilization, while Ca2+, Mg2+, K+ originated from terrestrial source. These influence the precipitations ionic content, especially during droughts. Spatial variations and the rim effect of the Eastern Carpathians on precipitation chemistry is also shown.