In order to understand the influencing factors on chemical composition of rainwater, the total 89 rainwater samples were collected at Chinese Culture University meteorological observation station.During from April 2009 to July 2010. The rainwater samples were analyzed for pH, major ions(Na＋、K＋、Ca2＋、Mg2＋、NH4＋、Cl－、NO3－、SO42－)and organic ions (HCOO－、CH3COO－). The intercorrelations of chemical composition are applied to understand possible sources of chemical composition in the rainwater.
Ion species Na＋ is regarded asmarine source in this study, compared to other species of ions to find the possible source. The Mg2＋ comes from sea salt mainly. Ca2＋ comes from dust.NH4＋ is influencing by agriculture. NO3－ and SO42－ come from motor exhausting, incinerator and the factory burning.
Concentration of SO42－, Ca2＋ and K＋ collected from October to March are higher than those from April to September. Those spices are influenced by long-range transport during the northeasterly monsoon episode. The daily variant acid-base neutralization ratio nss-(Ca2＋＋Mg2＋＋NH4＋)+ K＋/( NO3－＋nss-SO42－) is consistent with pH value during sampling period. The result means that pH of rainwater in Hwa-Kang is influenced by seasonal monsoon and neutralizationprocess of local materials.
