本文旨在探討桃園地區降水化學的特性，以了解影響桃園地區降水離子化學的主要貢獻來源。本研究使用，桃園酸雨網龍潭、桃園、新屋、復興和新屋五個測站，1993-2001年的降水化學資料，並應用多變量分析的方法分別對於降水化學和氣流軌跡做分析，以判別污染物源與受體的定性關係。 為了解化學離子可能來源，使用了因子分析。發現海鹽是桃園地區主要影響離子濃度變化的因子，在各站海鹽因子可以解釋50-70%離子濃度的變化，其次是當地污染和硫酸根因子，約可解釋15-20%離子濃度的變化。 聚類分析對於新屋、中壢和復興站三個測站的分析結果發現，源區是北方的氣流軌跡，對應的降水天氣型態為東北季風和秋冬季鋒面的降水，化學離子組成有較高的總離子濃度，其中大部分是海鹽離子與硫酸根離子，約分別佔了50%和20%的總離子濃度。源區是南方的氣流軌跡佔有較多的降水事件，約佔了50%-70%的降水事件，顯示對於桃園地區的降水特性有較大的影響，對應的降水天氣型態為春季鋒面和梅雨鋒面型降水。 桃園地區降水的pH值約在4.5-4.8之間，與亞洲鄰近國家相當，降水酸化的情況嚴重，硫酸根約佔總離子的20%左右，除了桃園和鄰近地區工業區所排放之外，冬季東北季風所伴隨的由中國東北方而來長程輸送貢獻也帶來相當可觀的硫沈降量。此外復興鄉硝酸根離子濃度較其他站高，推測有部分是由鄰近地區擴散而來。 The purpose of this study is to investigate the characteristic of rainwater chemistry in Taoyuan County. In this study used five stations of Taoyuan acid rain network. Rainwater chemistry data was collected from 1993-2001 and used multivariate statistical method to analyze rainwater chemistry and backward trajectory to understand the relationship of source and acceptor. Rainwater chemistry data were analyzed using factor analysis to find the possible sources of the measured chemical species. The result find out sea salt and local pollution sources can explain 50-70% and 15-20% the variance of ion concentration. Besides, I used cluster analysis in Shin Wu, Chung Li and Fu Shin to find the relationship of source and acceptor. When the trajectories come form north and correspond to northeast trend wind and fall &winter front, the sum of ions is the highest almost sea salt (50%) and SO42- ions (20%). When the trajectories come form south and correspond to spring front and mei-yu front include most precipitation events, about 50-70% events. The pH value in Taoyuan County is about 4.5-4.8 and is quite the same as neighbor Asian countries. Appears the acidity in Taoyuan is severe. And SO42- is about 20% sum of ions. The possibly reason is the sulfur emission in Taoyuan and neighbor County and long range transport form northeast China. Besides the NO3- concentration of Fu Shin station is higher then other stations. The possibly reason is the diffused pollutant from neighbor area.
