碩士 / 國立臺灣海洋大學 / 海洋環境資訊學系 / 94 / This study has been analyzed 84 samples of wet deposition during the period from August 2003 to October 2004. Anion ions (chloride and sulfate) and inorganic nitrogen species (ammonium, nitrite and nitrate) were identified and quantified by ion chromatography and UV spectrophotometer, respectively.
The result indicates that the mean value of pH is 4.59 and the occurrence probability of acid rain is 81.0%. The seasonal distribution of pH shows high in summer and low winter. This is due to the marine source materials carried by southwest wind and the continental source materials by northeast wind to the sampling site in summer and winter, respectively. The distributions of anion ion show that chloride has a similar trend as sulfate and wind speed which were normally higher in autumn and winter and lower in summer. This seasonal variation indicates that wind speed is one of the main factors for the distributions of marine source materials and continental source materials in this area. In nitrogen species, ammonium and nitrate are two major contributors with mean concentrations of 43.1 and 28.6 �嵱, respectively. According to the air mass back trajectories, the distributions of inorganic nitrogen species are mainly controlled by the continental materials.
The results of relevance analysis show that wind speed and wind direction are two of important factors to effect the compositions of wet deposition in the coastal area of northern Taiwan. From the results of component analysis, pH is mainly dominated by the total inorganic nitrogen, chloride and sulfate in the wet deposition samples. Wind speed is a major factor to control the concentration of chloride, therefore, it also play a significant role on the distribution of pH. Finally, the types of monsoon system are found to influence the sources for the nitrogen species in this study.
| Identifer | oai:union.ndltd.org:TW/094NTOU5282006 |
| Date | January 2006 |
| Creators | De-Min, Tseng, 曾德民 |
| Contributors | Hung-Yu, Chen, 陳宏瑜 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 64 |
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