頁籤選單縮合
題名 | 福山森林生態系之大氣酸沈降=Acidic Deposition in Fu-Shan Forest Ecosystem |
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作者 | 林文龍; 林能暉; | 書刊名 | 環境保護 |
卷期 | 27:2 2004.12[民93.12] |
頁次 | 頁242-258 |
分類號 | 361.526 |
關鍵詞 | 乾沈降; 溼沈降; 沈降速度; Dry deposition; Wet deposition; Deposition velocity; |
語文 | 中文(Chinese) |
中文摘要 | 本研究旨在估算臺灣福山試驗林大氣污染物的沈降量,藉以了解臺灣低海拔山區大氣污染物影響森林生態的情形。在1993年至1996年採樣期間,由模式所計算而得之HNO3、SO2、NH4-、SO42-及NO3-乾沈降速度分吸為0.64-1.75、0.19-0.38、0.07-0.27、0.08-0.31及0.10-0.38cmS-1。大致上可發現附季時的沈降速度較大,而春季較小。硫酸有較高的溼沈降量(10.7-36.6kg ha-1),為美東要之2倍以上,充沛的雨量是主因;硝酸鹽的溼沈附量為硫酸鹽沈降量的10-50%,乃因雨水中硝酸根離子濃度較低之故。硝酸與二氧化硫的季平均乾沈降通量範圍為0.04-1.45與0.09-0.53kg ha-1,而銨鹽、硫酸鹽及硝酸鹽的乾沈降量分別是0.07-0.32、0.06-1.29及0.03-0.38kg ha-1。日間的乾沈降通量比夜間大,主要來自風速及大氣穩定度的影響。在乾沈降對總沈附(乾+溼沈降)貢獻的比例上,硫酸鹽約為3.37%,而硝酸鹽約為2.35%,顯然多雨、潮溼的福山亞熱帶森林,乾沈降的貢獻遠不如溼沈降重要。 |
英文摘要 | The main purpose of this study is to estimate the deposition fluxes of acid pollutants in Fu-Shan forest in order to improve our understanding of their potential impact on forest ecosystems. During the 1993-1996 experimental periods, the model calculated dry deposition velocities of HNO3, SO2, NH4-, SO42-and NO3- ranged in 0.64-1.75, 0.19-0.38, 0.07-0.27, 0.08-0.31 and 0.10-0.38cmS-1, respectively. It was found that the deposition velocities had the largest values in winter but smaller in spring. Seasonal wet depositions of sulfates were between 10.7-36.6kg ha-1 which were more than twice that for eastern USA, primarily attributed to higher rainfall in Fu-Shan area. Seasonal wet depositions of nitrates were about 10-50% of those values of sulfates, owing to lower concentration levels of nitrates in rainwater. For seasonal dry deposition fluxes, NH3 and SO2 ranged in 0.04-1.45 and 0.09-0.53 kg ha-1, respectively, and 0.07-0.32, 0.06-1.29 and 0.03-0.38 kg ha-1 for NH4+, SO42- and NO3-, respectively. Daytime dry deposition was larger than nighttime because of high wind speed ad instability. As to the relative contribution of dry deposition to total deposition, it was 3.37% and 2.35% for sulfates and nitrates, respectively, indicating that wet deposition pathway is much more important than dry deposition in humid subtropical Fu-Shan forest. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。