颱風對翡翠水庫葉綠素甲濃度時空變化之影響

• Main Authors: 林靜英, Lin, Ching-Ying J.
• Other Authors: 戴昌鳳, 臺灣大學：海洋研究所
• Format: Thesis
• Language: Chinese; English
• Published: 2005
• Subjects: 颱風; 葉綠素; 葉綠素甲; 翡翠水庫; 紊流模式; typhoon; chlorophyll; chlorophyll a; Fei-Tsui Resvoir; turbulence model; Arctic
• Online Access: http://ntur.lib.ntu.edu.tw/handle/246246/56612; http://ntur.lib.ntu.edu.tw/bitstream/246246/56612/1/ntu-94-R92241213-1.pdf

為瞭解影響翡翠水庫水體中葉綠素甲(Chl a)時空變化之控制機制以及颱風的效應 ，本研究於2004年2月至次年4月期間，在翡翠水庫大壩站(週採樣)及水庫上至下游 縱走測線(月採樣)測量水溫、Chl a、非活性葉綠素甲(Phae a)及其比值(PhR＝Phae a/(Phae a+Chl a) )、總懸浮物質量(TSM)及可溶性反應磷(SRP)濃度。並在颱風過後進 行密集採樣。結果發現，在深度分布上，Chl a 濃度表水高底水低，最高值常在5m水 深處。水平分布上則為上游高下游低。在時間分布上，大壩站Chl a10 m積分平均值 (IChl a10m)最高值出現於秋季(5.2 mg L-1)，最低值出現於冬季(0.24 mg L-1)；全年平均值 為2.3 ± 1.2 mg L-1。複迴歸分析顯示，與IChl a10m全年變異相關之因子為水溫及PhR( 可代表浮游動物攝食或浮游植物本身凋萎作用之強度)。颱風季(8~12月)時除上述二因 子外，另需加入TSM。冷季(12月~次年3月)時，IChl a10m僅與SRP相關。在颱風或 暴雨事件過後，水庫中下水層(約水下20~80 m)出現次表層懸浮物團狀物(SSMP)，而 其上方水體內Chl a 濃度隨之升高，且Chl a 次表層極大值(SCM)所在深度有向下發展 之情形。數據分析顯示TSM 與SRP具正相關，表示SSMP能供應磷酸鹽，可能是水 庫颱風季出現Chl a高濃度值重要成因之一。數值模擬分析結果顯示夏季水溫層化強 烈時，颱風之強風仍無法將深水層所含之物質帶入上層水體；但在秋末因水溫層化微 弱，颱風則可有效地增加混合層的深度，使深水層所含物質進入上層水體。此結果說 明，夏季大壩站表水若出現高SRP或高Chl a濃度值，應來自於水庫上游的橫向輸送 。夏季颱風所引發之SSMP若積存於水庫內，則會因秋颱或冬季的寒潮暴發而進入表 水，而影響秋季及次年春季藻華的嚴重程度。 The propose of this research is to study on the temporal-spatial variation of chlorophyll a concentrations in the Fei-Tsui Reservoir and the mechanism of how typhoons impact on it. The surface water temperature (ST), chlorophyll a (Chl a), phaeopigments a (Phae a) ratio (PhR= Phae a/(Phae a+Chl a)), total suspended matters (TSM) and soluble reactive phosphorus (SRP) have been measured in the Fei-Tsui Reservior from 2004 Feb to 2005 Apr, especially made high frequent sampling after typhoons. The result during the researching period told that the vertical distribution of Chl a concentrations was higher at the surface but lower at the bottom. The highest Chl a concentrations often located at 5m depth of water. The horizontal distribution of the Chl a concentrations was higher in the upstream but lower in the downstream. About the temporal distribution, the average of integrated Chl a concentrations above 10m (IChl a10m) had the highest value in autumn (5.2 mg L-1) and the lowest in winter (0.24 mg L-1). For its annual average value was 2.3 ± 1.2 mg L-1. The multiple regression analysis shows that the change of IChl a10m during research is related with ST and PhR (indicated the grazing of the zooplankton or the descending of the phytoplankton). The term TSM is considered with IChl a10m during typhoon season from Aug to Dec. The term SRP reveals related with IChl a10m only during cold season from Dec to next Mar. After typhoon or heavy rain, high TSM turbidity current was presented in the middle and bottom water (about 20~80m water depth) of the reservoir; the Chl a concentrations rose at the upper water body of the turbidity current, which the depth of subsurface chlorophyll maxima appeared deeper. The data analysis shows that TSM is iii positive related with SRP. That indicates the turbidity current can be a source of phosphate. It could be one reason of why the high Chl a concentrations presents during the typhoon season. The numerical model analysis shows that the strong breeze of typhoon can’t draw the material of deep water up because the water temperture stratification is so strong in summer. But the stratification is weaker in the late autumn that typhoon can make the mixing layer deeper efficaciously and causes the material of deep water is brought into upper water body. As these results point out, if the SRP or Chl a concentrations reveal high value in summer, the input should come from upstream. If the high TSM and SRP water induced by summer typhoon accumulates in the reservoir, it will mix with surface water causing by the typhoon in autumn or surge in winter and will affect the magnitude of the bloom in this autumn or next spring. 目 錄 中文摘要 i 英文摘要 ii 誌謝 iv 目錄 v 表目錄 vi 圖目錄 vii 序論 1 材料與方法 4 結果 7 討論 16 結論 23 參考文獻 24 表列 27 圖列 29 附錄一．翡翠水庫1987~2004年各月份表水葉綠素平均值圖 42 附錄二．2004年8月至2005年4月螢光探針測值與手測值相關性 42 附錄三．總懸浮物質量與濁度間的關係 43 附錄四．群聚呼吸率 44 附錄五．葉綠素甲及相關色素沈降速率 45