環境變遷對櫻花鉤吻鮭棲地水溫之影響

外文標題: 
The Impacts of Environmental Changes on Stream Temperature of Taiwan Salmon''s Habitat
校院系所: 
國立臺灣大學 農業工程學研究所
指導教授: 
童慶斌
出版年份: 
2001年
主題類別: 
摘要: 

 在河川生態環境之研究中,水溫一直是非常重要的一項生態指標,水溫太高或太低都會對水中生物造成影響,使水域環境中的生物或魚類減少或失去覓食及移動的能力,所以使水溫穩定及維持在一適合之範圍,一直是國內外學者研究的重點。本研究為預測水溫之變動,發展一物理性水溫評估模式推估氣候變遷與土地利用改變下之水溫變動情形。為反應台灣溪流之特性,研究中考慮地形遮蔽影響水面所接受之太陽輻射及長波輻射,藉著能量平衡的觀點來推估水溫之變化。   利用四個大氣環流模式(Genernal Circulation Model, GCM)預測之氣溫變動及造成之流量變動表示氣候變遷之預設情境。模擬結果顯示,在氣候變遷下,夏季八月之水溫變動不大;十一月之水溫變動上升了 2%∼11%,約可使是七家灣溪一號壩水溫上升0.3°C,水溫的上升將對正值產卵季之櫻花鉤吻鮭造成衝擊。   假設三種土地利用型態作為不同開發程度下的土地利用狀態,模擬結果顯示,當土地利用開發的程度越高,河川之基流量越低,而使水溫有上升的趨勢;當土地覆蓋的森林面積比例越大,河川之基流量越高,使水溫有下降的趨勢。

外文摘要: 

 Stream temperature is taken as a very important ecological index while investigating ecosystem. The change of stream temperature might influence growth rate and survival of fish and other aquatic organisms, so many researchers have put emphasis on keeping stable stream temperature. This research offers a physical model for predicting the impact of climate change on stream temperature. Stream temperature is simulated by energy balance. Because upstream watershed in Taiwan is surrounded with high mountains, the influence of shade of mountains on solar radiation and long wave radiation is taken into account in this study.   Temperature and streamflow changes are derived from the predictions of four General Circulation Models (GCMs) and landuse change. Under the concentration of atmospheric carbon dioxide is doubled, the result indicates that it’s a little bit change of stream temperature in August and stream temperature increases 2%~11% in November. Under different landuse condition, the result indicates that base flow decreases and stream temperature increases when the higher development. On the contrary, base flow increases and stream temperature decreases when the lower development.