氣候變遷對大甲溪上游河川流量之衝擊

加強溫室效應可能造成全球氣候變遷，且因此改變各區域溫度及降雨。一般預測大氣CO_2濃度增加爲兩倍時，全球溫度約將上升1.5到4.5℃，且全球降雨量將增加，但各地區降雨變化將有不同。本研究目的為評估氣候變遷對大甲溪上游河川流量之衝擊。氣候變遷方案分成兩類：同時考慮溫度與降雨變化，及只考慮溫度變化。然後利用四個GCM模式預測之溫度及降雨變化設計八個不同的氣候變遷方案。大甲溪上游河川流量模擬結果顯示，在同時考慮溫度及降雨變化下，平均年流量可能增加4%；豐水期約增加7%，而枯水期水量約減少3%。若只考慮溫度變化，則平均年流量約減少4%；豐水期與枯水期水量分別約減少3%與10%。八個氣候變遷方案均導致枯水期河川流量趨於減少，這將增加大甲溪水資源管理之困難。為維持大甲溪流域水資源永續發展，應加以重視。

關鍵字

氣候變遷；全球暖化；水平衡

並列摘要

Enhanced greenhouse effects may cause global climate change, and thus change regional temperature and precipitation. Global mean temperature is expected to increase 1.5~4.5℃when atmospheric CO_2 concentration is doubled. Although global precipitation likely increase, regional precipitation may increase or decrease. The purpose of this study is to evaluate the impacts of climate change on the Dai-Chia creek upstream flows. Climate change scenarios are divided into two categories: with modifications of temperature and precipitation, and with modification of temperature only. Then, four GCMs' outputs were used to setup eight climate change scenarios. With temperature and precipitation modification, simulation results indicate that average annual streamflow may increase 4%; streamflow in humid periods could increase 7 % but in arid periods may reduce 3%. With modification of temperature only, results indicate that average annual streamflow could decrease 4%; streamflows in humid periods and in arid periods may reduce 3 and 10%, respectively. All eight climate change scenarios result in decrease of streamflows in arid period, which will bring more difficulties to water resources management. For sustainable development of the Dai-Chia creek watershed, it desires more attention.

並列關鍵字

Climate change ； Global warming ； Water balance

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