- 期刊
台灣界限斷層帶上沖積扇階地地形發育的複雜性
The Complexity for the Development of Alluvial fan Terraces along the Boundary Faults in Taiwan
摘要
本文由台灣界限斷層帶上的蘭陽溪、陳有蘭溪、荖濃溪流域，在更新世最末期至全新世的地形演育中，發育沖積扇階地地形的一致性與差異性，討論流域系統因應環境變化的複雜反應。地形發育的一致性與差異性，是指位於相似構造帶的流域，發育了特徵類似，生成年代卻有差異的沖積扇河階地地形。環境變化是指可能較全面地影響台灣地區的海水面變化、氣候變動，及可能各區域不同發生時間、不同進行速率的構造運動。複雜反應則是指各個流域，或流域內的各個支流，不一定均會對環境變化有對應的反應，反應顯現的時間可能有差異，反應速率亦不同，反應的型式則可能是穿插式的而非直接的，因而形成不同的地形。所以，吾人欲透過河階地和地形演育的研究，了解環境變遷時，或瞭解沖積扇河階地的成因時，增加許多困擾。這些困擾必須透過區域內更精細的研究，及更大區域的研究，方能獲得解決。
並列摘要
There are many alluvial fan terraces in Lanyang, Chenyoulan, and Laonon rivers, which develop their drainage basins along the boundary faults in Taiwan. Their thickness of mid-fan deposits is commonly close to or more than 100 meters. Factors that lead to the formation of alluvial fans and terraces, and that influence the landscape evolution of drainage systems, appear to include the base level changes, climatic changes and stream hydrologic condition changes as well as the complex response of drainage basins to environmental changes. This study focuses on how complex the drainage systems respond to environmental changes since the end of Pleistocene. The development of alluvial fan terraces depends not only on such environmental factors as climatic changes and the differential uplift of landmass on either sides of the boundary faults, but also on the fluvial systems themselves, the operating mechanisms of systems, and the interaction among subsystems.