2007-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/687919摘要：高屏溪每年往外海輸出49百萬噸的懸浮顆粒，大量的懸浮顆粒及伴隨著的陸源有機碳由河川向鄰近外海輸出，將會對周圍海域有相當程度的影響。而高屏河川向海洋傳輸懸浮顆粒的路徑機制，及其對於陸源有機碳之傳輸，最終於何處埋藏仍不是非常清楚。高屏峽谷對於高屏溪陸源物質及有機碳之傳輸與宿命扮演著什麼角色亦不瞭解。於此三年的計畫，本研究將探討台灣西南海域沉積物有機碳之空間及垂直（時間）分佈變化，本研究亦將探討陸源有機碳之埋藏與有機碳經由硫酸鹽還原作用氧化分解的重要性。本研究之目的為探討陸源及海源有機碳於台灣西南海域分佈、埋藏與氧化之差異大，並進一步探討峽谷地形對於陸源物質向海洋傳輸的重要性。本研究期望能瞭解小河川（亞洲高山型河川）對於陸源物質向海洋之傳輸、埋藏與氧化所扮演的角色與重要性。 目前研究結果顯示高屏溪外之陸棚、陸坡沉積物深受高屏溪向外傳輸之顆粒所影響，尤其於颱風過後，高屏峽谷水體中亦攜帶大量的懸浮顆粒往深海傳輸。而於平常季節河川輸出之river plume對於陸源物質向外海傳輸亦相當重要。 本計畫期能於高屏溪外海陸棚及陸坡海域採集長、短沉積物岩心樣品，並分析其顆粒大小組成、有機與無機碳含量、硫酸鹽還原速率等，藉由區域與垂直之變化來探討高屏溪輸出之陸源懸浮顆粒及有機碳之傳輸及埋藏範圍，並進一步探討有機碳之埋藏通量及來源，以期能瞭解高屏溪對於台灣西南海域有機碳之輸出與埋藏的重要性。此外，本研究將研究探討台灣西南海域陸棚及陸坡海域沉積物之硫酸鹽還原作用之空間變化差異與控制因子，並深入探討有機碳之埋藏通量及來源與硫酸鹽還原作用之變化的相互關係，以瞭解有機碳經由硫酸鹽還原作用所被消耗的程度與速率。<br> Abstract: Kaoping River exports very large amount of suspended particles, approximately 49 million tons/year, and an unknown fraction of organic carbon to the ocean. However, limited information is available concerning fate of these large amounts of inorganic particles and terrigenous organic carbon in the ocean. In addition, the extent, the direction and locations of deposition were rarely studied. The role of a long submarine canyon located at the edge of the Kaoping River mouth also was not well examined. In this three-year project, we intent to study spatial and vertical (temporal) organic carbon deposition in sediments offshore southwestern Taiwan and also to examine the role of terrigenous organic carbon deposition and carbon oxidation through sulfate reduction. Our main objectives were to examine the relative contributions of land and marine terrigenous organic carbon through study organic carbon deposition and oxidation in the region and to evaluate the role of submarine canyon in carrying detritus materials to the ocean. Our long-term goal is to examine the efficiency and the role of small rivers, in particular the Asian mountainous rivers, in producing, in transporting, in deposition and also in re-oxidation of land-derived organic materials to the ocean. Our present status in studying sediments on the southwestern Taiwan continental margin is mainly focusing on the extent of Kaoping River particle transport by studying suspended particle and sediment geochemical characterizations. We have found that Kaoping canyon is an important conduit in exporting terrigenous materials to the deep sea, especially during typhoon. However, normal surface river plume also carry important fraction of land-derived materials to the ocean. In our proposed project, we like to sample a series of cores on the continental shelf and slope offshore Kaoping River. Sulfate reduction rates, organic carbon and carbonate contents as well as grain sizes will be analyzed. Spatial organic carbon deposition rate and sulfate reduction rates will be used to construct a model in understating the fate of terrigenous organic carbon in the continental margin sediments offshore a small mountainous subtropical river.