指導教授：陳宏宇臺灣大學：地質科學研究所陳冠樺Chen, Kuan-HuaKuan-HuaChen2014-11-262018-06-282014-11-262018-06-282014http://ntur.lib.ntu.edu.tw//handle/246246/262008地質材料的風化可以分為物理風化及化學風化。河水中的溶解載與輸砂量，可以視為集水區內的物理風化以及化學風化產物。因此研究河水中的溶解載與輸砂量特性，有助於我們了解集水區內的風化侵蝕作用。颱風會在台灣山區造成大量的山崩，為輸砂量的重要來源。本研究以屏東縣林邊溪為例，利用1982年至2013年的31年間之輸砂量、2005至2012年的5個颱風事件以及2013年3月至2014年4月的河水化學性質，來探討河川化學性質、輸砂量與山崩之間的關係。 從輸砂量的研究中發現，這個區域的年輸砂量為介於0.06至8.08 Mt，平均為1.40 Mt。5月至10月的濕季期間，輸砂量佔全年輸砂量97.47 %。另外，颱風事件的研究中發現，颱風事件的輸砂量平均占全年輸砂量的39.02 %，崩塌率平均為4.69 %。此意義顯示，在濕季或颱風暴雨帶來的高降水因素，主導了林邊溪的輸砂特性。 颱風事件造成之崩塌地分布的分析結果顯示，輸砂量較高之2009年莫拉克颱風、2008卡玫基颱風與2005年的海棠颱風的新生率較高，顯示新發生的山崩會供應河川豐富的地質材料而提高事件輸砂量。 2013年3月至2014年4月的河水化學分析結果顯示，林邊溪河水中陽離子的組成以Ca (52.1 %)為主、；陰離子與溶解態矽酸鹽的組成成分以HCO3(66.6 %)為主。中上游的河水化學性質陽離子來自碳酸鹽的比例最大(82.33 %)，其次為矽酸鹽(13.82 %)，最少的則是大氣輸入(3.85 %)。顯示變質岩內少量分布的碳酸鹽可提供河水大量來自碳酸鹽的化學成分。河水中的高SO4來源為變質岩當中的黃鐵礦風化，而非外部因素。下游新埤測站樣品的陽離子中，來自碳酸鹽的比例最大(62.12 %)；其次為雨水(14.90 %)；再者為矽酸鹽(14.74 %)；最少的為外部因素(8.23 %)。外部因素的比例雖少，但對河水化學的影響不可忽視。 2013年3月至2014年4月林邊溪的月化學風化通量為125 ton至14,844 ton，平均為2,944 ton，而濕季期間的化學風化通量佔全年化學風化通量的88.38 %。林邊溪的化學風化速率為110 t km-2 yr-1，矽酸鹽化學風化速率為29 t km-2 yr-1，約為世界平均的5倍。研究期間林邊溪的物理風化速率為4,062 t km-2 yr-1，約為化學風化速率的40倍，顯示林邊溪流域的風化以物理風化為主。對林邊溪而言，每年濕季颱風事件所造成的高輸砂量與大量山崩，會持續搬運風化作用的產物，使母岩的新鮮面不斷暴露至地表接受化學風化，造成高化學風化速率，顯示物理風化對化學風化有重大影響。The weathering of geomaterial can be classified into physical and chemical weathering. The dissolved load and sediment discharge can be considered chemical and physical weathering product in a drainage basin. Therefore, we can understand the weathering in the drainage basin by studying the characteristics of dissolved load and sediment discharge in river water. The typhoon events would cause massive landslides in mountains, which are important sources of sediment discharge in Taiwan. This research utilizes sediment discharge during 1982 to 2013, 5 typhoon events during 2005 to 2012, and river chemistry during March 2013 to April 2014 of Linpien River to study the relationship between river chemistry, sediment discharge and landslide. The annual sediment discharges ranged from 0.06 Mt to 8.08 Mt, with an average of 1.40 Mt. The sediment discharge yielded during wet seasons (May to October) contributes 97.47 % to the annual sediment discharge. In addition, the average sediment discharge during typhoon events contributed 39.02 % to the annual sediment discharge and the average landslide ratio for five typhoon events during 2005 to 2012 was 4.69 %. It implies that the factor of high rainfall during wet seasons or typhoons controls the variations of sediment discharges in the Linpien River. The analyses of distributions of landslides caused by typhoon events revealed that the higher sediment discharge of Morakot in 2009, Kalmeigi in 2008 and Haitang in 2005 with higher newborn ratio, which implies that the newborn landslides would contribute abundant sediments to the river, and resulted in the increase of sediment discharge of the typhoon events. The analyses of major elements in water samples collected in the basin during March 2013 to April 2014 showed the major cation was Ca (52.1 %) and the major anion is HCO3 (66.6 %). The contribution of river chemistry from carbonate was highest (82.33 %), next was silicate (13.82 %), and the last was atmospheric input (3.85 %) in upstream samples. This implies that the trace carbonates in metamorphic rock could influence river chemistry significantly. The high SO4 in river water is contributed from chemical weathering of pyrite, not from anthropogenic pollution. The river chemistry of the downstream samples collected at Hsinpi Station was contributed most from carbonate (62.12 %), next was atmospheric input (14.90 %), then was silicate (14.74 %), and the last was external factor (8.23 %). Although the proportion of external factor is insignificant, the impact on river chemistry is innegligible. The monthly chemical weathering flux ranged from 125 ton to14,844 ton, with an average of 2,944 ton during March 2013 to April 2014. The chemical weathering flux during wet seasons contributed 88.38 % to annual chemical weathering flux. The chemical weathering rate of Linpien River was 110 t km-2 yr-1, and the silicate chemical weathering rate was 29 t km-2 yr-1. Both were 5 times higher than the world average. During the study period, the physical weathering rate was 4,062 t km-2 yr-1, which was about 40 times higher than the chemical weathering rate. It indicates that the weathering in the drainage of Linpien River is mainly physical weathering. For Linpien River, the high sediment discharge and the massive landslides caused by typhoon events during wet season would transport weathering products continuously. It makes the fresh surfaces of bedrock be exposed to earth surface, and results in the intense chemical weathering. In the conclusion, the physical weathering has significant influence on chemical weathering.致謝 I 摘要 II Abstract IV 目錄 VI 圖目錄 IX 表目錄 XI 第一章 緒論 1 1.1 研究動機與目的 1 1.2地理位置及交通狀況 2 第二章 文獻回顧 3 2.1河川化學性質相關研究 4 2.2降雨和山崩關係之研究 8 2.3輸砂量估算相關研究 10 第三章 研究區域概況 12 3.1地形概況 12 3.2地質概況 15 3.3土壤概況 18 3.4氣候與水文概況 20 3.5颱風事件 21 第四章 研究方法 24 4.1野外調查工作 24 4.1.1施密特錘試驗 24 4.2資料分析與處理 24 4.2.1輸砂量估算 24 4.2.2崩塌地判釋與資料分析 27 4.3河川化學性質分析 28 4.3.1樣品採集與前處理 28 4.3.2陰離子分析方法 30 4.3.3陽離子分析方法 30 4.3.4鹼度分析方法 30 4.3.5溶解態矽酸鹽分析方法 31 4.4河川化學性質之來源 31 4.4.1大氣輸入 31 4.4.2岩石化學風化 33 4.4.3外部因素 34 4.4.4化學風化速率與物理風化速率 35 第五章 研究結果 37 5.1輸砂量估計結果 37 5.1.1歷年輸砂量統計 37 5.1.2乾濕季輸砂量之差異 41 5.2崩塌地判釋與分析 45 5.2.1崩塌地統計 45 5.2.2崩塌地與地形及地質因子之關係 47 5.3河川化學性質分析結果 51 5.3.1主要元素濃度分析結果 51 5.3.2林邊溪中上游河水樣品之分析 56 5.3.3林邊溪下游河水樣品之分析 67 第六章 化學風化速率與物理風化速率 76 6.1化學風化通量與輸砂量的變化 76 6.2化學風化速率與物理風化速率之關係 79 第七章 討論 83 第八章 結論 88 參考文獻 90 附錄一 水樣採集方法與水樣前處理 102 附錄二 陰離子分析方法 103 附錄三 陰離子分析方法 104 附錄四 鹼度分析方法 105 附錄五 溶解態矽酸鹽分析方法 10621598233 bytesapplication/pdf論文公開時間：2016/08/25論文使用權限：同意有償授權(權利金給回饋學校)林邊溪崩塌地輸砂量化學風化[SDGs]SDG15thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/262008/1/ntu-103-R01224113-1.pdf