陳宏宇臺灣大學:地質科學研究所陳麒文Chen, Chi-WenChi-WenChen2010-05-112018-06-282010-05-112018-06-282009U0001-1208200910275700http://ntur.lib.ntu.edu.tw//handle/246246/182912本研究嘗試探討新竹頭前溪上游流域自1996年至2008年間之地層滑動與植生分佈狀態在6個不同的颱風事件中之關係。從河水取樣分析中發現，本研究區在乾季從每年10月至次年4月的顆粒性碳含量為介於5.57%至6.39%之間，碳濃度為介於0.22mg/l至2.39mg/l之間。在濕季從每年5月至9月的顆粒性碳含量介於1.43%至2.29%之間，碳濃度介於0.41mg/l至5.4mg/l之間。此意義顯示在濕季時，部分地層滑動或地表沖刷之地質材料進入河道中，增加了顆粒性碳的濃度。在高流量高輸砂量時，因為更多的懸浮質加入其中，使得懸浮質中的碳含量下降，顆粒性的碳濃度則相對升高，乾季時則呈現相反的結果。幾次颱風期間，顆粒性碳濃度高達0.7mg/l至23.67mg/l之間，主要是由於大規模的地層滑動將地表植生及土壤大量帶入河道所形成。10年來SPOT衛星影像的分析發現，本研究區常態化差異植生指標(NDVI)在颱風事件前為介於0.47至0.63之間，颱風事件後介於0.38至0.46之間。其中又以1996年賀伯颱風前、後之NDVI的差值0.22為最多，而2008年辛樂克颱風前、後的差值0.06為最少，這可能是因為區域內地層滑動面積的增加或大規模的植生崩落所造成。各不同颱風期間地層滑動的判釋結果發現，本研究區具有較高的新生率，介於69.98%至83.30%之間，重現率較低，介於10.93%至40.37%之間，崩塌率則介於0.60%至1.29%之間。新生率以2001年桃芝颱風為最高，1996年柯羅莎颱風為最低；重現率以2005年海棠颱風為最高，2001年艾利颱風為最低；而崩塌率則是以2007年柯羅莎颱風為最高，2004年艾利颱風為最低。就本研究區的3個地層，大桶山層、石底層與南莊層的岩石強度與崩塌率的相對關係而言，大桶山層之岩石強度60.52MPa最強，崩塌率最低，NDVI值為最高。此意義顯示，區域內岩石強度較高的地層，其植生狀態較為良好，較不容易發生地層滑動。輸砂量及降雨量的統計發現，各颱風事件的總輸砂量及平均日降雨量皆以2004年艾利颱風期間的3.52百萬噸及276.92mm為最高，2001年桃芝颱風期間的0.18萬噸及19.88mm為最低。就地層滑動與崩塌率的相關性而言，降雨量愈大時，輸砂量也愈大，但崩塌率並不一定有相對性之增加。此意義顯示，高降雨時，河流中的高輸砂量並不完全受到現地地層滑動物質的影響，可能是來自過去崩塌堆積物的沖刷，或高流量對河道本身沉積物的刮蝕所導致。In this study, we discussed the relationship between landslide and vegetation distribution in 6 different typhoon events from 1996 to 2008. Through analyzing the particulate carbon from rivers, we found that the average percentage of the particulate carbon is between 5.57% and 6.39% and the average concentration of the particulate carbon is between 0.22mg/l and 2.39mg/l in the dry season. In the wet season, the average percentage of the particulate carbon is between 1.43% and 2.29% and the average concentration of the particulate carbon is between 0.41mg/l and 5.4mg/l. This result indicated that in the wet season, some geological material from landslide or surface erosion entered the river, causing the increase of the concentration of particulate carbon. When the scenario of high flow and high sediment discharge happened, more suspended load joined in, bringing about the decrease of the percentage of the particulate carbon in the suspended load. The dry season had opposite result. Among several typhoon events, the concentration of the particulate carbon can reach 0.7mg/l to 23.67mg/l because the huge landslides caused a large number of vegetation and soil entering the river. With analyzing the different bands of the SPOT satellite in 10 years, the Normalized Difference Vegetation Index (NDVI) in this study area is between 0.47 and 0.63 before typhoon events and between 0.38 and 0.46 after typhoon events. The highest gap of NDVI value (0.22) occurred in Typhoon Herb and the lowest (0.06) occurred in Typhoon Sinlaku. Extreme disparity of NDVI value would caused by the numbers of landslide areas increasing or a huge scale of vegetation collapse. From mapping the landslide areas, we found that there are higher new generation ratio of landslide, between 69.98% to 83.30%, and lower reactivated ratio of landslide between 10.93% and 40.37%. The landslide ratio is between 0.60% and 1.29%. For the correlation between rock strength and landslide ratio of the three formations in the study area, we can found the highest rock strength of Datonshan formation has the lowest landslide ratio and highest value of NDVI. This result revealed that the formation with higher rock strength, the vegetation will be better and landslides are not easy to occur. From the statistics of the sediment discharge and rainfall in each typhoon events, there are the highest sediment discharge (3.52Mt) and average daily rainfall (276.92 mm) in Typhoon Aere and the lowest sediment discharge (1.8kt) and average daily rainfall (19.88mm) in Typhoon Taraji. For the correlation between landslide ratio, rainfall and sediment discharge we can found that higher rainfall caused the higher sediment discharge. But the landslide ratio would not increase relatively. This result revealed that when high rainfall occurred, the high sediment discharge is not affected by the landslide instantly but the erosion of the colluvial deposit previously or the high flow scraped the river itself did.致謝…………………………………..…….……...…….………I文摘要…………………………………………………………… II文摘要…………………………………………………………… IV錄………………………………………………………………… VI目錄……………………………………………………………… IX目錄……………………………………………………………… XI一章 緒論…………………………………………………… 1.1 研究動機與目的…………………………………… 1.2 地理位置與交通狀況……………………………… 2二章 前人研究……………………………………………… 4.1 河流中的顆粒性碳………………………………… 4.2 常態化差異植生指標……………………………… 5.3 生物量……………………………………………… 8.4 降雨對邊坡穩定的影響…………………………… 10.5 崩塌與輸砂特性…………………………………… 11三章 區域概況……………………………………………… 13.1 地形概況…………………………………………… 13.2 地質概況…………………………………………… 15.3 氣候及水文概況...…….…………………………… 17.4 林班地分布概況...…….…………………………… 21.5 颱風事件......….……….….….….….………… 24四章 研究方法……………………………………………… 26.1 顆粒性碳分析.….….…….………………………… 26.2 植生狀態分析….……….…….….….…….….…. 27.2.1 常態化差異植生指標分析.…….…….….………… 27.2.2 生物量估算.…….…….….……..…….…..….… 29.3 崩塌地判釋.…….…….….………………………… 31.4 輸砂量估算.……….….…….….…...…..…..… 32.5 野外調查.….….…….….….….….…..….….… 33.5.1 野外露頭量測.…….….….….….….….………… 33.5.2 施密特錘試驗.…..….….….….…..….….….… 35.5.3 樣品採集..….….….………..……..….….….… 35.6 地質材料性質試驗.…….…….…….……………… 35.6.1 自然物理性質試驗.….…….….….….….…..…. 35.6.2 岩石力學性質試驗.….………..….….….….….. 36五章 研究結果……………………………………………… 37.1 顆粒性碳分析結果.….…….….….…...…...…. 37.2 常態化差異植生指標分析結果…………………… 40.3 生物量估算結果.….….….………………………… 43.4 崩塌地之數化及統計結果………………………… 44.5 輸砂量的估算結果…..…..………………………… 46.6 地質材料性質試驗結果…………………………… 48.6.1 自然物理性質試驗結果…………….…..…….…… 48.6.2 岩石力學性質試驗結果…………….…..…….…… 50六章 崩塌地與植生作物的關係.……...….….....…… 56.1 溪水化性之特性..…..…..…..…………………… 54.1.1 顆粒性碳與輸砂量的關係.…...…….………...… 54.1.2 乾季與濕季的顆粒性碳………………..….….…… 55.1.3 歷年顆粒性碳量.….….……….….……..…….… 58.2 崩塌率與植生指標之關係..……..….…..…….… 60.3 地形因子相對崩塌與植生的影響.…....….…..… 61.4 崩塌率與岩石強度及NDVI的關係.…….…….…. 66.5 植生作物與崩塌的關係.…..…..…..….….….… 68.6 雨量與輸砂量及崩塌地的關係.……..…..…….… 70七章 討論…………………………………………………… 75.1 估算顆粒性碳的誤差.……………...……......… 75.2 林班地、非林班地與崩塌的關係.…….………….. 75.3 NDVI與崩塌在對比上的差………................ 77.4 影像解析度對崩塌判釋的影響…………………… 81八章 結論…………………………………………………… 84考文獻 ………………………………………………………… 86錄一 顆粒性碳試驗方法.…….….….…………………… 94錄二 施密特錘反彈數換算單壓強度表.…………………. 95錄三 自然物理性質試驗方法.…….….…….….….…… 96錄四 點荷重試驗方法.…….….….….…..……………. 98錄五 消散耐久性試驗方法………………………………… 100錄六 衛星影像基本資料…………………………………… 101錄七 自然物理性質試驗結果……………………………… 102錄八 施密特錘試驗數據…………………………………… 104錄九 點荷重試驗結果……………………………………… 113錄十 消散耐久試驗結果………………………………….. 116錄十一 常態化差異植生指標分析結果……………………… 117錄十二 崩塌地判釋結果……………………………………… 120錄十三 各年度率定曲線關係式……………………………… 122錄十四 新竹地區氣溫資料…………………………………… 124錄十五 林班地永久樣區調查資料…………………………… 125application/pdf15734831 bytesapplication/pdfen-US顆粒性碳常態化差異植生指標地層滑動輸砂量颱風particulate carbonNDVIlandslidesediment dischargetyphoonthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/182912/1/ntu-98-R96224209-1.pdf