河川プロセスと重力斜面プロセスによる地形発達 -地殻変動が活発な台湾山岳地における例-

京都大学0048新制・課程博士博士(理学)甲第18083号理博第3961号新制||理||1571(附属図書館)30941京都大学大学院理学研究科地球惑星科学専攻(主査)教授 千木良 雅弘, 教授 釜井 俊孝, 准教授 松四 雄騎学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDGA

山區河流階梯-深潭之渠槽實驗研究

Step-pools are fundamental components of channel morphology in mountain streams. Knowing the formation of step-pools will contribute to increasing the understanding of mountain streams morphology. Because of attention to river restoration more bio-engineering structures such as step-pools are adopted. But the mechanisms of river flow are complicated, in-stream structures can never be built directly. Bio-engineering structures should based on the river morphology. It is important to understand the formation process of step-pools. The formation process of step-pools under the conditions of sediment mixtures, different discharges, channel bed slopes(2-7) are studied experimentally in laboratory. On this basis, the mechanisms of step-pools are further investigated. We find some results as follows, many varied step-pools forms are observed which develop in conditions where the largest floods are just capable of transporting the largest debris. Those will tend to form steps acting as keystones retaining smaller debris. Eight types of steps are classified according to arrangement of sediments in this research. Dimensional analysis and the index namely Wsp coefficient is proposed to evaluate the relation between the formation of step-pools and the variation of sediment discharge. The expression is established according to the experimental data which can illustrate the step-pools as adjust their profile vertically, increase the channel-bed roughness and decrease the channel slope to minimize the time rate of expenditure of potential energy. These have effect on decreasing the sediment discharge of stream flow and stabilization of the channel-bed.階梯-深潭為山區河流常見之地貌，透過階梯-深潭的瞭解，將有助於增加對山區河床演變的認識；隨著人們對河流生態棲地復育之重視，採用生態工法進行河道治理的案例日益增多，亦常見運用砌石工法排列近似階梯-深潭之固床工進行整治，由於河流作用機制複雜，任何工法仍須順應河流自然調整機制，才能達到河流棲地復育之目的，故對瞭解階梯-深潭此一河床演變過程實為一不可或缺之課題。本研究採用混合泥砂粒徑，以渠槽實驗配合不同流量及渠槽坡度(2°-7°)方式進行清水流沖刷之動床實驗，藉此觀察床形演變之現象，並著重於階梯-深潭形成現象之定性描述。研究結果顯示，渠床呈現多樣化之階梯-深潭形式，與常見之肋骨狀橫向連續排列的階梯-深潭結構不同，且發現階梯的形成與關鍵性顆粒存在與否有關，本研究亦由顆粒排列方式將階梯分為八種形式，並藉由因次分析與階梯-深潭發育權重Wsp之定義，分析階梯-深潭的發育與輸砂率變化之關係，進而建立一關係式，從中說明當河流趨於動態平衡時，透過幾何形態的調節將使能耗率趨小，而階梯-深潭的發育則為水流縱向調整之結果；實驗顯示床面粗化將使渠床糙率增大，此外，階梯-深潭的發育增加了水流流路而減緩渠床坡降，兩者作用下皆使水流能耗率減小，進而降低水流輸砂的能力，達到穩定河床之作用。目 錄 中文摘要 i 英文摘要 ii 目 錄 iii 圖目錄 v 表目錄 vii 一、 前 言 1 二、 前人研究與分析方法 3 2.1 前人研究 3 2.1.1 階梯-深潭之簡介 3 2.1.2 階梯-深潭幾何因子間之研究 4 2.1.3 階梯-深潭形成之可能機制 7 2.1.4 階梯-深潭發育程度之定義 10 2.2 分析方法 12 2.2.1 水流條件 12 2.2.2 平均水深之估算 18 2.2.3 泥砂粒徑推估 19 三、 實驗設計與步驟 20 3.1 實驗渠槽設計 20 3.2 實驗流程 22 3.3 實驗條件 25 四、 實驗現象探討 28 4.1 實驗概要 28 4.2 實驗現象 29 4.2.1 渠床高程沿程變化 30 4.2.2 粗化層之形成 33 4.2.3 床形之調整 35 4.3 床形分類 39 4.4 階梯之分類 44 五、 實驗結果分析 47 5.1 輸砂率之探討 47 5.2 平衡條件下之輸砂率與床形發育之關係 55 5.3 水流於能耗率理論上之調整 62 5.4 深潭的營造 67 5.5 砌石工法之佈置 74 六、 結論與建議 78 6.1 結論 78 6.2 建議 80 七、 參考文獻 8

2009年台風モラコットによる台湾の深層崩壊災害

台湾南部の小林村は2009年8月9日に台風莫拉克(Morakot)によって深刻な崩壊がもたらされ，400人以上の死者が出た。三日間の累計降雨量は1676.5mmに達し，降雨強度のピークを迎えた翌日に崩壊が発生した。今回の崩壊は流れ盤に起こり，崩壊体積は25106m3に及んだ。その基盤は中新世後期から鮮新世前期にかけて形成した堆積岩であり，シルト頁岩，厚い泥岩と砂岩を含有する。大規模な斜面崩壊土が旗山川の谷を塞ぎ，向かい側の急斜面上に広がりながら，村の上流に高さ60mの天然ダムを形成した。天然ダムは形成後の1時間24分後に崩壊した。崩壊の移動速度は約20.4～33.7ms−1と推定され，また，見かけ摩擦角度は14°であった。崩壊源のディタッチメントは層理，節理及び断層であった。崩壊源の地層は重力変形を受けており，崩壊前には不規則な凹凸の地形を示していた。また，この地層の重力変形は崩壊後に座屈変形として確認された。崩壊の堆積物は泥岩，頁岩および砂岩などの岩屑を含有し，底部には広く粘度が認められ，それはイライト，緑泥石，石英，長石および方解石からなっていた。この粘度が高速かつ長距離の移動の大きな要因となったと推定される。Typhoon Morakot induced the catastrophic and deadly Shiaolin landslide insouthern Taiwan on 9 August 2009, resulting in more than 400 casualties. We undertooka geological and geomorphological investigation with the aim of reconstructing theevents leading up to this landslide and to clarify factors that contributed to itsdevelopment. The research results have been published with the title “Catastrophiclandslide induced by Typhoon Morakot, Shiaolin, Taiwan” to the Journal ofGeomorphology, volume 127, in 2011, where we provided the same contents as thispaper. Cumulative rainfall reached up to 1676.5 mm in about three days under theinfluence of the typhoon, and the Shiaolin landslide, with a volume of 25 106 m3, occurred one day after the peak in rainfall intensity. The landslide occurred on a dipslope overlying late Miocene to early Pliocene sedimentary rocks consisting of siltyshale, massive mudstone, and sandstone. It started as a rockslide in the upper third ofthe landslide area and transformed into a rock avalanche that crossed a series of terracesand displaced or buried the village below. It buried the riverbed of the Chishan Riverand ran up the opposite slope, creating a landslide dam 60 m high, which was breachedabout 1 hour and 24 minutes later, flooding the village. The velocity of the landslide isestimated to have been 20.4 to 33.7 m s−1 and its apparent friction angle was 14°, whichindicates its high mobility. The detachments in the source area consist of combinationsof bedding planes and joints or faults. The landslide was preceded by gravitationaldeformation, which appeared as hummocky landforms before the landslide and asbuckle folds exposed after the event. The landslide deposits consist of fragments ofmudstone, shale, and sandstone, as well as clayey material at its base. This clayeymaterial, consisting of illite, chlorite, quartz, feldspar, and calcite, is assumed to havestrongly influenced the long, rapid runout.台湾南部の小林村は2009年8月9日に台風莫拉克(Morakot)によって深刻な崩壊がもたらされ，400人以上の死者が出た。三日間の累計降雨量は1676.5mmに達し，降雨強度のピークを迎えた翌日に崩壊が発生した。今回の崩壊は流れ盤に起こり，崩壊体積は25106m3に及んだ。その基盤は中新世後期から鮮新世前期にかけて形成した堆積岩であり，シルト頁岩，厚い泥岩と砂岩を含有する。大規模な斜面崩壊土が旗山川の谷を塞ぎ，向かい側の急斜面上に広がりながら，村の上流に高さ60mの天然ダムを形成した。天然ダムは形成後の1時間24分後に崩壊した。崩壊の移動速度は約20.4～33.7ms−1と推定され，また，見かけ摩擦角度は14°であった。崩壊源のディタッチメントは層理，節理及び断層であった。崩壊源の地層は重力変形を受けており，崩壊前には不規則な凹凸の地形を示していた。また，この地層の重力変形は崩壊後に座屈変形として確認された。崩壊の堆積物は泥岩，頁岩および砂岩などの岩屑を含有し，底部には広く粘度が認められ，それはイライト，緑泥石，石英，長石および方解石からなっていた。この粘度が高速かつ長距離の移動の大きな要因となったと推定される。Typhoon Morakot induced the catastrophic and deadly Shiaolin landslide insouthern Taiwan on 9 August 2009, resulting in more than 400 casualties. We undertooka geological and geomorphological investigation with the aim of reconstructing theevents leading up to this landslide and to clarify factors that contributed to itsdevelopment. The research results have been published with the title “Catastrophiclandslide induced by Typhoon Morakot, Shiaolin, Taiwan” to the Journal ofGeomorphology, volume 127, in 2011, where we provided the same contents as thispaper. Cumulative rainfall reached up to 1676.5 mm in about three days under theinfluence of the typhoon, and the Shiaolin landslide, with a volume of 25 106 m3,occurred one day after the peak in rainfall intensity. The landslide occurred on a dipslope overlying late Miocene to early Pliocene sedimentary rocks consisting of siltyshale, massive mudstone, and sandstone. It started as a rockslide in the upper third ofthe landslide area and transformed into a rock avalanche that crossed a series of terracesand displaced or buried the village below. It buried the riverbed of the Chishan Riverand ran up the opposite slope, creating a landslide dam 60 m high, which was breachedabout 1 hour and 24 minutes later, flooding the village. The velocity of the landslide isestimated to have been 20.4 to 33.7 m s−1 and its apparent friction angle was 14°, whichindicates its high mobility. The detachments in the source area consist of combinationsof bedding planes and joints or faults. The landslide was preceded by gravitationaldeformation, which appeared as hummocky landforms before the landslide and asbuckle folds exposed after the event. The landslide deposits consist of fragments ofmudstone, shale, and sandstone, as well as clayey material at its base. This clayeymaterial, consisting of illite, chlorite, quartz, feldspar, and calcite, is assumed to havestrongly influenced the long, rapid runout

In-Memory Computing Architecture for a Convolutional Neural Network Based on Spin Orbit Torque MRAM

Recently, numerous studies have investigated computing in-memory (CIM) architectures for neural networks to overcome memory bottlenecks. Because of its low delay, high energy efficiency, and low volatility, spin-orbit torque magnetic random access memory (SOT-MRAM) has received substantial attention. However, previous studies used calculation circuits to support complex calculations, leading to substantial energy consumption. Therefore, our research proposes a new CIM architecture with small peripheral circuits; this architecture achieved higher performance relative to other CIM architectures when processing convolution neural networks (CNNs). We included a distributed arithmetic (DA) algorithm to improve the efficiency of the CIM calculation method by reducing the excessive read/write times and execution steps of CIM-based CNN calculation circuits. Furthermore, our method also uses SOT-MRAM to increase the calculation speed and reduce power consumption. Compared with CIM-based CNN arithmetic circuits in previous studies, our method can achieve shorter clock periods and reduce read times by up to 43.3% without the need for additional circuits

Incidence and Risk Factors for Urinary Tract Infection in an Elder Home Care Population in Taiwan: A Retrospective Cohort Study

Urinary tract infection (UTI) is a common infection worldwide. Numerous studies have demonstrated risk factors for UTI in facilities and communities. In this study, we aimed to identify risk factors for UTI in home care patients. Patients who received home care for at least three months in 2017 were included. A UTI episode was defined by admission for UTI treatment, and/or a visit to an outpatient department for UTI and receiving antibiotic prescription. A total of 598 patients aged 81.9 years were included. Overall 47% (281) had at least one UTI episode. After analysis, urinary catheter indwelling was the most important risk factor (odds ratio (OR), 3.21). Underlying diseases (coronary artery disease (CAD), chronic kidney disease (CKD), diabetes mellitus (DM)) were related to UTI with OR ranging from 1.46 to 1.79. Higher Alb (albumin) (OR 0.68) and Hb (hemoglobin) (OR 0.91) were inversely related to UTI. Polypharmacy (OR 1.84) and lower Barthel index scores (OR 1.62) were also related to UTI by different degrees. In conclusion, apart from the unmodifiable factors, avoiding prolonged urinary catheter placement, unnecessary prescriptions, and keeping good nutritional status may help to prevent UTI in home care patients