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全文: "流砂"
4,852件中 1-20の結果を表示しています
  • 現地計測(1)現地流砂観測(その1)
    堤 大三
    砂防学会誌
    2019年 72 巻 2 号 Pict02_1
    発行日: 2019/07/15
    公開日: 2020/07/15
    ジャーナル オープンアクセス
  • 田中 茂, 杉本 修一
    水理研究会講演集
    1957年 2 巻 29-30
    発行日: 1957年
    公開日: 2010/06/04
    ジャーナル フリー
  • 柿 徳市
    新砂防
    1958年 1958 巻 31 号 19-22
    発行日: 1958/11/20
    公開日: 2010/04/30
    ジャーナル フリー
  • 福岡 捷二, 山坂 昌成, 安陪 和雄
    水理講演会論文集
    1984年 28 巻 679-684
    発行日: 1984/01/17
    公開日: 2010/06/04
    ジャーナル フリー
  • 福岡 捷二, 柴田 高, 田村 浩敏, 田端 幸輔, 山形 勝巳
    水工学論文集
    2005年 49 巻 1027-1032
    発行日: 2005/02/01
    公開日: 2011/06/27
    ジャーナル フリー
    It is important to evaluate properly sediment discharge distribution of the meandering compound channel, because the plan shape of many rivers in Japan has a meandering compound change. We use conventional bed-load equation derived for a simple channel. An applicability of conventional bed-load equation should be examined for compound channels.
    In this paper, at first we investigate sediment discharge characteristics in the compound channel whose plan form changes longitudinally. In the second, we compare analytical sediment discharge rate obtained from our 3D-flow model and experimental result. Problems are raised to sediment discharge rate and distribution of compound channels with different plan forms.
  • 岩垣 雄一, 土屋 義人, 西平 福宏
    水理研究会講演集
    1961年 6 巻 1-5
    発行日: 1961年
    公開日: 2010/06/04
    ジャーナル フリー
  • 藤田 正治
    砂防学会誌
    2005年 58 巻 1 号 63
    発行日: 2005/05/15
    公開日: 2010/04/30
    ジャーナル フリー
  • 中谷 洋明
    砂防学会誌
    2009年 61 巻 6 号 11-18
    発行日: 2009/03/15
    公開日: 2013/09/02
    ジャーナル オープンアクセス
    Sediment transport process in mountain streams is not entirely controlled by flow discharge. As a result, the process does not concomitantly follow flow discharge pattern but shows non-consecutive partly independent dynamism. The process has been a subject of extensive studies in theoretical, experimental, as well as observational aspects. Based on direct sampling, experimental bed load equations have been tested to examine the relationship between flow discharge and sediment discharge. The sampling and observation efforts led to the development of more indirect but stable sediment transport monitoring methods (hereafter “indirect method") in recent years. One of the indirect methods, a hydrophone sediment discharge measuring system (hereafter “hydrophone system"), has been intensely studied for the development of practical sediment transport monitoring. Hydrophone systems have been tested quantitatively in relation to bed load equations as well as to directly sampled sediment discharge in 100 and 200 km2-scale river basins. Quantification efforts have been carried out both as site-specific comparison between direct and indirect methods, and as a year-long basin-scale examination utilizing reservoir sedimentation data. These efforts enabled us to take a longer view than a snap shot view of sediment discharge, which is transported in a collective form seen as sediment waves. Examination of the extent to which erosion and flood control structures such as sabo dams transform sediment discharge of floods has been a major practical concern for a long time. Bed load equations can analyze the effects of structures at a given moment but are not adequate to quantify those exerted upon collective forms of sediment discharge. Therefore, indirect measurement, together with flow discharge observation, was conducted in an upstream segment of a mountain stream in order to study the transformation processes and effects of structures. Since direct sampling is not readily possible in the segment, bed load analytical equations developed in a similar mountain stream was applied to quantify the sediment transport process in the segment. The result indicated that sediment discharge flowed down as a wave at a velocity about one-third of that of average stream flow and that the maximum sediment discharge did not grow as much as the aggregated sediment discharge of the waves in the structurally regulated segment of the stream. Flood cases studied here were minor in their intensities. Further observational efforts and analysis are needed to examine whether the quantification method is robust enough and whether the results obtained here hold to a larger flood. This study is a preliminary attempt to introduce an analytical framework that is applicable to larger flood cases.
  • 鮮川 登, 錦織 和紀郎, 杉山 弘泰, 下村 博史, 中川 正
    水理講演会論文集
    1982年 26 巻 147-152
    発行日: 1982/01/10
    公開日: 2010/06/04
    ジャーナル フリー
  • 星野 和彦, 酒井 哲也, 水山 高久, 里深 好文, 小杉 賢一朗, 山下 伸太郎, 佐光 洋一, 野中 理伸
    砂防学会誌
    2004年 56 巻 6 号 27-32
    発行日: 2004/03/15
    公開日: 2010/04/30
    ジャーナル フリー
    Sediment monitoring has been started at a branch of the Sumiyoshi River in Rokko Mountains. Rainfall, water level, bedload discharge and turbidity are measured. Bedload discharge rate are measured continuously with a hydrophone and a pit (slit) bedload sampler. Pressure pillows are used to measure the weight of trapped bedload in a pit on a torrent bed. The pit bedload sampler was adopted for the calibration of the hydrophone. They have worked properly and water and sediment monitoring were successful. The hydrophone's data were converted into instantaneous bedload discharge with the pit bedload sampler's data.
  • 中谷 洋明
    砂防学会誌
    2009年 61 巻 5 号 4-11
    発行日: 2009/01/15
    公開日: 2013/09/02
    ジャーナル オープンアクセス
    Sediment transport process in mountain streams has been studied chiefly in the development of theoretical as well as experimental bed load equations. Difficulties associated with field observation have been a major obstacle in testing and applying bed load equations properly. Direct sediment sampling is often impossible ; and its effective is limited due to its durability even if it is applicable. Attempts have been made to utilize more indirect but stable monitoring methods (hereafter “indirect method") in recently years such as a hydrophone sediment discharge measuring system (hereafter “hydrophone system"). Hydrophone systems count the times that bed load sediments strike the acoustic sensor of the system (hereafter “pulses") upon proper electric amplification. Early observation brought light on small to medium discharge non-equilibrium sediment transport phenomena which have not been adequately studied either theoretically or experimentally. Non-equilibrium states are influenced by many hydro-sediment factors, among which flow discharge is not always dominant. Therefore, sediment discharge as a functional form needs to be regarded as dependent on multiple variables. Expanding bed load equations and building ones from many primary hydro-sediment factors at one time seem to be beyond our reach. Thus, a step-wise approach is taken by introducing and adding to flow discharge an intermediary and secondary hydro-sediment factor called “sediment-related quantity," which is observed by indirect methods.In this study, hydrophone systems have been installed in 100 and 200 km2-scale river basins in order to observe hydrophone pulses that are used as sediment-related quantity. Sediment transport, water flow, and acoustic phenomenon are mutually intercorrelated. The phenomena were described by each corresponding observational variables, whose correlations were analyzed statistically. Hydrophone pulses have correlation with and are dependent upon both bed load discharge and flow discharge. Therefore, pulses alone can not provide suitable estimates of sediment discharge. In order to search analytical estimation equations of bed load, therefore, pulses and flow discharges were combined as an initial step. Additive forms both with and without interaction terms, and multiplicative forms were introduced and calibrated for the observation. Each bed load analytical estimation method was statistically assessed. The best method was a linear additive form with no interactive term. The introduction of sediment-related quantities facilitates us to construct a viable analytical estimation method of non-equilibrium sediment discharge. Its own dependency on other hydro-sediment factors needs to be examined for further physical understanding of the sediment discharge observation. Indirect method with the suggested forms of analytical estimation equations, with due care for its insufficient physical understanding,seems to be applicable for further development to analyze bed load discharge consecutively in the scale of full river section.
  • 鈴木 幸一, 山本 裕規, 藤岡 貴之
    水工学論文集
    1997年 41 巻 801-806
    発行日: 1997/02/20
    公開日: 2010/06/04
    ジャーナル フリー
    Sediment discharge in mountain rivers with steep slope bed and with wide range of grain size of bed materials usually fluctuates with time due to the formation and destruction of gravel concentration formed discretely in the longitudinal flow direction which forms stair-like or transverse limb bed. Experiments with sand-gravel mixture are carried out, and the characteristics of bed load fluctuations are discussed in connection with bed surface conditions both of roughness height and grain size composition due to the gravel concentration.
  • 木村 詩穂, 内田 太郎, 田中 健貴, 井内 拓馬, 桜井 亘, 杉山 実, 田方 智, 松田 悟, 伊藤 隆郭
    砂防学会誌
    2018年 70 巻 6 号 46-53
    発行日: 2018/03/15
    公開日: 2019/03/15
    ジャーナル オープンアクセス

    Bedload and wash load have been measured using indirect method such as pipe hydrophone and turbidity meter, for the basin monitoring and sediment management in the basin, and those monitoring are conducted at around ninety sites in mountainous basin in Japan. There are few researches for comparative studies of differences of sediment runoff on basin characteristics. In present study, characteristics of sediment runoff and related controlling factors were discussed using monitoring data in representative six basins with different characteristic of water and sediment runoff. Several groups were classified with sediment runoff for flow discharge and sediment transport capacity. Monitoring for sediment and water runoff could be effective tools for basin monitoring through present data analyses.

  • 今,なぜ流砂の計測か
    仲野 公章, 笹原 克夫
    砂防学会誌
    2001年 54 巻 1 号 90-97
    発行日: 2001/05/15
    公開日: 2010/04/30
    ジャーナル フリー
  • 橋本 晴行, 朴 埼藻, 池松 伸也, 田崎 信忠
    水工学論文集
    2003年 47 巻 571-576
    発行日: 2003/02/10
    公開日: 2010/06/04
    ジャーナル フリー
    We can distinguish four main types of sediment transport and their two itermediate types on movable bed in a steep open channel; those are bed and suspended load types, debris and mud flow types, and intermediate types between bed load and debris flow types. The flow model for hyperconcentrated sand-water mixtures proposed by Hirano and Hashimoto (1995, 1997) can be applied to all types of flows with sediment transport in a steep open channel. The flow model consists of granular and inertial layers; the intergranular stresses play major role in the former layer and inertial forces in the latter layer. On the basis of the flow model, sediment discharge formulas have been derived by Hirano and Hashimoto (1996, 1998). In the present study the sediment discharge formulas are compared with the experimental results and also with the other formulas. The calculation of sediment discharge formulas derived by Hirano and Hashimoto (1996, 1998) shows good agreement with experimental results.
  • 流砂系モニタリングのために
    浦 真, 下井田 実, 有澤 俊治, 横山 康二, 浜名 秀治
    砂防学会誌
    2001年 54 巻 3 号 81-88
    発行日: 2001/09/15
    公開日: 2010/04/30
    ジャーナル フリー
  • 福岡 捷二, 山坂 昌成
    水理講演会論文集
    1983年 27 巻 703-708
    発行日: 1983/01/17
    公開日: 2010/06/04
    ジャーナル フリー
  • 楊 永荻, 平野 宗夫, 藤田 恭三
    水工学論文集
    1997年 41 巻 795-800
    発行日: 1997/02/20
    公開日: 2010/06/04
    ジャーナル フリー
    Mean flow properties and turbulent characteristics of open channel flow with bed-load transport were experimentally studied in the 550×25.8×20cm flume with erodible gravel bed. The sand with the diameters of 0.59mm and 1.19mm were used and the rate of bed-load transport reach to 13g/cm·sec. The velocity were measured by ADV, and the characteristics of the turbulent intensity and the spectra of turbulent velocity were analyzed. The experimental results show that: 1) the mean velocity profile of open channel flow with bed-load can be expressed by a log-law; 2) the turbulent intensity near bed decreases with the increase of bed-load transport rate; 3) the spectrum of turbulent velocity also changes as the increase in bed-load transport.
  • 中谷 洋明, 鶴田 謙次, 吉村 暢也
    砂防学会誌
    2010年 63 巻 3 号 11-18
    発行日: 2010/09/15
    公開日: 2014/11/01
    ジャーナル フリー
    Sediment transport measurements in mountain torrents are pivotal to comprehend the nature of the process. Long-term continuous measurement in natural river basins with a substantial scale has been circumvented by many obstacles. Direct sampling, therefore, has been augmented by more indirect but stable methods (hereafter “indirect method”) in recent years such as a hydrophone pipe-microphone acoustic sediment discharge measuring system (hereafter “hydrophone system”). A statistical analytical method based on the hydrophone system has been developed, which enables us to calibrate and estimate bedload amounts sampled by a sediment pit within a limited width of river sections. Observation of sediment transport phenomena, however, has not been fully expanded across a river cross section. Crosssectional variability of bedload discharges has to be understood to select appropriate observation points in a section and to estimate full-width sediment discharges out of those at a unit-width.
    A bedload discharge observation facility consisting of a pair of sediment trap pits, together with a water level gauge, has been installed in a 100-km2 scale river basin, in order to make pair observations at the right and the central point in a cross section. 12 small-to-medium size flood cases were observed and analyzed in order to quantitatively understand the nature of bedload discharges at each point section and their mutual relationship in a sequential time series as well as in aggregated sums over each case. Intensities of bedload discharges underwent fluctuation of an order of magnitude at a different timing for each point over the observed cases. As a result, relative intensities between the two observation points, expressed by their differences, changed from positive to negative across zero, which gave a fluctuation cyclic period of from about 20 to 40 minutes. Further observation, if combined with the indirect method of hydrophone systems, which have a shorter time constant as an observation system, is likely to clarify cross-sectional variability of bedload discharges in a more reliable manner.
  • 水山 高久, 里深 好文
    砂防学会誌
    2003年 56 巻 3 号 55-56
    発行日: 2003/09/15
    公開日: 2010/04/30
    ジャーナル フリー
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