Journal of the Japan Society of Erosion Control Engineering
Online ISSN : 2187-4654
Print ISSN : 0286-8385
ISSN-L : 0286-8385
Volume 54 , Issue 6
Showing 1-16 articles out of 16 articles from the selected issue
  • Makoto TANI
    2002 Volume 54 Issue 6 Pages 1-3
    Published: March 15, 2002
    Released: April 30, 2010
    JOURNALS FREE ACCESS
    Download PDF (2605K)
  • Masao OKAMOTO, Yoshinori ARAKI, Hirotaka NAKAYAMA, Kohei FURUKAWA, Tak ...
    2002 Volume 54 Issue 6 Pages 4-15
    Published: March 15, 2002
    Released: April 30, 2010
    JOURNALS FREE ACCESS
    In this study, data mining based on the rough set theory is used for specifying critical factors that would cause slope disasters, such as, hillside landslides and debris flows, and for determining the relationship between these factors and disasters. Data on debris flow from the Hiroshima disaster on June 29, 1999, was used to illustrate this methodology. The area of the disaster geologically consists of granite. First, using the data from the primary valleys, we defined the critical geological and rainfall factors that caused the disaster. Then we identified the steps of sediment movement. The critical factors that contribute to transporting sediments are the maximum hourly rainfall, the steepest riverbed slope, and the width of a stream. We also identified particular steps for hillside landslides that resulted in debris flows. It was shown that the area of collapsed hillside and the slope directly under it are the critical factors for an occurrence of debris flow.
    Download PDF (5023K)
  • Katsumi IURA, Osamu SHINOHARA, Takahisa MIZUYAMA, Fumito WATANABE, Kes ...
    2002 Volume 54 Issue 6 Pages 16-24
    Published: March 15, 2002
    Released: April 30, 2010
    JOURNALS FREE ACCESS
    This report was organized the landscape design of a large culvert type Sabo dam named Jigokudaira Sabo dam.
    The figure of Sabo dam as a whole was configured mainly by curved line to match with the configuration along the river, which was composed of a loose curved line. That is to say, adopt a curved line to the plane figure, and the crown viewed from the front was configured as a loose-curved line. But the wings were configured as a vertical style to emphasize the curved line of the main body.
    The surface of main body was with a texture of a masonry style, by using natural stones that exist in the river. For the rim of culvert, white colored wedge-shaped stone was used to emphasize the circle line. And for the wings, gray pre-cut stone were used.
    The landscape design of Jigokudaira Sabo dam was examined as follows:
    (1)The basic concept was examined by constitute an examination committee.
    (2)The figure of the dam and both banks was examined comparatively by using a configuration model and a dam model.
    (3)The material of texture was examined comparatively by using an image drawing and CG.
    (4)The execution method of the texture was examined comparatively by implement on a trial at the execution site.
    Download PDF (17294K)
  • Katsuyuki FUKUDA, Kiyonori MATSUMOTO, Kazuya TANIGUCHI, Yasuyuki TSUBA ...
    2002 Volume 54 Issue 6 Pages 25-34
    Published: March 15, 2002
    Released: April 30, 2010
    JOURNALS FREE ACCESS
    In this research, in order to ascertain the effect of the slit sabo dam on a flood, a flood reproduction calculation was executed for an ordinary type of sabo dam and slit sabo dam that were built upstream in this turn, and the effects of these sabo dams were evaluated quantitatively. As a result, the diminishing effect of the slit dam on the peak outflow sediment quantity and also its effect in delaying the timing of the peak sediment outflow were confirmed. Moreover, it was estimated that 85% of the sediment and silt that were deposited in the slit sabo dam re-flowed within 2.5 days after the peak discharge was generated. Although the discharge rate of a slit sabo dam is usually around a range of 0.6-0.7, in this reproduction calculation the discharge rate was set to as little as 0.2 for the simulation calculation.
    when the last riverbed height, the maximum riverbed height, and the maximum water level grade are used as reproduction indexes, it is possible to calculate the flood reproduction calculation satisfactorily under many calculation conditions. Therefore, it is important to set up a certain reproduction index in the middle of the reproduction calculation.
    Download PDF (19062K)
  • Osamu TOMATSU, Wataru IWAMOTO
    2002 Volume 54 Issue 6 Pages 35-38
    Published: March 15, 2002
    Released: April 30, 2010
    JOURNALS FREE ACCESS
    Download PDF (3914K)
  • Satoru MASUDA, Takashi MIZUYAMA, Masaharu FUJITA, Hikoshichi ABE, Akir ...
    2002 Volume 54 Issue 6 Pages 39-42
    Published: March 15, 2002
    Released: April 30, 2010
    JOURNALS FREE ACCESS
    Download PDF (4866K)
  • Yoshinori TSUKAMOTO
    2002 Volume 54 Issue 6 Pages 43-50
    Published: March 15, 2002
    Released: April 30, 2010
    JOURNALS FREE ACCESS
    Two types of devastation of a mountain, man-made and natural, occur in Japan. Most sediment disasters for the past hundred years have been given rise to by man-made forest devastations. Historical changes of sediment disasters has analysied with the conceptual model in the previous paper. The past hundred years have divided into the following four periods. The characteristics of erosion types, sediment discharge types and sediment disasters are summerized as follows.
    I Predominant period of surface erosion.
    1) Age of the active front zone (1600-1900 A.D.)
    The most sivere surface soil loss, hillslope denudation and torrent devastations occurred. River beds rose up and formed dry rivers by heavy sediment discharges. Most countermeasures using today started during this period such as prohibitation of forest cutting, check dams and hillside works.
    2) Age of the bareland (1900-1950 A.D.)
    The widest bareland covered Japan. Recovery of barelands by hillside works and devastated torrent started during this period as the work of the central and the state government.
    II Predominant period of landslides.
    3) Age of the active preparatory zone (1950-1990)
    Shallow landslides predominate in sediment disasters during heavy storms. Warning and temporary evacuations started as a countermeasure for sediment disasters.
    4) Age of the sound forest(1990- )
    Mature forests have recovered on most mountains. The influence of human impacts on erosion and sediment discharge disappeared. All erosion process are natural and deep landslides predominate. Prediction and forcast of landslide occurrances are essential to prevent disasters.
    Download PDF (1218K)
  • [in Japanese]
    2002 Volume 54 Issue 6 Pages 51-55
    Published: March 15, 2002
    Released: April 30, 2010
    JOURNALS FREE ACCESS
    Download PDF (8035K)
  • Koichi UEDA
    2002 Volume 54 Issue 6 Pages 56-58_2
    Published: March 15, 2002
    Released: April 30, 2010
    JOURNALS FREE ACCESS
    Download PDF (4559K)
  • Jun-ichiro TAKAHAMA, Fumito WATANABE, Norio UKON, Nobuo ANYOJI
    2002 Volume 54 Issue 6 Pages 59-63
    Published: March 15, 2002
    Released: April 30, 2010
    JOURNALS FREE ACCESS
    Download PDF (5457K)
  • Mitsunobu OHNISHI
    2002 Volume 54 Issue 6 Pages 64-71
    Published: March 15, 2002
    Released: April 30, 2010
    JOURNALS FREE ACCESS
    Download PDF (12950K)
  • Sumiji KOBASHI
    2002 Volume 54 Issue 6 Pages 72-78
    Published: March 15, 2002
    Released: April 30, 2010
    JOURNALS FREE ACCESS
    Download PDF (2679K)
  • [in Japanese]
    2002 Volume 54 Issue 6 Pages 79
    Published: March 15, 2002
    Released: April 30, 2010
    JOURNALS FREE ACCESS
    Download PDF (2026K)
  • Shinya NUMAMOTO
    2002 Volume 54 Issue 6 Pages 80-82
    Published: March 15, 2002
    Released: April 30, 2010
    JOURNALS FREE ACCESS
    Download PDF (6199K)
  • Hiroyuki YAMADA
    2002 Volume 54 Issue 6 Pages 83-84
    Published: March 15, 2002
    Released: April 30, 2010
    JOURNALS FREE ACCESS
    Download PDF (300K)
  • 2002 Volume 54 Issue 6 Pages 87
    Published: March 15, 2002
    Released: April 30, 2010
    JOURNALS FREE ACCESS
    Download PDF (1816K)
feedback
Top