著者

吉田 英嗣 須貝 俊彦

出版者

日本地形学連合

雑誌

地形 (ISSN:03891755)

巻号頁・発行日

vol.30, no.1, 2009-01-25

被引用文献数

1

著者

松倉,公憲

出版者

日本地形学連合

雑誌

地形

巻号頁・発行日

vol.25, no.2, 2004-04-25

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We briefly review some problems arising in papers on the Schmidt hammer used in a geomorphological context. There are several types of Schmidt hammer, and many measurement methods including ways of collecting data have beeen proposed, but no standard method for taking measurerements has yet been established. We propose continueous (repeated) impacts for assessing the hardness of intact rock and single impact for assessing the hardness of a rock surface, including the weathering layer.

著者

松倉 公憲 青木 久

出版者

日本地形学連合

雑誌

地形 = Transactions, Japanese Geomorphological Union (ISSN:03891755)

巻号頁・発行日

vol.25, no.2, pp.175-196, 2004-04-25

参考文献数

147

被引用文献数

11

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We briefly review some problems arising in papers on the Schmidt hammer used in a geomorphological context. There are several types of Schmidt hammer, and many measurement methods including ways of collecting data have beeen proposed, but no standard method for taking measurerements has yet been established. We propose continueous (repeated) impacts for assessing the hardness of intact rock and single impact for assessing the hardness of a rock surface, including the weathering layer.

著者

松四,雄騎

出版者

日本地形学連合

雑誌

地形

巻号頁・発行日

vol.25, no.2, 2004-04-25

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To study the effect of bedrock permeability on hill morphology, we performed hydrological measurements and a slope stability analysis in the hilly terrains underlain by unconsolidated sandstones and consolidated mudstones around Mt. Kanozan, Boso Peninsula, central Japan. The sandstones provide high round-top hills with the low drainage density, and the mudstones comprise low rugged hills with the high drainage density. The permeabilities of sandstone and mudstone were 2 × 10^<-3> cm/s and 5 × 10^<-6> cm/s respectively. Slope failures in both areas have distinctive features: (1) failure-generating areas in the sandstone hills are confined to the lower parts of steep slopes adjacent to valleys; and (2) the slope failures in the mudstone hills take place almost on convergent hollows locating at the upper part of the hill slopes. The rainfall-runoff characteristics differed in the two areas. No increase in discharge was observed in the sandstone areas even during rainstorms. This implies that vertical percolation and deep groundwater flows are dominant in the sandstone hills. In contrast, rapid runoff and a large peak discharge responsive to rainfall were found in the mudstone areas. This indicates that subsurface storm flows mainly contribute to the discharge in the mudstone hills. A stability analysis on slipped slopes in both sandstone and mudstone areas revealed a difference in their instability mechanisms. Slope failures in the sandstone hills were caused by reduction of soil cohesion as a result of increasing moisture content in the regolith. Slope failures in the mudstone hills result from increasing pore water pressure derived from a rising subsurface water level in the regolith zone. These differences appear to be a result of the different behaviour of percolated water according to the different permeabilities of the two bedrocks. Morphology in the hilly terrains around Mt. Kanozan, such as the relative heights of the ridges, must be controlled by these slope instability mechanisms and locations of the slope failures.

著者

安田 正幸 遠藤 徳孝 砂村 継夫

出版者

日本地形学連合

雑誌

地形 (ISSN:03891755)

巻号頁・発行日

vol.24, no.3, 2003

著者

飯田 智之 水町 友美 水野 恵司 林 育史

出版者

日本地形学連合

雑誌

地形 (ISSN:03891755)

巻号頁・発行日

vol.23, no.3, 2002

著者

島津 弘

出版者

日本地形学連合

雑誌

地形 (ISSN:03891755)

巻号頁・発行日

vol.34, no.1, 2013-01-25

著者

村上 貴志 遠藤 徳孝

出版者

日本地形学連合

雑誌

地形 (ISSN:03891755)

巻号頁・発行日

vol.33, no.1, 2012-01-25

著者

早川 裕弌 松多 信尚 前門 晃 松倉 公憲

出版者

日本地形学連合

雑誌

地形 (ISSN:03891755)

巻号頁・発行日

vol.34, no.1, pp.21-36, 2013-01-25

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Recession rates of four waterfalls formed by the surface deformation of the Chelungpu Fault at the time of Chi-Chi Earthquake on September 21, 1999 in central Taiwan were measured in the field and assessed with an empirical model of waterfall erosion. The model represents the balance between the erosive force of streams versus bedrock resistance with relevant environmental parameters of discharge (drainage area and precipitation), waterfall form and bedrock strength. The recession rates of three waterfalls increased from the first 6 years to the following 4 years. This increase in the recession rates basically corresponds to the changes in environmental factors including precipitation increase and waterfall width narrowing. The recession rate of another waterfall decreased, but this can be explained by artificial modification of riverbed. The recession rates are very high comparing with waterfalls in other places, probably due to large amount of hard gravels transported on the weak bedrock from the upstream areas.

著者

宇多 高明 田中 常義 森 義将 峯 浩二 木村 尚

出版者

日本地形学連合

雑誌

地形 (ISSN:03891755)

巻号頁・発行日

vol.24, no.2, pp.215-228, 2003-04-25

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Formation of the barrier where the central part of Yokohama City is located was investigated by the comparison of old maps and geological surveys. This barrier was formed as the sand spit extending northwestward from the end of Ishikawa Upland. Behind this barrier, lowland mainly composed of alluvial cohesive soil extends. In this area, jet of sand and subsidence of structural foundation were observed during the Kanto Great Earthquake. Thus, the understanding of the formation of this barrier and lowland is important to consider potential vulnerability of this area. Comparison of profiles along several sections crossing Ishikawa Upland showed that sand was supplied from this upland while forming sea cliff. Supplied sand was carried by longshore sand transport caused by wind waves in Tokyo Bay. In this area predominant wind directions are N and NE. Waves from these directions make large incident angle greater than 45 degrees reference to the shoreline direction, and this large wave incidence accelerates the formation of sand spit by the mechanism given by Ashuton et al. (2001).

著者

鹿島 薫

出版者

日本地形学連合

雑誌

地形 (ISSN:03891755)

巻号頁・発行日

vol.28, no.3, 2007-07-25

著者

田村 俊和 加藤 仁美 松林 武 古田 智弘 チャタリジ デボスリ 李 穎

出版者

日本地形学連合

雑誌

地形 (ISSN:03891755)

巻号頁・発行日

vol.23, no.4, pp.675-694, 2002-10-25

参考文献数

17

被引用文献数

4

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This paper presents the results of observations at different hilly watersheds in Sendai area in different periods with the aim at contributing to the study of pipe-flow initiation, pipe-outlet shift and surface-slide occurrence on valley-head slopes with increase in rainfall. The critical rainfall for the initiation of pipe-flow at channel-heads is variable with rainfall characteristics including antecedent precipitation, and with micro-topographic, pedologic and geologic conditions of the valley-head. Soil pipes at more upstream position begin to operate when total rainfall increases, for instance, in a 2 or 3 hour storm with the intensity of more than 5-10 mm/h without antecedent precipitation. This is considered the results of stepwise expansion of contributing areas and contributing soil-mass. Sediment discharge and opening of new pipes as results of intra-pipe erosion and small-scale failures occur in the case of an almost yearly storm, i.e., several tens of millimeter of total rainfall with over 10 mm/h of maximum intensity After a storm, pipe-flow continues longer on the hilislopes where deep weathering crust of andesite is distributed than on the hilislopes composed of semi-consolidated siltstone or sandstone. It is considered to be due to water-supply from saprolite to soil pipes. Surface slides are triggered with an intense rain of about 30 mm/h following to a 10 to 15 hour storm with the intensity over 10 mm/h on lower hillslope segments, particularly immediately below the convex break of slope at the lower margin of head hollows. Stronger storm, for instance, a 80 mm/h rain following to a 3 hour storm reaching to 170 mm, induces surface slides on upper hillslope segments, particularly headmost walls. Pipe outlets are observed on any slide scar. These phenomena suggest that working pipe network is switched several times with the increase of both total rainfall and rainfall intensity.

著者

シャルコウスキ アネストリア 小玉 芳敬 中野 惠文

出版者

日本地形学連合

雑誌

地形 (ISSN:03891755)

巻号頁・発行日

vol.27, no.1, 2006-01-25

著者

羽田 麻美

出版者

日本地形学連合

雑誌

地形 (ISSN:03891755)

巻号頁・発行日

vol.28, no.1, pp.41-52, 2007-01-25

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Rillenkarren are well developed on the surface of pinnacles at four karst areas, i.e., Akiyoshi Plateau, Hirao Plateau and Yamazato (Okinawa) in Japan and Lipica in Slovenia. Total 325 rillenkarren on total 67 pinnacles were selected for measurements. The width and depth of rillenkarren were measured using a carpenter's profile gauge and the slope angles of the trough of rillenkaren, i.e., slope angles of pinnacles, were measured using a clinometer. The results are as follows: 1) the slope angle of pinnacles with rillenkarren ranges between 29°and 65°in Akiyoshi and Hirao Plateaus, while it takes between 40°and 77°in Yamazato and Lipica; 2) the width of rillenkarren in four areas ranges between 1.5 cm and 6.5 cm, and it is a little narrower at Yamazato than that of the other three areas; 3) there is a difference in depth of rillenkarren, i.e., it ranges between 0.2 cm to 2.1 cm at Akiyoshi and Hirao Plateaus, between 0.4 cm to 4.2 cm at Yamazato and between 0.7 cm to 3.2 cm at Lipica; and 4) there is a common characteristic in all areas between the slope angle of pinnacles and the shape of rillenkarren, i.e., both of depth and width of rillenkarren become larger with increasing in slope angle of pinnacles.

著者

羽田 麻美

出版者

日本地形学連合

雑誌

地形 (ISSN:03891755)

巻号頁・発行日

vol.26, no.3, 2005-07-25

著者

平岡 真合乃 恩田 裕一 水垣 滋 五味 高志 加藤 弘亮

出版者

日本地形学連合

雑誌

地形 (ISSN:03891755)

巻号頁・発行日

vol.28, no.3, 2007-07-25

著者

大槻 ゆう菜 松下 文経 恩田 裕一 水垣 滋

出版者

日本地形学連合

雑誌

地形 (ISSN:03891755)

巻号頁・発行日

vol.28, no.3, pp.300-301, 2007-07-25

著者

Ishimaru Satoshi Takami Masazo Oka Takao

出版者

日本地形学連合

雑誌

地形 (ISSN:03891755)

巻号頁・発行日

vol.23, no.4, 2002-10-25