著者
平野 昌繁 島津 俊之 野尻 亘 奥田 節夫
出版者
The Human Geographical Society of Japan
雑誌
人文地理 (ISSN:00187216)
巻号頁・発行日
vol.43, no.5, pp.493-503, 1991-10-28 (Released:2009-04-28)
参考文献数
21

A large number of gigantic landslides were triggered by typhoon rain in 1889 over the Totsukawa area, Nara prefecture, resulting a serious hazard. Their localities are identified exactly based on the Koaza name in the historical record, the Yoshinogun-Suisaishi. The identification of landslide localities over South- and East-Totsukawa areas was tried this time, and the results were summarized.Landslide larger than 4×104m2 in area have been shown by cliff marks on the topographic map in 1911 (Meiji-44) as same as in the case of West-Totsukawa area reported before. Topograhic features of gigantic landslides are still recongnized clearly on the aerial photos in 1953 taken even 65 years after the hazard.Description of the localities by Koaza name is frequent at the portions near the settlements or along the trafic routes at that day. In addition, some exaggeration in total number of large landslides is detected, if compared with the number of criff marks in the topographic maps in, 1911, even taking into account of the difference in threshold magnitude for description. Despite these biassed nature, it is clearly true that the Yoshinogun-Suisaishi surves the extraordinarily detailed record of the landslide localities, and this has come from the timing that the hazard occurred just after the detailed survey and registration of land-owner relationship there.
著者
奥田 節夫
出版者
京都大学防災研究所
雑誌
京都大学防災研究所年報 (ISSN:0386412X)
巻号頁・発行日
no.27, pp.p353-368, 1984-04
被引用文献数
8

Historical records of large slope failures in Japan and foreign countries were collected andanalyzed to investigate occurrence frequency of the large slope failures and some dynamical andgeometrical features of debris deposits of the slope failures.It is shown that large slope failures have occurred in Japan much more frequently than inWestern countries. The relationship between the volume of slided debris and the equivalentcoefficient of friction for the debris motion is common to Japan and Western countries. Thefeatures of deposits spreading of slided debris showed a similar relationship between deposit areaand volume, but different shape over a wide range of debris volume with various types of slopefailures.
著者
柏谷 健二 平野 昌繁 横山 康二 奥田 節夫
出版者
公益社団法人地盤工学会
雑誌
土質工学会論文報告集 (ISSN:03851621)
巻号頁・発行日
vol.18, no.1, 1978-03-15

昭和50年8月16,17日にわたる台風5号の豪雨による高知県下の山腹崩壊の資料を用いて, 崩壊地の分布と崩壊に関係する諸因子, たとえば, i)降水量, ii)地形的特徴, iii)地質的特徴, などの比較検討を行ない, 傾斜と降水量を考慮した崩壊予測式を作っている。崩壊地分布は, 災害直後の空中写真および現地調査で, 降雨量は32か所の雨量観測所のデータで, 傾斜は2万5千分の1の地形図を用い2km×2kmの方眼内の平均傾斜角をホートン法で求めている。その結果, 次のことが明らかにされている。(1)継続雨量が一定のとき, 崩壊数はある限界傾斜角まではコウ配に比例する。(2)傾斜が一様なとき, 崩壊数は日雨量から崩壊無効雨量を減じたものに比例する。(3)崩壊予測の一般式としては次式が推定できる。N(i, r)=k_<ir>・(i-i_0)^p(r-r_0)^q ただし, i=tanα ここで, N(i, r) : 単位面積当たり崩壊数, k_<ir> : 係数, i_0 : 限界傾斜角の正接, r : 継続雨量(mm), r_0 : 崩壊無効雨量(mm), α : 単位地域内の平均傾斜角