本論文では, 2004年新潟県中越地震の

と2016年熊本地震の南阿蘇村の集落の孤立確率を求め, 実際の孤立被害と比較した．孤立確率の計算に必要なデータは, 斜面の勾配, 地震動のPGA分布, 道路ネットワークである．では全域で孤立確率が高くなったのに対し, 南阿蘇村では一部の集落のみが孤立確率が高くなった．この結果は, では村全域が孤立状態になったこと, および南阿蘇村では一部の集落のみが孤立したことと良い一致を示した．

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平成16年10月に発生した新潟県中越地震では, 中山間地域に散在した集落へ至る交通網等が寸断され, 新潟県旧をはじめとする各地で集落が孤立し,「孤立集落」の深刻さを浮き上がらせた。本研究では, 中越地震において被害が最も甚大であった旧および小千谷市, 川口町の信濃川右岸地域を対象として集落の孤立リスクを既存のGISデータをもとに検討した。また, 容易に入手可能な50mメッシュ標高データを用いて, 中越地震発生時の道路寸断に伴う集落の孤立状況を勘案し, 各道路の寸断リスク・集落の孤立リスクの分布図作成を行った。

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This study investigates the discrepancies of heat budgets on snow surface between in the high alpine area and in the lower-lands through field observations. The energy exchanges across the snow surface were measured at two observation sites; one located at 2950 m a. m. s. l. on the northern slope of Mt. Fuji, and the other at 300 m a. m. s. l. in Niigata prefecture. Snowmelt was calculated using snow density measured by snow sampler once every week and melting depth by camera in every six hours. Role of turbulent heat flux in the high alpine area was more important than in the lower-lands. The latent heat flux was usually negative and the large positive latent heat flux associated with the warm, humid and strong wind sometimes caused the very intense snowmelt in the high alpine area.

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The spatial and temporal variation of energy budget on the snow surface were investigated at four experimental sites from March to June in 1992. The parameters in the energy budget equation describing snowmelt were determined based on the observated data at each site. The result of energy budget for each site showed that the ratio of the radiative and turblent energy to the whole depend on season and topography.

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1. The breeding of nishiki-goi (colorful carp) in Yamakoshi District, which is said to have begun in the 18 century, has now developed into an established business, because of the success in raising new breeds on one side, and of the increasing demand for carp on the other. This development was accelerated to an extreme degree, and ended up to have established the district as the greatest carp-producing center in Japan during the period of high Japanese economic growth.
2. Ever since the very beginning up to the present time, most nishiki-goi farms in this district have been on a small scale and carried on by farmers as their side job, depending entirely on the work of their family members.
3. In early days, nishiki-goi breeding was a very speculative business because the success in it depended on the mere luck of appearance of good mutations. But popularization of nishiki-goi appreciation among common people has brought great changes to it, that is, the increase in the amount of carp production and naturally following stability in the breeding business.
4. In order to answer the increasing demand for carp, farmers have managed to secure enough number of culture ponds by; 1 using irrigation ponds, 2 using watered rice fields, and 3 remaking rice fields into culture ponds.
5. Sales system, too, has been markedly improved and modernized, that is, main part of selling has gradually been changing from “spot sales” to “sales through brokers (koi-shi), followed by “sales through commission agents” and now by “sales by auction”.
6. Nevertheless, carp business is never free from ups and downs since general demand for carp wavers, as is often the case with so called “leasure industry”, in accordance with fluctuations of social-economic condition of the time.
7. The main reasons why this district has developed into the greatest producing center are considered to be; 1 enough number of irrigation ponds and amount of good water for carp, 2 years' ceaseless efforts to breed newer and better carp, 3 increasing demand created by the high economic growth and the government policy to decrease rice production, 4 the use of oxygen to transport carp alive and of vinyl pipes to supply water.
8. In this district the income from nishiki-goi now exceeds that from rice produce. This profit has meant economically a great deal to the people living there. It is owing to carp-business that this district, which used to be an isolated mountain village, has now been making great changes.

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中山隧道は新潟県の山間地、小松倉地区に在り、1998年12月に新トンネルが開通して50年間余の大役を終えた。手掘り隧道建設以前の小松倉は集落戸数が60戸余り、生活の不便はいうにおよばず、積雪深4m以上となる冬季には医療の恩恵を受けられぬまま生命の危険にさらされていた。
地域社会の将来を考え、集落の人々は私財を投げうち、自らの手でツルハシを握り、長さ約1kmに及ぶ全国一の手掘り隧道を昭和8年から16年間の歳月をかけて掘り抜いた。
住民の力にあまる長大な隧道を自らの手で造り上げた精神と行為は、改めて社会資本の意義、役割を考えさせる貴重な土木遺産であり、さまざまな角度から研究するに値する遺産である。

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東日本大震災の復旧・復興過程で，集団移転が進捗するにつれてコミュニティ再編が現実的な課題となるとされている。本報では，先行する2004年新潟県中越地震のコミュニティ再編事例を現地調査に基づき紹介する。2007年帰村時の統合を見送った近隣3集落では，過疎・高齢化で単独開催が困難化していた「さいの神」と盆踊りを，2011年以降，地域復興支援員の仲介で合同開催してきた。性急な統合型より伝統行事を介した連合型の再編の可能性を見いだすことができる。河道閉塞で水没した別の集落では，区長の強い意志のもと，被災翌年から集落に戻って盆踊りを行ってきた。こうした集落行事のほか，交流行事を外部者と連携して行っており，単独型再編として位置づけられる。

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1995年兵庫県南部地震ならびに2004年新潟県中越地震の特徴の1つとして上下動が大きかったことが挙げられる. この上下動が盛土の破壊に与える影響に関する検討はあまり行われていないのが現状であり, 盛土の耐震設計指針等においても鉛直地震動を考慮した耐震設計は含まれていない. そこで本研究では水平動だけでなく上下動を同時に考慮することができる修正Newmark法を用い, 地震時における盛土の破壊をすべり変位量によって評価した. そして数多くの強震動を入力地震動として採用することによりパラメトリックスタディを実施し, 上下動が盛土の破壊に及ぼす影響に関して検討を行った. その結果, 震央距離が比較的短い内陸直下型の地震においては, 上下動は盛土の破壊に対し危険側に作用する可能性が高いことがわかった.

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The earthquake of M6.8 occurred at 17:56 on Oct. 23, 2004 in mid Niigata prefecture, and seismic intensity 7 was recorded in Kawaguchi-cho. After that, the aftershock activity has continued so actively that several aftershocks of seismic intensity 6+ were observed, and they caused heavy damage in various places. The main shock appeared right near Yamakoshi-mura, and seismic intensity at this district was 6+. This area is the foremost area of frequent landslides in Japan, and by this earthquake many slope failures and landslides occured on the wide range of Higashiyama hill with center at Yamakoshi-mura. Slope failures and landslides appeared at 1, 662 points and the total of sediment yield is estimated to reach 7×10⁷m³ as a result of the analysis of aerial photographs. There are ten large-scale landslides that have sediment yield of more than 10⁶m³ individually, and five of them concentrate along the River Imo. Moreover, landslide dams were formed at more than 30 points along the River Imo, and urgent measures have been taken.

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IThis study is investigated the historical transfiguration of agricultural products, agricultural life and landscape in the Yamakoshi region of Nagaoka-city, Niigatta Prefecture. Before the great earthquake of Cyuetsu in 2007, this area was very popular for local cameraman and other people because of its beautiful agricultural landscape. Especially, pond terraces for breeding Nishikigoi carps created landscape characteristic of this area. In Japan, many people have loved Nishikigoi since the 1800s. Conclusion was that most of the landscape in this area went through major changes from 1960 to 1980, caused by the popular sales of Nishikigoi during the rapid economic growth. In this age, many rice terraces were transfigured into breeding ponds for Nishikigoi, and many houses were rebuilt. An agreement of rice acreage reduction started in 1970, pushing the change of rice products to carp production. Area dates of agricultural fields in Japan and in the Yamakoshi region, along with the area date of ponds in the Yamakoshi region confirm this situation. Transfiguration of agricultural products and life also help change the relationship of agricultural elements and people's life style. For example, the use of compost, woods for drying rice, sericulture, and carp's feed (pupa) was developed.

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