著者

吉川 泰弘 黒田 保孝 橋場 雅弘 入交 泰文

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B1(水工学) (ISSN:2185467X)

巻号頁・発行日

vol.71, no.4, pp.I_1327-I_1332, 2015 (Released:2016-01-29)

参考文献数

22

被引用文献数

1

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The aim of this study was to clarify the frazil slush generation mechanism on ice-covered rivers. This study developed a frazil slush generation calculation model which targeted skim ice, frazil ice, snow fall and anchor ice. The input values for this model were air temperature, wind velocity, sunshine duration, snow-fall depth, water depth of river, flow velocity of river and latitude. We carried out field observations at a location where frazil slush floats on the water surface, recording data with a camera. It was shown that the calculation model generated by this study can reproduce the frazil slush generation of the real river. It was also found that rising air temperature, an increase in frazil slush thickness and falling upstream water levels are important factors in predicting the occurrence of water intake blockage caused by frazil slush.

著者

関根 正人 浅井 晃一 古木 雄

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B1(水工学) (ISSN:2185467X)

巻号頁・発行日

vol.70, no.4, pp.I_1423-I_1428, 2014 (Released:2015-05-18)

参考文献数

6

被引用文献数

6

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Recently, the warming on the earth advances gradually. Under such circumstances, occurrence frequency of the torrential rain increases in Tokyo. The technique of numerical prediction of the inundation is an effective tool in order to reduce damage due to such a torrential rain in urban area. In this study, the numerical prediction was conducted by using the rain data of the X-band MP radar as the first step to realize a real-time inundation forecast at the time of the localized torrential rain occurrence. Inundation in Shinjuku area that was highly-urbanized was investigated in this study by using the actual rain data that was measured locally on August 26, 2011. It was suggested that an inundation forecast could be realized soon in future.

著者

矢野 真一郎 北川 洋平 谷口 弘明 西村 圭右 堂薗 俊多

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B1(水工学) (ISSN:2185467X)

巻号頁・発行日

vol.71, no.4, pp.I_721-I_726, 2015 (Released:2016-01-29)

参考文献数

10

被引用文献数

2

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The Northern Kyushu Heavy Rain in July, 2012 caused very serious damages. The event also caused many drift woods disasters in river basins and coastal areas. This research focuses on transport of drift woods in the Ariake Sea due to the rain event. Numerical simulation of their transport by 3D hydrodynamic model (DELFT3D) combined with assumed drift woods tracking model and comparison between the calculation result and collection data by Ministry of Land, Infrastructure Transport and Tourism were conducted. From the result, the followings were clarified: 1) total drift woods volume of discharged from all rivers into the sea was estimated as 17,500m3; 2) volume of discharged drift woods from each A-class river was estimated; 3) relationship between the volume and specific maximum river discharge was evaluated.

著者

濵口 舜 石垣 泰輔 島田 広昭 尾﨑 平 戸田 圭一

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B1(水工学) (ISSN:2185467X)

巻号頁・発行日

vol.71, no.4, pp.I_1387-I_1392, 2015

被引用文献数

4

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Some parts of Japanese mega cities such as Tokyo, Nagoya and Osaka are below sea level and these areas are prone to floods. These three areas are in coastal zone and over 1000 people were sacrificed by storm surge in the past time. Inundation of underground spaces by pluvial and tsunami flood in the center of Osaka have been investigated in our previous works. Underground inundation by storm surge caused by super typhoon is discussed in this paper. The results show that 50 percent of total overflow discharge intrudes into underground spaces. Almost all amount of intruding discharge into underground mall fall down to the subway stations connected to the mall. The damage is different from the results caused by pluvial and tsunami floods. This means that administrators of underground space have to make different countermeasures for each disaster.

著者

伊福 誠 増本 瑛也 佐伯 光 中田 正人

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B1(水工学) (ISSN:2185467X)

巻号頁・発行日

vol.67, no.4, pp.I_1567-I_1572, 2011

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The continuous monitoring of water quality at Nomura dam is carried out with a water-quality profiling system(YSI Inc.). It is equiped near the aerator and the effect of aeration on water quality is investigated. The sampling time and depth intervals are 2 hour and 1 m, respectively. The measuring items are water temperature, pH, turbidity, DO, Chl and the number of Blue-Green Alga per unit volume. Microcystis aeruginosa migrates up and down diurnally. Namely, it can be found near the water surface early in the morning and at midday exists at about 5m depth.

著者

安元 純 広城 吉成 末益 大嗣 高岡 秀朋 神野 健二

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B1(水工学) (ISSN:2185467X)

巻号頁・発行日

vol.67, no.4, pp.I_589-I_594, 2011 (Released:2012-03-14)

参考文献数

17

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Submarine Groundwater Discharge (SGD) is now recognized as a significant role to the ecology of coastal environment as well as river discharge. This paper takes a first step for highlighting nutrient transport through SGD to volcanic rock area along the Ariake Bay. SGD rates and their qualities along the coastal area of the Ariake Bay, Ohura, Saga Prefecture, Kawachi, Kumamoto Prefecture, and Fukae, Nagasaki Prefecture regions are investigated. As a result, SGD generally decreased with the distance from the shoreline except Ohura point where large seepage rate is observed. It is presumed that SGD could be classified into two types based on the rate of SGD and the geological structure. Then, it is indicated that the SGD oxidation-reduction condition varied with seepage rate and path way. The results of this study demonstrate that SGD may be considered as a significant source of nutrient to the coastal area in Ariake Bay.

著者

豊田 政史 加藤 宏章 今井 晶子 宮原 裕一

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B1(水工学) (ISSN:2185467X)

巻号頁・発行日

vol.67, no.4, pp.I_1465-I_1470, 2011 (Released:2012-03-14)

参考文献数

21

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Numerous attempts have been conducted in order to recover emergent plants and submerged plants in various lakes. However, floating-leaved plants, which make water quality worse, have been rarely focused. The purpose of this paper is to evaluate the effect of mowing down the floating-leaved plants area partially in Lake Suwa, where floating-leaved plants-dominated state is observed in shallow zone. We measure water temperature, turbidity and water velocity inside and outside of the floating-leaved plants area. It is confirmed that 1) The variation range of water temperature inside of floating-leaved plants area is smaller than that of outside. 2) Floating-leaved plants lessen the vertical water circulation. 3) Outside of floating-leaved plants area is easier to be influenced by cold water than inside when cold water intrude into water grass area. 4) Turbidity inside of floating-leaved plants area is higher than outside. 5) The leaves of floating-leaved plants become the resistance of surface current.

著者

朝位 孝二 古賀 将太 榊原 弘之

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B1(水工学) (ISSN:2185467X)

巻号頁・発行日

vol.67, no.2, pp.30-40, 2011 (Released:2011-05-20)

参考文献数

8

被引用文献数

1 1

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近年水害経験のある流域に配布されたハザードマップの公開効果を把握と流域住民の効果的な防災意識向上の方法を探索することを目的として,山口県岩国市の錦川中流部(美川地域,錦地域)住民にアンケート調査を行った.アンケート調査はハザードマップ配布前後の2回行った.調査の結果,水害対策行動に至る心理段階として「知識」が,規定因として「愛着感」「危機感」が主要な要因であることが分かった.水害対策行動の実施確率からハザードマップの配布効果があることが示唆された.さらに,「知識」「台風14号の被災経験」「危機感」「有効感」「負担感」「ハザードマップの分かりやすさ」が防災意識向上の鍵となることが分かった.

著者

和田 卓也 山田 朋人 SUSENO Dwi Prabowo Yuga

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B1(水工学) (ISSN:2185467X)

巻号頁・発行日

vol.68, no.4, pp.I_397-I_402, 2012

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Meteorological characteristics of the formation and environment of the Niigata-Fukushima heavy rainfall on 28~30 July 2011 were studied. Line-shaped rainfall systems were observed by using synthetic radar and Xband MP radar on 29 July at 09~17 and on 30 July at 00~04. The purpose of this study is to classify these events and to reveal the reason why these occur and stagnate. It was found that the former event can be classified as Back Building type while the latter can be classified as Back Building composite type. The development environments were focused by the convergence, relative humidity, wind and temperature by using the Japan Meteorological Agency GPV mesoscale model dataset. Results indicate that convergence area, flow of high-humidity air at 950hpa and incursion of dry-low-temperature air generated the event on 29 July at 09~17. The event on 30 July at 00~04 was generated by the effect of cold air at 400hpa which flowed into high-humidity region.