著者

Masaharu FUJITA Yoshifumi SATOFUKA Shinji EGASHIRA

出版者

Japan Society of Civil Engineers

雑誌

PROCEEDINGS OF HYDRAULIC ENGINEERING (ISSN:09167374)

巻号頁・発行日

vol.50, pp.1003-1008, 2006 (Released:2010-08-25)

参考文献数

2

---

So far huge sediment production due to the eruption of Mt.Kelud has given serious damage to the Brantas river basin. On the other hand the eruption has provided soil and sand for agricultural land and construction material. So, as a first step to establishing an advanced control system both of the sediment runoff and the sediment utilization, we have investigated the change of sediment transport properties after the eruption in 1990. The field survey result shows that the sever sediment deposition occurred immediately after the eruption, but 1 year after the eruption the bed aggradation changed into the bed degradation because of active sand mining. Also we obtained the sediment supply condition at the confluences with the tributaries after the eruption and presented a way to estimate the condition. Furthermore the field observation result on wash load indicates the wash load transport rate decreased rapidly after the eruption.

著者

後藤 仁志 林 稔 安藤 怜 酒井 哲郎

出版者

Japan Society of Civil Engineers

雑誌

水工学論文集 (ISSN:09167374)

巻号頁・発行日

vol.47, pp.547-552, 2003-02-10 (Released:2010-06-04)

参考文献数

11

被引用文献数

1 5

---

The Lagrangian model of solid-liquid two phase flow is proposed by combining the Moving Particle Semi-implicit (=MPS) method with the Distinct Element Method (=DEM). The governing equations of two fluid model is discretized by the MPS method, with the model of interparticle collision in solid phase based on the DEM. The relationships of present model with the previous Lagrangian model of a motion of single sediment particle and the non-Newtonian fluid model are discussed. The performance of the present model is investigated by simulating the dropping lump of mud into still water. By comparing the solutions of three models, such as the present model; the two fluid model by the MPS method without the DEM; and the MPS method with the passively moving solids module, the effect of cohesion of mud is reproduced well by the present model.

著者

天羽 誠二 中野 晋 木村 剛士 津川 茂

出版者

Japan Society of Civil Engineers

雑誌

水工学論文集 (ISSN:09167374)

巻号頁・発行日

vol.52, pp.1393-1398, 2008

---

We investigated the real-time forecast system of a storm surge to reduce its disaster. Typhoon properties such as central atmospheric pressure were forecasted before several hours by two methods. The one is forecasting by using neural network technique based on the past typhoon data and the other is utilization of typhoon forecast information by the Meteorological Agency. As a result of the comparison of both methods, it was found that the latter gave more correct forecast of typhoon properties. Based on the forecasting values of typhoon, we carried out the real-time forecasting of a storm surge and examined the practical utility of this system.

著者

渡辺 亮一 山崎 惟義 島谷 幸宏 河口 洋一 兼重 俊介 神尾 章記

出版者

Japan Society of Civil Engineers

雑誌

水工学論文集 (ISSN:09167374)

巻号頁・発行日

vol.52, pp.1153-1158, 2008 (Released:2010-08-25)

参考文献数

6

---

SAKUTA ditch is the oldest irrigation channel in Japan. The first description is described in the Japanese Chronicle of Japan that is the Japanese oldest history book. SAKUTA ditch is located in FUKUOKA Prefecture. In other words it is the very precious irrigation channel which continues being used for more than 1500 years. According to the field observation results performed in SAKUTA ditch, it becomes clear that 24 species of fishes are existed. In recent years, however, there have been increasing demands from local residents for the creation of the convenient irrigation channel.The objective of this study is to evaluate the fish habitat and to discuss the relationship between vegetation covered ration and physical environmental condition in SAKUTA ditch. The study results indicate that the density of fishes in channel is related to the vegetation covered ratio and the velocity distribution in the ditch. These results suggested that the water's edge structure and the vegetation covered ratio in channel are greatly influenced to fish habitat evaluation.

著者

野々村 敦子 森本 茂昭 河原 能久 野間 京二

出版者

土木学会

雑誌

水工学論文集 (ISSN:09167374)

巻号頁・発行日

vol.49, pp.1147-1152, 2005-02

被引用文献数

3

---

Oxygen levels in eutrophic water bodies can become rapidly depleted at the presence of stable thermal stratification. The anoxic condition induces the release of nutrients and heavy metals from bottom sediments, leading to water quality problems. In Goten reservoir, we installed two sets of jet flow generator. One jet flow generator transports the water near free surface and eject it near the bottom while the other discharges pumped groundwater near the bottom. Field measurement has been carried out to understand the destratification process by the induced flow and the resultant changes in water quality. It is demonstrated that the jet flow generators accelerate the destratification process considerably and that the spatial distribution of water quality in a horizontal plane shows little difference during the process. It is also found that further improvement with the jet flow generators is necessary to increase more effectively the dissolved oxygen concentration near the bottom.