著者

加藤 琢磨 手計 太一 土屋 修一 山田 正

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.277-282, 2008 (Released:2010-08-25)

参考文献数

7

被引用文献数

1

---

We carry out the microclimate field observation collaborated closely with local residents in the downtown of Tokyo in order to study the effect of watering on urban climatic environment. Local residents sprinkled recycled water which was rainfall and/or bath water in summer. Then we measured air temperature, humidity, solar radiation, aerosol number, wind velocity and wind direction all the day. We could observe atmospheric phenomena before/after watering. The following conclusions were obtained: 1) Air temperature at almost all observation stations were started to decrease immediately after watering started. Area-averaged air temperature declined by 0.5 deg. C. After Watering, it took an average time of 60 minitues to relapse to the air temperature immediately before the sprinkling. 2) Surface temperature of roadway decreased from 50 deg. C to 40 deg. C compared between before and after Watering. Assuming the surface of roadway could be black body, long-wave radiation declined from 620 W/m^2 to 510 W/m^2 compared between before and after watering. Heat environment mitigation action by watering could be divided into “fall of air temperature” and “restraint of radiation”.

著者

大槻 順朗 大八木 豊 島谷 幸宏 朴 埼〓

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.361-366, 2008 (Released:2010-08-25)

参考文献数

9

---

Urban development causes serious changes to watershed conditions by decreasing storage area, introducing pavement and channeling. As a result, the peak discharge has been increasing and the arrival time of peak becomes early. The purpose of this study is to investigate the state of retention facilities such as irrigation ponds and paddy area in Mikasa River watershed. The result of investigation shows the rate of the capacity of flood control of dam, ponds and paddy area are 37.1%, 14.6%, 48.3% and total capacity is 3, 063, 000m3.For the estimate of the storage facility effects, we applied the distributed runoff model considering ponds and paddy area effects. The result of calculation showed that the peak discharge at Sanno Bridge decreased 36m3/s by dam, 31m3/s by ponds and 36m3/s by paddy area.

著者

大八木 豊 島谷 幸宏 杉本 知佳子 加藤 憲介 朴 埼〓

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.50, pp.325-330, 2006 (Released:2010-11-30)

参考文献数

10

被引用文献数

1

---

Urban developments cause serious changes to watersheds conditions by decreasing storage area, introducing pavement and channeling. As a result, the peak discharge has been increasing and the arrival time of peak flow becomes early. The purpose of this study is to investigate the empty capacity of irrigation ponds in the Mikasa River watershed and to clarify flood control capacity of them. The result of this study, the catchments area of all irrigation ponds was about 18%, the capacity of flood control was about 450, 000m3 in the Mikasa river watershed. To estimate the flood control ability of irrigation ponds, we applied the distributed runoff model considering ponds effects about flood disaster in July 19, 2003. The result of calculation showed that the peak discharge at the Sanno Bridge decreased 36m3/s by the irrigation ponds.

著者

狩野 学 手計 太一 木内 豪 榊 茂之 山田 正

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.48, pp.193-198, 2004-02-01 (Released:2010-06-04)

参考文献数

8

被引用文献数

4 4

---

The large-scale social experiment, which many citizens including media representative participated for evaluating the effects of the watering on the “Heat Island Effect”, was carried out in Tokyo Metropolitan in Aug. 25 2003. About 14000l. water were sprinkled for about 20 minutes from noon. Air temperature and humidity were measured by moving observation system and fixed observation system at watering area in Eastern Tokyo. After the watering, the air temperature difference between outside and inside of watering area increases, and its difference was about 0.5°C. Temperature of watering area is lower than the temperature of outside area of watering after the watering. The effect of the watering was verified using the numerical simulation based on MM5. As a result of this analysis, air temperature degreased 2-2.5°C in watering area after the watering.

著者

前野 詩朗

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.51, pp.613-618, 2007 (Released:2010-08-25)

参考文献数

3

---

The rising backwater, which occurs due to the confluence of the Takahashi River and the Oda River, makes the water level rather higher during flood in the upstream of those rivers. The higher water level endangers embankments of those rivers. One of the possible means to reduce the water level is to relocate the present confluence site with the Oda River to the downstream site of the Takahashi River. This study aims to investigate the effect of the relocation of the confluence site using two-dimensional flow analysis. Numerical results under present river course condition were compared with the measured water level, and the effectiveness of the proposed analytical model was confirmed. It is also shown that the relocation of the confluence site has an effect to reduce the water levels of rivers considerably.

著者

入江 政安 西田 修三

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.51, pp.1129-1134, 2007 (Released:2010-08-25)

参考文献数

2

被引用文献数

4 1

---

A lot of rivers and channels which were cut for water traffic flow through the center of Osaka City. The Dotombori River flows along and across the city's main streets and the landmark of Osaka. However, it is polluted so that it is the target of urban renewal and some measures are carried out. The water quality of this river is controlled by two water gates because more polluted upstream water and saline seawater in which the concentration of dissolved oxygen is very low flow into the river. In the present paper field observation is conducted to clarify the characteristics of the water quality and asses the operation of the water gates in this tidal urban river. The operation is good for the maintenance of the water quality, but the oxygen-deficient seawater intrudes and spreads onto the river bottom and makes influence on the bottom sediment.

著者

和田 明 高野 泰隆 穂積 照雄

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.38, pp.331-336, 1994-02-28 (Released:2010-08-25)

参考文献数

2

被引用文献数

1

---

Tokyo Bay has been selected as a study area and the bay was divided into 215 blocks in order to analyze the exchange flow between various blocks by applying a non-linear programming method and to identify the characteristics of flows in the bay in four seasons.The analytical results obtained successfully revealed the occurrence of flow patterns which cannot be expressed by existing simulation analyses, and consequently made it possible to conduct discussion on the environmental values given to each block.Based on the results of flow analysis, particles were thrown into all boxes in the bay and the tracking of these particles was carried out, in an attempt to evaluate the size of bay-water retention time.

著者

土屋 修一 加藤 拓磨 手計 太一 山田 正

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.49, pp.367-372, 2005-02-01 (Released:2011-06-27)

参考文献数

6

---

The social experiment was carried out for the purpose of the mitigation of the heat island effect by watering on August 18th to 25th. The microclimate observation has been carried out at watering area in Eastern Tokyo. As the results, the effect of the watering on the thermal environment in urban area was evaluated as decreasing effect on temperature. The following results were obtained; 1) The temperature variation in the daytime is included to be different every site because of the dispersion of surface temperature. 2) The air temperature in the experiment area is from 2 to 9 [degree] higher than temperature in thermometer shelter by the effect of long radiation. 3) The temperature decrease instantaneously when watering starts. 4) The temperature decreases 0.66 [degree] on average, 1.93 [degree] on maximum after the watering. 5) Total amount of decreasing temperature is decreased linearly by the distance from the point of watering.

著者

竹内 邦良 切石 史子 今村 英之

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.39, pp.31-36, 1995-02-28 (Released:2010-06-04)

参考文献数

9

被引用文献数

3 3

---

The water balance analyses of the five lakes of Mt. Fuji were conducted for 1981-94. It was found that1. Lake Kawaguchi seems to leak in the order of 20 mm/d.2. Each lake has an Influence Aquifer Zone around it, which not only supplies water to the lake but often receives water from the lake when water level increased during the dry periods.3. Three lakes Sai, Shoji and Motosu seem connected under ground by porous volcanic rocks Their water levels are highly interdependent.4. Among the three lakes, Shoji and Motosu are more closely connected than Sai and Shoji.

著者

芝 定孝 平田 雄志 八木 俊策

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.43, pp.245-250, 1999-02-10 (Released:2010-08-25)

参考文献数

10

---

Cloud droplet formation is an important process in water cycle between the earth and the atmosphere. In order to investigate the nonsteady growth of cloud droplets due to the condensation of the atmopheric water vapor on (NH4) 2 SO4 particles, a mathematical model has been constructed and the nonsteady growth has been simulated numerically with use of the mathematical model. The mathematical model is constituted by the conservation laws of water mass and heat energy and the state equation of ideal gas. As the speed of time variation of droplet heat QW is very fast compared with that of droplet mass mw, droplet temperature Ta can be treated as in steady state. The equilibrium droplet size ae is dependent on the 3/2 power of the initial radius aso of cloud condensation nucleus (NH4) 2SO4. The larger as0 is, the more the droplet grows in its equilibrium size ae. It takes much time for large condensation nucleus to attain the equilibrium size ae. It also has been cleared that Kelvin's equation is not always applicable to estimate the cloud droplet siz

著者

石井 宏明 神田 学 森脇 亮 奥園 孝二

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.43, pp.233-238, 1999

被引用文献数

2

---

Field observation was performed on two islands located in Tokyo Bay to investigate the atmospheric environment over Tokyo Bay by using Radio Sonde, Dopper Sodar and airplane in summer 1998.<BR>The following results were obtained; 1) The atmospheric boundary layer (ABL) over Tokyo Bay was composed of multiple layers.Especially, it was composed of three layers on August 10. 2) These multiple layers were formed by the effect of various kinds of return flows from the land. The upper boundary layer about 1250-2000m over Tokyo Bay was hotter and drier than the one over the land. 3) The airplane observation suggests that the air pollutant might be more concentrated over Tokyo Bay rather than over the land due to the difference of the boundary layer structure.

著者

松本 大毅 広城 吉成 堤 敦 神野 健二 新井田 浩

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.49, pp.127-132, 2005-02-01 (Released:2011-06-27)

参考文献数

11

---

Sayanokami spring water exists in the new campus of Kyushu University, which is located on the western part of Fukuoka City. This spring water is one of the important water resources for agriculture around the new campus area. The construction of the new campus started last June, 2000. In this study, to understand the hydrological properties of the Sayanokami circumference, 222Rn and tritium were used as tracers, respectively. Consequently, it was found out that the residence time of Sayanokami spring water is 10-20 years. Moreover, the residence time and the catchment area of Sayanokami spring water were estimated using groundwater flow model. As a result, the residence time of Sayanokami spring water was evaluated to be about 25 years at most and the catchment area was specified. It is concluded that the accuracy of estimation of residence time and catchment area of the spring water can be improved by analysis of radioactive isotopes and groundwater flow model.

著者

松永 信博 増田 壮佑 中牟田 大嗣 徳永 貴久 矢野 真一郎 押川 英夫 橋本 彰博 藤田 和夫 古賀 雅之 岩下 智明 原田 敦彦

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.51, pp.1415-1420, 2007 (Released:2010-08-25)

参考文献数

11

---

Laboratory experiments were carried out on water quality purification by a porous concrete block including Bacillus subtilis natto group. The block is called EcoBio-Block (EBB). The time variations of biochemical oxygen demand (BOD) and chemical oxygen demand (COD) were obtained experimentally under the aerated condition by changing the weight ratio of EBB to water. The time variations of BOD and COD were expressed universally by normalizing the data. The reduction rate of BOD increases with the weight ratio. On the other hand, that of COD takes the maximum value at the weight ratio of 0.01 and decreases after that. The rapid reduction of BOD and COD seen in the early stage may be due to the adhesion or adsorption of organic matter by EBB. The mineralization of organic matter and the nitrification of NH4-N by EBB become active at the later stage and the activity increases with the weight ratio. It was experimentally revealed that EBB has also the very high ability for the water quality purification in the DO-saturated water and it depends strongly on the weight ratio of EBB to water.

著者

谷口 健司 小池 俊雄

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.50, pp.391-396, 2006 (Released:2010-11-30)

参考文献数

9

---

A cyclone over the Arabian Sea has lots of effect on people's life in India and it sometimes bring Indian summer monsoon. In the present study, cyclogenesis and its development over the Arabian Sea are investigated by using satellite observation data and atmospheric reanalysis data. There is large temperature gradient around the coastal area of the Arabian Peninsula between warmer air over land and cooler air over ocean. Baroclinic instability by the horizontal temperature gradient in that region easily generates a seed of cyclone at 850hPa. Regarding development of cyclone over the Arabian Sea, water vapor over the region of a seed of cyclone does not show significant difference between development and non-development case. On the other hand, occurrence of air disturbance in middle-upper troposphere and coupling of upper and lower air disturbances are considered to be more important for the development of cyclone over the Arabian Sea.

著者

馬籠 純 竹内 邦良 金丸 茂男 石平 博

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.46, pp.295-300, 2002-02-10 (Released:2010-06-04)

参考文献数

10

---

The purpose of this study is to understand the potential impact of reservoir induced water storage on the basin scale water cycle. In this study, the increase of the basin scale residence time of river water is used as the index of the effect of reservoir on water cycle, and its spatial and temporal distribution in Japan are demonstrated. The results of analysis show that the potential increase of residence time by dam reservoirs in Japan has gradually increased from 1960's and reached to 14.5 days in 1995. The actual residence time increase is also estimated in the Tone river basin where operation and seasonal variation of river discharge are taken into account. It is shown that the estimated actual residence time is much smaller than the potential, in the case of the Tone river basin, 45%.

著者

浪平 篤 後藤 眞宏 小林 宏康

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.1189-1194, 2008 (Released:2010-08-25)

参考文献数

14

被引用文献数

1 1

---

There is the case to have to make the slope of the fishway steeper than the standard range, according to the geographical features condition. In this research, measurement of flow structure and observation of swimming behavior of Leuciscus hakonensis at the hydraulic model of the pool and weir type fishway with slope 1/5 were conducted. Main results are shown as follows; 1) Ascending rate of this species in TYPE C which has short pools in flowing direction is higher than in TYPE B which has big steps between each pools when the overflow depth equals 5-10 cm, ascending rate of this species over 9-10 cm in TYPE B is higher than in TYPE C when the overflow depth equals 15-20 cm. 2) The difference of flow structure doesn't necessarily greatly influence ascending rate of this species. 3) About this species, it is necessary to select TYPE B or C corresponding to the assumed range of the overflow depth.

著者

中津川 誠 山田 正

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.37, pp.1-8, 1993-02-20 (Released:2010-06-04)

参考文献数

12

被引用文献数

1

---

The present study deals with the investigation of wind velocity observed by the Doppler radar. The first phase of paper is the observation of wind using the Doppler radar. Observations have been carried out by using the Doppler radar which is installed in the suburb of Sapporo, Hokkaido, Japan. Horizontal and vertical wind components are estimated by applying the VAD (Velocity Azimuth Display) method to the Doppler data. We make sure that the VAD method can precisely estimate the wind components. The second phase is the utilization of wind data for investigation of rainfall field. The geostrophic wind observed by the Doppler radar is incorporated into the Kao model so that three dimensional wind components are estimated in the planetary boundary layer. The rainfall field is simulated by applying such wind distribution to the Kessler parameterization. The above methodorogy offers considerable promise for the progress of physics-based rainfall models and forecast methods.

著者

河合 真由美 土屋 十圀

出版者

公益社団法人 土木学会

雑誌

水工学論文集 (ISSN:09167374)

巻号頁・発行日

no.51, pp.1331-1336, 2007

---

It is an important subject tomanage sedimentation of dams appropriately so that the continuity of rivers maybe maintained and the influence of the ecosystem on the downstream site may be made to reduce in lateyears. And it is necessary to examine measures of turbid water. In this study, changes of a pollutant load which sediment affects are cleared quantitatively on Siromaru Dam. Relation between turbidity and the diversity of benthic animals are clarified using a stochastic method. <BR>The correlating equation of between turbidityand SS was obtained reliably bycalculation of a pollutant load. And an annual discharge-duration curve on the turbidity has been created. A significant relation is accepted, that is between the non-exceeding probability of 355-day turbidity and the Simpson index using stochastic methods of turbidity and benthic animals. This relation is suiting a convex quadratic curve and having the maximum of diversity. Therefore, it became clear that the suitable non-exceeding probability, namely, moderate disturbance frequency exists.

著者

馬籠 純 竹内 邦良 金丸 茂男 石平 博

出版者

公益社団法人 土木学会

雑誌

水工学論文集 (ISSN:09167374)

巻号頁・発行日

no.46, pp.295-300, 2002

---

The purpose of this study is to understand the potential impact of reservoir induced water storage on the basin scale water cycle. In this study, the increase of the basin scale residence time of river water is used as the index of the effect of reservoir on water cycle, and its spatial and temporal distribution in Japan are demonstrated. The results of analysis show that the potential increase of residence time by dam reservoirs in Japan has gradually increased from 1960's and reached to 14.5 days in 1995. The actual residence time increase is also estimated in the Tone river basin where operation and seasonal variation of river discharge are taken into account. It is shown that the estimated actual residence time is much smaller than the potential, in the case of the Tone river basin, 45%.

著者

重枝 未玲 寺町 賢一 碇 正敬 高崎 秀一 松木 洋忠 秋山 壽一郎 中山 比佐雄 田邉 武司

出版者

公益社団法人 土木学会

雑誌

水工学論文集 (ISSN:09167374)

巻号頁・発行日

no.52, pp.829-834, 2008

被引用文献数

1

---

An analysis of behavior of over-land flows based on geophysical characteristics using geographic information system (GIS) was conducted. Firstly, the digital surface model (DSM), which is the data of the surface of ground, was verified against the data of bed elevation in the map of the city planning whose scale is 1/2500. Secondary, using digital surface model, a behavior of over-land flow was analyzed. Finally, the analyzed behavior of over-land flow was compared with the flood process examined in the field study and numerical simulation. It shows that the GIS and DSM are useful tool and data for examining the behavior of the inundation flows.