result 154 件
| Author | Noguchi, Osamu| Oshima, Mitsuko| Motomizu, Shoji| |
|---|---|
| Published Date | 2008-05-10 |
| Publication Title | Analytical Sciences |
| Volume | volume24 |
| Issue | issue5 |
| Content Type | Journal Article |
| JaLCDOI | 10.18926/fest/11574 |
|---|---|
| FullText URL | 003_127_134.pdf |
| Author | Shimada, Kiyoshi| |
| Abstract | This paper discusses the shear strength and volume change characteristics of a loose Fraser River sand. Suction-controlled simple shear tests were carried out for the unsaturated sand. Drained tests for the saturated sand were also carried out for the comparison with the unsaturated sand. The increase of the shear strength of the sand with the matric suction is very small and there is almost no increase of that over 20 kPa of the matric suction. The suppression effect of the matric suction on the volume change bahavior during shear is small, and the degree of dilation increases with the increase of the matric suction. |
| Keywords | unsaturated sand shear strength simple shear test matric suction volume change dilatancy |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1998-01-14 |
| Volume | volume3 |
| Issue | issue1 |
| Start Page | 127 |
| End Page | 134 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313902 |
| JaLCDOI | 10.18926/fest/11560 |
|---|---|
| FullText URL | 003_031_036.pdf |
| Author | Sasaki, Toru| Kajiwara, Tsuyoshi| Ishikawa, Hirofumi| |
| Abstract | We have computed the phase of spreading contaminations in Kojima Lake by using the upwind-type finite element method. We have treated the two cases: the pollutant flows from the Sasagase river and from the Kurashiki River. We see that the upwind-type finite element method is effective in both cases, when the diffusion constant is quite small. |
| Keywords | Upwind-type Finite element method Kojima Lake |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1998-01-14 |
| Volume | volume3 |
| Issue | issue1 |
| Start Page | 31 |
| End Page | 36 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313715 |
| JaLCDOI | 10.18926/fest/11502 |
|---|---|
| FullText URL | 010_083_088.pdf |
| Author | Kankam-Yeboah Kwabena| Darko Philip K.| Nishigaki, Makoto| |
| Abstract | Groundwater has been recognised as the most cost-effective option of safe water supply to rural communities in Ghana. The demand for potable water has led to the drilling of a large number of boreholes in many parts of the country. To establish the threshold of groundwater development from storage in a major river catchment (Pra River) in South-West Ghana, studies on recharge to the weathered aquifer and statistical evaluations of specific capacity and potential yield have been carried out. The SACSMA conceptual hydrological modelling system was used for the recharge estimate. With recharge rate of 50 mm/yr, the natural groundwater resources in the basin was estimated to support a maximum withdrawal of 12 l/s for a 10 hour per day pumping. The groundwater resources potential of 1.6 l/sｋ㎡ could be considered the threshold of groundwater exploitation in similar river basins in South-West Ghana. A study into the relation between permeability and recharge under different conditions and scenarios is required to define their limiting role in groundwater resources development. |
| Keywords | Groundwater storage recharge aquifer specific capacity base flow hydrologic budget |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2005-02-28 |
| Volume | volume10 |
| Issue | issue1 |
| Start Page | 83 |
| End Page | 88 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313829 |
| JaLCDOI | 10.18926/fest/11501 |
|---|---|
| FullText URL | 010_075_081.pdf |
| Author | Kankam-Yeboah Kwabena| Asare Enoch B.| Gyau-Boakye, Philip| Nishigaki, Makoto| |
| Abstract | The rapid impact assessment (RIAM), which was developed in Denmark, is a new tool for the execution of environmental impact assessments. RIAM is quite flexible, transparent and leaves a permanent record, which can be independently checked, validated or updated. RIAM has successfully been used to prioritize water resources management problems in Ghana in the order of which problems call for the most urgent attention. The priority list was easily validated and accepted to be the true reflection of the situation at a national workshop in which experts and representatives from water agencies, donor agencies, university faculties and departments, research institutes, private institutions and organizations including Non Governmental Organizations (NGOs) participated. The study has shown that RIAM, which can also be used in a developing country like Ghana, is a very useful tool in such prioritization process as has been applied in this exercise. |
| Keywords | Water resources management problems prioritization impact indicators RIAM river basins Ghana |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2005-02-28 |
| Volume | volume10 |
| Issue | issue1 |
| Start Page | 75 |
| End Page | 81 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313917 |
| JaLCDOI | 10.18926/fest/11496 |
|---|---|
| FullText URL | 010_057_065.pdf |
| Author | Dewan Ashraf M.| Alam Md. Mahabubul| Nishigaki, Makoto| |
| Abstract | This paper is an attempt to develop a series of maps that precisely depict flood prone areas in Greater Dhaka, Bangladesh using remote sensing techniques. Multi-temporal RADARSAT SAR data were acquired and employed to delineate open water flood boundary during the floods of 1998 and 2000. Using a threshold algorithm, SAR data is segregated into water and non-water areas. The empirical threshold value was obtained by using visual interpretation technique, local knowledge of the study site and by deriving corresponding pixel values to land/water from each image. The result demonstrated that 53 percent of the study area was heavily inundated in 1998 flood which is the largest submerged area during a catastrophic scenario. In contrast, 35.32 percent area was flooded during the year 2000 which represents the area under water for a normal event. Using the reference data acquired from field visit, derived flood maps were further validated. Moderate accuracy is obtained for all flood maps, however, July 1998 image attained the highest overall accuracy (86%) in the dataset. The derived flood maps are expected to be useful to mitigate losses of lives and property from river water flooding in Greater Dhaka. Furthermore, this information would be worthwhile to develop an efficient flood disaster management system. |
| Keywords | SAR open water flood 1998 and 2000 floods Greater Dhaka RADARSAT |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2005-02-28 |
| Volume | volume10 |
| Issue | issue1 |
| Start Page | 57 |
| End Page | 65 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313953 |
| JaLCDOI | 10.18926/fest/11484 |
|---|---|
| FullText URL | 010_023_028.pdf |
| Author | Watanabe, Masaji| Liu Ying| Wang Ming Jun| |
| Abstract | Topographical data of Kojima Lake have been updated by applying data obtained after dredging. Together with tide level of Kojima Bay and water levels of Kurashiki River and Sasagase river, the information was incorporated in computational analysis of unsteady flows generated in the lake when the water was discharged from Kojima Lake to Kojima, Bay. A finite element method was applied to equations governing unsteady flows, and the transition of discharge was obtained. |
| Keywords | water environment finite element method numerical simulation |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2005-02-28 |
| Volume | volume10 |
| Issue | issue1 |
| Start Page | 23 |
| End Page | 28 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313649 |
| JaLCDOI | 10.18926/fest/11467 |
|---|---|
| Title Alternative | Rows-of-houses Preservation in Maniwa City of Katsuyama Area, Okayama Prefecture |
| FullText URL | 012_141_149.pdf |
| Author | Luo, Yanjuan| Ichiminami, Fumikazu| |
| Abstract | The aim of the study is to explain the present condition of the rows-of-houses preservation policy of Okayama Prefecture and to examine the samples in Maniwa city, Katsuyama area. Besides, the interview investigation was mainly conducted for residents in the rows-of-houses of preservation area in Katsuyama for giving the concluding remarks about the findings. The traditional private houses in Katsuyama preservation area were partially restored in the 1985-89 and 1993-97 fiscal years by the subsidy from the prefecture. Furthermore, Katsuyamacho at that time founded the subsidy system for maintaining rows-of-houses preservation area (about 25.3 ha) independently in 1993, restored 9 private houses, and made and updated the shop curtains; "Noren". In the point of the observable items, the ground warehouse of structures with gable tile-roofing is visible and it is also in use. Moreover, a latticed window structure, a white wall, and a sea cucumber wall constitute the charm of new rows-of-houses. A stone pavement follows on the riverside at the site facing the Asahi River. There are the remains of an arrival-and-departure place of a flat boat and a brewery, etc. According to our investigation in 2002, the residents were satisfied with "It is easy to live quietly", "the beauty of a natural landscape", "harmony of rows-of-houses and a shop curtain", and "a historical atmosphere", but the recognition of "the creation of active rows-of-houses" was unexpectedly low. Therefore, cooperation between residents and informational sharing are much more required. Consequently, since both the visitors and the residents are satisfied very much with each facilities, such as the whole rows-of-houses, a samurai residence, a brewery, and a restaurant etc., town planning is well organized and attained the priority targets. |
| Keywords | Rows-of-houses Preservation Katsuyama area Visitors Residents |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2007-03-15 |
| Volume | volume12 |
| Issue | issue1 |
| Start Page | 141 |
| End Page | 149 |
| ISSN | 1341-9099 |
| language | Japanese |
| File Version | publisher |
| NAID | 120002313778 |
| JaLCDOI | 10.18926/fest/11466 |
|---|---|
| FullText URL | 009_099_110.pdf |
| Author | Dewan A.M.| Nishigaki, Makoto| Komatsu, Mitsuru| |
| Abstract | Dhaka city, the capital of Bangladesh and home for more than 10 million people, has been affected by seasonal flooding almost in every year, however, the situation aggravates depending on rainfall and surrounding river waters. The aim of this paper is to delineate the flood extent in Dhaka city using digital elevation model (DEM), an integral part of geographic information system. Catastrophic floods of the 1988 and 1998 events are taken into consideration. Hydro-meteorological assessment of these events revealed that the 1988 flood was severe due to the lack of flood protection in the city together with transboundary flow of the major rivers while the 1998 flood was become deluge due to incessant monsoonal downpour along with early peaked of the river water levels. The 1998 event has done colossal damage in the city compare to the 1988 event. Flood extent estimation showed that DEM data is very precious to model inundation in the city, however, in order to be spatially explicit flood model, high resolution DEM is necessary. Finally, flood management issues are reviewed and found that combination of structural and nonstructural measures are necessary to help reducing flood induced losses and damage in the city. |
| Keywords | Dhaka City Floods Digital Elevation Model 1998 and 1988 Floods |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2004-02-27 |
| Volume | volume9 |
| Issue | issue1 |
| Start Page | 99 |
| End Page | 110 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313678 |
| JaLCDOI | 10.18926/fest/11464 |
|---|---|
| FullText URL | 009_087_098.pdf |
| Author | Kankam-Yeboah Kwabena| Gyau-Boakye Philip| Nishigaki, Makoto| Komatsu, Mitsuru| |
| Abstract | Three principal river basins are found in Ghana and the Volta River Basin is the major one, covering about three -quarters of Ghana. The basin is shared with Mali, Burkina Faso, Cote d'Ivoire, Togo and Benin. Water from the Volta River Basin is used for drinking water supply, generating hydro-electric power, irrigation, inland fisheries and lake transport. The sustainable management of the Volta River Basin is thus of great importance. Land use activities in the basin are thus closely monitored not only in Ghana, but also in the other riparian countries as well. This paper presents information and data on the water resources and environmental management of the Volta River Basin in Ghana. |
| Keywords | water resources environmental management Volta River Basin Ghana water utilization |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2004-02-27 |
| Volume | volume9 |
| Issue | issue1 |
| Start Page | 87 |
| End Page | 98 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313917 |
| JaLCDOI | 10.18926/fest/11439 |
|---|---|
| FullText URL | 012_071_076.pdf |
| Author | Chen W.| Yoshida R.| Kawara, Osami| |
| Abstract | The Asahi River Dam reservoir is one of the important fresh water resources in Okayama, Japan, and its eutrophication has been noted since the 1980s. Therefore, aeration has been applied to control the growth of phytoplankton. In this study, we discussed the effect of aeration and water-intake depth on the water quality distribution in the reservoir, based on numerical simulation and observation. The principal conclusions were as follows:(1) The numerical simulation models applied here reproduced observations fairly well. (2) Water intake from the surfacce layer reduced the concentration of chlorophyll a in the surface layers. Water intake from the middle or bottom layer improved the deficit of dissolved oxygen in the bottom layers. (3) Aeration together with water intake from the middle or bottom layer improved the deficit of dissolved oxygen in the bottom layers. |
| Keywords | the Asahi River Dam Reservoir numerical simulation eutrophication water intake depth dissolved oxygen chlorophylla |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2007-03-15 |
| Volume | volume12 |
| Issue | issue1 |
| Start Page | 71 |
| End Page | 76 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002314056 |
| JaLCDOI | 10.18926/fest/11431 |
|---|---|
| FullText URL | 011_051_055.pdf |
| Author | Nishigaki, Makoto| Komatsu, Mitsuru| Akudago John Apambilla| Shinshi Yoshihide| Kawakami Kenji| Kumamaru Koji| |
| Abstract | A laboratory validation of a proposed new method of determining the in-situ effective porosity of unsaturated soils was carried out on unsaturated river sand. The proposed method consists of boring a small diameter hole into the soil and inserting an Amplitude Domain Reflectometry (ADR) probe at the bottom part of the hole. Water is supplied into the hole till saturation and later de-saturated. The water content with time is determined from the ADR probe voltage potential readings. The effective porosity is determined from the difference between the saturated and de-saturated water contents. However, in the laboratory, the water is supplied through the top and bottom parts of the sample. From the experiments the obtained effective porosity ranged from 0.28 to 0.29 for wetting from the top with an average of 0.287 and 0.29 to 0.30 for wetting from the bottom with an average of 0.293. The determined effective porosity ranged from 71.7-73.3% of the real initial porosity of 0.40 of the river sand. The maximum attained degree of saturation during the experiment was 91%. The results indicated that the method will be suitable and useful in determining the effective porosity of medium grained unsaturated soils. |
| Keywords | Underground dam Effective porosity Storage capacity Freshwater development |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 2006-03-15 |
| Volume | volume11 |
| Issue | issue1 |
| Start Page | 51 |
| End Page | 55 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313335 |
| Title Alternative | メダカハネカクシの尾部分分泌物 |
|---|---|
| FullText URL | 004_001_025_031.pdf |
| Author | Kanehisa, Katsuo| Tsumuki, Hisaaki| |
| Abstract | Rove beetles have a pair of pygidial excretory organs, each group secretes characteristic substances in a peculiar manner. The genus Stenus has a pair of pygidial organs, eversible by immersion in diethyl-ether at both sides of the anus. S. anthoracinus, S. melanarius vercecundus and S. rufescens were collected at ponds and river shores, and S. alienus was collected at tobacco and vegetable fields. Excretory substances were secreted in the diethylether, and identified by gas chromatography and mass spectrometry. Stenusin [N-Ethyl-3-(2-methylbutyl) piperidine], 1,8-cineole, isopiperitenol and 6-Me-5-hepten-2-one were identified. These may probably act as defensive substances against small attacking animals and microorganisms, and act as water suface moving active agents. |
| Keywords | Rove beetles Stenus Excretory secretion Pygidial organ Defensive secretion |
| Publication Title | 岡山大学資源生物科学研究所報告 |
| Published Date | 1996 |
| Volume | volume4 |
| Issue | issue1 |
| Start Page | 25 |
| End Page | 31 |
| ISSN | 0916-930X |
| language | English |
| File Version | publisher |
| Author | Watanabe, Tadashi| Okada, Junji| |
|---|---|
| Published Date | 1972 |
| Publication Title | 岡山大学農学部学術報告 |
| Volume | volume39 |
| Issue | issue1 |
| Content Type | Departmental Bulletin Paper |
