著者

林 誠二 村上 正吾 徐 開欽 渡辺 正孝

出版者

Japan Society of Civil Engineers

雑誌

地球環境シンポジウム講演論文集 (ISSN:18848419)

巻号頁・発行日

vol.12, pp.79-86, 2004-08-02 (Released:2011-06-27)

参考文献数

9

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To evaluate the protection effect of the Three Gorges Dam Project (TGP) on the flood in the middle region of the Changjiang River basin, we applied the integrated watershed hydrological model using gauged daily precipitation data of 1998 when the second largest flood occurred in the basin in the last century. From the results simulated by applying the discharge volume controlled by each upper limitation value from 40, 000 m3/s to 60, 000 m3/s, we could not find the clear effect on the reduction of the water level during flood period not only in the Dongting Lake but also in the Changjiang mainstream in the cases that the upper limitation discharge value were over 50, 000 m3/s. In the case that the upper limitation value was 40, 000m3/s, although the flood protection effect was clearly exerted in both the mainstream and the lake, the simulated storage volume of TGP remarkably exceeded the total flood control volume (221.5×108 m3) at the peak of inflow to TGP. These results suggested that TGP flood control ability does not efficiently work for the decrease of flood damage in the middle region of the Changjiang basin in case of the occurrence of 1998 type flood phenomena.

著者

山口 晴幸 横山 芳春

出版者

Japan Society of Civil Engineers

雑誌

地球環境シンポジウム講演論文集 (ISSN:18848419)

巻号頁・発行日

vol.6, pp.269-278, 1998-07-09 (Released:2011-06-27)

参考文献数

5

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In this report, the present authors discussed on the coastal pollution by foreign drifted garbages. The field investigations were carried out at the points of 224 in Japanese seashore-lines. The type and classification of foreign drifted garbages were investigated. It was points out from the results of field investigations that the coastal pollution by foreign drifted garbages was very important environmental problem in Japan.

著者

山口 晴幸 タンヤウィット ポンポー

出版者

Japan Society of Civil Engineers

雑誌

地球環境シンポジウム講演論文集 (ISSN:18848419)

巻号頁・発行日

vol.8, pp.111-120, 2000-07-06 (Released:2011-06-27)

参考文献数

4

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In this report, the authors discussed on the actual situation of coastal pollution by the drifted garbage in the Japan Island. The investigations of coastal environment were performed at a large number of seashores in the Sakishima Is.(Okinawa), Honshu and Hokkaido districts. The number of garbage drifted in seashore was counted and it was also divided according to its type and nationality. It was pointed out from the results of investigations that the problem of coastal pollution by the drifted garbage was a serious problem of environment in Japan. It is strongly required that both the prevention measure and the way of disposition of the drifted garbage must be established in a hurry.

著者

タンヤウイット ポンポー 山口 晴幸

出版者

Japan Society of Civil Engineers

雑誌

地球環境シンポジウム講演論文集 (ISSN:18848419)

巻号頁・発行日

vol.9, pp.263-272, 2001-07-18 (Released:2011-06-27)

参考文献数

5

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The investigations of coastal environment were performed from February 1997 to December 2000 at 620 places of Japan island seashores. The number of garbage drifted in seashores was counted and it was also divided according to its type and nationality. It is confirmed that large number of garbage have drifted from Japan and neighborhood countries such as China, Taiwan, Korea and Russia. In this study, the actual condition of coastal pollution by the drifted garbage is mainly described by the investigation in 2000. The ocean currents seem to be controlled the drifting direction of garbage. In Japan Sea, the high possibility that the most of garbage is drifted along Kuroshio and Tsushima Ocean current is pointed out. The investigation result of the remote islands in Japan Sea, Okinawa islands and Thailand seashores are arranged and compared.

著者

林 誠二 村上 正吾 徐 開欽

出版者

Japan Society of Civil Engineers

雑誌

地球環境シンポジウム講演論文集 (ISSN:18848419)

巻号頁・発行日

vol.15, pp.135-141, 2007-08-02 (Released:2011-06-27)

参考文献数

16

被引用文献数

1

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To evaluate the flood protection effect of the conversion of polders to retarding basin around the Dongting Lake in the middle region of the Changjiang River, China, we applied the integrated watershed hydrological model using gauged daily precipitation data of 1998 when the second largest flood occurred in the basin in the last century. While the estimated storage capacity of the Dongting Lake increased 11.5×109 m3 by the conversion of polders in comparison with the estimated capacity at the flood period in 1998 at the average water level of 35.0 m, the simulated daily average water levels of the lake showed that the protection of the flood was impossible by only increasing capacity in the confluence between the Changjiang mainstream and the Dongting Lake in case of 1998 flood. The model also simulated that the flood protection was fully achieved at the confluence by making the volume diverging from the Changjiang mainstream to the Dongting lake increase with the diverging ratio at 1950s under the appropriate discharge control by the Three Gorges Dam. These results suggest that “return land to lake” policy around the Dongting Lake probably brings the best flood protection effect when the increased capacity of the lake uses for the control of the water level in the Jinjiang section of the Changjiang mainstream.

著者

筒井 純一

出版者

公益社団法人 土木学会

雑誌

地球環境シンポジウム講演論文集

巻号頁・発行日

vol.8, pp.181-186, 2000

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To investigate the impacts of anthropogenic global warming on tropical cyclone (TC) activity, climate simulations were conducted under the present and CO<SUB>2</SUB>-warmed conditions using the National Center for Atmospheric Research Community Climate Model version 2. The CO<SUB>2</SUB>-warmed condition includes doubled atmospheric CO<SUB>2</SUB> concentration and about 1&deg;C of tropical sea surface temperature (SST) warming. Simulated TCs were objectively selected from twice daily instantaneous outputs during an eight-year time integration period of each simulation, and the changes associated with global warming were examined in terms of frequency of occurrence and mean intensity.<BR>The frequency of global TC occurrence remains unchanged in response to the CO<SUB>2</SUB>-induced warming. This fairly constant global TC frequency is in agreement with the almost neutral tendency in the zonally-averaged moist instability in the tropics. On the other hand, regional TC frequencies indicate relatively large tendencies depending on TC basins, including increased tendency in the western North Pacific and decreased tendency in the Western Hemisphere. These regional variations are connected with large-scale circulation and similar to the natural variability of observed TCs. Simulated changes in the mean TC intensity highlight increased tendencies over the warm SST regions in the western Pacific, which contribute to the significantly increased mean intensity of global TCs.

著者

宇野 宏司 柿谷 茂貴 辻本 剛三 柿木 哲哉 出口 一郎 有田 守

出版者

公益社団法人 土木学会

雑誌

地球環境シンポジウム講演論文集

巻号頁・発行日

vol.16, pp.35-40, 2008

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淡路島南西部に位置する吹上浜を対象に, 過去36年間の航空写真を用いて, 砂浜面積および護岸から汀線までの距離の経年変化を把握した. また, 飛砂・漂砂を考える上で重要となる吹上浜周辺の風特性について把握するため, 気象庁の風向風速データを整理し, それを用いた日飛砂量の推算を行った. その結果, 吹上浜においては過去36年間にわたり, 砂浜面積, 護岸からの汀線距離ともに動的に安定した砂浜であると判断された. また, 現地の平均風速は概ね3m/s程度であり, この程度の風では粒径0.1mm程度の飛砂しか起こりえない. 一方, 台風接近や冬季風浪により10m/s以上の風が出現することもわかった. さらに, 月別平均風速および出現風向特性を考慮した飛砂量計算では, 春季から夏季にかけて南から北方向, 冬季は西から東方向への飛砂が卓越することが明らかにされた.

著者

山口 晴幸 横山 芳春

出版者

Japan Society of Civil Engineers

雑誌

地球環境シンポジウム講演論文集 (ISSN:18848419)

巻号頁・発行日

vol.6, pp.269-278, 1998

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In this report, the present authors discussed on the coastal pollution by foreign drifted garbages. The field investigations were carried out at the points of 224 in Japanese seashore-lines. The type and classification of foreign drifted garbages were investigated. It was points out from the results of field investigations that the coastal pollution by foreign drifted garbages was very important environmental problem in Japan.

著者

奈良 松範

出版者

Japan Society of Civil Engineers

雑誌

地球環境シンポジウム講演論文集 (ISSN:18848419)

巻号頁・発行日

vol.14, pp.177-180, 2006

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According to the report of the United Nations (1998), one child has died at a time at 8 seconds owing to water-related illness, 80% of sick cause in a developing country is sewage, and there is no sewer institution in 50% of world population. 2, 500 million people who cannot drink safe sterilized water exist in the world. The way things stand, a situation is getting worse steadily. In this research, experimental examination was performed about the method for manufacturing water simple and cheap, and safe in view of a water shortage in a developmental-stage area, and the point that safe water is not supplied especially. Consequently, the thin laminar flow multi-stage processing process of having used the photocatalyst was developed as the suitable water purification method for a developing country. According to this method, the coliform bacteria count was removed by the conditions of 1cm in thickness of thin laminar flow, and 7cm of distance with a light source 100% in 5 hours after a processing start for holding time 3 hours. In order to evaluate water quality purification performance, the COD reduction which is a water pollution index, and the coliform bacteria count which are the health of water and the index of safety were examined.

著者

奈良 松範

出版者

Japan Society of Civil Engineers

雑誌

地球環境シンポジウム講演論文集 (ISSN:18848419)

巻号頁・発行日

vol.15, pp.101-106, 2007

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In this research, the water purification system using a photocatalyst was proposed and examination experimental about the effect and practical use possibility was performed. The titanium dioxide which is a photocatalyst is cheap, and exists abundantly as resources. The oxidization/reducing power which this titanium dioxide has are used for the purpose of decomposition removal of the quality of a water pollutant, and sterilization of a disease germ (typically estimated by coli form bacillus). Since the photocatalyst effect which a titanium dioxide has can provide the energy which advances an oxidation-reduction reaction by solar energy, it is energy saving very much in the point of not needing electric power using drained type resources. In old research, it was made difficult to use a photocatalyst for water disposal with many amounts of processing. So, in this research, while confirming the availability of solar energy, it inquired about the increase in the amount of water disposal by adopting the continuous processing method of a multilayer type. From the result of a batch type and a continuation type experiment, the validity of this method has been checked to the glucose which is model waste water, polluted river water, and all the object corruption water of sewage disposal water.

著者

奈良 松範

出版者

Japan Society of Civil Engineers

雑誌

地球環境シンポジウム講演論文集 (ISSN:18848419)

巻号頁・発行日

vol.13, pp.165-170, 2005-07-14 (Released:2011-06-27)

参考文献数

2

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Since the influence methane affects global warming matches by about 20 times (warming coefficient) the carbon dioxide, we consider more the influence by the methane generated from a nature. Especially the point that the quantity of the methane generated from the organic matter accumulated in soil or underwater by warming increases must attract attention from a viewpoint of warming prevention. However, the present condition is that impact evaluation which the greenhouse gases which occur from a plant or a microbe system give to global warming is not fully carried out. In this research, while carbon dioxide and methane examined the mechanism discharged from a nature, the experiment concerning the anaerobic fermentation of the laboratory scale about the increase in the amount of generating of the carbon dioxide by an environmental rise in heat and methane was conducted. The environmental impact by the gas which occurs from a nature was quantified by performing the impact evaluation simulation exerted on global warming using this experimental result.