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CST-10: Sustainable Coastal Development
STRATEGIC CONCEPT FOR ODAWARA REVIVE SYSTEM AS COASTAL CITY
Ryuta Torige, Turuta Kenji, Takeo Kondo and Kazukiyo Yamamoto
 
Nihon University Funabashi, Chiba, JAPAN
k04001@ocean.cst.nihon-u.ac.jp
 
For our country, the match to have aimed at an increase of interchange population is requested and in a city to have for many existing resources, recommends sightseeing as the one side plan. Such an inside, regional unique town to have corresponded to a change of a leisure activity collect that I adhere to is requested a guest effect is expected. With this research, collect further in order to obtain a guest effect, excursion, together with a regional peculiar attractive grasp I think it is necessary to construct a plan to plan improvement.
 
There, it grasps the sightseeing present state and point at issue at Odawara-city and introduces how it is a town to have utilized being peculiar charm and a coastal city that I adhere to. There exist a regional property the majority and report it for a visitor by display that I devoted myself to, experience for a creativity for Odawara-city. However, luring of a visitor to a marine side can't demonstrate a part as a stage of an interchange weakly.. There, position as considering Odawara castle as a place of an information dispatch ocean I attach it, advance a preparation of a beach further I promote a recreation function and raise an interest to sea.
 
By these, charm of Odawara-city, and the excursion to have utilized being a coastal city you can raise luring of a visitor to a marine side let's become it if a town there is that I adhere to is possible.
 
CST-10: Sustainable Coastal Development
EXPERIMENTAL STUDY ON THE BEHAVIOR OF SAND UNDER THE WATER
Tadayuki Yamamoto, Mitsuo Takezawa and Yoshihiko Maeno
 
Department of Civil Engineering, College of Science & Technology Nihon University Tokyo, JAPAN
takezawa@civil.cst.nihon-u.ac.jp
 
At the first step of the reclamation, the sand is dumped into the sea from hopper barges. The construction management requires the total amount of sand for completion of reclamation to study the sedimentation process and the range of the affected area of scattered sand to consider the enviroumental impact. In this paper the scattering range of dumped sand was estimated by the experimental study. The dispersion of sand both in a still water and in a jet flow of water was investigated by the model tests. The sedimentation process and the dispersion range of the dumped sand were obtained. A water tank for the model tests has a length of 2 m, a width of 1.3 m and a depth of 1.8 meters. Model tests were conducted by three types of the diameter of pumping pipes (D=35 mm, 50 mm and 75 mm, respectively), four gradations of sand grain size (d=0.3 mm, 0.3 mm-0.6 mm, 0.6mm- 1.2 mm, 1.2 mm-2.5 mm) and four levels of water depth (h=70 cm, 80 cm, 90 cm, 100 cm). Conclusions are as follows:
 
1. The sedimentation rate of sand was in proportion to the density of sand in a still water.
2. A horizontal width of scattered sand landing on sea bottom was in proportion to the sedimentation distance.
3. The sedimentation rate of sand increased as a diameter of pumping pipe became larger.
4. The critical velocity of jet flow where sand on sea bottom started to transfer, was 28 cm/sec - 31 cm/sec regardless of a sand grain size.
5. The larger grain of sand was, the faster dispersion was.
6. The dispersing width of sand on the sedimentation path was in inverse proportion to the sedimentation rate.
 
CST-10: Sustainable Coastal Development
THE GREAT INFLUENCE OF HUMAN ACTION ON THE DEVELOPMENT PROCESS OF COASTAL LANDFORM
Yang Dayuan and Wu Jianghua
 
Department of Urban and Resources Science Nanjing University, Nanjing, CHINA
yangdy@nju.edu.cn
 
The human action accelerated the development process of coastal landform since Mid-Holocene or reverse the process. The most notable acceleration of the development process of coastal landform took place in the mud-silt coast zone.
 
During from 1128 to 1855 Yellow River entering the sea through Mid-Jiangsu Province, the inundation of the Yellow River submerged the ancient Xuzhou city and the ancient Kaifeng city. However, the artificial dike in the Yellow River mouth area increased the in-sea sediments and resulted in the rapid growth of the Yellow River delta. During the 360 years before AD 1855, the coastal line advanced approximate 33 km toward the sea in the Mid-Jiangsu Province with the average rate of 91 m/a. While before that time, the average rate was only from 7m/a to 24 m/a. Since 1855, the Yellow River flew into the Yellow Sea. In the recent 50 years, there have no great inundation in the Yellow River. During from 1953 to 1982, in the Yellow River delta, the terrestrial land increased 1,100 km2. Till 1994, in the Yellow River mouth, there existed the modern Yellow River delta with the area of 2,200 km2 (The data coming from Cheng Chao, 2002). Additionally, in the middle and lower reaches of Yangtze River, the rapid increasing immigrants from the Northern China because of the ancient war, the reclamation of slope land and artificial levees also caused the rapid growth of the Yangtze River estuarine and coastal zone. Furthermore, in the recent 50 years, there have no great inundation in the Yangtze River too and the great amount of sediments poured into the River mouth reaches. It caused that in the near Zhenjiang area of Yangtze River, there deposited about 600×106 t sediments. The area of the Chongming Island of Shanghai, located in the lower reaches of Yangtze River, was about 600 km2 during the 1950s, but now its area increased to 1,200 km2. Because there constructed sea dike and sea pond along the coast of Jiangsu Province, it resulted in the rapid growth of low beach in front of the dike. Moreover, the Spartina Anglica Hubbard, which was planted on the sea beach, resulted in the rapid growth of beach land and beach surface. In Dafeng County, the area of beach lands increased about 7 km2 every year. In the eastern coast of Liaoning Peninsula, there existed the silty deposition located on rock beach and marine-eroded platform. In addition, the Quaternary depositional cliff coast took place rapid backward advance due to the human action and excavation.
 
The critical problem on the development of coastal zone is that it requires the stable coastal process, but the coastal process is controlled by many factors and so it is difficult to keep the coastal process stable or invariable. So, the sustainable development of coastal zone, which is very sensitive to natural change and human action, should pay attention to set up the long-range conservation plan and management of the coastal zone.







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