ABSTRACT：This paper describes on relations between slopes and beach topography on swash zones of the Sarukotsu coast before (1975) and after (1986) constructing training jetties at the river mouth of the Sarukotsu River of Hokkaido, Japan. The relation between the ratio tanα/tanβ ) of the slop tanα of the land side and the slop tanβ of the sea side from a criterion of the shoreline and ratio (hc/Xc) of the water depth hc on the bar top and the horizontal distance Xc from a criterion of the shoreline to the position at the bar top was clarified by the sounding in 1975 and 1986. Consequently, it is clear that the relation between (hc/ Xc ) and (tanα/tanβ) is given by hc/Xc A ・ (tanα/tanβ)+B, where A and B is a constant. In addition, it can be explained by the ratio tanα and tanβ that is the maximum of the wave run up that the wave reflection coefficient is large at tanβ of the steep slope and is small at tanβ of the gentle slope.

ABSTRACT: Long-term simulations for the ecosystem in Tokyo Bay were carried out in order to investigate dynamic response of ecosystem due to the change of terrestrial load. In the simulations, interannual variations of terrestrial load through the rivers, decrease of tidal flat area due to the reclamation, and removal of organic matters by fishing are considered as the external conditions. Nutrients behaviour in the benthic system and release flux from the sediment are also calculated. As the results, it is confirmed that contribution of the internal production is quite large for COD in the bay. It is also indicated that the effect of the terrestrial load reduction on DO concentration in the bay is almost cancelled by the influence of the reclamations.

ABSTRACT : In recent years, local fishers in Japan were financially challenged for various reasons associating to local community structures and oil prices, including considerable cost and efforts to obtain financial benefit from fishing. In such an economic situation, many fishing companies have had side businesses to support themselves. On the other hand, past surveys like a fishery census did not include information of these side businesses. To advise better combination of side businesses for local fishing companies and fishers in Minami Kayabe area, Japan, we examined the best possible combinations of primal and secondary fishery. These types, Operating Types designed with Prime and Secondary fishery (OTPS), gave us better understanding in local economic structures around fishing companies than the past surveys. Newly reported financial hotspots in the community and fishery-dependent variance of fiscal benefits in each type became obvious. We suggest that application of OTPS helps to advice fishers for survival in recent fishing economic situation.

ABSTRACT : IPCC( Intergovernmental Panel on Climate Change) reported that the sea level increases between 0.18m to 0.59m for the next 100 year. Moreover, it is also reported that intensity of rainfall increases about 20% in some scenario analyzed by the Earth Simulator. In urban area where the combined sewer system is developed, the indisposed water flows into the rivers from the storm outlet. If the river level increases more than the water level at sewer pipe due to global warming, it seems that the river water flows into the sewer system and this flow behavior causes increasing of water disaster in urban area. In this study, the inundation due to interior runoff considering sea-level rise and rainfall change by global warming is treated by numerical analysis. The influence of global warming on the water disaster due to interior runoff is shown and the safety level of risk management for the water disaster is also discussed.

ABSTRACT: In the recent years various problems occur in natural environments of coastal zones, including loss of tidal flats, water quality deterioration, decline of inshore fishery catches, and so forth. The objectives of this study is to build natural environments database around the Kitakyushu Airport island in Geographical Information System(GIS) and evaluate natural environments of the study area. The constructed database together with the GIS gives us a great tool to store, process and analyze data on the same platform, and to display analyzed results visually. According to the evaluation results, although the construction of the airport island and other landfill has worsened physical environments, the trend of degradation in chemical environment has not been observed.

ABSTRACT : The aim of this philology study is to analyze and confirm the historical transition structure and potential factors on the fishing villages in DONAN area, the Southern part of Hokkaido, using by over 70 historical literatures and data related with a geography industrial history in the region.

At the first step, meaningful division sets of age was constructed different from the ordinal social historical science study. At the next step, fragments of the history were reconstructed by the elements of environment features and the factors of fisheries, industries and trading in the region. Finely, the information about the transition factors of communities were unified into 5 categories as 1)natural condition, 2)fisheries and its production, 3) commercial transaction, 4)abilities of ship navigation, 5)inferences of local governments.

By the results of analysis, all of the ancient time fishery communities in Donan were opened up from seaside where was settled as the strongpoint of fisheries production power and trading to Honshu, which is the mainland of Japan. With completion of each small scale community, the twelve sets of Tate, where were the core site could support sustainable production and residence were constructed at the date of 14-15 centuries. Those Tate duplicated the reconstruction of communities by local war and expansion of trading needs to Honshu.

The inferences of the local geographical and natural environment, such as heavy currents in the Tsugaru straight where prevents human activities in fisheries and cruising for trading across to the other area , are clearly revealed as the most important factors in the formation and construction of communities. Location of the communities in the region depended on the developments of shipbuilding and cruising technology, which had surpassed the difficulties of crossing the sea. Always, the communities had been optimized by economic effects. And also, the formation factors of communities were according to the three elements of production in today as 1)Plot of land for residence, 2)Number of Labors for fisheries production and 3)Capital for economic achievements. Those factors are universally observed in the contemporary fishery villages.

Those results shows the unique fact that the natural environmental such as sea condition and geophysical feature in a region condition determines the early time construction of communities, and the three elements of production give arbitral change to the communities later till today. Especially, the development of Donan region was constructed by the local fisheries productivities and maritime affairs based on the terrain features.

ABSTRACT：This research, sampling southern part of Boso Peninsula, investigates site characteristics of algal beds by large scale spatial information. Spatial analysis between water quality and algal beds had brought some specialties of the algal beds. We assimilated the appropriate candidate sites for the generation of algal beds with the carbon dioxide consumption under consideration. This produced the data that creating algal beds in the depths of less than 50m could be 30 times more effective in consuming carbon dioxide, than the current status. These numbers are based on the maximum values of our simulation without any economical effects such as traffic, fishery, and adjustment between them under consideration. There are indeed enormous positive implications regarding generating algal beds, especially, the consumption of carbon dioxide.

ABSTRACT: The impact of mussels (Mytilus galloprovincialis), attached to quaywalls in Amagasaki port, on deposition of materials was studied in situ using sediment traps. Observed lowering concentration of dissolved oxygen and phytoplankton near the walls was attributed to metabolic activity of the mussels. Due to deposition of feces and pseudofeces discharged by filter-feeders, sedimentation rate were doubled under the mussels attached on the quaywall comparing to an adjacent reference site. Even more obvious impact was increase in particle organic carbon (POC) and particle nitrogen (PN) fluxes, which are tripled comparing to those at referent site leading to local organic enrichment near the walls. Increased deposition changed downward fluxes of all investigated metals (Zn, Cu, Pb, Cd and Cr). Results of factor analysis indicated influence of mussels on the redistribution of metals and their concentration in deposited matter, first of all, on redistribution and concentration of Zn and Cd through the selection of fine particles. However, contrary to organic matter, whose concentration in surface sediments and trapped material reflect a clear gradient, which decreases from the wall to the referent position, metal concentrations do not reveal similar effect.

ABSTRACT : The recent state of development along coastal line in Vietnam is reported based on the findings through a series of recent field surveys. In particular, an in-depth field survey was conducted at the area in Van Phong Bay where a nation-wide project to develop a sea port is ongoing. According to the results of the survey and interviews with local residents, industrial development along the coast currently appears to be limited. However, supported by a strong economy, it is expected that there will be rapid further developments over wider areas of the country.