The supply and demand for fishing products is considered to be tight in the future. At the aim of recovery of fishery resources, the necessity for the construction of fishing ground in the offshore and large depth waters which has been done little is rising from the point of view of the utilization of large Economic Exclusive Zone (EEZ) in our country. For this reason, Fishery Agency institutes the system of construction of fishing ground under the direct control.

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Since United Nations Convention on the Law of the Sea became effective, offshore fisheries have been pressured to find new fishing grounds. Then, the development of mound fishing grounds has become notable in recent Nagasaki prefecture. A mound fishing ground means a large-scale high-rise artificial reef with up-well structure.
In this paper, we compile and analyze the results of research and construction on mound fishing grounds in Nagasaki, and then suggest some important points for development of offshore fishing grounds.

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The research and development project to create the fishing ground in the open ocean by upwelling Deep Ocean Water (DOW) and discharging it in the euphotic layer where photosynthesis can be done with DOW's rich nutrient salt has been carried out since April 2000, sponsored by Japanese Government Fisheries Agency and Marino-Forum 21. In the open ocean, there are no successful means to meet such a mission, so far. Therefore, the focus of the project is a creation and proposition of the concept of the ocean nutrient enhancer nicknamed TAKUMI to contribute for increasing primary production and fish production at the open sea. The requisite technologies such as a density current generator, a spar type floating structure, a steel riser pipe, a set-up way of upending, etc. is discussed and integrated to create the concept of TAKUMI, whose principal particulars are the 100, 000m³/day DOW upwelling capacity, the about 1, 700tons displacement, and the 100KW Diesel engine. In May 2003, TAKUMI was set-up at the point of 1, 000m depth in Sagami Bay, and has been continuing experiment of DOW upwelling.

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The increasing of CO₂ sinks in the ocean is studied for the mitigation of global warming. In the present research, we studied the application of an artificial marine structure to generate an upwelling. The purpose of this research was to develop an evaluation technology of CO₂ fixation around an artificial upwelling area. In order to clarify the limiting factors of the CO₂ fixation in the area, field observations, laboratory experiments, and model calculation were carried out for the Ikitsuki artificial upwelling site, Japan. The fixation of 900-5000 ton-CO₂/yr was estimated from the biological processes and the physical processes of the Ikitsuki site by preliminary analysis. The total amount of the CO₂ emission for artificial marine structure in Ikituki site was 4, 100 ton. It was shown that cumulative CO₂ fixation exceeded the CO₂ emission after few years. Our results suggested that artificial upwelling system has a possibility of enhancement of CO₂ fixation in the ocean.

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This paper summarizes the special session “Coastal Disaster Prevention -Asset Management for Coastal Disaster Prevention Facility-. ”This session has been planned to understand the asset management and to contribute an application of the asset management for coastal disaster prevention facilities. Presentations include (1) asset management for infrastructure, (2) asset management for road infrastructure, (3) superannuation and destruction of shore protection facilities and (4) a current state and engineering subjects on investigation, measurement, diagnosis and deterioration forecast of port & harbor structure. After presentations, the subjects for applying the asset management to coastal disaster prevention facilities have been discussed. Throughout the presentations and discussions, many important matters have been pointed out.

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In the Life Cycle Cost model considering seismic risk, the method of accumulation of the annual loss expectation is almost adopted. The expectation value isn't suitable as an index of a decision making, because it's different from the actual amount of a loss. In this paper, the method of taking seismic risk probability density function into the LCC directly is proposed. In the evaluation of the probability density function, the seismic risk curve during the service time of the structure is calculated, that is discounted in the present value. The office building is adopted for example, and the cost-effectiveness of the aseismic reinforcement and the insurance are discussed for applicability of proposed method.

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In this paper, an approach for asset management of decrepit social infrastructures is proposed. The management system is based on a sequence of inspections. Since Japan is surrounded by sea, coastal revetment is necessary. However, a great number of the coastal facilities were built in the same period of rapid economic growth, and therefore they have aged at the same time. We need to maintain these social infrastructures efficiently in an aging society with a falling birthrate using asset management. It is important to integrate our practical knowledge, develop maintenance skills and produce a road map which indicates how to use this information in the field.

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Recently, deterioration of infrastructures has become social problem in Japan, and the application of the asset management system for the maintenance of infrastructures is attracting wide attention. In this study, comprehensive research to develop the asset management system for port facilities has been conducted in order to enable effective planning of maintenance strategy. The practical data management system is being developed, and its outline and characteristics are demonstrated in this paper. The system adopts ASP (Application service provider) system, and has good availability for the users. Furthermore, several analytical methods based on the statistical approach are proposed to assist the decision making in the management.

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To improve scientific knowledge of the relationship between tropical cyclones and global warming, recent research direction and extreme events have been reviewed. Past studies provide reasonably consistent results about intensity changes due to global warming. It is estimated from a theoretical model and numerical experiments that the central sea level pressure deepening of a developed tropical cyclone increases by 10-20% for about 2°C increase of sea surface temperature. On the other hand, the fidelity and duration of past observation records are not enough to detect a global warming signal. Although there is a report to indicate a rapid increase in the frequency of intense tropical cyclones during recent thirty years, the credibility of this report is not conclusive. Also, regarding the extreme tropical cyclone events, which frequently occurred in 2004 and 2005, any attribution to global warming is not approved. The long-term tendency of tropical cyclone activity including frequency and motion will be gradually elucidated with the accumulation of observation records and the development of numerical models.

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The asset management of public works such as shore protection facilities has lately attracted considerable attention. In the asset management planning, preparing of database is necessary to huge information management and analysis.
In this study, Hokkaido prefecture developed a database of shore protection facilities using GIS (Geographical Information System), and built a fundamental database with field survey and electronization of existing documents about shore protection facilities as a first step of the asset management.

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It is important to have a strategic approach for construction and management phase not only implement R&D itself in environmental restoration and conservation projects. “Adaptive management” is said good procedure for enabling feedback on a project by using monitoring results. From public administration sides, there are many difficulties to tackle with the issue. For example, a port planning and an administration is controlled by different governmental body, and public works are usually not ready for change in its project term. Thus, a recommendation for the frame work (strategies, methodologies, advantages, and disadvantages) and its classification of research topics were discussed and presented in Symposium on Civil Engineering in the Ocean 2005-2006, JSCE.

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There are high possibilities in the near future that great earthquakes occur and large-scale tsunamis attack Japan. In fishing ports facing on the ocean where a large number of fishing boats are moored, these boats would be littered in the ports, or drifting boats would collide with back-yard-structures, if such a tsunami attacks, like an event actually happened at Hokkaido in 1993. This is one of major concerns for tsunami countermeasures in fishing ports.
To predict and reduce these damages, it is absolutely indispensable to know the behavior of drifting boats and their collision forces. In the present study, hydraulic experiment was performed to investigate behavior of a boat and collision forces, as well as properties of tsunami. Based on a series of experiments, it is revealed that boats tend to be drifted keeping initial angle. Moreover, under higher incident wave conditions, the drifting velocity is influenced by the initial direction of boats than the height of draft.

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In this study, we introduced flood analysis using unstructured meshes to tsunami inundation computation. At first, we verified its validity for the tsunami inundation case by comparing with the result provided with usual numerical simulation using normal spatial meshes. Secondary, we applied it to the supposed case of the earthquake-induced tsunami at the area of Kesennuma bay under the condition that coastal defense facilities were deposed and the effect of houses were considered as the residential dominated ratio inside the mesh or water transparent ratio from the neighboring road meshes.
The simulation using unstructured meshes well reproduced local inundation flow around the land structures. And it implied that residences generally had mitigation effect for tsunami inundation disaster but it locally increased tsunami hazard especially on the road in case urbanization was progressed.

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The coasts of Shikoku Island, Japan are exposed to the tsunami, generated by Tonankai-Nankai earthquake and thus urgent countermeasures are needed. The storm surge, generated by two typhoons in 2004, caused a coastal disaster with flooding over a large area of Shikoku Island. It is necessary to gather and manage the damages by tsunami and storm surge in all coastal area. However, practically it is a hard to collect the disaster-related information and to analyze the damages. An alternative is numerical simulations. The numerical simulation is one of the best tools for the speedy analysis of disaster phenomena such as tsunami and storm surge that have large temporal spatial scales. The numerical system has been developed for coastal protection works of the coast of Shikoku Island. This system consists of three numerical simulation models (Wave, Storm Surge and Tsunami models), their supporting sub-systems and supporting databases. With this system, the coastal protection works can be supplied with more reliable information.

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We tried to devise a method for estimating the degree and geographic extent of tsunami damage using satellite photographs in two case studies of damage to Thailand's west coast due to the Indian Ocean tsunami. Following results were obtained from those case studies: the extent of a flood area can be generally estimated from discoloration of vegetation zone assuming such vegetation originally existed along the coast; house damage could be estimate by deciphering whether each roof was lost or not, however if the roof remained, the degree of damage to walls and pillars could not be discerned.
Therefore, we develop a method to get marginal thickness of walls and marginal width of pillars which break on arbitrary positions using a distribution of tsunami heights on a coastline and a distribution of ground heights. In addition, the extent of a flood area can be presumed if there are the above-mentioned distribution data and elapsed data of sea water levels at the time of a tsunami invasion.

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In order to predict the behavior of floating body under tsunami flood appropriately, numerical simulation is effective to reproduce the dynamics with drift. As analyzing the movement of flotsam, it is significant to evaluate the drag force exerted on the float shape.
We prepared the drift simulation model based on the Distinct Element Method (DEM). In the simulation, every flotsam shape was expressed by an assembly of individual sphere elements and current velocity field generated by tsunami was given from the result of the tsunami propagation simulation computed in advance
This paper shows experimental results of container's drag force coefficient as a function of every current angle. And we refer the application of a drift simulation method considering the drag force by comparing the drift motion obtained from the experiment in a 2-dimensional plane water tank with that of the simulation result for above-mentioned float model.

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The flap type gate is expected as one of new structures against tsunami, and we have kept developing it. In the past study, we have proposed a new mechanism of flap gate with the sway control plate, and confirmed that the modified flap gate worked enough for structures of disaster reduction. However, there are some uncertainties about both the dynamic characteristics of the flap gate with the plate and the hydraulic conditions accompanying the characteristics. In this study, two-dimensional hydraulic tests were carried out in a water channel with a wave generator, and the behavior of the flap gate was confirmed by measuring pressure and gate acceleration under several conditions. As a result, it is clarified that the modified flap type gate works effectively under some conditions.

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Tokai, Tonankai and Nankai earthquakes are predicted to generate great tsunamis which will attack the Pacific Coasts. The tsunami will arrive at the coasts within ten minutes after the shaking, and its height reaches 5m or more. To save lives of residents in these affected areas from the tsunami, a shelter tower is newly designed, and it begins to be constructed by the local governments. A hydraulic experiment is performed to check the stability of the shelter tower at exertion of the tsunami. It is confirmed that if there are no debris, the tower is enough stable because tsunami force is smaller than shear strength of the column connections. On the other hand, if the force is increased by debris, overturning moment becomes much larger than the resistant moment by the tower weight without considering the pullout resistance force of the columns. Presuming of tsunami force which acted on land structures such as the tsunami shelter was proposed by using newly derived tsunami velocity equation and the drag coefficient of the structures.

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The behavior of tsunami near the coast is similar to that of flow rather than high waves such as typhoons. Therefore, the stability and hydraulic functions against tsunami of coastal and harbor structures have to be investigated because several kinds of coastal and harbor structures are designed only for high waves. In this study, hydraulic experiments in a wave basin are conducted to investigate the influence of the configurations of the structures on the tsunami height. In the experiments, the time series of water surface elevation, water particle velocity and wave pressure acting on the structures are measured. The authors show that (1) the distribution of tsunami height along the coast is not corresponding to that of the water surface elevation. (2) Rapid increase in flow velocity is measured at an area where the configuration of the structures is complicated. The results obtained in this experiment are useful for verifying numerical models.

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A reliability of the tsunami warning system depends on its capacity for detecting tsunamis and the present systems use observed seismic waves to detect them. Unfortunately, the detection method may underestimate some kinds of tsunamis. Then, it is expected to develop a new tsunami detection system to observe sea surface directly by using remote sensing. The authors had proposed high frequency component of sea surface water waves due to a crustal deformation as the detection index. In this study, the waves were generated by using an underwater shaking table and spectral analysis was carried out to understand a relationship between the waves and bottom deformation.

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An innovative ‘buoyancy-driven vertical piling breakwater’ is under development to protect harbor facilities behind the breakwater against tsunamis and high waves. This breakwater consists of rows of steel pipe piles and each pile consists of upper and lower steel pipes. Upper steel pipe is normally encased in lower steel pipe which driven into seabed and thus there small gap exists between upper pipes. When tsunami or high wave is predicted, the upper pipes quickly rise up to the water surface driven by the buoyancy of air supplied into the upper pipes.
A few experimental researches have been conducted on the hydraulic characteristics of this type of breakwater with gaps. In this study, hydraulic model experiments and numerical simulations were carried out to investigate the wave transmission through the breakwater and wave pressures acting on the upper pipes. As a result of the study, the breakwater's performance against tsunamis and high waves has been verified.

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A lot of disaster due to the storm surge caused by the typhoon 0416 and 0418 in Hyogo Prefecture occurred. It is difficult to prevent such large-scale disaster completely. We must devise preliminary countermeasures, such as closing the floodgates and various gates, to minimize the damage. Real-time prediction of the storm surge at each port and coast is necessary to recognize highest water level and maximum variation during the storm surge. The main purpose of this study is to develop the real-time prediction model of storm surge in Hyogo Prefecture that the port managers can handle smoothly.
It was revealed that the real-time prediction model is useful and accurate by the verification of the model applied for the hind cast on the typhoons in 2004 and the forecast on the typhoon 0613.

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In order to reduce disaster, it is required to heighten self-defense power by offer of suitable disaster information. This research examined the mode of expression and the effective practical use method for promoting an understanding of common knowledge about a storm surge hazard map, practical use, and a disaster phenomenon distributed as a paper medium. For the purpose of the expression as an actually utilizable storm surge hazard map, danger was set up from a viewpoint of mitigation of human damage, or the propriety of refuge. Moreover, since it was thought that the emergency drill and fire drill as a local event had a high effect of common knowledge or practical use, it decided to use a storm surge hazard map.

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In this study, the physical mechanism of October 2006 storm surge in the east coast of Hokkaido, Japan, is examined by using a simple theoretical surge model. An approaching extratropical cyclone could generate abnormal high tide levels in Hanasaki even though along-shore (or shore-parallel) wind lasted nearly one day. Comparing to its features against the features of past typical storm surge events in Japan, its mechanism is considered to be different from the well-known type. In order to explain this unusual phenomenon, we introduce an analytical equation model including the Ekman transport term by which wind causes mass transport of 90 degree to the right of the wind not only due to the wind stress but also due to the earth's rotation. The analytical model can predict an increase of about 0.5m in high tide levels during 20 hours, which is consistent with present observations. The results suggest that the strong steady-state shore-parallel wind associated with a synoptic-scale extratropical system enables to generate a huge storm surge, even in coastal areas facing the deep open sea like the east coast of Hokkaido.

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To investigate some possible changes in occurrence probability of storm surge due to global warming in Ariake Sea, many numerical computations for storm surges were carried out. First, three different climate conditions were assumed in the computations, i. e., the present climate condition and two different future possible climate conditions under global warming used in Hashimoto, et. al. (2005). In each climate condition, a lot of various typhoon data for 500 years were generated with “a stochastic typhoon model” by using the Monte Carlo simulation. Next, storm surges in Ariake Sea were computed for many typhoon data. And, return periods of storm surge and tide on three climate conditions were obtained by extreme value analysis. Comparative investigation of the return periods of storm surges and tide among three climate conditions shows the possibility that large storm surge and large tide would be generated more frequently in the future due to global warming.

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In the present conditions that it became clear that influence of global warming is not avoided, we must decide the policy with a long-term view of more than 100 years, at least. It is in particular necessary for development of a disaster prevention plan, we should consider the Japanese present conditions that the birthrate has becoming lower, and an economic structure and sense of values are always changing. In this study, we analyzed an area characteristic to contribute to the disaster prevention plan that within long-term climate changing by information analysis with GIS, using the data which were already got ready as numerical land information, the altitude, population, roads, railroads, etc.

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When waves around harbors are computed with Boussinesq models, so-called “sponge layer” is placed along the computational region to absorb reflected waves going out to open sea. The wave absorbing characteristics of the sponge layer for long period waves have not yet been fully clarified. Using two-dimensional numerical wave-tank with a sponge layer just behind the wave generating boundary, regular waves of 20, 60, 100, 200 and 300 sec were generated, and its wave absorbing characteristics were investigated through the wave height of the standing waves generated in the wave tank. It was found that the reflected waves entering from the region to the sponge layer are almost completely absorbed by properly setting the sponge stiffness and the sponge thickness. Further investigation on water surface oscillations near the boundary of the harbor was carried out. It was found that by providing thin sponge layer along the impermeable boundary, abnormal water surface oscillations, which occasionally occur around the boundary corner, can be effectively suppressed.

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This study investigates interaction between current and waves propagating in opposite direction of the current, based on laboratory experiments and numerical simulation. In particular, the characteristics of solitary and periodic waves propagating against the current are examined. Hydraulic experiments are carried out in a three dimensional wave basin in which open channel is installed. Numerical analyses are performed within the numerical wave tank capable of direct simulation of the flow fields under almost same conditions as in laboratory experiments. In case of periodic waves, both results show that the wave and current interaction increases the wave height first, and then it attenuates as wave propagates against the flow when the interaction affects the wave height distribution. In addition, the attenuation of the wave height caused by wave-current interaction depends on incident wave period and current velocity. In the case of solitary waves, however, there is few change of wave height compared to periodic waves.

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The present study examines the soliton fission process of tsunami propagating over reef shallow water coast by hydraulic experiments. The effects of water depth above the reef, tsunami amplitude and period are investigated. In addition to the experiments, two different kinds of numerical models are employed in order to know how accurately the models can reproduce the process of tsunami transformation such as the occurrence of fission, amplitude, number of soliton waves and phase celerity propagating over the reef. It was found that even if the tsunami amplitude and period are the same, the transformation process of first water-level-rising tsunami is different from that of first-falling tsunami and that there are differences between experimental transformations and numerically obtained transformations generally.

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It was reported in the model experiments conducted by Yasuda et al. that the Indian Ocean tsunami penetrating the Andaman Sea coast was deformed and dispersed to soliton waves by the characteristics of the coastal cross section. In this paper, the numerical simulations using a Boussinesq type wave transformation model are conducted to reproduce the tsunami deformation, breaking and runup of dispersive soliton waves or pressure on the sea wall measured in their model experiments. The nonlinearity and dispersion of Boussinesq equation can estimate the generation and the development of dispersive soliton waves. The vertical gradient of pressure as the breaker index for wind waves is also available for solitons. The pressure equation given with Boussinesq approximation can evaluate the impulsive wave force on the vertical wall caused by breaking and runup of solitons.

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A seawall has to prevent a hinterland from incoming waves. The design of such maritime structure had been performed by hydraulic model tests or diagram conducted from experimental results. In recent years, precise numerical methods have been applied to the design of maritime structure. CADMAS-SURF is one of highly precise numerical models, and its applicability has been verified for various coastal phenomena. Although one of the authors proposed a method for generating irregular waves in the CADMAS-SURF, there is a problem awaiting for solution that a total mass variation of fluid in the model becomes greater with time step for H_1/3/L_1/3>0.02.
In the present study, a modified method for generating irregular waves is proposed and verified by results of a hydraulic test. In the result, 1) a total mass variation of fluid is reduced to less than 1% for severe wave steepness, H_1/3/L_1/3 is about 0.06, 2) the calculated value shows good agreement with experimental data for over topping.

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The fully nonlinear numerical simulation model was verified for 3D multi-directional waves. Inflow boundary conditions on a horizontal component of velocity of irregular wave were studied on superposition of linear wave components and mass transport. Propagation of unidirectional irregular waves in the uniform depth, 3D monochromatic wave refraction and diffraction due to a spherical shoal, an obliquely incident irregular wave, and multi-directional wave fields were simulated and compared with analytical solutions or experimental results. Effects of space sizes and time increment on simulated results were shown for the unidirectional irregular wave propagation. All the simulated results in the present work are not completely satisfied. The tasks to be solved for the next step are pointed about the inflow boundary condition and the space sizes.

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In the Tokyo International Airport (Haneda Airport) expansion project, the D runway will be constructed as a hybrid type structure with the piled-elevated platform and the reclaimed island. About 200 steel structures (jackets) will be used for the platform, and wave height may decrease when waves propagate through the jackets. Hydraulic model tests have been performed to measure the wave dissipation coefficient by jackets. In addition, an analytical model to estimate the wave energy dissipation due to the drag forces of cylindrical members of jackets is formulated. The analytical model well presented the wave dissipation of the hydraulic model tests. It is also effective to evaluate the difference between the real site and the model test, such as the relation between the drag coefficients of cylindrical members and the Reynolds' number and other experimental settings.

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In this study, the mechanism to produce impact pressure on a wall under fresh water and sea water jets is experimentally investigated through water drop tests. The effects of entrapped air, which is a model of an air pocket formed at coastal structure under breaking waves, are also discussed. Higher impact pressure is found to occur under sea water jets rather than fresh water jet for all cases. It is also found that the entrapped air has a role to reduce the pressure maximal and to change peak frequencies of the impacts. New model to estimate variations of the impact pressure with coefficients determined through the experiments is proposed. It is roughly applicable to estimate the maximum pressure and the duration of the impacts under the jets.

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Wave overtopping-caused disasters have occurred around revetments in Okinawa islands, which are one of the typhoon-prone areas in Japan and are mainly surrounded by coral reefs. To take countermeasures against wave overtopping are important from the viewpoint of disaster prevention and the design of coastal structures. The main purpose of this study is, therefore, to numerically examine wave deformation over a natural reef and wave overtopping around a road revetment in main Okinawa Island using a two-dimensional numerical wave flume “CADMAS-SURF”. The numerical results reveal that the CADMAS-SURF is able to simulate wave deformation over the reef including wave breaking and wave overtopping around the revetment appropriately and wave overtopping characteristics are greatly affected by bottom topography in front of the revetment. In addition, two methods to estimate the wave overtopping quantity are proposed in this study. The time variations of the wave overtopping quantities calculated by the two methods are found to be similar in the case of large overtopping quantity.

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Two- and three-dimensional numerical models of multiphase flow with solid-gas-liquid phase interaction ‘DOLPHIN-2D/3D’are newly developed in this study based on a CIP method and an extended SMAC method so that irregular mesh size grids and the dynamic motion analysis of multiple rigid bodies can be taken into account. The utility of the model developed here is confirmed by applying it to collision problems between water collapse-induced bore and two floating bodies in two-dimensional and three-dimensional multiphase flow fields. The results reveal that the model can compute multiphase flow fields with the dynamic behavior of multiple rigid bodies appropriately and is capable of reducing the computation time in comparison with the results with fine regular meshes.

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This study examined hindcast accuracy on numerical models of wind and waves during typhoons. By using meteorological objective analysis data GPV provided form Japan Meteorological Agency (JMA), the mesoscale model MM5 with typhoon bogus and data assimilation and 3^rd generation wave model WAM, we estimated the wind and waves with high accuracy as compared to a parametric model such as 2D-typhoon model. Additionally, we obtained similar result by using GPV provided from National Centers for Environmental Prediction (NCEP) with a coarser spatial resolution than JMA's GPV though there were some problems to be solved. So the estimation model of wind and waves in this study is applied to hindcast high waves needed for computation of design wave.

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It is important to estimate offshore winds with high accuracy in hindcasting ocean waves. In the open ocean areas, offshore winds have been estimated by using gradient wind which can be calculated with the sea surface pressure distribution. But in the inland sea areas, the offshore winds are more complicated, because they are affected by surrounding land topography. This study reveals that accuracy of offshore wind estimation and wave hindcast in inland seas such as Ariake Sea can be improved by using GPV (Grid Point Value) data presented by Japan Meteorological Agency and observed wind data.

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The Flood Fighting Law stipulates that prefectural governors shall issue a flood fighting warning of storm surges on coasts previously recognized as being at high risk of storm surges. However, forecasts of storm surges and high waves before a typhoon approaches are insufficient information to issue a flood fighting warning because the forecasts do not indicate that the wave runup exceeds coastal dikes and wave forecasts are imprecise. Also, wave forecasts are not very precise near coasts because wave models do not consider wave transformation in shallow water such as shoaling and refraction. Therefore we are developing a real-time wave forecast system for inland seas to ensure proper flood fighting warnings

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The directional wave observation should be done with the measurements of one vertical and two horizontal components of wave motions. The covariance method was examined for the GPS buoy. The vertical position and horizontal speeds of buoy were dealt as the data. However, the covariance method did not always estimate wave directions correctly because those buoy motions have each delay according to the wave frequencies.
The wave direction without a sign defined in 0-180 degrees is possible to be estimated with the measurements of two horizontal components of wave motions. We tried to estimate unsigned directions for the GPS buoy with the Longuet-Higgins method and horizontal GPS buoy positions. To change unsigned direction to signed direction defined in 0-360 degrees, the covariance for the unsigned direction is computed and the sign of the covariance is added to the unsigned direction. It is proved that the combined method proposed in this paper gives proper directions.

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Public works in coastal region require accurate and reliable wave information not only in deep-sea areas but also in coastal areas, especially in bay areas. However, WAM has some drawbacks in applying it to bay areas since some of the parameters in WAM were tuned for deep-water conditions. In this study we examined and discussed the applicability of WAM to bay areas, then discussed some method to improve the applicability of WAM to the areas. On the other hand, accurate wind estimation with high time-spatial resolution is indispensable for accurate estimation of wave conditions around the sea. We, therefore, applied MASCON model by which influence of geographical features can be taken into account in wind estimation, and discussed the applicability of MASCON model.

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Recently, people have become more conscious in disaster prevention and reduction, because the large-scale natural disasters have occurred frequently in the world. Shiranui-Matsuai coastal area and Minamata City had suffered from the storm surge disaster by Typhoon 9918 and the floods and debris flow disaster at July 2003. The aim of this study is to extract the victim consciousness and attitude for the disaster prevention and reduction form using the questionnaire research. As result of analysis, people still rely on disaster prevention though they understands the importance of disaster reduction, so the administration and the researcher should rouse them about beginning to disseminate the disaster reduction at the people level. Moreover, it seems to be a difference in the consciousness and attitude between the disaster victim and other

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Recently, local governments push forward not only structural measures but also non-structural measures for Tsunami disaster. However, there is not enough public information for beach user to make early evacuation from sea side in the occurrence of an earthquake. The reason is that it is usual for a local government to send public information to the local inhabitants. To let beach users evacuate earlier, it is necessary to improve the users' awareness of Tsunami vulnerability. In this study, the users'opinions on Tsunami disaster are discussed on the basis of a questionnaire research in Shirarahama Beach in Wakayama where is vulnerable to Tsunami induced by a forward-coming mega-earthquake. The results are also analyzed using the quantification method of multi-variate analysis. The results indicate that there are some effective means for improving the users' consciousness of Tsunami disaster.

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Our country is surrounded by the sea and it is always in danger of such disasters as seismic surges and tidal wave and people in the coastal areas need to prevent the damages at the minimum. A purpose of this project is to improve the people's knowledge and safety awareness about natural disasters. It is intended for the people who live near the Yatsushiro Sea in particular. We have educated the students from 10 years old to 20 years old, giving the information of specialized knowledge about the coastal characteristics and disasters. As a result, they have improved dramatically and an educational effect for students of low age was in particular high.

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Recently, coast environment in the ARIAKE sea and the YATSUSHIRO sea is getting worse. The cause is the decline of the water quality self-cleansing function and reduction of biological diversity by the reclamation and so on. Kumamoto Prefecture established the committee aiming at rehabilitation of the coast in 2004, and has had a discussion for two years. The work was pioneering the reproduction for a closed sea and decides upon the statement of coastal rehabilitation. We adopted the two technique newly. One is to have divided the characteristic of the coastal region by the character of the intertidal, the hinterland and the seashore area of the distribution of the halophilious plant and so on. The 2nd complemented the lack of the scientific data with the interview survey, as a result, we found the distribution of seagrass (Zostera marina Linnaeus) in the past in YATSUSHIRO sea. It wants to introduce the process of these efforts and gotten new knowledge at this article and we consider about the spread of the reproduction in the future.

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This paper proposes a concept of market-mechanism-based coastal and marine management, reviews and evaluates the system and the experience in China where is regarded as the first successful example. The results show that a coastal and marine management should be shifted to market-mechanism-based along with the use property of coastal and marine resources shifting from the public to the private. The experience in China implies market-mechanism-based coastal and marine management may play an important role in coordinating different stakeholders of coastal and marine resource users, protecting coastal and marine environment, and improving regional social economic development like in Xiamen City, China.

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This research is for the best use and comprehensive management of Tokyo bay based on the social and economical aspects to evaluate the economic value of ecosystem services. The ecosystem in Tokyo Bay is providing various services such as the provision of breeding or nursery function of many important marine species for commercial fishing, water purification, and the fields of recreation and environmental education etc. Those economic values were evaluated as several ten billion yen or more every year. It is necessary to consider the function and the value of such a variety of ecosystem services for the development in Tokyo Bay in the future and the plan of the utilization plan.

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The meteorological model WRF developed by NCAR in U.S was used for the study on the influence of coastal development of urban climate. At first, the model was calibrated for air temperature in Tokyo Area on August 5 to 8 in 2006. The computed results of air temperature show good agreement in daytime but disagreement in night time. This is because of the model doesn't consider the artificial heat discharge from the urban.
Next we investigated the influence of the reduction of area of Tokyo Bay due to reclamation works on urban climate by the model. From the results the air temperature in daytime in urban area rises up due to reclamation of the area of Tokyo Bay, but the rise-up rate is not linear to the area of reclamation land.
And the air temperature in night time in urban area drops due to heat radiation from the reclamation lands.

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The purpose of this study is to clarify relations between sea-surface temperature and air temperature of an urbanized bay area in summer seasons by observational data analysis and numerical simulation. The observational data analysis using the AMeDAS and the Meteorological Objective Data showed that the sea-surface temperature has great influences on the air temperature of the bay area and sea breeze in night time contributes to raise the air temperature. The numerical simulation with the HOTMAC represents that a control of sea-surface temperature may be an effective method of lowering the air temperature of the bay area in summer night time

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An analysis method is described in this paper for application of the registered ship data of 155 thousands, which is length, width and depth of ships, to design of mooring facilities in port or marina. A corresponding ship is a motorboat of pleasure boats. It is tried that the length, the width and the depth of ships which are registered into Japan Craft Inspection Organization are modified and completed to maximum and actual form which is needed to design of the facilities. Draft values of ships are completed from the depth, and accordingly actual designed dimensions are obtained from Japanese boat manufacturers.
The methods of modification and completion are proposed and discussed. From results, it is concluded that the making of design dimensions is statistically possible and the application of the registered ship data to the design of mooring facilities is feasible in this paper.

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