The technology for constructing artificial tidal flat which is enhancing the biological productivity in relatively oligotrophic tidal flat ecosystem by controlling the sediment nutrient for the benthos by using dredged sediment has been developed in AGO bay. The two types of experimental tidal flat were constructed (Experimental tidal flat 1: 3000m², Experimental tidal flat 2: 4200m²). And Zostera marina bed was planted in front of the experimental tidal flat 1, 2. Then these sediment qualities and benthos habitat were monitored every season for three years. After construction, It is clear that the abundance andspecies number of benthos in the artificial tidal flat were increased more than 3-4 times before construction. And more in Zostera bed, they were also increasedmore than 10 times without Zostera bed.

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As the assessment for the project of coastal regeneration, we have tried to expand HSI model (Habitat Suitability Index model) to the HSI model that is available for benthos group of class level. Inthis study, we determined the suitability ranges of IL, ratio of silt, and depth using the former model of HSI for each benthos such as ruditapes philippinarum and batillaria multiformis, and the HSI model was verified as the model for benthos group of class level such as groups of polychaeta, gastropoda, bivalvia using field data in Ago Bay. Further HU (Habitat Unit) of field study in Ago bay was calculated by these models. The result shows that the model may be a tool of general index for the project of coastal regeneration.

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The present paper dealt with the distribution and dynamics of oxygen at the artificial tidal flat of Hannan Second District, Osaka Bay.
Oxygen-deficient waters were found on September 2005 and July 2006 at the bottom of shallow area of the artificial tidal flat where ground levels were from D. L.-2.3 to D. L.-1.9m. Photosynthesis of phytoplankton and seaweed played an important role on the dynamics of oxygen at the artificial tidal flat. Release of oxygen by phytoplankton changed depending on photon flux density, while dominant seaweed, Ulva sp. showed active photosynthesis in spite of low photon flux density. Oxygen consumption by respiration of Ulva sp. promoted hypoxia at night at the ground level of ca. D. L.-1. Om of the artificial tidal flat.

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The movement of fines in soil under one-dimensional water pressure change was studied experimentally. The sandy soil containing 10% fines were subjected to the cyclic water pressure change, and in some conditions, it was observed that the fines, whose diameters were 10-75μm, moved to the upper directions in the soil and finally reached to the surface. When the soil was fully saturated and the liquefaction did not occur, the upward movement was not observed. The upward movement of fines occurred when the soil was liquefied on the shaking table. It is concluded that the occurrence of liquefaction under cyclic water pressure change is closely related to the upward movement of fines in the soil.

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A 600-m-longs and bar extends in Sanbyakkenr egion in Nakatsut idalf lat and a salt marsh has been developed behind this sand bar, forming the habitat for many kinds of lives.The relationship between the habitat conditions of animals and plants and tidal range in this salt marsh is investigated through the field observation. This salt marsh has such characteristics that it is protected from strong wave actions by sand bar, a gentle slope extends between+0.4m and 0.6m above HWL, and there has a large time lag in changes in tide level by the existence of the meandering channels, keeping the brackishe nvironment for a long time.To soundlypreserve a salt marsh, the conservation of the geomorphology with these characteristics is required.

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The disposal of a large amount of scallop shell becomes a problem in Hokkaido. Authors developed the artificial reef that used the scallop shell as a measure ofwater pollution and sediment contamination in ports and harbors. Experimental reefs were installed at a port, then the species swarming the reefs were identify, counted and analyzed. In this study, the organic removal capacity of detritivorous organisms and their purification rates in the area were estimated. The organic removal capacity per 1-gram biota was found to be 20.0 mg-C/gDW/day for organic carbon and 0.327mg-N/gDW/day for organic nitrogen. It can be explained thatthe reef creates the biotope for the species to the space between the shells andthat it is useful for the removal of organism in the port.

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The artificial shoal area on the basis of ecosystem engineering has been appliedto the breakwater newly established at Mishima-Kawanoe Port, in Ehime Prefecture. The objective of this study is to evaluate how the target indicators established during the planning stage is achieved and to obtain ideas adopting to other environmental restoration projects relevant to port structure construction in future. The evaluation points of the ecosystem function are, 1) Index species appearing on the artificial shoal, 2) Reduction of organic carbon loaded from attached animals by various organisms activities. As a result, it is suggested that theecosystem is currentlyfunctioning well in the artificial shoal. Additionally, adaptive management concepts in developing the environmental restoration facilities are proposed.

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Considering Blue mussel, Mytilus galloprovincialis as resources of the marine products, it provides for collecting them from the seawall and using them effectively in the land region to prevent a deteriorating coastal environment as well asto get rid of nonnative species. In this study, we estimated M. galloprovincialis biomass that could be taken for a year. Organic carbon per wide of the seawallattaching living thing, is 1.4 kgC/m in July when the width of M. galloprovincialis becomes maximum growth. Collecting M. galloprovincialis twice a year is considered to be most effective. We recommend harvesting M. galloprovincialis for the first time in May when their biomass is large and for the second time on the day before it drops out in August.

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The marina in Sakata Port was blockaded with the floodwood and suspended particles, and the blockage was deemed to be caused by the flood from Mogami River in July 2004 and the typhoon that approached the port in August 2004. In consideration of phenomena obtained from the interviews with the port managers, etc. and the records of the damage, numerical simulation was conducted with calculation of currents, waves and winds. The typical movement of suspended material under the two natural phenomena was reproduced with the simulation.

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Wave measurement data acquired over more than two decades along the coasts of Japan and the Pacific coast of USA are analyzed from three points of view (1) year-to-year variation, (2) jumps and (3) trends for wintertime- and summertime-meanvalues of significant wave height and period. Main findings are as follows:(1) the winter of 1998, containing the severest El-Nino period, gives the highest mean wave height along the western Pacific coast of Japan and the Pacific coast of USA.(2) a seesaw-like variation with a two-year period of season-separated meanwave heights along the Pacific coast of Japan may be observed and (3) one jump and an increasing trend in summer-time mean wave period data may be observed along the coasts of Japan.

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Based on the global meteorological forecasting system starting in 1990's, earth system simulation models, such as earth simulator, have been developed and applied to many kind of environmental assessment. This paper introduces the frame work and applications of the Asian Environment Simulator (AES) which consists of main models for atmosphere, land surface, ocean, hydrology, dynamic vegetation, and coastal, river, estuary models and urban air-water environment model. AES has been developed in IDEC, Hiroshima University for international sustainable development and cooperation. Some examples of its application to the Coastal Engineering problems were shown for future development of coastal engineering studies collaborating with river engineering, hydrology, biology and meteorology.

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This paper explores the evaluating system of coastal landscape by using the KANSEI engineering as well as the social sciences to collect data for the landscape data base. The system have been found to be useful in designing and evaluating of coastal landscape with various types of beach protection works such as detached breakwaters and submerged artificial reefs. The landscape KANSEI design systemconsists of the coastal landscape data base and Kansei designing system in whichprincipal component analysis was introduced. The system was applied to the actual castal improvement works for shore, and it was shown that the system is also very useful to get the agreement formation for the design at the citizens' participation in municipal general affairs.

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Working environments at fishery ports and harbors during the winter in cold, windy regions are very severe for workers. Such environments may affect the worker's health, as well as lowering the work efficiency. To examine the necessity of facilities such as the wind and snow shelters, we should quantitatively evaluate in terms of human sensation. We conducted sensory experiments on subjects to examine the practical application of some thermal indices and “work efficiency” under the cold condition. There were no differences between sexes regarding the thermal responses. Of five thermal indices studied in this report, the WCI was the most useful index from a practical point of view. We also clarified influences of thermal environment and elapsed time (exposure time) on the work efficiency.

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The stratification of upper layer of coastal water can be regarded as an unused energy source for heat pump systems near coastal area in the summer. This study examines feasibility of heat pump system for coastal area using a cold water mass beneath the thermal stratified upper water. The field observations for thermalcharacteristics in the harbor were conduced through the summer season. The characteristics of stratified water are investigated by the field observations and numerical simulations. The breakdown of stratification is also examined by the numerical simulations for the heat pump system using the coastal water.

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In recent years, anchored vessels sometimes dragged their anchor and stranded incoastal zones during the evacuation at stormy weathers. It is very important to verify the accuracy of numerical simulation of anchored ship motions. In this study, some points of numerical simulations are improved to reproduce accurately the phenomenon of stranded casualties. The situation of the dragging anchor can be reproduced by solving the equation of motion at seabed. The approximated hydrodynamic forces of the anchor chain make the accuracy better. Finally, the detailedsituation can be reproduced by considering the dragging anchor, the drifting of ship and the hydrodynamic forces of mooring chain. It makes possible to simulateaccurately the safety of anchored vessels offshore harbour as the new planningscheme.

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The disaster reduction facilitating emergency relief transport is one of the important tasks to manage the extensive disaster that caused by To-nankai and Nankai earthquake. Marine transport plays important roles in such disaster managementbecause of it's massiveness of transportation capacity. Especially preparing forthe case that tsunami debris close port facilities, it is necessary to develop the framework for efficient transport. With this purpose in mind, this paper compiles the estimation methods on the amount of debris for the removal planning, and quantifies the effect of early opening of port using the network analysis method. As the result of the test estimation in Wakayama prefecture, amount of debris, removal workload and the efficiency of marine transport on emergency were quantified.

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An integrated inundation model that consists of a 2D overland flow model, a rainfall-runoff model and a 1-D sewerage network flow model is developed. The overland flow model is refined to capture the effects of urban structures on flooded flows on Cartesian coordinate system using the concept of flow porosity and a CIP scheme. The integrated model is applied to the inundation due to the high tide brought about by Typhoon 0416 in the downtown of Takamatsu city. The numerical simulations are carried out using the computational mesh of 12.5m×12.5m withand without the sewerage system.The comparisons with the flooded records clearlyshow that the heavy inundated areas are well reproduced by the present model andthat the numerical simulation taking account of the sewerage system gives betterresults.

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Questionnaire surveys were conducted to investigate discrepancies between consciousness of citizens for tsunami disaster prevention assumed by administrations and actual consciousness of residents and visitors in tsunami vulnerable areas. It was found that the residents expect hardware measures (structures) against tsunami attacks, whereas visitors prefer software measures for evacuation. It is important to guide citizens toward software measures and give appropriatei nstructionsf or effectivee vacuation. Citizenws ho have experienceo ft sunamia ttack orlivingn ear the coastlineh ave clear images for threat of tsunamis.Goodc ommunicationb etween administrationsa nd citizensc an restrain the reduction of efficiencyf or tsunamip rotectionm easures.

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The authors have developed the evacuation model against tsunami, which can handle the evacuation behavior in a district with several buildings. The main purposeof the paper is to verify the model based on evacuation training data. Evacuation behavior of 184 employees among three buildings in a company was recorded during evacuation training against tsunami. Also, the authors have simulated evacuation behavior during training under the same condition with training and comparedthe predicted results of the model with the ones which are obtained from training. The main indexes for evacuation behavior such as the predicted time to complete the evacuation are almost the same with the data in training and it was confirmed that the model could precisely predict evacuation behavior against tsunami.

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Coastal dike should be constructed and maintained to prevent damage in the hinterland caused by the design tsunami, but can not always be constructed because ofland availability etc. Besides this, larger tsunamis may overtop thecoastal dikeand run up on the hinterland. In such cases, “hard” measures in the hinterlandas well as measures prompting resident's evacuation should be considered. The measures, such as forest zones, elevating land and secondary dikes, can mitigate damage to houses and humans through tsunami runup control in the hinterland. To realize the measures, we evaluated tsunami damage mitigation effects ofthe “hard” measures in the hinterland.

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The fishing boat damage and its reduction plan are discussed in the present study through developing hazard maps in the sea. Although the countermeasures on the land against the tsunami attack have been developed by constructing sea walls and creating hazard maps, but one in the sea is less at the present. The evacuation flow for fishing boat is discussed by the process of issuing warning and making decision and action, depending on the location of occurrence of tsunami and that time. A hazard map on the sea could be made by adding the information of tsunami arrival time, maximum water level and velocity and boat damage index developed in the present study.

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The destruction of storage of flammable materials by the hydrodynamic force of tsunami may result spread of large fires, flammable materials such as spilled oiland ignited material advected and diffused by the tsunami current in a harbor oron inundation land. To prevent damage from spreading in tsunamis and oil spills and functional decline in harbors, we carried out numerical simulation for oil spreading in the 1964 Niigata Earthquake Tsunami, in which the initial conditionsof land, water level, and oil are carefully given by considering the fault motion, liquefaction, and storage of oil. We proposed some conventional method to estimate each initial condition in the tsunami simulation.

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This paper is intended as an investigation of synthetic education to disaster prevention for the Next Great Earthquake and Tsunami. Two points need to be made. The first is continuation. The second is effectiveness. Pursuing these questions, we almost reach the core of technique for Disaster Prevention Education. So the purpose of this paper is to study as Disaster Prevention Education. The authors showed technique of “pleasant disaster prevention” as a subject ina disaster prevention drill. One is a simulation game; the other is a street dance for disaster prevention drill. The following results were obtained:“Pleasant disaster prevention” and Disaster prevention training is effective.Cooperation of school teachers are necessary by disaster prevention training of education for the handicapped schools.

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It is said that Tonankai-Nankai Earthquake will occur along Nankai - trough in near future. The countermeasures for this earthquake become urgent problems for the local governments in Kinki region. Furthermore, the evacuation of vulnerable people to disasters becomes problem from some resent flood disasters. And the population aging will advance rapidly in Japan, the evacuation of vulnerable people to disasters will be big problem. This paper suggests the strategy planning ontsunami evacuation countermeasures. This strategy planning was discussed by somelocal government staffs of disaster management division in Kinki region and someresearchers.

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In this study, run-up tsunami simulation with high-resolution topographic model is applied for design of tsunami countermeasure such as sea wall and breakwater in the case of coastal area in Sanriku. The topographic model of 10m grid DEM (Digital Elevation Model) is made by LiDAR (Light Detection and Ranging) data. Theresolution of the altitude of LiDAR data is 15 cm. The behaviors of tsunami on the land with three plans of the countermeasure in the coast are carried out using tsunami simulation and compared. The effect to reduce the inundation area and damage, and the coast to construct them for each plan are discussed.

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Recently, coastal forests have received much attention because they provide both environmental and tsunami mitigation benefits. Individual trees in a coastal forest have distributed trunk diameters, so their endurance strength against tsunami fluid force will vary. In order to assess the tsunami attenuation performance of the forest, the trunk diameter distribution is essential information. This study examines the applicability of the Weibull distribution to describe the trunk diameter distributions, and discusses the time varying characteristics of the Weibull parameters as the forest grows up. Furthermore, for a model forest possessing the distributed trunk diameters, a mathematical model to quantify the tsunami attenuation rates including tree falling down effects is proposed.

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Tsunami prevention effects of coastal forest with several species of tropical tree have been investigated by one dimensional numerical simulation based on the non-linear long wave equations. The effects vary greatly with the species, the wood size and their combination. It is found that a coastal forest system consisting of 100m wide Rhizaphora apiculata woods in the water from the shoreline on the bottom of 1/200 slope, 50m wide mixed woods of Pandanus odoratissimum and Casuarina equisentifolia, and 50m wide Pandanus odoratissimum woods on the land of 1/100 slope can reduce the run-up height from 6.3m to 4.7m and the tsunami force at the end of forest from 14kN/m to 3.3 kN/m for a tsunami of 15 minutes in the period. The tsunami height at the shore line in case of no forest is about 5m.

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The amount of water required for an exclusion salinity of 0.5g/cm² density in argillaceous soil was calculated by a field experiment for salt damage reduction of farmlands by Tsunami. Next, a simple salt damage estimation method that was proposed to be performed through meteorological observatory data was demonstrated. Stripping off the surface salinity soil so that the surface saline water with salt flows out by rainfall or watering through the drainage canal is effective as a salt exclusion measure that farmers can perform. A decision flow chart for salt exclusion planning to reduce tsunami salt damage was shown based on these results.

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Songkhla Lake is located in the Southern part of Thailand, connected with the Gulf of Thailand through a narrow channel. In the southernmost lake, Thale Sap Songkhla, aquaculture of sea bass plays an important role in the area's economy. In recent years, however, there have frequently been sudden deaths of fishes which may be due to the significant change in water quality in this lake. In-situ investigation has been carried to thoroughly clarify the mechanism of the changes of water quality parameters in Songkhla Lake. In this field investigation, automated water quality measuring instruments are installed in an aquaculture area to obtain time variation of current, dissolved oxygen (DO), salinity and temperature. In addition to investigate the water quality changes in the lake, an artificial neural network (ANN) model is applied to evaluate the mechanism of DO concentration in the Songkhla Lake.

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he sand banking on the front of the coast protection was examined to achieve the development of a new coast maintenance technology considering both environmental protection and disasterprevention in Tamana-Yokoshima coast, Kumamoto. The change of the natural topography generally maintained stable from the investigation of the embankment front sea area, and there was little change in the bottom quality. In addition, the bottom topography would stabilize for a certain period, and benthos increased in one year after the sand banking had been made.

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A lot of environmental restoration projects at the coastal zone have been implemented, though the evaluate method is still under the developing stage. Therefore it is important to understand theecosystem and establish the evaluation technique for the tidal flat ecosystem. This study applied and examined the Habitat Suitability Index (HSI) model to evaluate benthos habitat suitability on the tidal flat. As a result, to use amethod of “Minimum Function” which selects the minimum Suitability Index (SI) could improve the accuracy of the HSImodel. This does not means improvement of the data obtained, but specification and selection of the dominant factor affecting on the benthos habitats.

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Field survey of storm surges and inundation caused by Typhoon 0415 was conducted along north coast of Yamaguchi Prefecture that is normally considered a safety region to the typhoon-induced surges and waves. Storm surge hind-cast was carried out by the atmosphere-wave-ocean coupled model for surges and waves to verify the model predictability and to get the information of maximum wave and surge height distribution. Both meteorological/coastal observations and surveyed run-up heights support the applicability of the numerical model. As the recent global warming has changed the coastal climate, reconsideration to storm surge disasters should be done even in the safety coasts until now.

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Kitaebi Coast is attacked by the 12^th Typhoon on the 5^th of September and an extraordinary low pressure zone on the 6^th of October in 2006. The first attack destroyed bank-filled concrete and the second attack destroyed whole coastal banks. Emergency countermeasure was done after the second attack. On the 13^th of October, the next typhoon arose and approached to Japan. Then the emergency countermeasure level was increased as the previous permanent facility level, because officers considered resident fear of the third attack on the assumption that main cause of the disaster is the change of submerged topography. Detailed survey was done after November. Additional causes are waves and broken-down banks. Fear by residence was surveyed by questionnaire to common people and emergency countermeasure was evaluated. The study suggests that strong emergency countermeasure after the continuous damage should be reasonable.

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This report is to summarize the result of our field survey for 2006 Java Tsunami. Major conclusions are as follows; 1) The area from 108.0 E to the eastward was affected by the tsunami with the wave height of 3-5 m. 2) Tsunami run-up and inundation around tombolo or sand dune are investigated. Some topographical or artificial factors in tsunami disasters are found out: tombolo, the places where river mouths cut across sand dunes, roads or paths leading to coast lines, and drifting fishery boats. 3) There is the area in oval shape with the water depth of over 3000 m off the south cost of Java Island. Tsunami numerical simulation proves that the tsunami refracts toward north direction when it propagates out of this area. Such bathymetry and refraction can cause the tsunami to reach to the distant area like Yogyakarta.

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The novel instrument based on a Lagrangian Acoustic drogue (LAD) has developed for estimating the sediment transport parameters in the estuary. This instrument consists of GPS, ADCP and Nephiometer with Lagrangian drogue. The field experiments using LAD was conducted in Brisbane River, Australia on Dec. 7, 2006. Time-space distributions of the turbidity, horizontal current velocity and direction were obtained. The settling velocity is estimated by analyzing the temporal and spatial changes of the turbidity contour lines. The linear correlation was found to be existed between suspended sediment concentrations (SSC) and settling velocity. An Approximated equation using the method of least means squares agrees well with the results by Van Leussen (1999).

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It is important to grasp water surface profile when we discuss various phenomena in coastal zone. For example, sediment transport and rip current are determined mainly by the spatial distribution of waves in surf zone. Measurement of waves using Euler's method is a general. However it is difficult to determine spatial distribution of waves. A considerable number of studies have been conducted on the spatial wave distributions by using two video camera images. These studies analyzed azimuth difference of digital images taken by video cameras. In this study, the authors proposed the procedure to measure surface profile by applying stereo matching method of two images of the sea surface without any targets or tracers. The validity of the proposed procedure was examined through the experiment in a wave basin.

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A new method of estimating doppler spectra from HF ocean radar backscatter has been developed to obtain higher signal-to-noise ratio in doppler spectra. This method uses a linear filter technique to remove a noise in ocean radar data and multivariate auto-regression model to estimate highly accurate spectra using the minimum AIC method. The Doppler spectrum estimated using the linear filter technique includes the squared coherency of real and imaginary parts of the complex Fourier coefficients of ocean radar backscatter. This method is applied to in-situ observation data and compared with the doppler spectra estimated by existing method using the FFT spectral amalysis.The method can produce highly accurate estimates with higher SN ratio in Doppler spectra than those by other method.

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Averaged X-band radar images have been analyzed to detect occurrence of rip current. Radar images were collected at research pier HORS on a straight sandy coast. Rader images capture wave propagation, breaking and run-up motions. Hourly averaged images have been processed, in which characteristic cross shore patterns have been observed frequently.This pattern resembles to neck and head of a rip current captured in aerial images. Cross shore wave propagation speeds were smaller at zones where the pattens were observed suggesting existence of offshore-wards current. Wave and tide conditions were analyzed, showing the pattern formation was most frequent when the waves are high, shore normal incident, and tide level is low, which are equivalent to the known conditions of rip current occurrence.

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DBF ocean radar can detect surface currents widely with high resolution in all weather conditions. We developed 24-hours real-time oceanographic monitoring system, which based on automatic figuring system for surface currents and wireless communication system with high-speed packet communications (up to 384 bps). Figures of surface currents can be delivered every 15 minutes with time lag of about 45 minutes through the Internet. The Dragon System is feasible for emergency observation after sudden ocean accident such as oil spills because of high portability. Field observations showed a measurable rating is more than 90% within 15 km along the receiving beam lines. Amount of measuring points in one operation periodically change over time. Its fluctuations were related with tidal variability.

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We develop a method automatically identifying peak frequencies in the sea echo Doppler spectrum measured by DBF Marine Rader system to estimate coastal surface currents, and then evaluate the accuracy and Iimitation of this method. The velocities from the Radar system estimated with this method are compared well with near-surface data with ADCP. The processing time of this method is short in about 40 seconds.These results suggest that this method allows one to estimate remotely coastal surface current in real timeusing DBF Marine Radar system.

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An accurate information on sea grass distribution is an essential prerequisite for managing sea grass resources in a coastal area. In this study, the four-flux model for the estimation of sea grass mapping is developed based on an inversion of reflectance estimation at sea bottom. This method considers parallel and radiative light transfers in the water and has capability for sea grass distribution and water depth estimation, together. The validity of the method was verified by the field surveys for sea grass meadows, bottom bathmetry and aerial photograph. The estimated sea grass coverage from the image shows nice agreement with the observed data.

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The method of velocity measurement using an Ocean Radar has already come into practical use.However the measured velocity is sometimes not reliable because the first order Doppler spectra may have double peaks or flat peaks.To reveal the influent factor on the shape of the spectrum, effects of currents and waves are analyzed using observed data and model calculation results of Doppler spectra.Results show that current unsteadiness make the spectrum peaks flattened, and that horizontal shear and convergence of current cause double-peaked spectra.The second order Doppler spectra depend on the period and direction of the sea surface wave.We propose a simple equation estimating the significant waveheight from the measured Doppler spectrum.

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This paper describes the observation of wave fields by X-band radar at Sumiyoshi coast in Miyazaki Prefecture. Wave propagation was monitored directly from radar images, and two-peak directional wave spectra were obtained. Wave direction acquired from X-band radar agreed fairly well with the measured data from the Doppler-type Wave Directional Meter (DWDM). The correlation was examined between the ratio of radar image amplitude and the significant wave height for dataset classified by local wind speeds.

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A three-dimensional visualization method (3D-BTV) for bubble measurements was developed to measure bubble shapes and velocities in a liquid. The 3D-BTV method is based on the combination the 3D shadow graph method and 3D super resolution particle tracking velocimetry. The proposed method was verified by virtual experiments and the real measurements of air bubble motions in the water, respectively. In this study, it can be realized that The 3D-BTV method has capability to measure the both bubble shapes and motions in the 3D space with highly temporal-spatial resolution in comparison with the previous technique.

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