Future change of tropical cyclone (TC) climatology is discussed by GCM ensemble runs. With GCMs, large degrees of uncertainty exist in future change in TC climatology at basin scale, and central pressure changes for each basin. The projection of future change of TC characteristics was conducted based on a series of ensemble experiments by the high-resolution AGCMs. The model ensemble means and their standard deviations of cyclogenesis and cycloysis are disucssed in detail. The future change of location and intensity of TC are analyzed with synoptic climate.

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Based on the climate scenario (MIROC-ESM, RCP4.5), distribution of sea-level rise (SLR) were shown globally, as well as shown in details around Japan and Southeast Asia coasts. A new SLR risk index (Relative sea-level rise ratio; R-SLR) were developed in the present study by using the annual variation and the averaged rise for 100 years obtained from the sea level data. Global distribution of the R-SLR were also shown, and the comparison of the distribution of SLR were discussed. Since the distribution of R-SLR was significantly different from that of SLR, it is necessary to focus on the areas where R-SLR is high although SLR is low, when the adaptations are considered against the future sea-level rise and climate change.

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The presence of sea ice in the polar region plays an important role in the global climate system, and it is therefore important to understand the characteristics on the temperature and salinity in growing process of sea ice. The objective of our study is to investigate characteristics of the temperature and the concentrations of salt under the ice conditions of grease ice and grease-pancake ice in wave fields. We used a wave tank installed in a cold room and measured the surface temperature, the water temperature, salinity, and ice thickness. As a result, it was found that the ice thickness and salinity rapidly increase when the water temperature became less than minus 2.2 degree. The grease ice condition showed the strong tendency than the pancake ice condition.

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The influences of climate change due to global warming have been estimated on not only sea level rise but also wave characteristics such as height or energy flux. In this study, the characteristics of medium and long term beach profile change is investigated based on the observed beach profile data at HORS for past 24 years and the relationship between the wave characteristics observed at Kashima port and the climate indexes. In order to estimate the influences of the medium and long term wave characteristic change, a theory is introduced based on equilibrium beach profile with wave parameter, which is theoretically based on sediment characteristic. Moreover, the validation of the theory is evaluated based on the observed beach profile data and wave data.

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Horizontal and vertical characteristics of the tidal energy distribution around Okinawa and Tsugaru Strait are investigated in this study. We computed tidal currents using MIT general circulation model which developed to compute non-hydrodynamic and three-dimensional current fields. Semi-diurnal and diurnal tidal currents were dominant in Okinawa and Tsugaru Strait respectively. Strong tidal currents more than 1.5 m/s are found to appear by concentrating in the channels formed between the islands in both domains, which brings the tidal power of 0.51 and 1.69 GW in the entire cross section of the straits. The timing of the peak current velocity, therefore tidal power, is shown to vary 30 min to 2 hours depending on its vertical level.

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A new reflection wave dissipater that has also a wave energy extraction function for the electric power generation has been developed. In order to expand the effective range of wave frequency, a double-water-chamber type of seawall was newly proposed. The wave energy extraction devices presumed in this study are air and water turbines. The oscillating water column type of wave power extraction was assumed. Typically, by mounting a horizontally rolling turbine near the opening of the water chamber, the kinematic energy of wave induced jet flows from the opening can be extracted. The basic characteristic of a double-water-chamber type of seawall has been extensively examined from both the theoretical and experimental points of view.

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It has been confirmed that the energy extraction rate is significantly improved by adopting the flow guide equipment which has curved fins on the circumference of a Savonius-type vertical turbine. In the real field, it would be required to install several turbines in a series, say parallel or tandem allocations, in order to obtain large amount of electric power from tidal currents. In this study, it was presumed that the installation site of the tidal power turbines was limited to the vicinity of coastal area along islands in Kurushima Straits. Under such limitations, it becomes important to know how to specially allocate a group of the turbines to maintain the energy extraction efficiency. In this study, the interaction effect among the specially allocated turbines was examined by both experimental and theoretical studies.

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In the present work, a numerical model is presented for the wave energy converting system which consists of mooring plates, floating breakwater, gear box and dynamos. In the calculation, the dynamic response of the floating breakwater is analyzed considering the interactions among water waves, the impermeable mooring plate, the floating body and the gear box. A direct-forcing Immersed Boundary (IB) method is applied to handle solid object boundaries and the VOF method is employed to track the free surface. The applicability of the proposed model is examined using available experimental measurements including the water surface profiles, the displacements of the floating breakwater and the wave energy conversion, and good agreement is achieved.

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A typhoon potential vorticity bogussing scheme and an atmosphere-ocean-wave coupled model were used to calculate strong winds, heavy rainfall, storm surges and high waves caused by maximum potential typhoons in Ise Bay under present and future climates. The calculated results showed that the time differences among the peak times of external forces caused by the maximum potential typhoon gather within 2 hours and the possibility exists of an occurrence of the coupled hazard in Ise Bay. Times exceeding design values for the storm tide, significant wave height, and wind speed were shown simultaneously to evaluate the risk of coupled hazards. The results showed that Tsu Port is an extremely dangerous area for coupled hazards and that the time exceeding design values reaches 111 min.

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Elementary and junior high schools are important evacuation facilities that have large capacity and high reliability. Local government offices are also important as command centers at and after tsunami disaster. This study analyzes an inundation risk at disaster response bases (DRBs) such as schools and local government offices based on variation of tsunamis assumed by changing of earthquake moment magnitude (M_w) varying from 8.7 to 9.0 in increments of 0.1. Among the 283 DRBs in Wakayama Prefecture, the number of lost DRBs is 18 at M_w 8.7, but increases to 75 at M_w 9.0. For 16 % of DRBs, the inundation height increases linearly with the increase in M_w, whereas 69 % of DRBs inundation height increases markedly at the M_w exceeding 8.9. The inundation risk level at DRBs becomes significantly high when M_w becomes 9.0.

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A lot of coastal forest was broken or knoked down by the tsunami of the Tohoku Earthquake. The damage in Iwate and Miyagi prefecture was too much to be classified. Therefore we surveyed the damage in Iwaki city, Fukushima Prefecture where the coastal forest had limited damage. This survey is the consideration about the damage and the breakdown limit of the Tohoku district Pacific Ocean coastal forests. The researches have been advanced that the disaster prevention effects and limits against tsunami external force for coastal forest with the investigations about historical tsunami or The 2004 Sumatra Tsunami. In this research we focused on and referred to the research done by Dr. Shuto in 1985. He analyzed the disaster case of Japanese coastal forest which mainly consisted of black pine and red pine.

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The gap between predicted tsunami height and the realized that increased the amount of damage and delivered a lot of difficulties on the operations of the 2011 Great East Japan Earthquake Disaster. In this paper, the authors analyzed the stochastic property of resultant tsunami height considering the uncertainty in source parameters. Tsunami height at each site is estimated using probabilistic simulations and represented as a probability density function or inverse distribution function. Using these probabilistic description, we can evaluate not only probable maximum tsunami height but also most typical tsunami height at each site or the probability that tsunami will exceed the assumed tsunami height. And combining this with the level of tsunami preparedness, we can revisit the progress of countermeasures quantitatively.

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The effect of tsunami energy dissipation of disaster-prevention farmland was evaluated. We conducted hydraulic model tests to evaluate the delay of tsunami run-up to a residential area, and found the tsunami was delayed by 130 s for short-wavelength tsunami. The short-wavelength tsunami did not reach the residential area in the case of disaster-prevention farmland, but reached the top of the residential area in the case of normal farmland. In the case of long-wavelength tsunami, the volume of tsunami that overflowed the coastal dike exceeded the capacity between the coastal dike and a third dike and reached the residential area.

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In this paper, a model on car evacuations and traffic jams in case of tsunamis is newly proposed and applied to the tsunami evacuation simulation in the case of Kesen-numa city when Tohoku - Pacific Ocean Earthquake Tsunami attacked. While walk evacuation simulations imply some inhabitants hard to escape only by walk, car evacuation calculations introducing the optimum velocity model represent the actual traffic jams recorded by the video images well. The testified causes of some bottlenecks on car evacuations such as narrow roads toward upland and restricted entrance to roof parking or the bridge can be sufficiently explained through the simulations, which reveal that success rate by car evacuation significantly changes according to driving unit number and are expected to apply to disaster prevention plans.

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On March 11, 2011, the 2011 off the Pacific coast of Tohoku Earthquake occurred. The tsunami generated by the earthquake struck and caused extensive damage to Japan's coastal areas. In Iwate prefecture, 35 of elementary and junior high schools were inundated. We conducted questionnaire hearing survey to investigate the evacuation of students of elementary and junior high schools. The results of the study are as follows, (1) Some schools were inundated while the school buildings are not in expected inundation area. (2) The schools in expected inundation area and low elevation area tend to start evacuating within 10 minutes after the earthquake occurred. (3) After evacuation, in over 20 percents of the schools, they moved to another place for safety or to find shelter.

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The purpose of this research is to develop a Tsunami Trace Database by collecting historical materials as well as documents concerning tsunamis which had hit Japan and, of which the reliability of tsunami run-up and related data is taken into account. Based on acquisition and surveying of references, tsunami trace data over past 400 years of Japan has collected into a database, and reliability of each trace data was evaluated according to categorization of Japan Society of Civil Engineers (2002). As a result, trace data can now be searched and filtered with reliability levels accordingly whilst utilizing it for verification of tsunami numerical analysis and estimation of tsunami sources. By analyzing this database, we have quantitatively revealed the fact that the amount of reliable data tends to diminish as it goes older.

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Mechanisms of erosion of soil embankment due to tsunami were investigated on the basis of field survey in Unosumai, Kamaishi City, Iwate Prefecture, where a railway embankment located 600m inland to the seawall was eroded by the 2011 Tohoku Tsunami. The topography survey revealed significant erosion at the central part of the embankment where the maximum erosion reached 2m. The erosion was correlated with the temporal integration of bottom shear stress in the region where the topography is relatively flat whereas the correlation was found to be poor for the region where the inland topography was steep. The phenomenon called momentary liquefaction appeared to play an essential role in causing the instability of the embankment, especially in the region where the rapid drawdown of tsunami was observed owing to the steep inland topography.

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Many coastal structures, especially embankment and revetment, were damaged seriously by Tsunami of Tohoku Earthquake occurred at March 11, 2011. However, many Gentle Slope-type Revetments were not broken and remain the function of disaster prevention. In this study, we focused generation mechanism of robustness of Gentle Slope-type Revetments to overflowing tsunami on the basis of field observation in Miyagi Prefecture and numerical analysis.The field observation revealed that almost no Gentle Slope-type Revetments were broken. Numerical results suggest that the robustness of the Gentle Slope Revetments is due to the decrease in the water surface elevation of the overflow and the landside scour depth.

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In order to investigate the damage mechanism on fishery port facilities and to revise the external force in the planning of the facilities, field surveys were given in the 12 fishery hub ports. Damaged facilities checked cyclopaedically in these ports, and then 5 facilities were surveyed in particular. In the survey, it is revealed that the breakwaters were damaged by the water-level difference in the undertow and by the scour of the foundations due to overflow in addition to the traditional reason which causes the pressure in the silling wave under non-overflow condition. Therefore, another wave pressure expression which refers water-level difference in the overflow and can use in the undertow was advanced. The body stabilities of the facilities using the new expression were good corresponding with the damaged facilities in the survey.

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In order to investigate the damage mechanism on fishery port facilities at Onagawa fishery port, field surveys were conducted and these body stabilities were checked using the tsunami simulation modeled with water overflowing structures. In the survey, caisson and riprap foundations of the north and south breakwater at the mouth of the port collapsed outward and inward of the port, respectively. The modeled results explained that the caisson withstood the pressure of the spilling wave but was broken with the undertow and that riprap foundations were destroyed with the spilling wave. In addition, the modeled results demonstrated the breakwater head destruction which was affirmed in the video that the head part is destroyed finally.

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In order to investigate the damage mechanism on fishery port facilities at Taro fishery port, field surveys were conducted and stabilities of the facility bodies was examined using the tsunami simulation modeled with flooding. The east and south breakwaters were found to be collapsed inward of the port, wave-dissipating blocks were found scattered in all directions and the breakwater substructions were also destroyed. The modeled results were verified with the flood areas as well as with the height of the watermarks. The results revealed that the height of the watermarks could not be reproduced without the facility collapses in the model. The stability analysis of structures was consistent with the survey results well, in which the east, south and west breakwaters collapsed while the offshore breakwater was intact.

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For the preparedness against huge tsunamis, the following were conducted: An investigation of buildings damaged by a huge tsunami caused by the earthquake off the Pacific coast of Tohoku was executed for April 9-15, 2011. Wooden buildings had suffered heavy damage when inundation depths exceeded 1.5m and rein-forced concrete buildings had broken when inundation depths exceeded 5m. Then, the comparison between these damage data and diagrams of Yamamoto et al. (2011) for predicting a building destruction grade was executed, and it turned out that the diagrams could explain the actual building damage well. Finally, it was also shown that the method of applying inundation depths got using a numerical simulation model of Yamamoto et al. to the diagrams predicts the actual damage with sufficient accuracy.

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Huge damage of the civil structures caused by Tohoku-Pacific Ocean Earthquake and Tsunami in 2011 has never been seen before in our latest history in terms of that the tsunami has done tremendous damage to the large area. The strong wave power and flow generated by the run-up of it has destroyed many sea and river embankments and buildings in coastal area. Additionally, they caused a large-scale geographical variation. This paper shows one's consideration of the structural damages with massive geomorphic change due to Tohoku-Pacific Ocean Earthquake and Tsunami in 2011.

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The Great East Japan Earthquake occurred on March 11, 2011 and the coastal zones along the Pacific Ocean in Tohoku area have received severe damage by tsunami. Though most of the coastal forestation has been suffered and has been swept away due to currents induced by tsunami, some forestations have remained partially up to now. In this paper, an inspection on the state of the damage of forestations in Iwate and Miyagi prefectures is stated. Also, the investigation concerned with the forestation which has not been swept away by tsunami at Nagahama Seaside Park located in the city of Ishinomaki, Miyagi prefecture is performed in order to clarify an effect of the forestation to reduce impact of tsunami. Furthermore, improvements to diagrams by existing studies are proposed to evaluate the effect of forestation more properly.

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The Port of Hachinohe suffered severe damage by the 2011 off Pacific Coast of Tohoku Earthquake Tsunami. To understand the tsunami and its-induced damage, a field survey was conducted. Further, numerical simulations were also carried out to understand propagation and inundation of the tsunami. Results of the field survey and numerical simulations indicated that the tsunami of about 8 m high hit the port, and caused inundation, various debris including shipping containers, destruction of breakwaters and sea-bottom deformation in the port. It seems that the breakwaters and coastal forest contribute to reduction of tsunami impact.

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The present paper reports the trace heights of the 2011 off the Pacific coast of Tohoku Earthquake Tsunami along the Pacific coast of Aomori Prefecture, Japan. The trace heights were low (2-3 m) along the southern coast of Tsugaru Strait, in the north of Shimokita Peninsula, except for the neighborhood of Noushi area, where the heights reached up to 6 m. On the eastern coast of the peninsula, the trace heights were measured around 2 m from Misawa and its northwards; meanwhile the heights exceeded 10 m on the southwards. Result of the numerical tsunami modeling suggests that the local variability of the tsunami heights along the Shimokita Peninsula is explained by the edge waves and bay resonance.

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We examined tsunami behavior of the 2011 off the Pacific coast of Tohoku Earthquake in the Shikoku coast by conducting field survey and data analysis of tide gauges installed in harbors and river mouths. In Tachibana Bay and Susaki Bay those are both V-shaped, the highest sea level by the tsunami has reached more than 3m. As a result, the floor flooded damage and extensive fishing damage were occurred in several districts. In Tachibana Bay, the tsunami was amplified to approximately 2.5 times the height at the bay mouth.

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In this study, simple field surveys were conducted at 29 fishing ports whose shore protection facilities had been damaged by the Tohoku Earthquake Tsunami occurred on March 11, 2011. Among the sites, 10 fishing ports were selected in order to investigate the characteristic of damage mechanism by conducting detailed field surveys. Based on the detailed field surveys, tsunami numerical simulations with non-linear long wave equation or CADMAS-SURF are implemented to investigate damage mechanism of the port facilities.

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We conducted a field survey to quantify the tsunami damage of the village surrounding the Moune bay. We measured the runup height of the tsunami at 29 points around the bay and estimated the surface velocity during the rundown phase using video records. More than 90% of houses existed in the runup area were completely broken and the resultant debris were distributed over the path of the tsunami. We setup computational conditions based on the field survey and numerically investigated the transport process of the debris of different sizes and densities. Based on the numerical experiments, we found that the most of floating debris were flushed out from the bay, while sinking debris were dragged over the bottom and mainly accumulated along the thalweg.

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Field survey on coastal dike damage and scouring induced by the Great East Japan Earthquake Tsunami was conducted in the Southern Part of Sendai Plain. Erosion rate of dike cross section was estimated by using topographical data obtained by airborne laser scanner. The erosion rate tends to increase with relative height of coastal dike from the landside ground. Tsunami overtopping caused scouring at the landward toe of coastal dike, being a trigger of dike failure. Cross-sectional shape of the ground induced by scouring and thickness of tsunami deposit was estimated by portable dynamic cone penetration test and trench survey.

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We investigated the detail of house damage and inundation depth by the 2011 Tohoku earthquake tsunami at Sendai, Japan. The results showed that the inundation depth and house damage decline from 1.3 to 1.6 km inland, although the damage is severe less than 1 km inland. We further simulated the tsunami to clarify the inundation flow at the coast of Sendai city. The numerical results indicated that the mound in front of Arai area blocked the tsunami flow and reduced the current velocity. Using the detailed field data, we finally proposed the fragility and damage function of house damage against the 2011 Tohoku earthquake tsunami. The functions clarified that the house damage significantly increases from 2 - 3 m tsunami inundation depth.

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Many civil engineering structures such as sea walls etc. were damaged severely by Tsunami flood in the 2011 Off the Pacific Coast of Tohoku Earthquake. On the other hand, several important lessons on the damaged or non-damaged sea walls etc. were shown for the future countermeasures against Tsunami. This paper shows the several effective lessons on the damage characteristics of sea walls, breakwaters, earth banks, dug pools etc. based on the field survey conducted at Sendai Plain. Furthermore, based on the above lessons, the performance-based design concepts on the hardware countermeasures including sea walls etc. against Tsunami are discussed for the future reconstruction.

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In this study, we surveyed the tsunami damage in Asahi City, Chiba, which was devastated by the tsunami. In addition, the damage caused by tsunami revealed the importance of soft countermeasures to supplement the disaster prevention functions of hard countermeasures. Therefore, we devised a method whereby residents hand down lessons from disasters. The inundation height above T.P. (Tokyo Bay mean sea level) was about 4.6 meters in Shimonagai, Asahi City. The tsunami run-up height in the district was about 5.1 meters. This reach point is consistent with the data from interviews with eyewitnesses. The method for handing down lessons from disasters is composed of four stages: (i) survey on disaster subculture, (ii) summary of the results of the survey, (iii) plan for implementation, and (iv) achievement of residents' evacuation.

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In the field survey, a great deal of time and effort is required to investigate the broad range disaster such as the Tohoku Great Earthquake and accompanying tsunami inundation. In this paper, we estimated the tsunami damaged area in the Tohoku district, using the object-based image analysis. Comparing the damaged areas estimated by image analysis of the inundation traces obtained by "2011 Tohoku Earthquake Tsunami Joint Survey Group", an accuracy of this analysis was also investigated. It is confirmed that the object-based image analysis can reproduce the inundation area of more than 80 % when 15m tolerable margin is allowed in the multi-buffer zone.

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In order to develop a method to evaluate building damage in the tsunami affected area in a quantitative manner, the authors conducted visual damage inspection using an oblique aerial photos in Wakabayashi-ward in Miyagi Prefecture. As the result of damage inspection, building damage were classified into six classes to identify the damage distribution in Wakabayashi-ward and the validity of this method was demonstrated to comprehend the impact in the aftermath of the disaster.

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Coastal forest has a function to mitigate tsunami damage that is known from some field investigation after tsunami disaster. However some trees are broken by high tsunamis and flows. In this study, the field test on the lodging limit of Casuarina is examined and the moment limit model is proposed for lodging. And the numerical simulation in Painan, Indonesia investigates the tsunami mitigation effect of coastal forest. Tree is selected Casuarina which based on the results of field survey. In the numerical simulation, the coastal forest is treated as resistant obstacles against tsunami flow. The tsunami inundation area is simulated with Casuarina with tree-lodging model.

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Field study was carried out to investigate the distribution of submerged debris generated by the tsunami on March 11, 2011. We used a digital sonar to measure the distribution and amount of the debris scattered on sea floor of a small bay. The volumes of the debris were estimated from its lateral and base areas which were detected by down and side scans of the sonar, respectively. We identified a total of 147 debris and estimated the total volume of the debris on the sea floor inside the bay. The velocity distribution was computed in the bay in the phase of the tsunami rundown using 3D hydrodynamic model. We found the debris were mostly distributed along the thalweg where the computed velocity showed the maximum value about 3.5m/s.

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In Hokkaido, Northern Japan, the tsunami of 2011 Tohoku Pacific-Coast Earthquake broke river ice and transported thousands of meter-long ice floes in rivers whose mouths are on the Pacific Coast. The objectives of this study are to investigate sizes and areas of ice floes by using photographs obtained during the field survey conducted after the tsunami and, on that basis, to estimate the masses of floes transported by the tsunami. Sizes and areas of them were measured using an image analysis technique and ice thicknesses are measured on site. In an extreme case, the estimated masses were approximately 1.2 to 20 ton on average and 5.0 to 170 ton as maximums of floes retained near the bridge piers. This work highlights the potential risks of ice floes, which can be hazardous to river structures such as bridge piers.

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The coastal area of Hai Hau district, located in the northeast Vietnam, has a 30 km-long of shoreline, which is facing serious erosion. The area is part of the Red River Delta and is a depositional land. From the beginning of 20th century, erosion became prominent in the area and huge efforts have been put in the last 50 years. The damages on local activities were characterized through interviews with local government officers and residents. Remote sensing data analyses and 1-line numerical modeling have been applied to trace and reproduce the processes of shoreline recession. Incident waves were calculated based on 20 years wave data (1989-2008) at an offshore grid point given by the European Center Medium-Range Weather Forecast. The calculated shoreline change agreed fairly with the result of remote sensing data analyses.

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A method using granulated coal ash (GCA) is proposed for the restoration of sea bottom environment in Yong-Won Bay (Busan, Korea) based on numerical calculations of flow field, laboratory experiments, and analysis results of sediment properties. The results strongly supported that high turbidity water at the sea bottom in the central part of the bay intrudes into the western part of the bay. It is expected that organic matter is transported by the current of high turbidity water, leading to the aggravation of the sea bottom environment. Experiment results, however, suggest that this aggravation can be prevented by scattering GCA on the sea bottom at the entrance of the western part of the bay. This is because, 16.8 to 54.6% of the organic matter will be captured in the GCA layer due to 20% decreases of flow velocity after scattering GCA.

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At present, a floating type wind farm project located offshore Kabashima Island in Nagasaki Prefecture, Japan, is being performed. The present paper examined the validity of wind and wave predictions by statistically comparing predicted values with measured data recorded at the project site. The wind and wave prediction system is an integration of individually developed GFS-WRF-SWAN and GFS-HAGPV-SWAN prediciton systems. Satisfactorily good agreement between prediction and observation was found when evaluationg the indicies of correlation coefficient, root mean square error, and Brier score. The prediction system is shown to be useful for obtaining vital offshore wind and wave information.

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Beach sand color is one of important components of coastal landscape. But color information has not been used to coastal engineering. Color determination of sand grains collected in 164 coastal sand beaches was performed with a scanner and the relative frequency of sand color was calculated based on RGB color palette. The principle component analysis and cluster analysis were applied to the relative frequency of sand color. The sand beaches were classified into two general groups; gray and brown. The artificial beach is consisted of many colored grains. Tan and brown colored grains are seen at singing sand beaches. Sand color changes are confirmed before and after the tsunami which has attacked the beach in Japan last year.

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In beach nourishment using gravel, the macadam gravel is used so that the sharp-pointed shape of gravel is of concerned. In this study, the change in the shape of gravels due to wave abrasion was investigated. Gravel samples were collected from the Jinkoji and Akashi coasts in Ibaraki Prefecture, where beach nourishment using coarse materials have been carried out since 2005, and grain size and roundness were measured. It was found that roundness of gravels with an initial value of 0.2 converged to 0.4-0.5 within four years and nine months. Due to the abrasion test of sampled gravels without steel bowls, the content of gravel was as high as 92% of all the volume after the rotation of 1200 times.

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Quantification of the distribution and activity of shallow water vegetation is important given that such vegetation provide a variety of ecosystem functions and services. We estimated the distribution and coverage of seagrass patches using both GIS and high-resolution multi-band satellite imagery. The estimation accuracy of the distribution was greatly improved when field observation data were incorporated into the image analyses. However, supervised classification is greatly affected by "training data". Thus, it is still necessary to develop a valid method for the choice of "training data" in order to improve the analysis results.

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We computed the quantity of macro plastic litter by detecting the pixels of colored plastic litter using photographs taken by webcams installed at four coastal locations in Japan, and applying a projective transformation to the photographs. The technique involves generating color references using a uniform color space to detect plastic litter pixels and removing misdetected pixels by using a composite image method. We successfully obtained a time series of the quantity of plastic litter. The use of webcams to monitor the quantity of plastic litter enables beach cleanups to be performed effectively and to clarify the mechanism by which plastic litter is beached. Our final goal is to grasp the transportation of plastic litter in the East Asian seas by combining an ocean circulation model and the webcam monitoring of plastic litter quantity.

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The authors developed a new observation system to visualize the present status of the surface current in a bathing beach area, which utilizes GPS sensor floats and a network system that connects multiple sensors. This system can detect a real time trajectory and flow velocity of the GPS sensor floats to a computer, and can display the data on the screen. In this paper, the specification of the system and the results of its application to a bathing beach are described. In the observation, the GPS sensor floats and a person having a GPS sensor were floated together and compared.

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In this paper, an estimation of wave parameters in the shallow area using fishing operational records obtained from a fishfinder and GPS was described. The operational pattern that the boats run slowly in the shallow area during the fishing operation was shown by the records. Time series of changes in the records from fishfinder were separated into two components: one is associated with bathymetry and the other is due to the ships heaving motion generated by waves. Wave height and period estimation was based on power spectrum analysis of the time series. The wave parameters obtained by the present method were in good agreement with the wave measurement in the field.

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Remote sensing reflectance (Rrs) and absorption coefficient were measured by carrying out field observation in Tokyo bay to figure out optical properties of high eutrophicated coastal area and to develop estimated model of high concentrated Chlorophyll-a (Chl-a). It was the result that when Rrs of high concentrated Chl-a was observed, green wavelength of Rrs decreases, red wavelength of Rrs increases, and absorption coefficient of the phytoplankton of the green wavelength increases. Based on consideration, we developed estimation model for high concentrated Chl-a using the correction term of estimated error. In the result of verification of suggested model, it could appropriately improve the accuracy. Furthermore, behavior of Chl-a distribution in Tokyo Bay was discussed using the satellite data which was applied for suggested model.

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It is important to evaluate the water mixing effect before applying water exchange technologies for resolving the pycnocline which causes some environmental problems. In this study, a new image analysis method was developed to estimate the spatial distribution of salinity for evaluating the water mixing effects in density stratified fluid. The effectiveness of developed image analysis was validated by comparing the estimated salinity with the measured salinity by salinometer. Furthermore, the water mixing effect for the case of supplying the surface water to the bottom in density stratified fluid was discussed by using the developed image analysis.

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