ABSTRACT : This paper describes the power take-off performance of a wave energy convertor and the way in order to improve the performance with theoretical calculations. The authors showed the effects of the projecting walls (PWs) attached onto in front of oscillating water column (OWC) type wave energy convertors on the improvement of the power take-off performance with the model experiments. The paper studied the effects with theoretical series calculations based on the linear potential theory. From the calculations, the paper investigated behaviours of an OWC and the water sounded the PWs and clarified the effect of the PWs on the characteristic of the power take-off. The three-dimensional singular point distribution method was applied and the paper showed the formulations. The validity of the present method was verified by comparing with the experimental results.

As a result, the results of the calculations suggested that the longer the PWs were useful for the improvement in wider wave period band and the new concept the end-walls were also successful for it despite of the PWs shortened.

ABSTRACT : The sandy beaches of Enshu Coast (Omotehama), in the centre of Japan, support a large nesting habitat for the endangered loggerhead sea turtles (Caretta caretta). It is important that the sandy beaches provide a suitable environment for turtle oviposition. The “turtle tracks” that are created by turtle landings give a lot of information on various turtle behaviors after their landing. It was found that the necessary beach width is more than 40m from high tide level on the beach by investigating the landing distance of sea turtles. In the coastal area of Toyohashi, many precast armor units were placed in the middle of the beach for the purpose of shore protection. These construction units sometimes interrupt the turtle landing and ovipositing activities . There is an action to restore the beach called Eco-coast work that makes it easy for the sea turtle to land which starts in Toyohashi city. That is the barrier-free model for the sandy beaches. After removing precast units, the coastal topography and the behavior of the sea turtle tend to change toward those of natural beaches and the rate of oviposition failure seems to decrease.

ABSTRACT : Beach changes of Mizushima Island in Tsuruga Bay were investigated using aerial photographs. The construction of three groins disrupted water exchange and wave propagation via the channels between the islands, resulting in sand deposition behind the islands connected by the groins. The mechanism of sand discharge over the groins during low pressure was investigated using the tide observation data and photographs from a fixed position on the island. Furthermore, the effect of the extension of existing offshore reefs to widen the sandy beach was investigated using the contour-line-change model. With increase in wave dissipating effect of the offshore reef, sand discharge by longshore sand transport from behind the Mizushima Island was reduced.

ABSTRACT : The changes of seashore geographical features on the periphery of the Ishikari Bay New Port along the coast in Hokkaido of Japan was considered by field in this paper.It emerged that the seashore geographical feature was formed by the flow velocity coefficient φ and the non-dimensional tractive force τ_*,and moreover,that the factor 1 was return flow ( large and small) , and the factor 2 was the coast flow velocity ( large and small) as results in the factor analysis of 5 factors,consisted of return flow,non-dimensional parameter of geographical feature,non-dimensional tractive force ,coast flow velocity and coefficient of velocity.

ABSTRACT: On the Ichinomiya coast located in the southern part of Kujukuri Beach,　a conflict regarding the construction of artificial headlands as a measure against beach erosion took place among surfers, fishermen and users of the coast in 2010. Public meetings to build consensus regarding conservation and use of the coast were opened to solve the issues since June 27, 2010. Meetings were held five times between June 27, 2010 and September 3, 2011, and the shore protection measures of the coast and the impact of construction of artificial headlands to the beach and surf grounds were discussed with the fishermen, surfers and users of the beach. Finally consensus was built among the administrator of the coast, surfers and users of the beach.

ABSTRACT: The Marine Protected Area (MPA) concept is internationally recognized as a management tool for marine biodiversity conservation and sustainable resource use. In Japan, the term MPA was written in the Basic Ocean Plan for the first time and its concept was officially defined in the National Marine Biodiversity Conservation Strategy in March 2011 and at the 8^th meeting of the Headquarters for Ocean Policy in May 2011. Adequate establishment and management enhancement of MPAs is now specified in the New Basic Plan on Ocean Policy of April 2013. In response to current trends, this article comprehensively analyzes the characteristics of present MPA systems in Japan regarding the extent of their formation processes, objectives, and management structure and then examines their future challenges. The research reveals that MPAs in Japan 1) conform to various existing systems, 2) with most of them having fishery resource management objectives, 3) under either a government-based or community-based management approach. In order to overcome the challenges created by such characteristics and to promote adequate establishment and management enhancement of MPAs, there is a need to develop an integrated and concrete system to support and manage existing different institutional systems and their relevant data.

ABSTRACT : After the dumping of waste, it takes a long time to stabilize the water quality retained in a waste disposal site in coastal area. This is one of the primary factors to increase the total cost to maintain a waste disposal site. For sustainable management of the site, it is required to reduce the cost of each management phase, such as construction, dumping and stabilization, and to reduce the period to stabilize the water quality retained in the site. In this study, it is revealed the cost of each management phase through the questionnaire survey, and the cost structure of the waste disposal site project. Then, modeling the cost effect to induce the new techniques to stabilize disposed waste materials, appropriate cost structure is examined through numerical analysis.

ABSTRACT : The entire Pacific coastal region of the Tohoku was widely affected by the Great East Japan Earthquake that occurred on March 11, 2011. The maximum magnitude recorded in the history of earthquakes is 9.0. The earthquake had an epicenter at 142.9° east longitude and 38.1° north latitude, a depth of 24 km. This was an opportunity for the authors to collect data on the shaking of the ship body during its actual sea voyage in order to evaluate the safety of vessels and cargo loaded. There are a few studies in which seaquakes have actually been measured; records consist of navigators remarks.

As we had experienced a seaquake because of an undersea earthquake during a voyage and had installed a measuring device for the shaking of the ferry hull, we succeeded in measuring the seaquake as the hull motion. This type of measured data does not exist elsewhere, and hence is extremely valuable. This report contains our measured earthquake data and analysis.

ABSTRACT : The entire Pacific coastal region of the Tohoku was widely affected by the Great East Japan Earthquake that occurred on March 11, 2011. The maximum magnitude recorded in the history of earthquakes is 9.0. In the coastal areas, a historically unparalleled tsunami generated because of this earthquake, causing extensive damage. As the caution of extensive damage, it is considered that the early forecasting of tsunami was delayed. If the early forecasting of the propagation of tsunami becomes possible, it is considered that the extensive damage is reduced.

The object of this paper is to discuss about the early forecasting of tsunami by AIS data obtained from many sailing ships in coastal sea area. This study is the first in the world and very original. The conclusion obtained in the present study is that AIS data is possible to offer the early forecasting of propagation of tsunami.

ABSTRACT : In 1999 the Coast Act was revised to add environmental protection and utilization adjustment for its purpose. In the hinterland of sandy coasts in Japan, coastal protection forests have long been developed and designated for disaster prevention in accordance to the Forest Act, representing a considerable institutional no-man’s-land created by the Coast and Forest Acts. Currently, sandy coasts and coastal protection forests are faced with a common crisis arising from erosion, waves etc. However, there has been little cooperation between their administrators, with damages being dealt with separately; as a result, problems in terms of environment and utilization are caused by the compartmentalized social system, as evidenced by the piling up of wave dissipation blocks in the vicinity of their boarders. Therefore, in this study, sandy coasts and coastal protection forests are considered as the "beaches,”—and towards their integrated administration—related legislation as well as relevant statutory and prefectural comprehensive plans are mainly analyzed, and cases of cooperation are identified by clarifying the structure of the problem. The result confirms the cases where a statutory or prefectural comprehensive plan is functioning as the basis for horizontal cooperation, or a section/organization with the purpose and mandate is formed; and shows that for horizontal cooperation, local governments are expected to play a role of coordinating and integrating various policies.

ABSTRACT : Because of the industrial withdrawals of dissolved methane and groundwater, land subsidence has been occurring at the southern Kujukuri Plain in Chiba Prefecture, Japan, with the maximum value of accumulated subsidence of ca. 100 cm in the last 42 years. At the same time, beach erosion of the area has been observed. Therefore, it is concerned that continuous land subsidence has caused and will cause further beach erosion. Judging from sediment budget of the beach sand in the study area as a whole during the period from 1975 to 2005, land subsidence has had greater effect on beach erosion than other factors such as sand discharge into submarine canyon or sea-level rise caused by global warming.