Miguel Esteban

Assessment of future stability of breakwaters under climate change

Climate change is expected to lead to increases in both sea level and typhoon intensity, which could threaten the stability of breakwaters in the future. In this study, calculations using the SWAN model showed that a 10% potential increase in the future wind speed of typhoons resulting from the warming of surface sea temperatures can lead to a 21% increase in the significant wave heights generated by these winds. To understand the effect that this would have on breakwater stability, the expected sliding distances for the breakwaters at Shibushi Ports in Japan were estimated using a probabilistic design method. The results show that in the future the expected sliding distances may become five times greater than at present, due to a combination of increases in sea level and wave height.

Classification of Tsunami and Evacuation Areas

On March 11, 2011, a large earthquake that occurred offshore the north-east coast of Japan generated a large tsunami which devastated extensive areas of the Tohoku coastline. Despite Japan being considered a country well prepared for these types of disasters, large casualties were recorded, with numerous discussions amongst the Japanese coastal engineering community ensuing. As a result, two different levels of tsunamis have been proposed and now recognized in Japan, depending on the frequency of such extreme events. The idea that hard measures can protect the lives of inhabitants of coastal areas has been abandoned, and these measures are only considered to be effective in protecting properties against the more frequent but lower magnitude events. Soft measures should always be used to protect against the loss of lives, and to this respect, the authors of the paper propose the introduction of a Classification of Evacuation Areas, to show which of these should be prioritized by residents as they seek to evacuate.

Climate Change and Renewable Energy from the Ocean and Tides: Calming the Sea of Regulatory Uncertainty

We examine the state of ocean energy in 2009 and consider its potential as a source of renewable energy. We provide a background on the current state of technology and commercial development, and examine the implications for law and policy of the re-emergence of ocean energy as a source of renewable energy in 2009. In the 1970s much of the academic and policy literature highlighted jurisdictional uncertainty surrounding ocean energy under international law. This is not the case today. Although some questions remain with respect to navigation rights, most questions surrounding the nature and extent of coastal State jurisdiction in relation to ocean energy have been resolved by the 1982 United Nations Convention on the Law of the Sea. Instead we argue that one of the biggest challenges faced by ocean energy today is the uncertain state of regulation under domestic legal systems. We highlight issues requiring attention by policy-makers and legislators, including managing hazards to navigation, providing further financial incentives for wide-scale commercialisation of this technology (such as increased research and development funding and feed-in tariffs) and managing ocean energys relatively benign environmental impacts.

Atoll Island States and International Law

Chapter 1: Geography, Economy and Environment of Low-lying Island States.- Chapter 2: Climate Change and its Effects on Low-lying Island States.- Chapter 3: Climate Change Negotiations and AOSIS.- Chapter 4: Low-lying Island Future Scenarios, Adaptation Strategies and their Implication under UNCLOS.- Chapter 5: Alternative Solutions to Preserve the Sovereignty of Atoll Island States.- Chapter 6: climate Change Displacement in Atoll Island States.- Concluding Remarks.

Improvement in calculation of resistance force on caisson sliding due to tilting

The aim of the present paper is to investigate the long-term deformations of the rubble mound of a breakwater during its working life. Understanding these deformations is essential for the sliding and tilting to be able to be measured effectively. In order to do so, laboratory experiments were carried out, from which probability distribution functions of sliding and tilting were obtained for a series of three storms of similar intensity. The laboratory results were then reproduced using a computer model, which decomposed the movement of the caisson into its vertical and horizontal components. The horizontal movement uses the equation of Shimosako and Takahashi [1998] as modified by Kim and Takayama [2005], whereas for the vertical deformation the method of Esteban and Shibayama [2006] is employed. A new methodology for the calculation of the resistance force caused by the caisson tilting is proposed. The results obtained overestimate the deformation slightly during the first storm but can predict well the deformation during the subsequent storms.

Increase in Port Downtime and Damage in Vietnam Due To a Potential Increase in Tropical Cyclone Intensity

It is currently feared that the increase in surface sea temperature resulting from increasing levels of greenhouse gases in the atmosphere could result in an increase in tropical cyclone intensity in the future. Although the economic consequences have been studied for a number of developed countries, very little work has been done on developing countries. The present paper attempts to indicate what are the likely economic effects of this, by using a Monte Carlo simulation that magnifies the intensity of historical tropical cyclones between the years 1978 and 2008. This tropical cyclone model is then coupled with a socioeconomic model that attempts to provide a projection of the likely development course of the Vietnamese economy and society. The simulation shows how annual downtime from tropical cyclones could increase from 0.23 to 0.37% by 2085 which could cause the loss of between 0.015 and 0.035% of GDP growth per year (between 600 bn and 1,400 m USD after factoring in the likely growth in the Vietnamese economy by this time). The effect that this could have on port operations and a preliminary assessment on the potential for increases in direct damage due to high winds are also made, showing a typical 33 to 65% increase for the centre and north of the country.

Evaluation of the Productivity Decrease Risk Due to a Future Increase in Tropical Cyclone Intensity in Japan

A number of scientists have recently conducted research that shows that tropical cyclone intensity is likely to increase in the future. This would result in an increase in the damage along with a decrease in economic productivity due to precautionary cessation of the economic activity of the affected areas during the passage of the cyclone. The economic effect of this stop in economic activity is a phenomenon that has not received much attention in the past, and the cumulative effect that it can have on the Japanese economy over the next 75 years has never been evaluated. The starting point for the evaluation of the economic risks is the change in the patterns of tropical cyclone intensity suggested by Knutson and Tuleya. The results obtained show how a significant decrease in the overall productivity of the country could be expected, which could lower GDP by between 6% and 13% by 2085.

Recent Developments in Offshore Renewable Energy in the Asia-Pacific Region

This article examines the emergence of offshore renewable energy (i.e., offshore wind, ocean, and tidal energy) in the Asia-Pacific region with a particular focus on developments in China, South Korea, Australia, and New Zealand. It outlines plans for the development of offshore wind, tidal, and wave energy projects as well as emerging legal and policy measures supporting the growth of offshore renewable energy in the region. The article highlights that, although some progress has been made on laws and other measures to facilitate offshore renewable energy in the Asia-Pacific region, clear regulatory frameworks are still emerging in these jurisdictions.

MODIFIED HEEL PRESSURE FORMULA TO SIMULATE TILTING OF A COMPOSITE CAISSON BREAKWATER

Susami West Breakwater, a composite caisson breakwater located in Japan, was damaged by high waves caused by typhoon Tokage on the 20th of October 2004. The failure mode was characterized by the sliding/tilting of the caissons and the removal of the concrete armoring units. The failure of these armor units is believed to increase the pressures exerted by the waves on the caisson, and thus exacerbate the expected deformations in the rubble mound foundation, a fact which has thus far been ignored in previous research. The present paper proposes a methodology to take into account the effect of these concrete armor units to estimate the deformations that took place in the rubble mound foundation. The methodology uses a modification of the method by Goda [1985] proposed by Esteban et al. [2009] that can approximate to the right order of magnitude the vertical deformations at the back of the caisson by using a Monte Carlo simulation.

SEA LEVEL RISE AND THE INCREASE IN RUBBLE MOUND BREAKWATER DAMAGE

acceptance number: p0129 SEA LEVEL RISE AND THE INCREASE IN RUBBLE MOUND BREAKWATER DAMAGE 1 st Author: ESTEBAN, Miguel 2 nd Author: TAKAGI, Hiroshi 3 rd Author: SHIBAYAMA, Tomoya Breakwaters Climate Change Rubble Mound Sea Level Rise Limiting Breaker Height