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A long-term field study on corrosion of STK400 steel was established at Phu My port. The large steel pile, which was equivalent to real structures, was placed in all environmental zones to evaluate the overall corrosive effects of the brackish water. After 5 years, the corrosion rate over the entire length of the steel pile was measured and the rust at the boundary altitude between the zones was characterized. The corrosion rate profile shows the polarization of the entire pile length into two large anodic areas at the highest water level and submerged zones, where had high corrosion rate and pitting corrosion form. X-ray diffraction and metallographic of rust layers showed that Fe3O4 phase increased with water depth, allowing to strong diffusion of Fe2+ ion from steel substrate into the environment. The change in organism populations along water altitude in the tidal and submerged zones made the rust layers more complicated. Such distribution of polarized electrodes and composition of rust were due to the renewal of the corrosive agent by tidal cycles and organism population in water. As a result, the steel substrate in the tidal and mud zones was protected as cathodic areas.

Sea level rise and land subsidence — induced flooding are projected to have severe impacts on highly populated Asian deltaic cities. These cities are already suffering from frequent floods, though few comparative analyses have been conducted on the similarities and differences of their adaptation approaches. Thus, this study aims to investigate the current adaptation pathways of Asian deltaic cities to flooding induced by slow onset events such as urbanization-induced land subsidence and sea level rise, by looking at Tokyo, Jakarta, Manila, and Ho Chi Minh City as case studies. Evidence from them shows that an engineering approach towards flooding adaptation is shaping the future of Asian deltaic cities. However, emerging challenges question the sustainability of this approach. Recommendations on how to improve current adaptation pathways and direction for future research are also provided.

Estuarine/river engineers often encounter a problem that it is hard to specify an upstream boundary of a delta in the numerical modeling because of lack of good quality discharge data. This...

In the past two decades there have been fears that many low-lying atoll islands around the world could disappear as a consequence of climate change and sea level rise, leading to mass migration and threatening the existence of several island nations. Here we show how sea level rise does not inevitably lead to coastal areas becoming uninhabitable, and that humans have an innate and often underestimated capacity to adapt to changes in their environment. To do so we showcase three instances of human- and earthquake-induced land subsidence that have taken place in the 21st century, where the coastal/island areas are still inhabited despite the challenge of living with higher water levels: the Tohoku coastline following the 2011 Tohoku Earthquake Tsunami (subsidence ∼0.4–1.0 m), the present day situation of coastal areas in Jakarta due to ground water extraction (>5.0 m), and the islands of Tubigon, Bohol in central Philippines after the 2013 Bohol Earthquake (∼1.0 m). Humans are able to adapt and arrive at solutions even when confronted with cases of rapid rises in water levels, and thus it is likely that in the future vulnerable coastlines will be engineered and largely remain at present day locations, particularly in densely populated areas. If anything, around densely populated areas it is more likely that humans will continue to encroach on the sea rather than the reverse. We caution, however, that small islands are not homogeneous, and many are unlikely to respond to rising sea levels in the manner that atolls do (in fact, many might just resort to build at higher elevations). Where engineering and other adaptation responses become necessary, the financial and human resource requirements may well be beyond capacity of some small islands, which could lead to impoverishment and associated challenges in many communities.

In developing countries, coastal protection with wooden piles may be a low-cost and eco-friendly countermeasure option that can be readily implemented by local communities or even individuals. However, the effectiveness of these piles in a realistic environment has yet to be scientifically proven, and there have been no established design guidelines for this type of improvised coastal protection to date. This study focuses on Phan Thiet City, Vietnam, where local people are resorting to wooden piles to mitigate severe coastal erosion immediately in front of their houses. A 3D hydrodynamic modelling with irregular waves is applied to evaluate complex wave mechanisms and hydrodynamics around and between wooden piles. The complicated interaction mechanisms between incident and reflected waves cannot be adequately evaluated using a common 2D numerical model or mathematical analysis, demonstrating the benefit of using a 3D hydrodynamic model. The performance of wooden piles are simply assessed using two criteria: wave run-up and bending stress. The result shows that wooden piles installed at a severely eroded beach in Vietnam can reduce wave run-up on the beach slope to some extent. The reduction in wave run-up occurs because of the creation of turbulence and oscillation triggered by the partial reflection of waves on the piles, diverting water flows into various directions. A case study shows that wave pressure in the seaward direction is about a half of that in the shoreward direction. However, the pressure in the negative direction can be instantaneously increased due to a significant reflection from a steep shore. This paper discusses whether such a state-of-the art computational fluid dynamics model can contribute to the assessment of wooden pile breakwaters.

Most adaptation studies suggest that sea-level rise will lead to relocation as flooding worsens. Here we identified and evaluated potential adaptation strategies for adapting to sea-level rise, based on the experiences of four low-lying island communities in central Philippines that have experienced flooding during normal high tides since a 2013 earthquake that induced land subsidence. Coastal surveys, interviews and household questionnaires showed that island residents generally prefer in situ adaptation strategies rather than relocation to the mainland. These results are unexpected, particularly because a relocation programme has been developed by authorities on the mainland. Direct measurements during a flooding event indicate stilted housing as the most effective type of adaptation strategy. Many households have also raised their floors using coral stones, although this might inadvertently increase their vulnerability to typhoons and storm surges in the long-term. It is often assumed that increased flooding due to sea-level rise will lead to mass migration. However, this study shows that residents of island communities in the Philippines prefer to implement local adaptation measures in response to frequent severe flooding rather than relocate.

Corrosion test of mild steel (graded JIS-STK400) was investigated in brackish water environment of Phu My industrial port (Ba Ria - Vung Tau Province, Vietnam). Steel sample was exposed in 3 years. X-ray diffraction (XRD) results show that formed rust powder was composed of a-FeOOH, Fe3O4 and a- Fe2O3 in which the amount of first component is larger than second and third one. It demonstrates that natural corrosion products evolved from low to high oxida-tion state of iron by presence of dissolved oxygen in brackish environment. The mechanism of phase conversion is revealed by metallographic of rust layer cross section. a-Fe2O3 (white phase) was gathered at bank of cracking paths where was favouring diffusion of oxygen and water into inner layer. After contacting Fe3O4 (dark gray phase), corrosive agents converted it to a-FeOOH and a-Fe2O3. The phase conversion changes the weight density of materials and creates the porous tunnels in rust scales. The growth of micro tunnels to form the tunnel network allowed internal stress and cracks of rust scales evolved.

Introduction: Typhoon-induced disasters including storm surge and high wave are obvious threats to coastal areas in Vietnam. Thus, many researchers have paid their attention to this issue. The approaching methods are varied, including statistical methods and also numerical methods. This study suggests the coupled models Delft3D-FLOW and WAVE, using the meteorological output data from the Weather Research Forecast (WRF) for investigating the typhoon induced disasters in the coastal areas in Viet Nam. Method: WRF is run in multiple domains with different grid resolutions simultaneously and there is an interaction between them to reproduce the wind field during the typhoon events. Delft3D-FLOW is coupled with Delft3D-WAVE (SWAN) through a dynamic interaction, in which the FLOW module considers the received radiation stresses calculated by the wave module. On the other side, the updated water depth including the contribution of the storm surge will be used by the WAVE module. Both Delft3D-FLOW and Delft3D-WAVE models used wind fields from the WRF simulation output as the meteorological input data. The total surge level includes the storm surge, wave-induced setup and the tidal level. Results: The case of extreme weather event Typhoon Kaemi (2000) was used to validate the wind field and the wave height. The calibration process of the the storm surge level was based on the observed data during Typhoon Xangsane (2006), while Typhoon Durian (2006) were used to validate the coupled models. The comparisons show the good agreement between simulated results and observed data, especially in terms of the peak water level and highest significant wave height, which mainly governed by the typhoon wind field. The simulated results reveal that the surge height durring Typhoon Durrian period along its path was ranged from 1.2 to more than 1.4m, which can be considered to pose the greatest risk to low-lying coastal areas of the Mekong Delta. Conclusion: The suggested coupled models can be used to investigate the impact of typhoon induced disasters.

The Philippines is highly exposed and vulnerable to natural hazards. As a result, the country has an extensive disaster risk database that consists of different hazard and risk maps to be used as reference in creating development plans. However, some communities are in relatively low risk zones, such as those in Puerto Princesa City, Palawan (with many inhabitants of the city believing it to be safe). This study seeks to ascertain how disaster risk is understood in coastal areas that are only slightly susceptible to natural hazards, in order to provide strategies to improve disaster risk governance. The study validated national data on coastal disaster risk through a topographical survey, questionnaire surveys, and group interviews (in March 2016 and 2017) to understand whether residents knew the risks they are exposed to. The research found that national data reflects local conditions but community members do not have a clear understanding of the risks, particularly coastal hazards. Moreover, the research found that there has been a recent disaster event, though it was not properly archived and transmitted to the next generation. Thus, there is a need to raise awareness to correctly explain and transmit knowledge about potential hazards even in communities that have relatively lower disaster risk.

Category 5 Typhoon Haiyan (known as Yolanda in the Philippines) made landfall in the Philippines on the 8 th November 2013 at almost the peak of its power, devastating the islands of Leyte and Samar, amongst other places. The present paper analyses the degree of awareness and preparedness of the islands of Samar and Leyte in the Philippines against storm surges prior to the arrival of typhoon Haiyan. The analysis was based on field surveys and interviewed with a variety of local residents and officials conducted during field surveys in the months after the event. One of the key problems identified during the interviews was how people were not able to clearly conceptualize the concept of storm surge. Despite receiving storm surge warnings it appears that many residents and local authorities “under-estimated” the event and thought that they could evacuate at a later stage or during the storm itself. The results clearly highlight the need for better education and for development strategies in the region to focus on improving the resilience of local inhabitants.

The authors have examined the characteristics of Typhoon Haiyan (Yolanda), which made landfall on the coast of the Philippines on November 2013, generating a substantial storm surge. In order to better understand the storm surge phenomenon, its nature and severity were analysed by means of a numerical simulation and a field survey. Unlike most other tropical cyclones that weaken before they hit land, Haiyan struck Leyte Island at near peak strength, with maximum sustained wind speeds of 160 knots, the strongest in the recorded history of the Western North Pacific. Haiyan approached very quickly with a forward speed of 41 km/h towards Leyte, which was also the fastest among typhoons with similar intensities. As a result of these extreme gusts and the exceptionally low central pressure of the typhoon (895 hPa), Haiyan caused the largest storm surge in the recorded history of the Philippines. Numerical simulations show that the maximum storm surges occurred in Leyte Island and Samar Island. A storm surge field survey conducted by the authors corroborated this, with maximum inundation height of 7 m recorded in Tacloban, located at the northern end of Leyte Gulf. The simulation results also corroborate the fact that water levels at some locations first lowered and then rapidly began to increase after an hour.

Typhoon Linda (1997) was the worst storm in the Mekong Delta. However, very little scientific information is available. Of the last 228 storms to make landfall in Vietnam, this tropical cyclone took the southernmost course, and the estimated reoccurrence period is once in 150 years or longer. Our analysis reveals that the storm surge reached 1.5-m high along the eastern coast of the low-lying delta, and it even propagated until the regional capital of Can Tho, which is located 80-km inland from the river mouth. Despite the fact that local people in Can Tho still clearly remember Linda after almost 20 years, curiously all of the interviewees replied, I am not afraid of a typhoon. On the other hand, the islanders of Con Dao, which was directly impacted by Linda, acknowledged a high degree of awareness of typhoon disasters. This study demonstrates that only a memory of the past significant event does not necessarily improve people's awareness. Because the delta was a nearly uninhabited mangrove jungle before the 20th century, this particular typhoon event needs to be better studied to envisage a future catastrophic gray swan event.

The design of breakwater armour units against tsunami attacks has received little attention in the past because of the comparative low frequency of these events and the rarity of structures designed specifically to withstand them. However, field surveys of recent events, such as the 2011 Great Eastern Japan Earthquake Tsunami and the 2004 Indian Ocean Tsunami, have shown flaws in the design of protection structures. During these extreme events, many breakwaters suffered partial or catastrophic damage. Although it is to be expected that most normal structures fail due to such high order events, practicing engineers need to possess tools to design certain important breakwaters that should not fail even during level 2 events. Research into the design of critical structures that only partially fail (i.e., “resilient” or “tenacious” structures) during a very extreme level 2 tsunami event should be prioritized in the future, and in this sense the present paper proposes a formula that allows the estimation of armour unit damage depending on the tsunami wave height.

The present paper investigates fluvial flood hazards in urban areas in the Mekong Delta to inundation due to seasonal flooding, a phenomenon which is likely to be exacerbated by future sea-level rise. Unlike past researches which mainly focus on flooding due to river discharge from upstream or heavy precipitation, the present paper scrutinises the influence of ocean tides. The research reveals that ocean tides predominantly determine water elevation even in an upstream location such as Can Tho City, 80 km inland from the river mouth, and that the river flow causes tidal damping and effectively reduces the energy of the incoming tides. This tidal damping is especially pronounced during the rainy season. Analysis based on the water levels monitored by the Mekong River Commission revealed that the ground near the riverbank of Can Tho had experienced inundation for a total of 215 h between July 2009 and June 2010 (2.5% of the time over a 1-year period). Assuming three scenarios of sea-level rise of 20, 40, and 60 cm, all within the range of the Intergovernmental Panel on Climate Change (IPCC) AR4's projections, it was found that the duration of inundation will be prolonged from the present percentage of 2.5% to 6%, 13%, and 24% of the year, respectively. Furthermore, the field survey carried out by the authors shows that inundation reached up to a height of 47 cm above the roads of Can Tho downtown.

Climate change will likely affect the effectiveness of future management of coastal ecosystems, impacting communities that reside within the coastal area. In order to formulate appropriate adaptation counter-measures it is important to understand the actual vulnerability of the communities that depend on these ecosystems. The present research proposes a tool for assessing the vulnerability of coastal communities to climate change by combining survey results with secondary and observed data available from national and local governments. The study focused on fisheries, given that they constitute the source of livelihood for many communities in developing countries such as Vietnam. The results showed that two coastal wards in Binh Thuan province, Vietnam, are highly vulnerable to the impacts of climate change, mainly because of their dependence on fisheries and the topography of the area. The seasonality of their source of livelihood affects the adaptive capacity of residents, making it less likely that they will be able to successfully adapt to changes in fishery resources that could be brought about by climate change. The results also showed that the communities are particularly vulnerable to sea level rise, given that they are both located in the immediate vicinity of the sea and are particularly low in elevation.

The present paper demonstrates that inundation levels in the Mekong Delta’s largest city, Can Tho, are predominantly determined by ocean tides, sea-level rise, and land subsidence. Our analysis of inundation patterns projects that the duration of inundation at an important road in the city will continue to rise from the current total of 72 inundated days per year to 270 days by 2030 and 365 days by 2050. This is attributed to the combined influence of sea-level rise and land subsidence, which causes relative water level rises at a rate of 22.3 mm·yr−1. People in the Mekong Delta have traditionally lived with floods, and thus there is certain resilience among residents in coping with small floods. At present, daily maximum inundation depth, which is generally shallower than 10 cm on the road, seems to be still manageable; however, our analysis indicates that this will start drastically increasing in the coming decades and reach an average depth of 70 cm by 2050. Effective and well-planned actions to mitigate the effects of land subsidence and sea-level rise are urgently required, otherwise, local inhabitants will encounter an unmanageable increase in inundation depth and duration in the coming decades. This study, which considers both sea-level rise and land subsidence, suggests that inundation depth and duration are projected to rise much faster than those indicated by previous studies, which only consider sea-level rise.

Breaking waves on coastal structures produce impulse pressures that are high in magnitude and short in duration, compared with pressures exerted by non-breaking waves. The present study is concerned with a theoretical approach, which is based on the momentum impulse, to simulate the impact pressures on a vertical wall. The theoretical impact pressures are determined using varied velocity before impact process. The velocity field in the vicinity of structure is calculated by LES model including turbulence. The necessary coefficient λ* to evaluate impulse pressures is tentatively obtained through a comparison between the laboratory tests and the numerical results. The computational results using the coefficient obtained show time-histories of pressure with nonlinearity rather than linearity considered ever.

Despite the regularity with which tsunami waves attack a variety of countries around the world, comparatively little attention has been paid in the past to the design of tsunami-resilient breakwaters. This chapter will highlight some of the problems related to the failure mechanisms of caisson and armored caisson breakwaters against tsunami attack, focusing mainly on two modes: bearing capacity failure at the heel of the caisson and the stability of primary armor units. A methodology for the design of such armor will be provided for the case of overtopping waves, based on real life analysis of the failure of such armor. This method takes into account not only the tsunami level and height, but also the function of the structure (in terms of the importance of what it has been designed to protect), highlighting the need for an approach that can minimize the cost of such countermeasures.

Vietnam, with 3260 km coastline and two vast low-lying deltas (the Red River Delta and Mekong Delta), could be considered one of the most vulnerable countries against coastal disasters and climate change. However, it appears that people outside Vietnam do not notice the vulnerability of this country's coasts against disasters, and even the vast majority of Vietnamese people may not be aware of the extent of the perils faced by their neighboring coastal communities, even though they suffer from frequent coastal floods. The challenges faced by this country in the future will have important regional and global repercussions. This chapter briefly examines threats such as tropical cyclones, sea-level rise, flooding, and coastal erosion in Vietnam. The authors wish this chapter to be an important source of information for all those who are looking at the challenges posed by impending coastal problems in Vietnam as well as other developing countries.

Climate change is expected to lead to increases in sea levels which could threaten the stability of rubble mound breakwaters in the future, as greater water depths will allow larger heights to reach the structures. Although this phenomenon is widely understood, the authors of the present chapter argue that an acceleration in the pace of sea level rise will require a more detailed assessment of risks and maintenance of breakwaters than at present, especially after 2050. This will alter port and breakwater design philosophy and lead to substantial increases in the cost to build and maintain these costly structures, especially in countries with relatively shallow coastal bathymetries such as Vietnam. The generic average increases in breakwater cross-sections were evaluated for four different rates of sea level rise showing that for the more extreme scenarios cases (for a sea level rise of 1.3 m over 50 years) a breakwater designed in 2050 could require between 8% (for the deeper sections) and 66% (for the shallower sections) more material than one designed in the 20th century not taking into account sea level rise. A case study of one such port, that of Phan Thiet in Vietnam, was used to showcase the problems involved.

The 2004 Indian Ocean tsunami was the first significant transoceanic tsunami in the digital age, allowing the population of the entire world to witness the destructive power of such phenomena. Despite the fact that such events form part of the culture of countries such as Chile and Japan, many other places had virtually not heard about them before 2004. However, subsequent events in the past 10 years have led to the emergence of a heightened stage of tsunami awareness not only in countries affected recently by these events, but also in other countries which have not experienced them for a long time, such as Vietnam. The present chapter will analyze tsunami awareness in 3 countries—Chile, Indonesia, and Japan—that recently experienced a tsunami and contrast them to the case of Vietnam. The analysis will include observations on whether a multi-layer-countermeasure system existed in each area, together with interviews conducted with local residents to understand their awareness about such events. It is clear that awareness in all countries has greatly increased, though further efforts are required to increase resilience so that the inhabitants of coastal areas are adequately protected.

The present chapter investigates seasonal fluvial flood hazards to the city of Can Tho in the Mekong Delta, a phenomenon which is likely to be exacerbated by future sea level rise (SLR). Unlike past research, which has mainly focused on flooding due to river discharge from upstream or heavy precipitation, the present chapter scrutinizes the influence of ocean tides, revealing how these can determine water elevation even in an upstream location such as Can Tho city, 80 km inland from the river mouth. In fact, river flow causes tidal damping and effectively reduces the energy of the incoming tides, an effect especially pronounced during the rainy season. Analysis based on the water levels monitored by the Mekong River Commission revealed that the ground near the riverbank of Can Tho had experienced inundation for a total of 215 h between July 2009 and June 2010 (2.5% of the time over a 1-year period). Assuming two scenarios of SLR, of 25 cm by 2050 and 60 cm by 2100, all based on the IPCC AR5’s projections, it was found that the duration of inundation will be prolonged from the present percentage of 2.5% to 7.5% and 24% of the year, respectively. Furthermore, field surveys carried out by the authors showed that recent inundation episodes reached a height of up to 47 cm above the roads of Can Tho’s downtown, highlighting the need for future adaptation measures in the city.

Vietnam has a long coastline and thus is highly susceptible to coastal disasters. The southern part of Vietnam has generally been perceived to be less vulnerable to typhoons or storm surges compared to the northern and central parts of the country. However, according to an analysis of tropical cyclone tracks, it appears that a substantial number of typhoons have approached southern Vietnam in the past, though the chance of occurrence is substantially smaller than along the northern or central coasts. Nevertheless, tropical cyclones in lower latitudes can sustain intensities similar to those in higher latitudes. Thus, tropical cyclones on the southern coast should not be underestimated when planning disaster risk reduction measures. In terms of climate change, historical tropical cyclone tracks do not provide any definitive conclusions regarding the separation of climate change influences from natural variability. The randomness inherent in natural variability can be considered to be more important than climate change from the point of view of disaster risk management. The authors also simulated past tropical cyclones approaching southern Vietnam and estimated that the highest water elevation due to storm surges in the past six decades was approximately 1 m.

Introduction. The Challenges of Natural Disasters in Vietnam Chapter 1. Economic Development, Port Construction and Natural Hazards Chapter 2. Tsunami Risk along the Vietnamese Coastline Chapter 3. Projections of Future Climate Change in Vietnam Chapter 4. Tropical Cyclones in Southern Vietnam Chapter 5. Tropical Cyclones Damage on Coastal Defences Chapter 6. Coastal Structures and Breakwaters in Vietnam Chapter 7. Coastal Risks and Design Standards of Coastal Defences in Vietnam Chapter 8. Climate Change and the Use of Bamboo Breakwaters Chapter 9. Climate Change and Water Resources Management in Coastal Areas of Vietnam Chapter 10. Impact of Typhoons on Coastal Dunes and Dikes in Vietnam Chapter 11. Assessment of Vietnam Coastal Erosion Chapter 12. Salinity Intrusion in Vietnam Chapter 13. Vulnerability of Urban Areas in Lower Mekong to Flood in the Course of Sea-level Rise Chapter 14. Climate Change, Sea-level Rise, Saline Intrusion and Irrigation Systems in Mekong Chapter 15. Possible Impacts of Sea-water Intrusion and Strategies for Water Management in Coastal Areas in the Vietnamese Mekong Delta Chapter 16. Mainstreaming Climate Change Adaptation as a New Policy Arrangement in Vietnam Chapter 17. Sea-level Rise and its Implication for Vietnamese Maritime Zones around the Mekong Delta Chapter 18. Coastal Erosion in the Red River Delta

Greater concentrations of greenhouse gases could bring about an increase in the pace of sea level rise and typhoon intensity in the future. The number of hours that buildings and infrastructure will be affected by high wind speeds is likely to increase in the future, and this could create a number of problems for coastal infrastructure and housing. The effect that sea level rise will have on the construction of breakwaters is also investigated, showing how this will cause an increase in the required materials (and thus the cost) to build and maintain these and other types of sea defenses. Although higher typhoon wind speeds could also increase the size of waves reaching the coastline, the mild slope bathymetries in the south of the country are likely to limit this effect. In areas such as Phan Thiet, the shallow nearshore bathymetry breaks the waves long before they reach the coastline, effectively shielding it from the worst types of waves. However, an increase in sea levels will allow bigger waves to reach the coastline, and require heavier armor to be used in revetments and breakwaters.

Climate change is arguably one of the main challenges facing humanity in the twenty-first century, and the threat that it poses to ports and other coastal areas has only recently started to be fully understood. In this sense, climate change will probably have a disproportionate effect on coastal regions, and due to the forecast increase in sea level and tropical cyclone intensity caused by global warming, many ports in Vietnam could come under increased pressure in the course of the next century. In order to respond to such challenges, an action plan should be drafted to effectively respond to climate change, taking into account the activities of coastal communities and the development stage of the country. The present chapter aims to investigate and assess the long-term development of ports in Vietnam in the context of rapid economic growth and climate change. In order to do so, it is important to understand that the development of ports is tied to population growth and socioeconomic development. Thus, a brief summary on the ports in Vietnam will be given, followed by a discussion of the effects that climate change can have on these ports. Due to the importance that ports are expected to play in the economic development of Vietnam, it is clearly important that careful consideration should be given to long-term planning on where new ports should be located. Furthermore, how these ports will adapt to future climate change should be carefully assessed, in order to mainstream climate change adaptation into port development plans.

The Vietnamese coast faces a number of potential coastal hazards, mainly storm surges and typhoons originating or propagating along the East Sea. In particular, an earthquake in the Manila Trench could generate a 5- to 7-m-high tsunami that would strike the central coast of Vietnam within 2 h of the earthquake, according to computer simulations (see Chapters 13 and 14). Also, the region is frequently hit by typhoons, which can sometimes generate significant storm surges (see Chapters 1, 2, 3, 6, and 8). However, for a successful evacuation it is not only necessary to have a warning system, but for the local population to be aware of the dangers posed by a tsunami or storm surge and know what to do in such an event. Thus, in the present research the authors both surveyed the warning systems currently being constructed along the central coast of Vietnam (south of Da Nang) and administered questionnaires among local inhabitants on their awareness and preparedness against tsunamis and storm surges. The results show that, generally speaking, the local population has a high degree of awareness of the dangers posed by coastal natural disasters, with 76% of respondents being aware of the danger of storm surges and 81% of tsunamis. However, there is a clear difference in preparedness between these disasters, with 70% knowing how to evacuate in the event of a storm surge, but only 58% for the case of a tsunami. The research thus highlights the need to improve disaster awareness and preparedness against coastal disasters in Vietnam, given the potentially disastrous consequences that a tsunami or a storm surge could have, especially along the central coastline of this country.

Typhoon Haiyan (Yolanda) struck the islands of Leyte and Samar, the central part of the Philippines, on 8 November 2013, bringing large-scale devastation to coastal areas due to the high winds and large storm surge and waves associated with it. In order to obtain the distribution of storm surge heights and damage covering the wide stretch of affected coastline, the authors carried out a series of field surveys in the aftermath of the typhoon (in December 2013, May 2014, and October 2014). In the present paper, the authors detailed the results of these field surveys and summarized the characteristics of the storm surge and main causes of the damage, especially focusing on the Leyte Gulf coast, which is surrounded by the eastern coast of Leyte and the southern coast of Samar. Finally, the wide range of types of storm surge disasters were also discussed by comparing Typhoon Haiyan with other recent major events.

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.