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Pahang beaches draw more than thousand visitors throughout the year. From the year 2006 to 2018, more than 30 drowning and near-drowning cases were recorded mainly from rip currents. Rip currents are defined as unexpected currents that carried beachgoers away to seaward direction more than approximately 50 m from shore. The prediction of rip current development is very important for the protection of human life. This study aims to conduct preliminary survey and field works to identify rip current hazards.

The output would be an early warning preventative mitigation to public in Pahang. Beach state model, dimensionless fall velocity, littoral environment observation and relative tidal range were recorded for five recreational beaches during two different months (March and April 2018). The morphodynamic parameters such sediment fall velocity, sediment grain size and beach slope are then analysed using software PROFILER. Classification of risks was done based on beach morphodynamic model. The morphodynamics are classified as low tide bar rip, barred and low tide terrace associated with rip current, bar dissipative, reflective, non-bar dissipative, low tide terrace and ultra-dissipative.

Result shows three out of five recreational beaches may develop high-risk rip currents. During the first month of the survey, Batu Hitam (BH) was recorded the only one recreational beach that may develop high-risk rip current followed by Teluk Cempedak (TC) and Kempadang (KEM) as middle-risk rip current beaches, while Balok (BA) and Sepat (SEP) as low-risk rip current beaches. Different during second month of the survey, BA, BH and SEP were recorded as high-risk rip current beaches while TC and KEM as low-risk rip current beaches.

The results are consistent with beach incidents (drowning and near-drowning) reported.

In Kumamoto, Japan flood risk information is made available on several websites. In the event of heavy rainfall, local citizens need to access these websites and make household-level decisions. It is difficult for citizens to monitor all these sites, analyze and make effective decisions. Evacuation orders are issued by the local government who then filters the information to the relevant multiple stakeholders and local citizens. This takes time and reduces the response lead time of citizens especially in fast-onset floods. There was a therefore a need for illustrative integrated approaches, integrating these data sets.

Using precipitation, river water and tide level data, user-friendly real-time graphs were set up for the Shirakawa River, Kumamoto, Japan. Flood data were collected and used to create numerical simulations, and electronic community-based hazard maps were created.

The data gathered from the July 2012 flood event were used as a demonstrator, illustrating a flood event, as well as how to utilize the information provided on user-friendly real-time graphs’ website, to determine the location, future time and possibility of flooding. Additionally, an electronically generated flood hazard map-making process was developed for distribution across Japan.

These illustrative approaches are relatively new and have only been tested and evaluated in communities across Kumamoto, Japan. As such, it is too early to determine robustness and generalized applications worldwide, especially in data-scarce countries and communities. Improvements and maintenance are ongoing.

These illustrative approaches can be adopted and utilized in cities and communities around the globe, thereby helping in overall disaster risk-reduction initiatives and better flood risk management strategies.

These illustrative approaches are new to Kumamoto City and Japan. These provide citizens with user-friendly real-time graphs that can be accessed anytime and used in flood hazard preparations, warnings, response or recovery.

The purpose of this paper is to present a fully conservative numerical algorithm for solving the coupled shallow water hydro-sediment-morphodynamic equations governing fluvial processes, and also to clarify the performance of a conventional algorithm, which redistributes the variable water-sediment mixture density to the source terms of the governing equations and accordingly the hyperbolic operator is rendered similar to that of the conventional shallow water equations for clear water flows.

The coupled shallow water hydro-sediment-morphodynamic equations governing fluvial processes are arranged in full conservation form, and solved by a well-balanced weighted surface depth-gradient method along with a slope-limited centred scheme. The present algorithm is verified for a spectrum of test cases, which involve complex flows with shock waves and sediment transport processes with contact discontinuities over irregular topographies. The computational results of the conventional algorithm are compared with those of the present algorithm and evaluated by available referenced data.

The fully conservative numerical algorithm performs satisfactorily over the spectrum of test cases, and the conventional algorithm is confirmed to work similarly well.

A fully conservative numerical algorithm, without redistributing the water-sediment mixture density, is proposed for solving the coupled shallow water hydro-sediment-morphodynamic equations. It is clarified that the conventional algorithm, involving redistribution of the water-sediment mixture density, performs similarly well. Both algorithms are equally applicable to problems encountered in computational river modelling.

The purpose of this paper is to present a new numerical model for shallow water flows over heterogeneous sedimentary layers. It is already several years since the single-layered models have been used to model shallow water flows over erodible beds. Although such models present a real opportunity for shallow water flows over movable beds, this paper is the first to propose a multilayered solver for this class of flow problems.

Multilayered beds formed with different erodible soils are considered in this study. The governing equations consist of the well-established shallow water equations for the flow, a transport equation for the suspended sediments, an Exner-type equation for the bed load and a set of empirical equations for erosion and deposition terms. For the numerical solution of the coupled system, the authors consider a non-homogeneous Riemann solver equipped with interface-tracking tools to resolve discontinuous soil properties in the multilayered bed. The solver consists of a predictor stage for the discretization of gradient terms and a corrector stage for the treatment of source terms.

This paper reveals that modeling shallow water flows over multilayered sedimentary topography can be achieved by using a coupled system of partial differential equations governing sediment transport. The obtained results demonstrate that the proposed numerical model preserves the conservation property, and it provides accurate results, avoiding numerical oscillations and numerical dissipation in the approximated solutions.

A novel implementation of sediment handling is presented where both averaged and separate values for sediment species are used to ensure speed and precision in the simulations.

The coast at Berakas in the Brunei-Muara district of Brunei Darussalam suffers from erosion caused by a combination of fluvial and marine processes. This paper investigates the rate and pattern of erosion along a 1.8-km stretch of coast to compare the difference between the unprotected and protected sections. We used (i) image and spatial analysis and (ii) field geomorphology. The Digital Shoreline Analysis System (DSAS) in ArcGIS was used to compare the study area using two Google Earth images. The study found that the unprotected section had receded by 4.6 m between 2009 and 2019, while the protected section had advanced by 8.0 m over the same period; intense gullying and slumping of cliff continued at both sections. The detached headland breakwaters in the protected section were effective in stabilizing the coast. A concrete drain installed parallel to the cliff edge appears to be capable of intercepting storm runoff, but its effectiveness was undermined by lack of maintenance. We conclude that terrestrial-fluvial processes continue to erode coastal land and cause slumping of the cliff face at Berakas. However, coastal protection structures that curb the marine process could stabilize the coastline, even where sediment transport is active.

The Aso area of Kumamoto Prefecture and the western part of Oita Prefecture in Japan experienced heavy rainfall from midnight until morning on 12 July 2012. Flooding and landslides caused by this torrential rain killed 31 people and injured 11. This paper aims to analyze a time series of flood risk perception and evacuation behavior, and to identify factors that promote effective autonomous evacuation.

A time series of flood risk perception and evacuation behavior following the 2012 flood was developed and systematically analyzed. Differences between the data sets (compiled from survey data) for the evacuated group and the non-evacuated group were statistically evaluated. Then, an evacuation behavior model was developed to simulate which households would be likely to evacuate in different scenarios. The relationship between disaster prevention and activities of a local community were also statistically assessed.

This study concludes that an assessment of river conditions and evacuation advice from fellow local community members are the factors that most strongly influence and promote autonomous evacuation. This study also revealed that the everyday activities of a local community have the potential to foster effective disaster prevention and emergency responses if they promote the building of relationships between community members.

The research focused on actual decision-making and autonomous evacuation behavior. Whereas previous studies were limited to the analysis of activities of disaster prevention on a normal day, this study proved that the usual activity level in local community activities and relationships significantly affected evacuation behavior.

Coastal flooding has disastrous consequences on people, infrastructure, properties and the environment. Increasing flood risk as a result of global climate change is a significant concern both within the UK and globally. To counter any potential increase in future flooding, a range of potential management options are being considered. This study aims to explore future coastal management practice for flood alleviation, incorporating the influence of climate change.

The Taf estuary in South West Wales, a macro-tidal estuary which has a history of coastal flooding, was chosen as the case study in this paper to investigate the impact of coastal management interventions such as construction of hard defences, managed realignment or altering land use of affiliated ecosystems such as salt marshes on the complex hydrodynamics and hence flooding of the surrounding areas of the estuary. The study was carried out using a numerical hydrodynamic model of the Taf estuary, developed using the process-based Delft3D modelling software.

The role of the selected management interventions on coastal flooding was investigated using an extreme storm condition, both with and without the impact of future sea level rise. The results highlight the scale of the effect of sea level rise, with the selected management interventions revealing that minimising the increase in flooding in future requires careful consideration of the available options.

This paper explores the highlighted role of coastal management practice in future with the influence of climate change to study how effective alternative methods can be for flood alleviation.

The purpose of this chapter is to address the issue of climate change and its effects on developing insular countries like the Maldives in order to identify adaptive mechanisms and new opportunities in the international context towards achieving sustainable development, taking into account its environmental and social incidences.

Firstly, the chapter introduces some generalities of the Republic of the Maldives and its current challenges. Next, there is a description of the economy of the islands: here the importance of its major source of income, the tourism industry, is highlighted. Then, vulnerabilities and adaptive mechanisms are explored for the particular case of tourism.

Maldivian current efforts in disaster risk management (DRM) mitigation, preparedness, response, and reconstruction stages, and the work between government, private organizations, and civil society, implemented since the 2004 tsunami; and as a response to climate change, are examples of how to apply collaborative approaches proposed by Sustainable Development Objectives, COP21 agreement, and Sendai Framework.

It is difficult to measure the consequences of sustainable development actions by the Maldivian government, especially in the international environment.

The study of the Maldivian DRM strategy in the context of climate change and the lessons from the Maldives’ tourism sector development under climate action serves as a model for other international business organizations which aim to reach sustainable development standards in the Post-2015 Development Agenda.

This chapter evaluated important opportunities for sustainable development agenda that can be learned from DRM measures in Maldives.

The purpose of this article is to discuss the assessment and inclusion of stakeholders' perception, and citizen participation instances to implementing management options to deal with climate threats within the existing institutional framework in Uruguay.

The approach being followed has different directional approaches and integrates them within a single assessment. First, a prescriptive climate change top-down path. Second, stakeholders' perception is assessed within a bottom-up risk-management model. Third, institutional agreements, arrangements, and consensus are reached. Considering the need for agreed and effective options, the approach is customized and turned flexible enough to accept inputs from scientists, managers, and stakeholders.

The co-production of knowledge and the achievement of agreed and feasible options is achieved by means of a consultation process which results in adaptive co-management agreements and collective decisions. This process is seen as both an empowerment of local actors and a multi-stakeholder learning-by-doing experiment. This allows for both an increase in coping capacity to climate threats and facilitates long standing conflict resolution.

Much literature discusses the importance of the role of social power in inclusive processes towards adaptation, and how difficult is ceding a genuine voice to stakeholders. The co-production of knowledge is a way to achieve the rapprochement of scientists with institutional and community actors. Thus, the participatory process gives stakeholders responsibility for identifying their specific needs and priorities and helps to establish community ownership.

The purpose of this paper is to perform a comparative analysis between Aveiro's Lagoon (Portugal) and Sepetiba Bay (Brazil), in order to understand the similarities and differences between these two coastal zones, in terms of human occupation.

This paper is supported by works (papers and scientific projects being developed) produced in Portugal and Brazil, by researchers from different areas of expertise.

These two coastal zones have a similar geomorphologic evolution, due to the fact that both appeared because of a sandy spit, which started to grow and separated these areas from the sea, converting them into sheltered coasts. It was because they are protected that these two study cases early became targets for human occupation. The anthropic impacts in the systems were sustainable until the middle of the twentieth century. Since then, however, the economic development options, based first in industry and second in tourism exploration, have compromised the natural healthy balance.

This paper could be a contribution to a scientific support for political decisions on the coastal zone management (namely in these studied areas).

The paper provides and increases the knowledge of the coastal zones’ evolution and occupation – from a multidisciplinary perspective – produced and made available to scientists, local politicians, students and local populations.

The paper provides a truly interdisciplinary approach, which allows a better understanding of the evolution of these two systems, discussing the causes and consequences of human activities in both coastal areas.