scholarly journals UPGRADING BREAKWATERS IN RESPONSE TO SEA LEVEL RISE: PRACTICAL INSIGHTS FROM PHYSICAL MODELLING

Author(s):  
Daniel Howe ◽  
Ron J Cox

Coastal structures in many parts of the world are typically designed for depth-limited breaking wave conditions. With a projected sea level rise of up to 90 cm by 2100 (Church et al., 2013), the design wave height for these structures is expected to increase. Many of these structures will require significant armour upgrades to accommodate these new design conditions (for example, a 25% increase in wave height will require the mass of similar density armour to be doubled).

Author(s):  
Fransisca Handayani ◽  
Alvin Hadiwono

"Dwelling" basically means living in a place. However, Dwelling itself has a broader meaning when we understand how humans decided to inhabit. In the book The Nature of Order, Christopher Alexander says "Dwelling is Living-Structure" which means to live is a life participating in a living-structure. This quote directly describes a relationship between nature and humans in the process of living. Seeing the conditions that exist in the world today, there are many aspects that can affect the way humans will live in the future. One of the problems that humans have to face is climate change which causes sea level rise. Realizing that humans must face these events and know that in reality, humans cannot be separated from their natural surroundings, "The Dynamic of Adaptive Shelter" was designed with the aim of wanting to unite aspects of habitation (especially nature and humans) as well as provide solutions for buildings that are adaptive to sea level rise. Located in Kamal Muara, North Jakarta, this project begins by studying the selected site, community activities, the shape of the buildings around the site, as well as the natural characteristics around the site, as a method that refers to a quote from Martin Heidegger's book about "the thing It-self". Referring to the results of the selected site, this project is complemented with programs that are suitable for the activities of the residents of the area and have been developed with systems which can adapt to the issue of sea level rise. Keywords:  Adaptive-Dynamic; Coastal; Dwelling; Fishermen ; Sea Level Rise Abstrak“Dwelling” atau Berhuni pada dasarnya memiliki arti hidup pada suatu tempat. Namun Dwelling sendiri memiliki arti yang lebih luas saat kita memahami awal mula manusia memutuskan untuk berhuni. Dalam buku The Nature of Order Christohper Alexander mengatakan “Dwelling is Living- Structure” yang berarti berhuni adalah hidup berpartisipasi dalam Struktur-kehidupan (Living- structure). Kutipan tersebut secara langsung menggambarkan sebuah keterkaitan antara alam dan manusia dalam menuju proses berhuni. Melihat kondisi yang ada didunia saat ini banyak aspek yang dapat mempengaruhi cara manusia berhuni dimasa depan. Salah satu permasalahan yang harus dihadapi manusia adalah perubahan iklim yang menyebabkan kenaikan permukaan air laut. Menyadari bahwa manusia harus menghadapi peristiwa tersebut dan mengetahuni bahwa pada dasarnya dalam proses berhuni manusia tidak terlepas dari alam sekitarnya, “Wadah Adaptif- Dinamis” dirancang dengan tujuan ingin mempersatukan aspek-aspek berhuni (khususnya alam dan manusia) dan juga memberikan solusi akan bangunan yang adaptif akan kenaikan permukaan air laut. Berlokasi di Kamal Muara, Jakarta Utara proyek ini diawali dengan mempelajari site terpilih, aktivitas masyarakat, bentuk bangunan sekitar tapak, dan juga karakteristik alam sekitar tapak, sebagaimana metode yang mengacu pada kutipan buku Martin Heidegger tentang “the thing It-self”. Mengacu pada hasil analisis tapak terpilih, proyek ini dilengkapi dengan program-program yang sesuai dengan aktifitas penduduk daerahnya dan telah dikembangkan dengan sistem-sistem yang mana dapat beradaptasi dengan kondisi alam sekitar dan menjawa isu akan kenaikan permukaan air laut.


2018 ◽  
Vol 5 (1) ◽  
pp. 119
Author(s):  
Karina Santoso ◽  
I Dewa Nyoman Nurweda Putra ◽  
I Gusti Bagus Sila Dharma

Bali is one of the islands where there are many surf zones with various characteristics. In addition, Bali is also a heaven with a classy wave for the surfers of the world. One of the most challenging places to surf in Bali is Uluwatu Beach. Uluwatu Beach is ranked the 3rd best surf spot in the world version of CNN Travel in 2012. Wind causes sea waves, therefore wind data can be used to estimate the height and direction of the waves. Wave Hindcasting with Sverdrup, Munk and Bretschneider (SMB) method is calculated based on wind data for 10 years (2001 - 2010) from BMKG Ngurah Rai Station - Denpasar to obtain a significant wave height and period. In this research, it is necessary to approach through Hindcasting procedure, wave transformation analysis and surfing Terminology in determining the type of breaking wave and classification of surf zone in Uluwatu Beach area. Wave calculation result in Uluwatu Beach dominated by wave that coming from west side with significant wave height (Hs) of 0.98 m and significant wave period (Ts) of 5.21 s. The wave height due to the influence of wave refraction and shoaling is 0.976 m. The breaking wave height obtained from the calculation is 1.04 m at a depth of 0.849 m. From the result in this research, it can be concluded that the breaking wave type that occurred at Uluwatu Beach is plunging type according to the calculation result from its Irribaren number (0.4 <Ni <2.3). The classification of the surf zone at Uluwatu Beach based on its breakup type of wave is thought to be a good zone for surfers on intermediate level.


2021 ◽  
Vol 33 (6) ◽  
pp. 298-307
Author(s):  
A Jeong Kim ◽  
Myeong Hee Lee ◽  
Seung Won Suh

Typhoons occur intensively between July and October, and the sea level is the highest during this time. In particular, the mean sea level in summer in Korea is higher than the annual mean sea level about 14.5cm in the west coast, 9.0 to 14.5cm in the south coast, and about 9.0 cm in the east coast. When the rising the sea level and a large typhoon overlap in summer, it can cause surges and flooding in low-lying coastal areas. Therefore, accurate calculation of the surge height is essential when designing coastal structures and assessing stability in order to reduce coastal hazards on the lowlands. In this study, the typhoon surge heights considering the summer mean sea level rise (SH_m) was calculated, and the validity of the analysis of abnormal phenomena was reviewed by comparing it with the existing surge height considering the annual mean sea level (SH_a). As a result of the re-analyzed study of typhoon surge heights for BOLAVEN (SANBA), which influenced in August and September during the summer sea level rise periods, yielded the differences of surge heights (cm) between SH_a and SH_m 7.8~24.5 (23.6~34.5) for the directly affected zone of south-west (south-east) coasts, while for the indirect south-east (south-west) coasts showed -1.0~0.0 (8.3~12.2), respectively. Whilst the differences between SH_a and SH_m of typhoons CHABA (KONG-REY) occurred in October showed remarkably lessened values as 5.2~ 14.2 (19.8~21.6) for the directly affected south-east coasts and 3.2~6.3 (-3.2~3.7) for the indirectly influenced west coast, respectively. The results show the SH_a does not take into account the increased summer mean sea level, so it is evaluated that it is overestimated compared to the surge height that occurs during an actual typhoon. Therefore, it is judged that it is necessary to re-discuss the feasibility of the surge height standard design based on the existing annual mean sea level, along with the accurate establishment of the concept of surge height.


2015 ◽  
Vol 12 (6) ◽  
pp. 2955-3001
Author(s):  
H. Cannaby ◽  
M. D. Palmer ◽  
T. Howard ◽  
L. Bricheno ◽  
D. Calvert ◽  
...  

Abstract. Singapore is an island state with considerable population, industries, commerce and transport located in coastal areas at elevations less than 2 m making it vulnerable to sea-level rise. Mitigation against future inundation events requires a quantitative assessment of risk. To address this need, regional projections of changes in (i) long-term mean sea level and (ii) the frequency of extreme storm surge and wave events have been combined to explore potential changes to coastal flood risk over the 21st century. Local changes in time mean sea level were evaluated using the process-based climate model data and methods presented in the IPCC AR5. Regional surge and wave solutions extending from 1980 to 2100 were generated using ~ 12 km resolution surge (Nucleus for European Modelling of the Ocean – NEMO) and wave (WaveWatchIII) models. Ocean simulations were forced by output from a selection of four downscaled (~ 12 km resolution) atmospheric models, forced at the lateral boundaries by global climate model simulations generated for the IPCC AR5. Long-term trends in skew surge and significant wave height were then assessed using a generalised extreme value model, fit to the largest modelled events each year. An additional atmospheric solution downscaled from the ERA-Interim global reanalysis was used to force historical ocean model simulations extending from 1980–2010, enabling a quantitative assessment of model skill. Simulated historical sea surface height and significant wave height time series were compared to tide gauge data and satellite altimetry data respectively. Central estimates of the long-term mean sea level rise at Singapore by 2100 were projected to be 0.52 m (0.74 m) under the RCP 4.5 (8.5) scenarios respectively. Trends in surge and significant wave height 2 year return levels were found to be statistically insignificant and/or physically very small under the more severe RCP8.5 scenario. We conclude that changes to long-term mean sea level constitute the dominant signal of change to the projected inundation risk for Singapore during the 21st century. We note that the largest recorded surge residual in the Singapore Strait of ~ 84 cm lies between the central and upper estimates of sea level rise by 2100, highlighting the vulnerability of the region.


Author(s):  
James E. Neumann ◽  
Daniel E. Hudgens ◽  
Jane Leber Herr ◽  
Jennifer Kassakian

Author(s):  
Hill and

Whether the world is prepared for it or not, climate change will drive large-scale migration. The impacts of climate change—both slow-onset changes, such as sea-level rise and drought, and sudden-onset events, such as extreme storms and wildfires—push people from their homes. Managed well, migration can yield enormous benefits, offering greater opportunities for those who relocate and injecting new talent and energy into receiver communities. But climate change threatens to unleash “disruptive migration,” that is, sudden migration that could strain social, economic, and political stability. The task ahead in the face of climate change is to encourage managed, gradual migration that minimizes disruption, moves people out of harm’s way, and turns displacement into economic opportunity. This chapter outlines the strategies and tools that exist to make this possible.


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