scholarly journals TRANSIENT DAM-BREAK WAVE LOADING ON PIPELINES NEAR SLOPING BED

2020 ◽  
pp. 55
Author(s):  
Behnaz Ghodoosipour ◽  
Tomoyuki Takabatake ◽  
Ioan Nistor ◽  
Majid Mohammadian ◽  
Go Hamano ◽  
...  
Keyword(s):  
Experimental Research ◽  
Extreme Events ◽  
Coastal Areas ◽  
Dam Break ◽  
Experimental Program ◽  
Wave Loading ◽  
Comprehensive Understanding ◽  
Changing Climate ◽  
Hydrodynamic Loading ◽  
Sloping Bed

Extreme events such as tsunamis and floods have caused massive damaging consequences to nearshore infrastructures. This has been more significant recently due to a changing climate. Transmission pipelines are among such infrastructures and need to be protected against potential extreme events. Design of pipelines requires comprehensive understanding of the exerting hydrodynamic forces. Such pipelines are often placed on sloping beds in coastal areas. Therefore, to address the uncertainties and parameters involved in extreme hydrodynamic loading on pipelines near sloping bed, an experimental program was conducted at the hydraulic laboratory in WASEDA University, Tokyo, Japan. This study is a complement of another experimental research conducted by Ghodoosipour et al., 2019a and b to investigate loadings from tsunami-like dam-break waves on pipelines located on flat bed.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/y6nSfe34SAw

scholarly journals Experimental Study on Extreme Hydrodynamic Loading on Pipelines. Part 1: Flow Hydrodynamics

2019 ◽  
Vol 7 (8) ◽  
pp. 251 ◽  
Author(s):  
Ghodoosipour ◽  
Stolle ◽  
Nistor ◽  
Mohammadian ◽  
Goseberg
Keyword(s):  
Flow Characteristics ◽  
Dam Break ◽  
Water Levels ◽  
Coastal Communities ◽  
Experimental Program ◽  
Flow Conditions ◽  
The Past ◽  
Hydrodynamic Loading ◽  
Extreme Flood ◽  
Dam Break Flow

Over the past two decades, extreme flood events generated by tsunamis or hurricanes have caused massive damage to nearshore infrastructures and coastal communities. Utility pipelines are part of such infrastructure and need to be protected against potential extreme hydrodynamic loading. Therefore, to address the uncertainties and parameters involved in extreme hydrodynamic loading on pipelines, a comprehensive experimental program was performed using an experimental facility which is capable of generating significant hydraulic forcing, such as dam-break waves. The study presented herein examines the dam-break flow characteristics and influence of the presence of pipelines on flow conditions. To simulate conditions of coastal flooding under tsunami-induced inundation, experiments were performed on both dry and wet bed conditions to assess the influence of different impoundment depths and still water levels on the hydrodynamic features.

scholarly journals Synergy between satellite observations and model simulations during extreme events

2018 ◽  
Author(s):  
Anne Wiese ◽  
Joanna Staneva ◽  
Johannes Schultz-Stellenfleth ◽  
Arno Behrens ◽  
Luciana Fenoglio-Marc ◽  
...  
Keyword(s):  
Satellite Data ◽  
Extreme Events ◽  
Wave Model ◽  
Coastal Areas ◽  
In Situ Measurements ◽  
Model Simulations ◽  
Significant Wave ◽  
Operational Analysis

Abstract. In this study, the quality of wind and wave data provided by the new Sentinel-3A satellite is evaluated. We focus on coastal areas, where altimeter data are of lower quality than those for the open ocean. The satellite data of Sentinel-3A, Jason-2 and CryoSat-2 are assessed in a comparison with in situ measurements and spectral wave model (WAM) simulations. The sensitivity of the wave model to wind forcing is evaluated using data with different temporal and spatial resolution, such as ERA-Interim and ERA5 reanalyses, ECMWF operational analysis and short-range forecasts, German Weather Service (DWD) forecasts and regional atmospheric model simulations -coastDat. Numerical simulations show that both the wave model forced using the ERA5 reanalyses and that forced using the ECMWF operational analysis/forecast demonstrate the best capability over the whole study period, as well as during extreme events. To further estimate the variance of the significant wave height of ensemble members for different wind forcings, especially during extreme events, an empirical orthogonal function (EOF) analysis is performed. Intercomparisons between remote sensing and in situ observations demonstrate that the overall quality of the former is good over the North Sea and Baltic Sea throughout the study period, although the significant wave heights estimated based on satellite data tend to be greater than the in situ measurements by 7 cm to 26 cm. The quality of all satellite data near the coastal area decreases; however, within 10 km off the coast, Sentinel-3A performs better than the other two satellites. Analyses in which data from satellite tracks are separated in terms of onshore and offshore flights have been carried out. No substantial differences are found when comparing the statistics for onshore and offshore flights. Moreover, no substantial differences are found between satellite tracks under various metocean conditions. Furthermore, the satellite data quality does not depend on the wind direction relative to the flight direction. Thus, the quality of the data obtained by the new Sentinel-3A satellite over coastal areas is improved compared to that of older satellites.

scholarly journals An experimental decomposition of nonlinear forces on a surface-piercing column: Stokes-type expansions of the force harmonics

2018 ◽  
Vol 848 ◽  
pp. 42-77 ◽  
Author(s):  
L. F. Chen ◽  
J. Zang ◽  
P. H. Taylor ◽  
L. Sun ◽  
G. C. J. Morgan ◽  
...  
Keyword(s):  
High Order ◽  
Quality Data ◽  
Wave Group ◽  
Wave Loading ◽  
Harmonic Force ◽  
Wave Basin ◽  
Wide Range ◽  
Time Histories ◽  
Focused Wave ◽  
Sloping Bed

Wave loading on marine structures is the major external force to be considered in the design of such structures. The accurate prediction of the nonlinear high-order components of the wave loading has been an unresolved challenging problem. In this paper, the nonlinear harmonic components of hydrodynamic forces on a bottom-mounted vertical cylinder are investigated experimentally. A large number of experiments were conducted in the Danish Hydraulic Institute shallow water wave basin on the cylinder, both on a flat bed and a sloping bed, as part of a European collaborative research project. High-quality data sets for focused wave groups have been collected for a wide range of wave conditions. The high-order harmonic force components are separated by applying the ‘phase-inversion’ method to the measured force time histories for a crest focused wave group and the same wave group inverted. This separation method is found to work well even for locally violent nearly-breaking waves formed from bidirectional wave pairs. It is also found that the $n$th-harmonic force scales with the $n$th power of the envelope of both the linear undisturbed free-surface elevation and the linear force component in both time variation and amplitude. This allows estimation of the higher-order harmonic shapes and time histories from knowledge of the linear component alone. The experiments also show that the harmonic structure of the wave loading on the cylinder is virtually unaltered by the introduction of a sloping bed, depending only on the local wave properties at the cylinder. Furthermore, our new experimental results reveal that for certain wave cases the linear loading is actually less than 40 % of the total wave loading and the high-order harmonics contribute more than 60 % of the loading. The significance of this striking new result is that it reveals the importance of high-order nonlinear wave loading on offshore structures and means that such loading should be considered in their design.

Coastal flooding in the Balearic Islands during the 21st century caused by sea level rise and extreme events

2020 ◽  
Author(s):  
Pau Luque Lozano ◽  
Lluís Gómez-Pujol ◽  
Marta Marcos ◽  
Alejandro Orfila
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Sea Level ◽  
21St Century ◽  
Extreme Events ◽  
Storm Surges ◽  
Coastal Flooding ◽  
Coastal Areas ◽  
Balearic Islands ◽  
Mean Sea Level

<p>Sea-level rise induces a permanent loss of land with widespread ecological and economic impacts, most evident in urban and densely populated areas. The eventual coastline retreat combined with the action of waves and storm surges will end in more severe damages over coastal areas. These effects are expected to be particularly significant over islands, where coastal zones represent a relatively larger area vulnerable to marine hazards.</p><p>Managing coastal flood risk at regional scales requires a prioritization of resources and socioeconomic activities along the coast. Stakeholders, such as regional authorities, coastal managers and private companies, need tools that help to address the evaluation of coastal risks and criteria to support decision-makers to clarify priorities and critical sites. For this reason, the regional Government of the Balearic Islands (Spain) in association with the Spanish Ministry of Agriculture, Fisheries and Environment has launched the Plan for Climate Change Coastal Adaptation. This framework integrates two levels of analysis. The first one relates with the identification of critical areas affected by coastal flooding and erosion under mean sea-level rise scenarios and the quantification of the extent of flooding, including marine extreme events. The second level assesses the impacts on infrastructures and assets from a socioeconomic perspective due to these hazards.</p><p>In this context, this paper quantifies the effects of sea-level rise and marine extreme events caused by storm surges and waves along the coasts of the Balearic Islands (Western Mediterranean Sea) in terms of coastal flooding and potential erosion. Given the regional scale (~1500 km) of this study, the presented methodology adopts a compromise between accuracy, physical representativity and computational costs. We map the projected flooded coastal areas under two mean sea-level rise climate change scenarios, RCP4.5 and RCP8.5. To do so, we apply a corrected bathtub algorithm. Additionally, we compute the impact of extreme storm surges and waves using two 35-year hindcasts consistently forced by mean sea level pressure and surface winds from ERA-Interim reanalysis. Waves have been further propagated towards the nearshore to compute wave setup with higher accuracy. The 100-year return levels of joint storm surges and waves are used to map the spatial extent of flooding in more than 200 sandy beaches around the Balearic Islands by mid and late 21st century, using the hydrodynamical LISFLOOD-FP model and a high resolution (2 m) Digital Elevation Model.</p>

scholarly journals Fikih Mangrove: Formulasi Fikih Lingkungan Pesisir Perspektif Eko-Syariah

2017 ◽  
Vol 7 (1) ◽  
pp. 107-127
Author(s):  
Moh. Mufid
Keyword(s):  
Coastal Area ◽  
Local Governments ◽  
Coastal Environment ◽  
Coastal Areas ◽  
Coastal Communities ◽  
Religious Values ◽  
Land Conversion ◽  
Comprehensive Understanding ◽  
New Paradigm ◽  
Islamic Jurisprudence

Abstract: This article is a study of mangrove management in eco-sharia perspective. Conservation efforts in the coastal areas must be constructed based on religious values ​​so that it is expected to create a collective attitude of environmental awareness among coastal communities. Eco-sharia as an approach can provide a new paradigm related to the preservation of the coastal environment with anthropo-cosmic insights. The concept of eco-ecology and ecosystem can also provide a comprehensive understanding in the effort to support the existence of coastal environment jurisprudence. Normatively, the perspective of Islamic jurisprudence on mangroves preservation can be built through an in-depth understanding of Islamic recommendations in rehabilitating mangrove habitats in coastal area; Procedure of mangrove land conversion based on consideration of principle of benefit; Thus, it is urged that local governments to issue regulations to manage mangrove preservation in a sustainable manner. Abstrak: Artikel ini merupakan kajian pengelolaan mangrove dalam perspektif eko-syariah. Upaya pelestarian di wilayah pesisir harus dikonstruksi berbasis nilai-nilai religius sehingga diharapkan mampu melahirkan sikap kesadaran lingkungan secara kolektif di kalangan masyarakat pesisir. Eko-syariah sebagai suatu pendekatan dapat memberikan paradigma baru terkait pelestarian lingkungan pesisir dengan wawasan antropokosmis. Konsep ekoteologi dan ekosofi juga dapat memberikan pemahaman yang komprehensif dalam upaya mendukung eksistensi fikih lingkungan pesisir. Secara normatif, fikih mangrove dapat dibangun melalui pemahaman secara mendalam tentang anjuran Islam dalam merehabilitasi habitat mangrove di pesisir; prosedur alih fungsi lahan mangrove berdasarkan pertimbangan asas manfaat-mafsadat; keniscayaan pemerintah daerah menerbitkan regulasi untuk mengatur pengelolaan mangrove secara berkelanjutan.

scholarly journals How Does Changing Climate Bring More Extreme Events?

Eos ◽  
2017 ◽  
Vol 98 ◽  
Author(s):  
S.-Y. Wang ◽  
Jin-Ho Yoon ◽  
Christopher Funk ◽  
Robert Gillies
Keyword(s):  
Climate Change ◽  
Extreme Events ◽  
Changing Climate ◽  
Weather And Climate

The editors of a new book describe how and why weather and climate phenomena are intensifying with climate change.

scholarly journals The Curvature Effect

2020 ◽  
Author(s):  
Guido Corradi ◽  
Enric Munar
Keyword(s):  
20Th Century ◽  
Interior Design ◽  
Experimental Research ◽  
Applied Research ◽  
The Other ◽  
Curvature Effect ◽  
Comprehensive Understanding ◽  
Unified Framework ◽  
The Past ◽  
Experimental Aesthetics

Preference for curved over sharp-angled contours is a well-known effect. However, it was quite unexplored during the 20th century and only a few sporadic studies dealt with it. Nevertheless, there has been renewed interest in this topic over the past two decades. This interest has come from two perspectives, one related to the current experimental aesthetics and the other from different applied approaches: marketing, packaging, interior design, and security perception, among others. Quite a few studies have demonstrated the effect with different stimuli, conditions, and participants. However, a comprehensive understanding of this effect is still lacking. We present the salient issues of the current studies in order to provide a more complete picture of this phenomenon. The applied research line is a promising field to combine with research from experimental aesthetics. Finally, we indicate a few challenges that experimental research should address to achieve a unified framework for a better understanding of the curvature effect.

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