scholarly journals The influence of infragravity waves on the safety of coastal defences: a case study of the Dutch Wadden Sea

2022 ◽  
Vol 22 (1) ◽  
pp. 1-22
Author(s):  
Christopher H. Lashley ◽  
Sebastiaan N. Jonkman ◽  
Jentsje van der Meer ◽  
Jeremy D. Bricker ◽  
Vincent Vuik

Abstract. Many coastlines around the world are protected by dikes with shallow foreshores (e.g. salt marshes and mudflats) that attenuate storm waves and are expected to reduce the likelihood and volume of waves overtopping the dikes behind them. However, most of the studies to date that assessed their effectiveness have excluded the influence of infragravity (IG) waves, which often dominate in shallow water. Here, we propose a modular and adaptable framework to estimate the probability of coastal dike failure by overtopping waves (Pf). The influence of IG waves on overtopping is included using an empirical approach, which is first validated against observations made during two recent storms (2015 and 2017). The framework is then applied to compare the Pf values of the dikes along the Dutch Wadden Sea coast with and without the influence of IG waves. Findings show that including IG waves results in 1.1 to 1.6 times higher Pf values, suggesting that safety is overestimated when they are neglected. This increase is attributed to the influence of the IG waves on the design wave period and, to a lesser extent, the wave height at the dike toe. The spatial variation in this effect, observed for the case considered, highlights its dependence on local conditions – with IG waves showing greater influence at locations with larger offshore waves, such as those behind tidal inlets, and shallower water depths. Finally, the change in Pf due to the IG waves varied significantly depending on the empirical wave overtopping model selected, emphasizing the importance of tools developed specifically for shallow foreshore environments.

2021 ◽  
Author(s):  
Christopher H. Lashley ◽  
Sebastiaan N. Jonkman ◽  
Jentsje Van der Meer ◽  
Jeremy D. Bricker ◽  
Vincent Vuik

Abstract. Many coastlines around the world are protected by coastal dikes fronted by shallow foreshores (e.g. saltmarshes and mudflats) that attenuate storm waves and are expected to reduce the likelihood of waves overtopping the dikes behind them. However, most of the studies to-date that assessed their effectiveness have excluded the influence of infragravity (IG) waves, which often dominate in shallow water. Here, we propose a modular and adaptable framework to estimate the probability of coastal dike failure by overtopping waves (Pf). The influence of IG waves on wave overtopping is included using an empirical approach, which is first validated against observations made during two recent storms (2015 and 2017). The framework is then applied to compare the Pf  of the dikes along the Dutch Wadden Sea coast, with and without the influence of IG waves. Findings show that including IG waves results in 1.1 to 1.6 times higher Pf  values, suggesting that safety may be overestimated when they are neglected. This increase is attributed to the influence of the IG waves on the design wave period, and to a lesser extent the wave height, at the dike toe. The spatial variation in this effect, observed for the case considered, highlights its dependence on local conditions – with IG waves showing greater influence at locations with larger offshore waves and shallower water depths. Finally, the change in Pf  due to the IG waves varied significantly depending on the empirical wave overtopping model selected, emphasizing the importance of tools developed specifically shallow foreshore environments.


2020 ◽  
Vol 43 ◽  
Author(s):  
Michael Lifshitz ◽  
T. M. Luhrmann

Abstract Culture shapes our basic sensory experience of the world. This is particularly striking in the study of religion and psychosis, where we and others have shown that cultural context determines both the structure and content of hallucination-like events. The cultural shaping of hallucinations may provide a rich case-study for linking cultural learning with emerging prediction-based models of perception.


Author(s):  
Pramukti Dian Setianingrum ◽  
Farah Irmania Tsani

Backgroud: The World Health Organization (WHO) explained that the number of Hyperemesis Gravidarum cases reached 12.5% of the total number of pregnancies in the world and the results of the Demographic Survey conducted in 2007, stated that 26% of women with live births experienced complications. The results of the observations conducted at the Midwife Supriyati Clinic found that pregnant women with hyperemesis gravidarum, with a comparison of 10 pregnant women who examined their contents there were about 4 pregnant women who complained of excessive nausea and vomiting. Objective: to determine the hyperemesis Gravidarum of pregnant mother in clinic. Methods: This study used Qualitative research methods by using a case study approach (Case Study.) Result: The description of excessive nausea of vomiting in women with Hipermemsis Gravidarum is continuous nausea and vomiting more than 10 times in one day, no appetite or vomiting when fed, the body feels weak, blood pressure decreases until the body weight decreases and interferes with daily activities days The factors that influence the occurrence of Hyperemesis Gravidarum are Hormonal, Diet, Unwanted Pregnancy, and psychology, primigravida does not affect the occurrence of Hyperemesis Gravidarum. Conclusion: Mothers who experience Hyperemesis Gravidarum feel nausea vomiting continuously more than 10 times in one day, no appetite or vomiting when fed, the body feels weak, blood pressure decreases until the weight decreases and interferes with daily activities, it is because there are several factors, namely, hormonal actors, diet, unwanted pregnancy, and psychology.


Author(s):  
Melanie SARANTOU ◽  
Satu MIETTINEN

This paper addresses the fields of social and service design in development contexts, practice-based and constructive design research. A framework for social design for services will be explored through the survey of existing literature, specifically by drawing on eight doctoral theses that were produced by the World Design research group. The work of World Design researcher-designers was guided by a strong ethos of social and service design for development in marginalised communities. The paper also draws on a case study in Namibia and South Africa titled ‘My Dream World’. This case study presents a good example of how the social design for services framework functions in practice during experimentation and research in the field. The social design for services framework transfers the World Design group’s research results into practical action, providing a tool for the facilitation of design and research processes for sustainable development in marginal contexts.


2015 ◽  
Vol 11 (1) ◽  
pp. 41-54 ◽  
Author(s):  
Zsófia Demjén

This paper demonstrates how a range of linguistic methods can be harnessed in pursuit of a deeper understanding of the ‘lived experience’ of psychological disorders. It argues that such methods should be applied more in medical contexts, especially in medical humanities. Key extracts from The Unabridged Journals of Sylvia Plath are examined, as a case study of the experience of depression. Combinations of qualitative and quantitative linguistic methods, and inter- and intra-textual comparisons are used to consider distinctive patterns in the use of metaphor, personal pronouns and (the semantics of) verbs, as well as other relevant aspects of language. Qualitative techniques provide in-depth insights, while quantitative corpus methods make the analyses more robust and ensure the breadth necessary to gain insights into the individual experience. Depression emerges as a highly complex and sometimes potentially contradictory experience for Plath, involving both a sense of apathy and inner turmoil. It involves a sense of a split self, trapped in a state that one cannot overcome, and intense self-focus, a turning in on oneself and a view of the world that is both more negative and more polarized than the norm. It is argued that a linguistic approach is useful beyond this specific case.


Author(s):  
David Ungemah ◽  
Malaika Rivers ◽  
Stuart Anderson
Keyword(s):  

2020 ◽  
Vol 24 (2) ◽  
pp. 228-240
Author(s):  
Stefania Pontrandolfo ◽  
Marco Solimene

This article reflects on the conceptual debt that anthropology has developed towards the peoples it studies, by exploring the case-study of Gypsy/Roma anthropology. We argue that ethnographically-grounded research has enabled anthropologists to access and incorporate Gypsy/Roma visions and practices of the world. The flexible Gypsy epistemologies, which Gypsies/ Roma use in the social and cultural construction of particular forms of identity and mobility, have thus translated into a specific practice of theory, which has provided more adequate tools for grasping the complexity of reality and contributed to a decolonialisation of anthropological thought.


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