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Henk Jan Verhagen

Bio: Henk Jan Verhagen is an academic researcher. The author has contributed to research in topics: Meaning (existential). The author has an hindex of 1, co-authored 1 publications receiving 3 citations.

Papers
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DOI
05 Aug 1997
TL;DR: In this paper, the meaning of education for coastal engineers is discussed, and what the meaning is for education of coastal engineers will be worked out in this paper, as well as what the importance of knowledge from five years ago to be applied in the next five to 15 years is discussed.
Abstract: In general the problem in education is that we teach nowadays students the knowledge from five years ago, to be applied in the next 5 to 15 years (I admit, the student of today will have reached his retirement when he will participate in the 50th ICCE, the title is exaggerating reality). When one analyses the developments in the profession, it is clear that teaching present day facts is not very useful. We have to teach approaches, design philosophy, concepts, etc. What the meaning is for education of coastal engineers will be worked out in this paper.

18 citations


Cited by
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01 Jan 2003
TL;DR: In this paper, the authors bring some international perspectives on the policy, design, construction, and monitoring aspects of Hydraulic and Coastal Structures in general, and whenever possible, to present some comparison (or reasons for differences) between the experiences of various countries and/or geographical regions.
Abstract: The objective of this paper is to bring some international perspectives on the policy, design, construction, and monitoring aspects of Hydraulic and Coastal Structures in general, and whenever possible, to present some comparison (or reasons for differences) between the experiences of various countries and/or geographical regions. This chapter reviews the trends of our hydraulic/coastal engineering profession and presents an overview of miscellaneous aspects, which should be a part of the entire design process for civil engineering structures. This overview ranges from initial problem identification boundary condition definition and functional analysis, to design concept generation, selection, detailing an costing and includes an examination of the construction and maintenance considerations and quality assurance/quality control aspects. It also indicates the principles and methods, which support the design procedure making reference as appropriate to other parts of the chapter. It must be recognized that the design process is a complex iterative process and my be described in more than one way. Some speculation on the possible future needs and/or trends in hydraulic and coastal structures in the larger international perspective is also presented briefly.

6 citations

Book ChapterDOI
01 Aug 2012

3 citations

Journal ArticleDOI
TL;DR: The idea that the groundwater table plays a role in the mobilization of the sediment grains underlies the application of the beach drainage system (BDS) as a tool able to modify the natural dynamics of groundwater table at sandy beaches as discussed by the authors .
Abstract: The beach drainage can be included among the soft engineering methods aimed to counteract the shoreline retreat related to the sediment redistribution along the beach profile. The idea that the groundwater table plays a role in the mobilization of the sediment grains underlies the application of the beach drainage system (BDS) as a tool able to modify the natural dynamics of groundwater table at sandy beaches. Indeed, BDS consists of a series of alongshore buried drains aimed to lower the groundwater table. Due to the drainage, the thickening of the layer of dry sand makes the solid grains less prone to be mobilized by the action of the waves at the swash zone, where interaction phenomena between the percolating and the incoming water lens take place. This tool had a troubled history. Its first applications were encouraging. Since then, controversial performances of both experimental and prototype scale experiences have been observed around the world. This paper aims to present an up-to-date full review of the studies and experiments carried out so far, in order to provide the reader with a complete perspective on its strength and weakness as well as open challenges to be faced in the near future.

3 citations

Journal ArticleDOI
TL;DR: In this article , the authors examined how seagrass may affect shoreline morphodynamics by making inferences from existing knowledge of conventional submerged structures, such as breakwaters and artificial reefs, on adjacent shorelines.
Abstract: Coastal ecosystems, such as seagrass meadows, have been heralded as a nature-based solution for coastal protection. However, the functions of seagrass meadows, including wave attenuation and sediment stabilisation, have typically been measured offshore and do not directly translate to coastal protection at the shoreline. In contrast, the protective effects of conventional submerged structures, such as breakwaters and artificial reefs, on adjacent shorelines have been well described and are predictable. Importantly, these artificial structures often cause erosion in adjacent areas. This study examines how seagrass may affect shoreline morphodynamics by making inferences from existing knowledge of conventional submerged structures. Both conventional submerged structures and seagrass meadows affect wave height and direction, yet this effect on longshore sediment transport has only been considered within the context of coastal defence structures. From the conventional literature on submerged structures, it is known that a constant rate of longshore sediment transport will result in a constant shoreline shape. Therefore, a change in the rate of longshore sediment transport, or gradient, generates changes in the shoreline shape and, hence, the shoreline morphodynamics. We propose that seagrass also has spatially heterogeneous effects on shoreline morphodynamics, with protection occurring in some locations and downstream erosion likely in others. Empirical and modeling research is required to test this hypothesis. In the meantime, this review suggests contexts under which seagrass may affect shoreline morphodynamics and provide shoreline protection. This research bridges the gaps in knowledge across marine ecology, physical oceanography and coastal engineering to overcome some of the challenges of interdisciplinary coastal science.

2 citations

Journal ArticleDOI
TL;DR: In this paper , the issue of wave-breaking closure for the well-known Green-Naghdi model and attempt at providing some more understanding of the sensitivity of some closure approaches to the numerical set-up is considered.
Abstract: We consider the issue of wave-breaking closure for the well-known Green–Naghdi model and attempt at providing some more understanding of the sensitivity of some closure approaches to the numerical set-up. More precisely and based on Kazolea and Ricchiuto (Ocean Model 123:16–39, 2018), we used two closure strategies for modeling wave-breaking of a solitary wave over a slope. The first one is the hybrid method consisting of suppressing the dispersive terms in a breaking region and the second one is an eddy viscosity approach based on the solution of a turbulent kinetic energy model. The two closures use the same conditions for the triggering of the breaking mechanisms. Both the triggering conditions and the breaking models themselves use case depended/ad/hoc parameters which are affecting the numerical solution while changing. The scope of this work is to make use of sensitivity indices computed by means of analysis of variance to provide the sensitivity of wave-breaking simulation to the variation of parameters such as the mesh size and the breaking parameters specific to each breaking model. The sensitivity analysis is performed using the UQlab framework for uncertainty quantification (Marelli et al., UQLab user manual—sensitivity analysis, Technical report, Chair of Risk, Safety and Uncertainty Quantification, ETH Zurich, Switzerland, 2019).

2 citations