1,720,990 research outputs found
Hydro-morphological modelling of small, wave-dominated estuaries
No full textAbstractSmall, intermittently open or closed estuaries are characteristic of the coasts of South Africa, Australia, California, Mexico and many other areas of the world. However, modelling attention has tended to focus on big estuaries that drain large catchments and serve a wide diversity of interests e.g. agriculture, urban settlement, recreation, commercial fishing. In this study, the development of a simple, parametric, system dynamics model to simulate the opening and closure of the mouths of small, wave-dominated estuaries is reported. In the model, the estuary is conceived as a basin with a specific water volume to water level relationship, connected to the sea by a channel of fixed width, but variable sill height. Changes in the form of the basin are not treated in the model, while the dynamics of the mouth channel are central to the model. The magnitude and direction of the flow through the mouth determines whether erosion or deposition of sediment occurs in the mouth channel, influencing the sill height. The model is implemented on the Great Brak Estuary in South Africa and simulations reveal that the raised low water levels in the estuary during spring tide relative to neap tide, are occasioned by the constriction of the tidal flow through the shallow mouth. Freshwater inflows to the estuary are shown to be significant in determining the behaviour of the inlet mouth, a factor often ignored in studies on tidal inlets. Further it is the balance between freshwater inflows and wave events that determines the opening or closure of the mouth of a particular estuary
Editorial
No full textGreen Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Policy Analysi
Voices on Sustainable Ports in Africa: Stories from Tema Port, Ghana
No full textPorts provide an essential link to the world market, enabling countries to trade their goods and strengthen their economies. However, the global and regional benefits of port developments do not always translate into benefits to local stakeholders. There is often a mismatch between the positive global and regional effects of port development and the impacts that can be experienced locally. Port development requires a paradigm shift from a conventional economic and engineering oriented approach to a stakeholder-inclusive and environmentally, economically and socially integrated approach to become sustainable. The research project ‘Integrated and Sustainable Port Development in Ghana within an African Context’ aims to learn how to develop integrated and sustainable African ports that meet economic, social and environmental needs now and in the future. The Port of Tema, which has evolved from a small fishing village to Ghana’s leading industrial centre and seaport in the last decades, forms the focal case study of the research. A specific objective of the governance component of the project is to find out what local stakeholders value as a sustainable port. This book is an outcome of this endeavor, seeking to present and share the voices of a range of stakeholders on Tema and its port.Rivers, Ports, Waterways and Dredging EngineeringPolicy AnalysisCoastal Engineerin
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
A specific transdisciplinary co-design workshop model to teach a multiple perspective problem approach for integrated nature-based design
No full textInter- and transdisciplinary place-based learning by international groups of students formed an integral component of the Partnerships for International Research and Education Coastal Flood Risk Reduction (PIRE-CFRR) program “Integrated, multiscale approaches for understanding how to reduce vulnerability to damaging events.” The program aimed to create “authentic learning environments” that supported and benefitted from ongoing research on flood risk management. Accordingly, an eight-step transdisciplinary, collaborative design workshop method was developed and applied to two problem situations: (i) the erosion hotspot of the southwest coast of Texel island and (ii) the future noncompliance of the old Hondsbossche Pettermer Sea Dike with Dutch flood defense standards. The effects of the workshop method were evaluated in terms of the process of co-design, the substantive outcomes, and the learning outcomes of individual students. Findings indicate that the co-design process created an open and authentic environment in which students from different disciplinary backgrounds could experience undertaking integrated, nature-based design. Wide-ranging nature-based solutions were produced with diverse biogeophysical and social features in all designs. This indicated that the students were equipped to work collaboratively to produce novel designs that incorporated multiple perspectives. Survey results affirmed the success of the transdisciplinary co-design workshop method as a means of teaching integrated, nature-based infrastructure design.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Policy AnalysisHydraulic EngineeringHydraulic Structures and Flood Ris
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