1,721,008 research outputs found
Guidance note on the application of coastal modelling for small island developing states: Part of the NOC-led project “Climate Change Impact Assessment: Ocean Modelling and Monitoring for the Caribbean CME states”, 2017-2020; under the Commonwealth Marine Economies (CME) Programme in the Caribbean
Full text linkSmall Island Developing States (SIDS) are a diverse group of 51 countries and territories vulnerable to human-induced climate change, due to factors including their small size, large exclusive economic zones and limited resources. They generally have insufficient critical mass in scientific research and technical capability to carry out coastal monitoring campaigns from scratch and limited access to data. This guidance report will go some way to addressing these issues by providing information on monitoring methods and signposting data sources. Coastal monitoring, the collection, analysis and storage of information about coastal processes and the response of the coastline, provides information on how the coast changes over time, after storm events and due to the effects of human intervention. Accurate and repeatable observational data is essential to informed decision making, particularly in light of climate change, the impacts of which are already being felt. In this report, we review the need for monitoring and the development of appropriate strategies, which include good baseline data and long-term repeatable data collection at appropriate timescales. We identify some of the methods for collection of in situ data, such as tide gauges and topographic survey, and highlight where resources in terms of data and equipment are currently available. We then go on to explore the range of remote sensing methods available from satellites to smart phone photography. Both in situ and remotely sensed data are important as inputs into models, which in turn feed in to visualisations for decision-making. We review the availability of a wide range of datasets, including details of how to access satellite data and links to international and regional data banks. The report concludes with information on the use of Geographical Information Systems (GIS) and good practice in managing data
Guidance note on the application of coastal modelling for small island developing states: Part of the NOC-led project “Climate Change Impact Assessment: Ocean Modelling and Monitoring for the Caribbean CME states”, 2017-2020; under the Commonwealth Marine Economies (CME) Programme in the Caribbean.
No full textSmall Island Developing States (SIDS) are very diverse, but have something in common: they are all vulnerable to human-induced climate change, but have contributed very little to causing the problem, due to their small size and limited development. Much time has been spent in debating climate change and adaptation strategies for such countries, but little has been done in developing practical tools to assist them in managing the coastal zone. In this report we aim to address that. In April 2017, some senior staff members from the National Oceanography Centre (NOC) visited St Vincent and the Grenadines, as part of the UK Foreign and Commonwealth Office-funded Neptune programme. At that time, some of the issues around coastal erosion on the east coast of St Vincent were identified, as well as some extreme events from which St Vincent and the Grenadines had suffered substantial losses of GDP. This was followed up by a workshop in January 2018 on ‘Implementing and Monitoring the Sustainable Development Goals in the Caribbean: The Role of the Ocean’, which was co-sponsored by the UK Government-funded Commonwealth Marine Economies Programme (CMEP) via the NOC (CMEP being the successor to Neptune). During the period September 2017 to March 2020, the National Oceanography Centre, funded by the CMEP, has been working with St Vincent and the Grenadines to provide knowledge, data and training about data analysis application and software for the use of coastal managers, particularly in order to address the problem of coastal erosion. We held a stakeholder workshop in Kingstown, St Vincent, in March 2018 and a hands-on technical training workshop in January 2019. A final workshop is being held in March 2020. Here we present an overview of coastal modelling methodology for use by Small Island Developing States (SIDS), including references to previous model review studies and guidance on how to access and apply model outputs, which will be presented at the workshop, entitled ‘Applying Knowledge of Coastal Processes for Coastal Zone Management into the Future’. This report seeks to collate the information on Coastal Modelling, which may be relevant to all SIDS, in order to support evidence-based decision-making. The case study is built around work done for St Vincent and the Grenadines. It is not the intention to explain in detail the technical working and development of models, as it is envisaged that SIDS will not want or need to run complex models themselves, but if this is desired, information on further reading and training is provided. Some of the simpler and more accessible models, with particularly useful applications in the coastal zone, which do not require computer resources beyond a laptop computer, are described in more detail for in-house application and their use in decision-making is explained. The way forward in regional collaboration and capacity-building is discussed
Modelling daily soil salinity dynamics in response to agricultural and environmental changes in coastal Bangladesh
Full text linkUnderstanding the dynamics of salt movement in the soil is a prerequisite for devising 23 appropriate management strategies for land productivity of coastal regions, especially low lying 24 delta regions which support many millions of farmers around the world. In this research, we 25 develop a novel holistic approach to simulate soil salinization comprising an emulator-based soil 26 salt and water balance calculated at daily time steps. The method is demonstrated for the 27 agriculture areas of Coastal Bangladesh. This shows that we can reproduce the dynamics of soil 28 salinity under multiple land uses, including rice crops, combined shrimp and rice farming, as 29 well as non-rice crops. The model also reproduced well the observed spatial soil salinity for the 30 year 2009. Using this approach, we have projected the soil salinity for three different climate 31 ensembles, including relative sea-level rise for the period 2041-2050. The results indicate an 32 increase in soil salinity in 21-44% of the simulated area. This can potentially cause significant 33 crop yield reductions, especially for vegetables and local rice varieties. The modelling approach 34 will enable planners and land use managers to investigate future trajectories of salinity impacts 35 on crop production, considering expected changes in relative sea level, groundwater pumping 36 and water quality in the rivers and estuary, and management responses to augment freshwater 37 supplies
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Numerical investigation of river discharge and tidal variations impact on the salinity in deltaic systems
Full text linkThe present project is an effort to identify key parameters and controlling factors of salinity variations in deltaic systems. The salinity’s driving mechanisms and response to hydrodynamic changes are under investigation. This is demanded because of the risks that these ecosystems are subject to by increases of salinity due to sea level rise and human activities. Numerical modelling is implemented to study the salinity distribution in idealized deltas configuration under various hydrodynamic conditions. In particular, variations of the river discharge and tidal levels are considered.
The results indicate that salinity undergoes significant seasonal changes due to dynamic flow variability. Sustained drought periods could result in critical conditions with salt intrusion in the delta’s trunk (fluvial) channel. On the contrary, high river discharges during wet periods could mix completely the vertical column with freshwater for at least some distance from the river mouth. Tides could contribute further in mixing improving the conditions in the delta by decreasing the salinity in the downstream delta areas. Hence, many tidally influenced deltas could contain higher freshwater volumes than river dominated systems. Nevertheless, tidal level increases could limit significantly the deltas freshwater availability in mesotidal or macrotidal regimes. Results analysis and implementation of simple and innovative techniques uncovered the existence of certain correlations that could be useful as prognostic tools of salinity. Channels classification by their class or number of links provides a correlation that shows the salinity to increase with the decrease of either the channels order or delta’s cross-section width. In addition, radial and depth averages of salinity are negatively and exponentially correlated with the river discharge. The extracted exponential equation summarizes successfully the complex 3D delta dynamics into a 1D analytical solution. The equation resembles theoretical solutions of the 1D advection-diffusion equations under certain theoretical assumptions of which many are satisfied in the present idealized models setup. The above correlations incur modifications when external (e.g. hydrodynamic forcing) or intrinsic (e.g. bathymetry) parameters cause changes to the spatial salinity distribution. Bathymetric effects affect the salinity distribution in both horizontal and vertical directions especially at low flow periods when the bottom friction becomes stronger. Increases of the river discharge and/or tidal level override these effects.
This study aspires to provide knowledge that could be useful for the development of technical or non-technical solutions for the aversion of salinization issues in deltas. With the goal of contributing to the efforts for the development of environmentally friendlier solutions, the last part of this work investigates the effect of different shape but equal volume hydrographs on the salinity. The results show that it is possible to alleviate the consequences of increased salinity by better management of existing water resources instead of seeking for additional ones
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Comparing Water Level Estimation in Coastal and Shelf Seas From Satellite Altimetry and Numerical Models
Full text linkAccurately resolving coastal Total Water Levels (TWL) is crucial for socio-economic and environmental reasons. Recent efforts in satellite altimetry and numerical modeling have improved accuracy over near-shore areas. In this study we used data from tide gauges (TGs), SAR-mode altimetry from two satellites [Sentinel-3A (S3) and CryoSat-2 (C2)], and a state-of-the-art high-resolution regional coupled environmental prediction model (Amm15) to undertake an inter-comparison between the observations and the model.The aim is to quantify our capability to measure TWL around the United Kingdom coast, and to quantify the capacity of the model to represent coastal TWL. Results show good agreement between the satellite and TG data [the mean correlation (R) over seventeen TGs between June 2016 and September 2017 is 0.85 for S3 and 0.80 for C2]. The satellite-model comparison shows that the variability is well captured (R = 0.98 for both satellite), however, there is an offset (−0.23 m for S3, −0.15 m for C2) between the satellite and model data, that is near-constant across the domain. This offset is partly attributed to the difference in the reference level used by the satellites and the model, and residual differences linked to the temporal resolution of the model. The best agreement between model and satellite is seen away from the coast, further than 3–4 km offshore. However, even within the coastal band, R remains high, ∼0.95 (S3) and∼0.96 (C2). In conclusion, models are still essential to represent TWL in coastal regions where there is no cover from in-situ observations, but satellite altimeters can now provide valuable observations that are reliable much closer to the coast than before.<br/
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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