scholarly journals BEACH RESTORATION IN THE TARRAGONA COAST (SPAIN); SAND MANAGEMENT DURING THE LAST 25 YEARS AND FUTURE PLANS

2018 ◽  
pp. 20
Author(s):  
Jordi Galofré ◽  
José A. Jiménez ◽  
Herminia I. Valdemoro
Keyword(s):  
Adaptation Strategy ◽  
Management Plan ◽  
Sediment Budget ◽  
General Context ◽  
River Sand ◽  
Protection Measure ◽  
Shoreline Evolution ◽  
Nw Mediterranean ◽  
Transport Patterns

Erosion is the dominant behavior along worldwide coastlines. Although many factors can locally influence processes governing coastline evolution some common factors can be identified. Thus, the sediment budget has largely been modified in most of developed coasts, with river sand supplies being drastically reduced due to human influence in drainage basins. On the other hand, coastal segmentation due to infrastructures alters sediment transport patterns and induces and/or accelerates coastline erosion. Within this general context, artificial nourishment has been one of the most used coastal engineering measure by mimicking the role played by river sediment supplies to compensate local erosion problems. Since nourishment is not acting on the origin of the problems, erosive processes will continue to control shoreline evolution. Thus, the evolution of beach fills will be controlled by the sediment budget within the coastal cell where works have been done and, this will determine required sediment volumes to maintain the future shoreline. Within this context, we present data on long-term (25 years) shoreline evolution and nourishment operations in the Tarragona coast (Spain, NW Mediterranean). The main aim of the work is to analyze the coastal stability and the effects of beach fills along the coast taking into account the type of the coastal cell where works have been implemented. Once this has been evaluated, the sustainability of an adaptation strategy based on the use of this protection measure to cope with climate change induced scenarios is also assessed to propose a long- term sediment management plan.

Analyzing the roles of newspaper articles and tweets to help alleviate sudden physician absenteeism: case study of Takano Hospital in Fukushima in the long-term aftermath of the 2011 Japan’s triple disaster (Preprint)

2020 ◽  
Author(s):  
Akihiko Ozaki ◽  
Yosuke Onoue ◽  
Anju Murayama ◽  
Taishi Tahara ◽  
Yuki Senoo ◽  
...  
Keyword(s):  
News Media ◽  
Median Number ◽  
Medical Doctor ◽  
Fund Raising ◽  
General Context ◽  
Social Media Networks ◽  
Chronological Change ◽  
The Government ◽  
Newspaper Articles

BACKGROUND Rural physician undersupply is a universal concern, leading to sudden physician absenteeism or unavailability on occasion. While media and social networking services may help mitigate these emergencies, information is lacking about their actual contribution in times of physician absenteeism. On December 30, 2016, the director and sole physician of Takano Hospital in Fukushima, Japan, died. The physician’s passing placed many hospitalized patients in danger. This sudden case of physician unavailability, named the Takano Hospital Crisis, provoked massive attention from the general public, in the media and on social media networks such as Twitter. OBJECTIVE The aim of this study was to analyze newspaper articles, tweets and Twitter accounts relating to Takano Hospital Crisis. METHODS Newspaper articles and tweets were searched for keywords associated with Takano Hospital Crisis and its former director between October 2016 and June 2017. We first evaluated the chronological change in the number of articles and tweets, and the number of characters and relevant keywords in the articles. Then tweets and influencers who were popular on the Twitter platform from December 30, 2016 to February 28, 2017, were categorized. RESULTS We assessed 151 newspaper articles and 67,006 tweets. The results show that number of newspaper articles and tweets steeply increased and then diminished within the first month of the incident. The median number of characters in newspapers articles was 436 and the most frequent keyword was medical doctor. There were 753 original tweets that were retweeted more than four times from December 30, 2016 to February 28, 2017. Of these, 245 (32.5%) expressed concern. Notable influencers were journalists, news media outlets, and healthcare professionals that helped with fund raising and providing clinical service in the hospital. CONCLUSIONS Twitter could temporarily function in cases of sudden physician absenteeism to attract volunteers and funding, however, this would not be a long-term solution. In a more general context, a long-term effort of supports from the hospitals themselves and the government will be required to manage the persistent state of physician absenteeism.

scholarly journals A Holistic Framework for Evaluating Adaptation Approaches to Coastal Hazards and Sea Level Rise: A Case Study from Imperial Beach, California

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1324
Author(s):  
David Revell ◽  
Phil King ◽  
Jeff Giliam ◽  
Juliano Calil ◽  
Sarah Jenkins ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Public Trust ◽  
Adaptation Strategy ◽  
Public Benefits ◽  
Study Results ◽  
Local Risk ◽  
Over Time

Sea level rise increases community risks from erosion, wave flooding, and tides. Current management typically protects existing development and infrastructure with coastal armoring. These practices ignore long-term impacts to public trust coastal recreation and natural ecosystems. This adaptation framework models physical responses to the public beach and private upland for each adaptation strategy over time, linking physical changes in widths to damages, economic costs, and benefits from beach recreation and nature using low-lying Imperial Beach, California, as a case study. Available coastal hazard models identified community vulnerabilities, and local risk communication engagement prioritized five adaptation approaches—armoring, nourishment, living shorelines, groins, and managed retreat. This framework innovates using replacement cost as a proxy for ecosystem services normally not valued and examines a managed retreat policy approach using a public buyout and rent-back option. Specific methods and economic values used in the analysis need more research and innovation, but the framework provides a scalable methodology to guide coastal adaptation planning everywhere. Case study results suggest that coastal armoring provides the least public benefits over time. Living shoreline approaches show greater public benefits, while managed retreat, implemented sooner, provides the best long-term adaptation strategy to protect community identity and public trust resources.

Influence of ground ice and permafrost on coastal evolution, Richards Island, Beaufort Sea coast, N.W.T.

1996 ◽  
Vol 33 (5) ◽  
pp. 664-675 ◽  
Author(s):  
Scott R. Dallimore ◽  
Stephen A. Wolfe ◽  
Steven M. Solomon
Keyword(s):  
Coastal Erosion ◽  
Sediment Budget ◽  
Storm Event ◽  
Ground Ice ◽  
Coastal Evolution ◽  
Thermal Erosion ◽  
Ice Wedge ◽  
Mechanical Erosion ◽  
Sea Coast

A long-term sediment budget (1947−1985) for northern Richards Island shows that, when ground ice and offshore erosion are accounted for, there is a near balance between headland erosion and coastal deposition. Excess ice constitutes about 20% of the total volume of eroded material from the headlands, with massive ground ice contributing nearly 9% and segregated ice lenses and ice wedges making up the remainder. Coastal response to major storms in 1987 and 1993 suggests that erosion is episodic, with short periods of intense disruption followed by readjustment of cliff profiles. Processes characteristic of this environment include mechanical erosion of ice-bonded sediments creating unstable erosional niches, mechanical failure of niches along ice-wedge planes, and longer term thermal erosion of ice-bonded sediments. Where ice contents are high, localized thaw slumps initiated by coastal erosion may retreat at rates substantially higher than those observed at other sections of the coast. Cliff-top retreat rates may be out of phase with storm-event chronology.

scholarly journals Erosion assessment in the middle Kali Gandaki (Nepal): A sediment budget approach

2013 ◽  
Vol 46 ◽  
Author(s):  
Monique Fort ◽  
Etienne Cossart
Keyword(s):  
Drainage Basin ◽  
Sediment Budget ◽  
Mountain Range ◽  
Primary Concern ◽  
Stream Power ◽  
Sediment Budgets ◽  
Relative Chronology ◽  
Wide Range ◽  
History Of

Active mountains supply the largest sediment fluxes experienced on earth. At mountain range scale, remote sensing approaches, sediments provenance or stream power law analyses, collectively provide rough long-term estimates of total erosion. Erosion is indeed controlled by rock uplift and climate, hence by a wide range of processes (detachment, transport and deposition), all operating within drainage basin units, yet with time and spatial patterns that are quite complex at local scale. We focus on the Kali Gandaki valley, along the gorge section across the Higher Himalaya (e.g. from Kagbeni down to Tatopani). Along this reach, we identify sediment sources, stores and sinks, and consider hillslope int eractions with valley floor, in particular valley damming at short and longer time scales, and their impact on sediment budgets and fluxes. A detailed sediment budget is presented, constrained by available dates and/or relative chronology, ranging from several 10 kyr to a few decades. Obtained results span over two orders of magnitude that can best be explained by the type and magnitude of erosional processes involved. We show that if large landslides contribute significantly to the denudation history of active mountain range, more frequent medium to small scales landslides are in fact of primary concern for Himalayan population.

scholarly journals Vegetation and seed bank dynamics highlight the importance of post-restoration management in sown grasslands

2020 ◽  
Author(s):  
Orsolya Valkó ◽  
Balázs Deák ◽  
Péter Török ◽  
Katalin Tóth ◽  
Réka Kiss ◽  
...  
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Rapid Development ◽  
Management Plan ◽  
Landscape Scale ◽  
List Type ◽  
Restoration Management ◽  
Seed Bank Dynamics ◽  
Term Management

AbstractSowing grass seeds generally supports the rapid development of a closed perennial vegetation, which makes the method universally suitable for fast and effective landscape-scale restoration of grasslands. However, sustaining the recovered grasslands, and increasing their diversity is a challenging task. Understanding the role of seed bank compositional changes and vegetation dynamics contributes to designating management regimes that support the establishment of target species and suppress weeds. Our aim was to reveal the effect of post-restoration management on the vegetation and seed bank dynamics in grasslands restored in one of the largest European landscape-scale restoration projects. Eight years after restoration we sampled the vegetation and seed bank in a total of 96 plots located in 12 recovered grasslands in the Great Hungarian Plain. In each recovered grassland stand we designated a mown (mown from Year 1 to Year 8) and an abandoned sample site (mown from Year 1 to Year 3 then abandoned from Year 4 to Year 8). Mown and abandoned sites showed divergent vegetation and seed bank development. Abandonment led to the decline of sown grasses and higher cover of weeds, especially in the alkaline grasslands. Our study confirmed that seed bank has a limited contribution to the maintenance of biodiversity in both grassland types. We found that five years of abandonment had a larger effect on the seed bank than on the vegetation. We stress that long-term management is crucial for controlling the emergence of the weeds from their dense seed bank in restored grasslands.Implications for practiceSeed sowing of grass mixtures can be a feasible tool for restoring grasslands at large scales. However, the developed vegetation usually has low biodiversity and a high seed density of weeds is typical in the soil seed bank even several years after the restoration. Therefore, post-restoration management is necessary for suppressing weeds both aboveground and belowground.We recommend to design the long-term management of the sites subjected to grassland restoration already in the planning phase of the restoration projects and ensure that the management plan is ecologically and economically feasible.We recommend to complement the monitoring of vegetation with the analysis of soil seed bank for evaluating restoration success.

scholarly journals LONG TERM MORPHOLOGICAL MODELLING

2011 ◽  
Vol 1 (32) ◽  
pp. 64
Author(s):  
Sten Esbjørn Kristensen ◽  
Rolf Deigaard ◽  
Martin Anders Taaning ◽  
Jørgen Fredsøe ◽  
Nils Drønen ◽  
...  
Keyword(s):  
Time Scale ◽  
Surf Zone ◽  
Coastal Structures ◽  
Model Concept ◽  
General Applicability ◽  
Shoreline Evolution ◽  
Realistic Representation ◽  
Morphological Modelling ◽  
Constant Shape

A morphological modelling concept for long term nearshore morphology is proposed and examples of its application are presented and discussed. The model concept combines parameterised representations of the cross-shore morphology, with a 2DH area model for waves, currents and sediment transport in the surf zone. Two parameterization schemes are tested for two different morphological phenomena: 1) Shoreline changes due to the presence of coastal structures and 2) alongshore migration of a nearshore nourishment and a bar by-passing a harbour. In the case of the shoreline evolution calculations, a concept often used in one-line modelling of cross-shore shifting of an otherwise constant shape cross-shore profile is applied for the case of a groyne and a detached breakwater. In the case of alongshore bar/nourishment migration an alternative parameterization is adopted. All examples are presented, analysed and discussed with respect to the question of realistic representation, time scale and general applicability of the model concept.

Effect of Stone Powder Content on the Diffusing Parameter and Diffusion Attenuation Coefficient of Chloride Ion of Mechanical Sand Concrete

2014 ◽  
Vol 584-586 ◽  
pp. 1818-1822
Author(s):  
Ming Qiang Qin ◽  
Wen Zhan ◽  
Wen Bing Xu ◽  
Jin Hui Li
Keyword(s):  
Attenuation Coefficient ◽  
Chloride Ion ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
River Sand ◽  
Moderate Amount ◽  
Powder Content ◽  
And Diffusion ◽  
Better Than

The effect of stone powder content on the chloride diffusion coefficient and diffusion attenuation coefficient of chloride ion of mechanical sand (MS) concrete was studied. The results showed that the resistance to chloride ion permeability of MS concrete firstly increased and then decreased with the increase of the content of stone powder. The anti-permeability of the concrete which had moderate amount of stone powder was better than that of the natural river sand (NS) concrete. The diffusion attenuation coefficient of MS concrete was greater than that of the NS concrete, which was good for long-term durability of concrete structure.

scholarly journals SIMULATION OF LONG-TERM SHORELINE CHANGE DRIVEN BY LONGSHORE AND CROSS-SHORE SEDIMENT TRANSPORT

2020 ◽  
pp. 31
Author(s):  
Yan Ding ◽  
Sung-Chan Kim ◽  
Richard B. Styles ◽  
Rusty L. Permenter
Keyword(s):  
Sediment Transport ◽  
Shoreline Change ◽  
Breaking Wave ◽  
Beach Profile ◽  
Shoreline Evolution ◽  
Longshore Sediment Transport ◽  
Wave Energy Flux ◽  
Semi Empirical ◽  
Evolution Modeling

Driven by wave and current, sediment transport alongshore and cross-shore induces shoreline changes in coasts. Estimated by breaking wave energy flux, longshore sediment transport in littoral zone has been studied for decades. Cross-shore sediment transport can be significant in a gentle-slope beach and a barred coast due to bar migration. Short-term beach profile evolution (typically for a few days or weeks) has been successfully simulated by reconstructing nonlinear wave shape in nearshore zone (e.g. Hsu et al 2006, Fernandez-Mora et al. 2015). However, it is still lack of knowledge on the relationship between cross-shore sediment transport and long-term shoreline evolution. Based on the methodology of beach profile evolution modeling, a semi-empirical closure model is developed for estimating phase-average net cross-shore sediment transport rate induced by waves, currents, and gravity. This model has been implemented into GenCade, the USACE shoreline evolution model.

Forecasting long-term shoreline evolution in highly antrhopized coastal areas

2021 ◽  
Author(s):  
Moisés Álvarez-Cuesta ◽  
Alexandra Toimil ◽  
Iñigo J. Losada
Keyword(s):  
Climate Models ◽  
Regional Scale ◽  
Mediterranean Coast ◽  
Multiple Time Scales ◽  
Multiple Time ◽  
Coastal Zones ◽  
Climate Data ◽  
Shoreline Evolution ◽  
Automated Technique

<p>A new numerical model for addressing long-term coastline evolution on a local to regional scale on highly anthropized coasts is presented. The model, named IH-LANS (Long-term ANthropized coastlines Simulation tool), is validated over the period 1990-2020 and applied to obtain an ensemble of end-of-century shoreline evolutions. IH-LANS combines a hybrid (statistical-numerical) deep-water propagation module and a shoreline evolution model. Longshore and cross-shore processes are integrated together with the effects of man-made interventions. For the ease of calibration, an automated technique is implemented to assimilate observations. The model is applied to a highly anthropized 40 km stretch located along the Spanish Mediterranean coast. High space-time resolution climate data and satellite-derived shorelines are used to drive IH-LANS. Observed shoreline evolution (<10 meters of root mean square error, RMSE) is successfully represented while accounting for the effects of nourishments and the construction and removal of groynes, seawalls and breakwaters over time. Then, in order to drive the ensemble of end-of-century shoreline evolutions, wave and water level projections downscaled from different climate models for various emissions scenarios are employed to force the calibrated model. From the forecasted shoreline time-series, information from multiple time-scales is unraveled yielding valuable information for coastal planners. The efficiency and accuracy of the model make IH-LANS a powerful tool for management and climate change adaptation in coastal zones.</p>

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