scholarly journals EFFECT OF RIP CURRENT BARRIER ON HARBOR SHOALING

1984 ◽  
Vol 1 (19) ◽  
pp. 140 ◽  
Author(s):  
Tamio O. Sasaki ◽  
Hiroshi Sakuramoto
Keyword(s):  
Surf Zone ◽  
Cost Effective ◽  
High Energy ◽  
Rip Current ◽  
Rip Currents ◽  
Effective Measure ◽  
The Pacific ◽  
Small Craft ◽  
The Pacific Ocean ◽  
Cost Effective Measure

Prototype experiments on rip currents and sediment transport around structures were conducted at two fishery harbors on microtidal high energy beaches facing the Pacific Ocean. The purpose of the experiments was to examine the performance and mechanism of rip current barrier structures on harbor shoaling. Based on the results of five experiments, the wave breaker heights during which varied from 1.1 m to 3.0 m, it is concluded that shore-parallel rip current barriers are effective if their length is greater than the surf zone width and if they are located outside the surf zone. When the above conditions are satisfied, the rip current barrier is a cost-effective measure against shoaling of small craft harbors.

scholarly journals A Bayesian network approach to modelling rip-current drownings and shore-break wave injuries

2021 ◽  
Vol 21 (7) ◽  
pp. 2075-2091
Author(s):  
Elias de Korte ◽  
Bruno Castelle ◽  
Eric Tellier
Keyword(s):  
Bayesian Network ◽  
Environmental Conditions ◽  
Surf Zone ◽  
High Energy ◽  
Environmental Data ◽  
Tidal Range ◽  
Boreal Summer ◽  
Rip Current ◽  
Rip Currents ◽  
Awareness Campaigns

Abstract. A Bayesian network (BN) approach is used to model and predict shore-break-related injuries and rip-current drowning incidents based on detailed environmental conditions (wave, tide, weather, beach morphology) on the high-energy Gironde coast, southwest France. Six years (2011–2017) of boreal summer (15 June–15 September) surf zone injuries (SZIs) were analysed, comprising 442 (fatal and non-fatal) drownings caused by rip currents and 715 injuries caused by shore-break waves. Environmental conditions at the time of the SZIs were used to train two separate Bayesian networks (BNs), one for rip-current drownings and the other one for shore-break wave injuries. Each BN included two so-called “hidden” exposure and hazard variables, which are not observed yet interact with several of the observed (environmental) variables, which in turn limit the number of BN edges. Both BNs were tested for varying complexity using K-fold cross-validation based on multiple performance metrics. Results show a poor to fair predictive ability of the models according to the different metrics. Shore-break-related injuries appear more predictable than rip-current drowning incidents using the selected predictors within a BN, as the shore-break BN systematically performed better than the rip-current BN. Sensitivity and scenario analyses were performed to address the influence of environmental data variables and their interactions on exposure, hazard and resulting life risk. Most of our findings are in line with earlier SZI and physical hazard-based work; that is, more SZIs are observed for warm sunny days with light winds; long-period waves, with specifically more shore-break-related injuries at high tide and for steep beach profiles; and more rip-current drownings near low tide with near-shore-normal wave incidence and strongly alongshore non-uniform surf zone morphology. The BNs also provided fresh insight, showing that rip-current drowning risk is approximately equally distributed between exposure (variance reduction Vr=14.4 %) and hazard (Vr=17.4 %), while exposure of water user to shore-break waves is much more important (Vr=23.5 %) than the hazard (Vr=10.9 %). Large surf is found to decrease beachgoer exposure to shore-break hazard, while this is not observed for rip currents. Rapid change in tide elevation during days with large tidal range was also found to result in more drowning incidents. We advocate that such BNs, providing a better understanding of hazard, exposure and life risk, can be developed to improve public safety awareness campaigns, in parallel with the development of more skilful risk predictors to anticipate high-life-risk days.

scholarly journals NEARSHORE CURRENTS ON A PARTIALLY ROCKY SHORE

1980 ◽  
Vol 1 (17) ◽  
pp. 65
Author(s):  
T.O. Sasaki ◽  
H. Igarashi ◽  
S. Harikai
Keyword(s):  
Rocky Shore ◽  
Surf Zone ◽  
High Energy ◽  
Sandy Beaches ◽  
Physical Experiment ◽  
Low Energy ◽  
Rip Current ◽  
Rip Currents ◽  
Wave Regime ◽  
Wave Refraction

Nearshore circulation on a partially rocky shore at Haranomachi Beach, Fukushima Prefecture, Japan has been studied in terms of field observations and numerical experiments for a low energy wave regime and with a physical experiment for a high energy wave regime. No significant distinctions were found in current velocity and rip current spacing between rocky and sandy beaches for the low energy wave regime, however the positions of rip currents were affected by wave refraction from the offshore exposed rocky bottom. On the other hand, since the surf zone bed is largely occupied by an exposed rocky floor for the high energy wave regime, the circulation exhibited fairly irregular patterns, so that a rip current becomes difficult to define, however the positions of inflow across the breaker line were found to be coincident with wave convergence zone.

scholarly journals A Bayesian network approach to modelling rip current drownings and shore-break wave injuries

2021 ◽  
Author(s):  
Elias de Korte ◽  
Bruno Castelle ◽  
Eric Tellier
Keyword(s):  
Bayesian Network ◽  
Environmental Conditions ◽  
Surf Zone ◽  
High Energy ◽  
Environmental Data ◽  
Tidal Range ◽  
Boreal Summer ◽  
Rip Current ◽  
Rip Currents ◽  
Awareness Campaigns

Abstract. A Bayesian network (BN) approach is used to model and predict shore-break related injuries and rip-current drowning incidents based on detailed environmental conditions (wave, tide, weather, beach morphology) on the high-energy Gironde coast, southwest France. Six years (2011–2017) of boreal summer (15 June–15 September) surf zone injuries (SZIs) were analysed, comprising 442 (fatal and non-fatal) drownings caused by rip currents and 715 injuries caused by shore-break waves. Environmental conditions at the time of the SZIs were used to train two separate Bayesian networks (BNs), one for rip current drownings and the other one for shore-break wave injuries, each one with a hidden hazard and exposure variables. Both BNs were tested for varying complexity using K-fold cross-validation based on multiple performance metrics. Validation (prediction) results slightly improve predictions of SZIs with a poor to fair skill based on a combination of different metrics. Shore-break related injuries appear more predictable than rip current drowning incidents as the shore-break BN systematically performed better than the rip current BN. Sensitivity and scenario analyses were performed to address the influence of environmental data variables and their interactions on exposure, hazard and resulting life risk. Most of our findings are in line with earlier SZI and physical hazard-based work, that is, that more SZIs are observed for warm sunny days with light winds, long-period waves, with specifically more shore-break related injuries at high tide and for steep beach profiles, and more rip current drownings near low tide with near shore-normal wave incidence and strongly alongshore non-uniform surf zone morphology. The BNs also provided fresh insight, showing that rip current drowning risk is approximately equally distributed between exposure (variance reduction Vr = 14.4 %) and hazard (Vr = 17.4 %), while exposure of water user to shore-break waves is much more important (Vr = 23.5 %) than the hazard (Vr = 10.9 %). Large surf is found to decrease beachgoer exposure to shore-break hazard, while this is not observed for rip currents. Rapid change in tide elevation during days with large tidal range was also found to result in more drowning incidents, presumably because it favors the rapid onset of rip current activity and can therefore surprise unsuspecting bathers. We advocate that such BNs, providing a better understanding of hazard, exposure and life risk, can be developed to improve public safety awareness campaigns, in parallel with the development of more skillful risk predictors to anticipate high life-risk days.

In vitro assessment of mineral blocks as a cost-effective measure to reduce oral bioavailability of lead (Pb) in livestock

2020 ◽  
Vol 27 (20) ◽  
pp. 25563-25571 ◽  
Author(s):  
Jennifer Pareja-Carrera ◽  
Jaime Rodríguez-Estival ◽  
Rafael Mateo ◽  
Mónica Martinez-Haro
Keyword(s):  
Oral Bioavailability ◽  
Cost Effective ◽  
Effective Measure ◽  
In Vitro Assessment ◽  
Cost Effective Measure

Interventions to reduce social isolation amongst older people: where is the evidence?

2003 ◽  
Vol 23 (5) ◽  
pp. 647-658 ◽  
Author(s):  
ROBYN A. FINDLAY
Keyword(s):  
Older People ◽  
Social Isolation ◽  
Evaluation Studies ◽  
Cost Effective ◽  
Adverse Impact ◽  
Living Alone ◽  
Empirical Literature ◽  
Effective Measure ◽  
Health And Wellbeing ◽  
Cost Effective Measure

As the population ages and more people are living alone, social isolation amongst older people is emerging as one of the major issues facing the industrialised world because of the adverse impact it can have on health and wellbeing. This article reviews the empirical literature published over the last 20 years on the effectiveness of interventions that target social isolation amongst older people. The results reveal that although numerous such interventions have been implemented worldwide, there is very little evidence to show that they work. It is concluded that future intervention programmes aimed at reducing social isolation should have evaluation built into them at inception, and that the results of the evaluation studies, whether positive or negative, should be widely disseminated. Where possible, as a cost-effective measure, pilot or demonstration projects should precede these interventions. Some key elements of successful interventions to counter social isolation amongst older people are presented.

scholarly journals Handwashing: a household social vaccine against COVID 19 and multiple communicable diseases

2020 ◽  
Vol 8 (7) ◽  
pp. 2708
Author(s):  
Swayam Pragyan Parida ◽  
Vikas Bhatia
Keyword(s):  
Health Care ◽  
Hand Hygiene ◽  
Wide Spectrum ◽  
Age Groups ◽  
Cost Effective ◽  
Developed Countries ◽  
Effective Measure ◽  
Household Level ◽  
Cost Effective Measure ◽  
Soil Transmitted Helminthiasis

Handwashing is the most cost-effective measure for prevention of a wide spectrum of diseases from respiratory, intestinal, soil transmitted helminthiasis, health-care associated illness to infection with pandemic potential like SARS, MERS and COVID 19. Experts view that handwashing can be the greatest investment in the mankind as it reduces under nutrition, morbidity, mortality and paves way for growth, development, educational attainment of people and thereby achieving healthier communities. Though the evidence of handwashing on health is two centuries old but change in human behaviour seems critical in both developing and developed countries. Hand hygiene is rarely practiced during crucial moments and even rarely soap is used. Therefore emphasis should be given towards a societal shift in behaviour change among children, caretakers and people of all age groups. Every school, community and hospital should be provided with Safe water, Sanitation and adequate Hygiene (WASH) services. Hand hygiene to be given top priority in national health plans by which millions of unnecessary deaths and burden on health care system can be avoided. Nevertheless under the looming threat of the current COVID 19 pandemic, where the exact epidemiology is still evolving and a vaccine doesn’t seem feasible as an immediate measure to control the disease, handwashing should be considered as a ‘social vaccine’ for everyone at every household level.

scholarly journals Occurrence features of Rip current at Ha My (Dien Ban district) and Tam Thanh (Tam Ky city) beaches, Quang Nam province

2019 ◽  
Vol 19 (4A) ◽  
pp. 43-53
Author(s):  
Le Dinh Mau ◽  
Nguyen Van Tuan ◽  
Nguyen Chi Cong ◽  
Tran Van Binh ◽  
Pham Ba Trung ◽  
...  
Keyword(s):  
Wave Energy ◽  
Surf Zone ◽  
Transition Period ◽  
Current System ◽  
Southwest Monsoon ◽  
Northeast Monsoon ◽  
Rip Current ◽  
Rip Currents ◽  
Open Sea ◽  
Study Results

Rip current is a relatively strong, narrow current flowing outward from the beach through the surf zone and presenting a hazard to swimmers. This paper presents some occurrence features of Rip current at main swimming beaches in Quang Nam province, Central Vietnam. Study results show that most of swimming beaches along Quang Nam province coast are directly opposed to open sea and strongly affected by swell. Therefore, Rip current system can occur at any time in the year with large dimension and intensity. During Northeast monsoon (November to March) beach morphology is considerably changed by strong wave action, thus the strongest rip current is formed. However, in this period careful swimmers can easily identify where that rip current occurs along the beach. During the transition period from Northeast monsoon to Southwest monsoon (April to May) wave energy is reduced, thus Rip current intensity is also decreased. During Southwest monsoon (June to August) wave energy is not strong and beach is accreted, therefore some Rip currents remain at reasonable morphology places along the beach. During the transition period from Southwest monsoon to Northeast monsoon (September to October) Rip current can occur at deep places along the beach with characteristics of narrow dimension, thus causing more danger to swimmer. Especially, dangerous rip current is caused by swell which comes from active region of tropical cyclone in open sea. In this period wave field in the nearshore region is not rough, thus most of swimmers are not cautious when swimming at dangerous rip current places.

scholarly journals The effect of face mask mandates during the COVID-19 pandemic on the rate of mask use in the United States

2020 ◽  
Author(s):  
Michael J. Maloney
Keyword(s):  
United States ◽  
Economic Impact ◽  
Cost Effective ◽  
Face Mask ◽  
Public Spaces ◽  
The United States ◽  
State Governments ◽  
Strongly Correlated ◽  
Effective Measure ◽  
Cost Effective Measure

ABSTRACTAs COVID-19 continues to spread throughout the United States, there has been a search for policies to prevent individual infections, to slow the spread of the virus in general, and to mitigate the economic impact of the pandemic. Masks have proven to be a cost-effective measure in all regards, and as such some state governments have begun to mandate their use. However, while the efficacy of masks has been demonstrated, the efficacy of public policies which mandate the use of masks has not been demonstrated. This paper compares the rates of mask use in counties as defined by state policy. It finds that state mandates are strongly correlated with higher rates of mask use, and that mandating use by all individuals in public spaces is more effective than a less comprehensive mandate for mask use by all public facing employees.

Sign in / Sign up

Export Citation Format

Share Document