scholarly journals OCEANOGRAPHIC CRITERIA FOR DESIGN OF SMALL CRAFT HARBORS

1966 ◽  
Vol 1 (10) ◽  
pp. 68
Author(s):  
Richard C. Timme
Keyword(s):  
Optimum Design ◽  
Water Levels ◽  
Wave Statistics ◽  
Small Craft ◽  
Bodies Of Water ◽  
Incident Waves

The most important oceanographic criteria which are required in establishing the optimum design of a harbor complex for small craft harbors located adjacent to large bodies of water are: 1. Wave Statistics Incident to the Site. 2. Effects of Breakwaters or Jetties upon Incident Waves. 3. Design of Interior Configuration and Water Levels. 4. Littoral Processes at the Site.

scholarly journals Environmental controls on surf zone injuries on high-energy beaches

2019 ◽  
Vol 19 (10) ◽  
pp. 2183-2205 ◽  
Author(s):  
Bruno Castelle ◽  
Tim Scott ◽  
Rob Brander ◽  
Jak McCarroll ◽  
Arthur Robinet ◽  
...  
Keyword(s):  
Wave Height ◽  
Surf Zone ◽  
High Tide ◽  
High Energy ◽  
Water Levels ◽  
Small Scale ◽  
Beach Morphology ◽  
Environmental Controls ◽  
Flow Activity ◽  
Incident Waves

Abstract. The two primary causes of surf zone injuries (SZIs) worldwide, including fatal drowning and severe spinal injuries, are rip currents (rips) and shore-break waves. SZIs also result from surfing and bodyboarding activity. In this paper we address the primary environmental controls on SZIs along the high-energy meso–macro-tidal surf beach coast of southwestern France. A total of 2523 SZIs recorded by lifeguards over 186 sample days during the summers of 2007, 2009 and 2015 were combined with measured and/or hindcast weather, wave, tide, and beach morphology data. All SZIs occurred disproportionately on warm sunny days with low wind, likely because of increased beachgoer numbers and hazard exposure. Relationships were strongest for shore-break- and rip-related SZIs and weakest for surfing-related SZIs, the latter being also unaffected by tidal stage or range. Therefore, the analysis focused on bathers. More shore-break-related SZIs occur during shore-normal incident waves with average to below-average wave height (significant wave height, Hs = 0.75–1.5 m) and around higher water levels and large tide ranges when waves break on the steepest section of the beach. In contrast, more rip-related drownings occur near neap low tide, coinciding with maximised channel rip flow activity, under shore-normal incident waves with Hs >1.25 m and mean wave periods longer than 5 s. Additional drowning incidents occurred at spring high tide, presumably due to small-scale swash rips. The composite wave and tide parameters proposed by Scott et al. (2014) are key controlling factors determining SZI occurrence, although the risk ranges are not necessarily transferable to all sites. Summer beach and surf zone morphology is interannually highly variable, which is critical to SZI patterns. The upper beach slope can vary from 0.06 to 0.18 between summers, resulting in low and high shore-break-related SZIs, respectively. Summers with coast-wide highly (weakly) developed rip channels also result in widespread (scarce) rip-related drowning incidents. With life risk defined in terms of the number of people exposed to life threatening hazards at a beach, the ability of morphodynamic models to simulate primary beach morphology characteristics a few weeks or months in advance is therefore of paramount importance for predicting the primary surf zone life risks along this coast.

Some implications of crustal movement in engineering planning

1970 ◽  
Vol 7 (2) ◽  
pp. 628-633 ◽  
Author(s):  
R. H. Clark ◽  
N. P. Persoage
Keyword(s):  
Great Lakes ◽  
Lake Ontario ◽  
Water Levels ◽  
Crustal Movement ◽  
Earth’S Crust ◽  
Lake Huron ◽  
Great Lakes Basin ◽  
Lake Outlet ◽  
Earth's Crust ◽  
Bodies Of Water

Movements of the earth's crust causing progressive changes in the levels of large bodies of water relative to their shorelines may influence the formulation of water resource projects and/or their continuing effectiveness with time. In the Great Lakes basin there is evidence of an uplift of the earth's crust, of about 1 ft per 100 y, in the northeasterly part of the basin relative to that in the southwest. This results in a corresponding lowering of water levels along the northeasterly shorelines and a rise in water levels along the southwest shores. In at least two of the lakes, Lake Huron and Lake Ontario, the average depth of water will change with time. In Lake Huron, it will gradually decrease because the bed underlying the lake is rising with respect to the lake outlet. In Lake Ontario, the depth of water will increase since the lake outlet is rising with respect to the remainder of the lake. This paper reviews some of the engineering implications of the relative rates of crustal movement in the Great Lakes region on long-term management of the water levels of the Great Lakes.

Estimation Local Strength of Bow Structure for High Tensile Steel Yacht Based on Optimum Design

2006 ◽  
Vol 326-328 ◽  
pp. 1463-1466
Author(s):  
Joo Shin Park ◽  
Yun Young Kim ◽  
Tetsuya Yao
Keyword(s):  
Optimum Design ◽  
Minimum Weight ◽  
Analysis Model ◽  
Element Analysis ◽  
Stress Criterion ◽  
Local Strength ◽  
The Finite Element Analysis ◽  
Small Craft ◽  
Weight Design

The optimum design for bow structure of high tensile steel yacht belongs to the nonlinear constrained optimization problem. The determination of scantlings for the bow structure is a very important matter out of whole structural design process of a yacht. The optimum design results are produced with the use of Real-coded Micro-Genetic Algorithm including evaluation LR small craft guideline, so that they can satisfy the allowable stress criterion. In this study, the minimum weight design of bow structure on the HTS yacht was carried out based on the finite element analysis. An analysis model is a bow structure of HTS yacht with structural scantling derived from the minimum weight optimization. The weight of bow structure and the main dimensions of structural members are chosen as an objective function and design variable, respectively. Optimization results were compared with a pre-existing design. From the FE analysis results, bow structure with high tensile steel (AH40) designed by using RμGA has a volume efficiency of 19% than the design of the actual mild yacht.

scholarly journals Environmental controls on surf zone injuries on high-energy beaches

2019 ◽  
Author(s):  
Bruno Castelle ◽  
Tim Scott ◽  
Rob Brander ◽  
Jak McCarroll ◽  
Arthur Robinet ◽  
...  
Keyword(s):  
Wave Height ◽  
Surf Zone ◽  
High Tide ◽  
High Energy ◽  
Water Levels ◽  
Small Scale ◽  
Beach Morphology ◽  
Environmental Controls ◽  
Flow Activity ◽  
Incident Waves

Abstract. The two primary causes of surf zone injuries (SZIs) worldwide, including fatal drowning and severe spinal injuries, are rip currents (rips) and shore-break waves. SZIs also result from surfing and body boarding activity. In this paper we address the primary environmental controls on SZIs along the high-energy meso-macrotidal surf beach coast of SW France. A total of 2523 SZIs recorded by lifeguards over 186 sample days during the summers of 2007, 2009 and 2015 were combined with measured and/or hindcast weather, wave, tide and beach morphology data. All SZIs occurred disproportionately on warm sunny days with low wind likely because of increased beachgoer numbers and hazard exposure. Relationships were strongest for shore break and rip related SZIs and weakest for surfing related SZIs, the latter being also unaffected by tidal stage or range. Therefore the analysis focussed on bathers. Shore-break related SZIs disproportionately occur during shore-normal incident waves with average to below-average wave height (significant wave height Hs = 0.75–1.5 m) and around higher water levels and large tide range when waves break on the steepest section of the beach. In contrast, rip related drownings occur disproportionally near neap low tide, coinciding with maximized channel rip flow activity, under shore-normal incident waves with Hs > 1.25 m and periods mean wave period longer than 5 s. Additional drowning incidents occurred at spring high tide, presumably due to small-scale swash rips. The composite wave and tide parameters proposed by Scott et al. (2014) are key controlling factors determining SZI occurrence, although the risk ranges are not necessarily transferable to all sites. Summer beach and surf zone morphology is highly interannually variable, which is critical to SZI patterns. The upper beach slope can vary from 0.06 to 0.18 between summers, resulting in low and high shore-break related SZIs, respectively. Summers with coast-wide highly (weakly) developed rip channels also result in widespread (scarce) rip related drowning incidents. With life risk defined in terms of the number of people exposed to life threatening hazards at a beach, the ability of morphodynamic models to simulate primary beach morphology characteristics a few weeks/months in advance is therefore of paramount importance to predict the primary surf-zone life risks along this coast.

Offshore Urban Extension of the Anse Du Portier In Monaco

2021 ◽  
Author(s):  
Pierre Aristaghes ◽  
David Compte
Keyword(s):  
Development Strategy ◽  
Time Frame ◽  
Water Levels ◽  
Swimming Pool ◽  
Urban Context ◽  
Small Craft ◽  
Wave Slamming ◽  
Wide Scale ◽  
Seismic Forces ◽  
Maritime Infrastructure

Abstract As part of the Monaco offshore urban extension project, Bouygues TP is in charge of design & build a maritime infrastructure as the first step of the six-hectare expansion of the city into the sea. This maritime infrastructure consists of a fill enclosed by a band of trapezoid concrete caissons and will serve as base for construction of the new residential area. The paper focuses on some of the problems which had to be solved: optimization of promenade level and wave absorbing chambers in conjunction with minimal reflection and safety related to overtopping, accounting for sea level rise and correlation between extreme waves and water levels. caissons and rubble mound foundation stability related to waves and seism, including extra seismic forces due to buildings considering the high reclamation height and the immediate proximity of building foundations. the way in which caissons representing nearly 80,000 m3 of concrete can be built in a floating and continuous manner via a caisson box (or "caissonnier" in French), within a particularly short time frame presence of a small craft harbor with shops along the quays, whose location was fixed for urbanistic reasons, which requested optimizations in detail of anti-overtopping devices as much as possible integrated in the urban context, need to convert a breakwater caisson into a low crested swimming pool caisson, with plexiglas windows exposed to wave slamming from outside, but also from inside due to overtopping impacts over the swimming pool basin. Ecodesign has been closely associated with hydrodynamic and coastal engineering, based on estimation of wave pressures and induced velocities in the different possible locations (chambers, walls, structures toes …). The eco-friendly development strategy is based on the wide-scale deployment of a range of 11 solutions which will be described (potential for caissons to be colonized, nursery function development, etc…). Moreover, posidonia transplantation has been done via concrete open boxes, whose stability under storm waves has requested CFD calculations to model local velocities and optimize their shape.

The Establishment of Wave Model in Qingdao Fushan Bay

2010 ◽  
Vol 156-157 ◽  
pp. 1181-1186
Author(s):  
Shui Yu Li
Keyword(s):  
Boundary Conditions ◽  
Wave Height ◽  
Return Period ◽  
Wave Energy ◽  
Wave Model ◽  
Energy Generation ◽  
Water Levels ◽  
Rectangular Grid ◽  
Generation Planning ◽  
Incident Waves

A wave model in Qingdao Fushan Bay is established in the paper. The effect of the variety of terrain, dredging in the basin, the shelter of the structure, the reflection of the piers and breakwaters are taken into account. Rectangular grid is applied in the calculation. For reducing the errors and ensuring the precision, normally incident waves and completely-absorbed boundary conditions are considered in the calculation. The result gives the wave height at each point in different water levels, and wave directions of 50-years return period, which provides a basis for the shoreline structure of wave energy generation planning and designing.

Spatial and temporal distribution of Ligula intestinalis (Cestoda: Diphyllobothriidea) in usipa (Engraulicypris sardella) (Pisces: Cyprinidae) in Lake Nyasa

2017 ◽  
Vol 92 (4) ◽  
pp. 410-416 ◽  
Author(s):  
N.P. Gabagambi ◽  
A. Skorping
Keyword(s):  
Temporal Distribution ◽  
Infected Fish ◽  
Water Levels ◽  
Spatial And Temporal Variation ◽  
Ligula Intestinalis ◽  
Transmission Success ◽  
Behavioural Effects ◽  
Marked Decline ◽  
Bodies Of Water ◽  
Over Time

AbstractEngraulicypris sardella is an endemic and economically important cyprinid species in Lake Nyasa/Malawi which has recently been infected by the tapeworm Ligula intestinalis. This parasite is known to induce severe pathological and behavioural effects on other cyprinids, including castration, followed by a collapse of infected populations. As a first step to understanding the dynamics between this parasite and E. sardella, we studied the spatial and temporal variation in prevalence over a period of 1 year. Overall prevalence was about 15%, but we observed a consistently higher prevalence in the littoral compared to the pelagic zone. Fish in the upper water levels showed the highest prevalence, with a marked decline with increasing water depth down to 150 m. The proportion of infected fish varied over time, with a significantly higher prevalence in the rainy season. In a huge lake like the Nyasa, with a surface area of 29,000 km2 and a maximum depth of 785 m, the transmission success of the parasite appears to show large variations in time and space. We suggest that these conditions could lead the parasite to become persistent within the lake, rather than the typical epidemic situation as observed in smaller bodies of water.

scholarly journals Effects of anomalous high temperatures on carbon dioxide, methane, dissolved organic carbon and trace element concentrations in thaw lakes in Western Siberia in 2012

2013 ◽  
Vol 10 (4) ◽  
pp. 7257-7297 ◽  
Author(s):  
O. S. Pokrovsky ◽  
L. S. Shirokova ◽  
S. N. Kirpotin ◽  
S. P. Kulizhsky ◽  
S. N. Vorobiev
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Trace Element ◽  
Western Siberia ◽  
Full Range ◽  
Water Levels ◽  
The Body ◽  
Element Concentrations ◽  
Bodies Of Water ◽  
Thaw Lakes

Abstract. During the anomalous hot summer in 2012, surface air temperatures in Western Siberia were 5 to 10 °C higher than those observed during the previous period of > 30 yr. This unusual climate phenomenon provided an opportunity to examine the effects of short-term natural heating of water in thermokarst ponds and lakes in discontinuous permafrost zones and compare these observations to previous field results obtained when the temperature was normal during the summer of 2010 in the same region. Thermokarst bodies of water shrank significantly, water levels dropped approximately 50 cm in large lakes and small (< 10–100 m2) ponds, and shallow soil depressions disappeared. Based on samples from ~ 40 bodies of water collected previously and in 2012, first-order features of changes in chemical composition in response to increased water temperatures (from 14.1 ± 2.2 to 23.8 ± 2.3 °C in 2010 and 2012, respectively) were established. In these thermokarst bodies of water that covered a full range of surface areas, the average conductivity and pH were almost unchanged, whereas dissolved organic carbon (DOC), Cl− and SO42− concentrations were higher by a factor of ~ 2 during summer 2012 compared to periods with normal temperatures. Similarly, most divalent metals and insoluble trivalent and tetravalent elements were more concentrated by a factor of 1.7–2.4 in the summer of 2012 than normal periods. The average concentrations of dissolved CO2 and CH4 during the hot summer of 2012 increased by factors of 1.4 and 4.9, respectively. For most of the trace elements bound to colloids, the degree of colloidal binding decreased by a factor of 1.44 ± 0.33 (for an average of 40 elements) during the hot summer of 2012 compared to normal periods. Increases in CO2 and CH4 concentrations with the decreasing size of the body of water were well-pronounced during the hot summer of 2012. The concentrations of CO2 and CH4 significantly increased by factors of 5 and 150, respectively, in small (≤ 102 m2) compared to large (≥ 104 m2) thermokarst (thaw) lakes. Taken together, these trends suggest that, for a conservative scenario of lake size distribution, lake water warming at high latitudes will produce (1) a significant increase in methane emission capacity from thaw lake surfaces; (2) decrease of molecular sizes of TE complexes and increase of potential bioavailability of metal micronutrients in water columns; and (3) relatively conservative responses by CO2, DOC and trace element concentrations.

scholarly journals Impact of western Siberia heat wave 2012 on greenhouse gases and trace metal concentration in thaw lakes of discontinuous permafrost zone

2013 ◽  
Vol 10 (8) ◽  
pp. 5349-5365 ◽  
Author(s):  
O. S. Pokrovsky ◽  
L. S. Shirokova ◽  
S. N. Kirpotin ◽  
S. P. Kulizhsky ◽  
S. N. Vorobiev
Keyword(s):  
Trace Element ◽  
Western Siberia ◽  
Full Range ◽  
Water Levels ◽  
The Body ◽  
Trace Metal Concentration ◽  
Large Lakes ◽  
Discontinuous Permafrost ◽  
Bodies Of Water ◽  
Thaw Lakes

Abstract. During the anomalously hot summer in 2012, surface air temperatures in Western Siberia were 5 to 15 °C higher than those observed during the previous period of > 30 yr. This unusual climate phenomenon provided an opportunity to examine the effects of short-term natural heating of water in thermokarst ponds and lakes in discontinuous permafrost zones and compare these observations to previous field results obtained when the temperature was normal during the summer of 2010 in the same region. In 2012, thermokarst bodies of water shrank significantly, water levels dropped approximately 50 cm in large lakes and small (< 10–100 m2) ponds, and shallow soil depressions disappeared. Based on samples from ~ 40 bodies of water collected previously and in 2012, first-order features of changes in chemical composition in response to increased water temperatures (from 14.1 ± 2.2 to 23.8 ± 2.3 °C in 2010 and 2012, respectively) were established. In these thermokarst bodies of water that covered a full range of surface areas, the average conductivity and pH were almost unchanged, whereas dissolved organic carbon (DOC), Cl- and SO42- concentrations were higher by a factor of ~ 2 during summer 2012 compared to periods with normal temperatures. Similarly, most divalent metals and insoluble trivalent and tetravalent elements were more concentrated by a factor of 1.7–2.4 in the summer of 2012 than normal periods. The average concentrations of dissolved CO2 and CH4 during the hot summer of 2012 increased by factors of 1.4 and 4.9, respectively. For most of the trace elements bound to colloids, the degree of colloidal binding decreased by a factor of 1.44 ± 0.33 (for an average of 40 elements) during the hot summer of 2012 compared to normal periods. Increases in CO2 and CH4 concentrations with the decreasing size of the body of water were well-pronounced during the hot summer of 2012. The concentrations of CO2 and CH4 rose by factors of 5 and 150, respectively, in small (≤ 102 m2) compared to large (≥ 104 m2) thermokarst (thaw) lakes. Taken together, these trends suggest that, for a conservative scenario of lake size distribution, lake water warming at high latitudes will produce (1) a significant increase in methane emission capacity from thaw lake surfaces; (2) decreased molecular sizes of trace element complexes and potential bioavailability of metal micronutrients in water columns; and (3) relatively conservative responses by CO2, DOC and trace element concentrations.

Stereological Analyses of Hepatocyte Ultrastructure Monitor Arsenic Liver Burdens

1980 ◽  
Vol 38 ◽  
pp. 442-443
Author(s):  
E. M. B. Sorensen ◽  
R. R. Mitchell ◽  
L. L. Graham
Keyword(s):  
Drainage System ◽  
Water Levels ◽  
Ultrastructural Changes ◽  
Hepatocyte Ultrastructure ◽  
Lepomis Cyanellus ◽  
Large Numbers ◽  
Activation Data ◽  
Water Analyses ◽  
Municipal Lake ◽  
Green Sunfish

Endemic freshwater teleosts were collected from a portion of the Navosota River drainage system which had been inadvertently contaminated with arsenic wastes from a firm manufacturing arsenical pesticides and herbicides. At the time of collection these fish were exposed to a concentration of 13.6 ppm arsenic in the water; levels ranged from 1.0 to 20.0 ppm during the four-month period prior. Scale annuli counts and prior water analyses indicated that these fish had been exposed for a lifetime. Neutron activation data showed that Lepomis cyanellus (green sunfish) had accumulated from 6.1 to 64.2 ppm arsenic in the liver, which is the major detoxification organ in arsenic poisoning. Examination of livers for ultrastructural changes revealed the presence of electron dense bodies and large numbers of autophagic vacuoles (AV) and necrotic bodies (NB) (1), as previously observed in this same species following laboratory exposures to sodium arsenate (2). In addition, abnormal lysosomes (AL), necrotic areas (NA), proliferated rough endoplasmic reticulum (RER), and fibrous bodies (FB) were observed. In order to assess whether the extent of these cellular changes was related to the concentration of arsenic in the liver, stereological measurements of the volume and surface densities of changes were compared with levels of arsenic in the livers of fish from both Municipal Lake and an area known to contain no detectable level of arsenic.

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