scholarly journals REDUCTION OF MAINTENANCE BY PROPER ORIENTATION OF SHIP CHANNELS THROUGH TIDAL INLETS

2000 ◽  
Vol 1 (2) ◽  
pp. 22
Author(s):  
W. Armstrong Price
Keyword(s):  
Tidal Inlet ◽  
Tidal Inlets ◽  
Inlet Channel ◽  
Engineering Studies ◽  
Strong Current ◽  
Channel Outlet ◽  
Maintenance Dredging ◽  
Set Up ◽  
Inland Water Bodies ◽  
Current Engineering

The inherited courses of some hay-port ship channels take them through tidal inlets along courses running across dominant directions of strong current movement and scour, or on courses that upset the natural tidal regimes. Such discordance may make necessary excessive maintenance dredging. Geological study of a section of the Texas coast shows that, in a unit coastal environment, there may he a predictable stahle position of a tidal inlet and a common stahle orientation for its channel which might better have been used for the ship channel outlet. Among probable damages to the natural environment resulting from a wrong orientation is excessive sedimentation in the inlet channel. Engineering studies are needed to determine the economics of reorientation and relocation of misfit channels of the type described. The tidal inlet or "pass" is the central channel of a tidal delta. The delta is an enlargement of a barrier sand island at a gap where tidal and other flow into and out of large inland water bodies forms a strong local field of force with a longshore sediment drift and current. Engineering works in this field of force should utilize its characteristics, not fight them. As the coastal section studied here is only one of many, extension of the geologic study, with accompanying engineering studies, should be made to permit general laws of inlets, tidal deltas and barrier islands to be set up for both geology and engineering.

Taphonomic Redistribution of Mollusk Shells in a Tidal Inlet Channel, Sapelo Island, Georgia

Palaios ◽  
1986 ◽  
Vol 1 (1) ◽  
pp. 3 ◽  
Author(s):  
Stephen W. Henderson ◽  
Robert W. Frey
Keyword(s):  
Tidal Inlet ◽  
Inlet Channel ◽  
Mollusk Shells ◽  
Sapelo Island

scholarly journals NUMERICAL MODEL INVESTIGATION OF SELECTED TIDAL INLET-BAY SYSTEM CHARACTERISTICS

1978 ◽  
Vol 1 (16) ◽  
pp. 76
Author(s):  
William N. Seelig ◽  
Robert M. Sorensen
Keyword(s):  
Sediment Transport ◽  
Numerical Model ◽  
Transport Model ◽  
Tidal Inlet ◽  
Inlet Channel ◽  
Astronomical Tide ◽  
Order Of Magnitude ◽  
Flow And Sediment Transport ◽  
Transport Factors ◽  
System Characteristics

A spatially integrated one-dimensional numerical model of inlet bay hydraulics has been combined with a simple sediment transport model to investigate selected tidal inlet-bay system characteristics. A parametric study has been performed using the models to determine the effect of various factors on the net direction and order of magnitude of inlet channel flow and sediment transport. Factors considered include astronomical tide type, storm surge height and duration, variation in bay surface area, time-dependent channel friction factor, and the addition of a second inlet connecting the bay and sea.

Tidal Inlet Protection Strategies for Oil Spill Response; Concepts, Testing, and Considerations

2014 ◽  
Vol 2014 (1) ◽  
pp. 287225
Author(s):  
Bradford Benggio ◽  
Kimberly Chesteen ◽  
Jason DeSantis ◽  
Richard Knudsen ◽  
John Slaughter
Keyword(s):  
Oil Spill ◽  
Oil Spills ◽  
Local Area ◽  
Tidal Inlet ◽  
South Florida ◽  
Environmental Resources ◽  
Tidal Inlets ◽  
Operational Strategies ◽  
Protection Strategies ◽  
Oil Spill Response

Coastal Area Contingency Plans (ACP) developed by local Area Committees are the consensus stakeholder documents that guide response actions to oil spills. Key to these ACPs are the Geographic Response Plans (GRPs) that identify specific areas and resources that are priorities for protection during spill response. Within the GRPs, the operational strategies to protect each priority are pre-identified and depicted on maps. One of the priorities contained within the GRPs are tidal inlets. They are the gateways to much of the most sensitive habitat and resources to protect in the event of an oil spill. To address protection of these important gateways, Tidal Inlet Protection Strategies (TIPS) for Oil Spill Response have been developed that are scientifically and operationally based. They are designed to protect the resources inside the inlet from oil that may enter from an offshore source. Tidal inlets, while among the most important areas to protect, are also some of the most difficult to effectively protect. This is due to strong currents created by flood and ebb tidal flows (which are often not fully known), associated bathymetry stability issues (shoaling), responder access, and sensitive resource concerns subject to impact from the oil as well as from response actions. The inlets, in addition to being so critical for the protection of environmental resources, are also typically very important gateways for commerce and other waterway use activities. The TIPS concept has been tested for several inlets over the years. Most recently, a class A inlet (highest degree of difficulty) strategy was tested in South Florida. This poster will present issues related to the value and importance of developing and testing TIPS, hurdles and difficulties to overcome when planning TIPS projects and tests, positive outcomes from an operational perspective as well as from benefits derived from education, coordination and management of expectations of government, industry, and the public when it comes to protection of environmental resources during a major oil spill. Finally, the poster will offer recommendations and issues for discussion that area committees should consider relative to TIPS and area contingency planning in general.

Development of subaqueous barchanoid-shaped dunes due to lateral grain size variability in a tidal inlet channel of the Danish Wadden Sea

2005 ◽  
Vol 110 (F4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Verner B. Ernstsen ◽  
Riko Noormets ◽  
Christian Winter ◽  
Dierk Hebbeln ◽  
Alex Bartholomä ◽  
...  
Keyword(s):  
Grain Size ◽  
Wadden Sea ◽  
Tidal Inlet ◽  
Inlet Channel ◽  
Size Variability

scholarly journals The Impact of Storm-Induced Breaches on Barrier Coast Systems Subject to Climate Change—A Stochastic Modelling Study

2020 ◽  
Vol 8 (4) ◽  
pp. 271 ◽  
Author(s):  
Koen R. G. Reef ◽  
Pieter C. Roos ◽  
Tessa E. Andringa ◽  
Ali Dastgheib ◽  
Suzanne J. M. H. Hulscher
Keyword(s):  
Nearest Neighbor ◽  
Morphological Evolution ◽  
Stochastic Modelling ◽  
Barrier Islands ◽  
Monte Carlo Analysis ◽  
Tidal Inlet ◽  
Degree Of Saturation ◽  
Tidal Inlets ◽  
The Creation ◽  
The Impact

Storms can have devastating impacts on barrier coasts causing coastal erosion, partial inundation, and possibly the breaching of barrier islands. The breaching of barrier islands provides a mechanism for the creation of new tidal inlets that connect the backbarrier basin (or lagoon) and the outer sea. As a new tidal inlet affects both the basin and the hydrodynamics of existing inlets, it is important to understand why an initial breach either closes or may evolve into a new tidal inlet. To this end, we performed a Monte Carlo analysis using an idealized model capable of simulating the long-term morphological evolution of multiple tidal inlets connected to a single backbarrier basin. To do so required the creation of a stochastic shell, as a new element around this existing barrier coast model. Our results demonstrate that barrier coast systems tend towards an equilibrium value for the number of inlets per kilometer of barrier coast and total inlet cross section. This even holds with the continuous stochastic forcing of storm-induced breaches. This finding implies that if a new breach opens in a coast that is already in equilibrium, existing inlets will shrink and may close if the new breach remains open. Furthermore, we find that climate-driven changes in storm frequency will modify the timescales in which barrier coasts reach their equilibrium state. Finally, we find that the distance between a new breach and its nearest neighbor is more important for its survival than the size of the breach or the degree of saturation of the barrier coast.

A Possible Eddy Retention Mechanism for Ichthyoplankton in Hecate Strait

1990 ◽  
Vol 47 (7) ◽  
pp. 1356-1363 ◽  
Author(s):  
William R. Crawford ◽  
Albert V. Tyler ◽  
Richard E. Thomson
Keyword(s):  
Retention Mechanism ◽  
Recruitment Rate ◽  
High Rate ◽  
Return Flow ◽  
High Productivity ◽  
Strong Current ◽  
Pelagic Larvae ◽  
Juvenile Habitat ◽  
Current Flows ◽  
Set Up

The cause of the high rate of production of groundfish in Hecate Strait is uncertain. It is likely that the large, shallow areas of the Strait contribute to the high productivity because of their suitability as juvenile habitat. In winter, however, when many groundfish species spawn, a strong current flows northward through the Strait into Dixon Entrance and likely carries many of the pelagic larvae out of the Strait. A recent study shows that the recruitment rate of Pacific cod varies inversely with this current, which is to be expected if the larvae are swept out of the Strait by the flow. We examine current and wind data from a variety of field programs in Hecate Strait, and find evidence for a return flow toward the southwest in Hecate Strait, counter to the wind-driven transport. This return flow is driven by the set-up of sea level along the Strait by the wind, and its strength increases with the intensity of southeast storm winds. We believe the return flow will recirculate a significant fraction of the larvae in the Strait, increasing their residence time sufficiently to allow settling out, thus enhancing recruitment.

Processes driving circulation, exchange and flushing within intermittently closing and opening lakes and lagoons

2007 ◽  
Vol 58 (8) ◽  
pp. 709 ◽  
Author(s):  
Emma Gale ◽  
Charitha Pattiaratchi ◽  
Roshanka Ranasinghe
Keyword(s):  
Surface Water ◽  
Maximum Depth ◽  
Tidal Effects ◽  
Inlet Channel ◽  
Regional Area ◽  
Strong Current ◽  
The World ◽  
Order Of Magnitude ◽  
Estuarine Systems ◽  
Salinity Structure

The circulation and exchange between two intermittently closing and opening lakes and lagoons (ICOLLs) and the ocean were analysed using salinity and current meter data. Wamberal Lagoon was shallow (~2.5 m maximum depth) with a small (<1 km2) waterway area and a short opening duration (2 weeks), and Smiths Lake was deeper (~5 m maximum depth) with a larger (~11 km2) waterway area and a longer opening duration (4 months). An absence of river inflow and a restricted sill type inlet channel characterised both systems. The results showed that the smaller ICOLL exhibited a salinity structure similar to a partially or well-mixed estuary, whereas the larger ICOLL exhibited stronger separation of flow with a salt wedge-type structure. Both ICOLLs had strong current velocities in the surface water during ebb tide. The results also demonstrated that tidal effects controlled the circulation and exchange in the smaller ICOLL, whilst the wind also had a significant influence. In the larger ICOLL, subtidal effects over the fortnightly tidal cycle significantly influenced the circulation and exchange, but the influence of tide and wind effects was weaker. An analysis of the flushing for the two ICOLLs illustrated that the timescales were an order of magnitude different but comparable to the duration of opening for each ICOLL, ranging from 4 days in the smaller ICOLL (Wamberal Lagoon) to 113 days in the larger ICOLL (Smiths Lake). This research suggests that intermittent estuarine systems may be quite complex and variable within the same regional area, and consequently throughout the world.

scholarly journals SHOALING WITH BYPASSING FOR CHANNELS AT TIDAL INLETS

1982 ◽  
Vol 1 (18) ◽  
pp. 91
Author(s):  
Cyril Galvin
Keyword(s):  
Tidal Inlet ◽  
Tidal Inlets ◽  
Littoral Drift ◽  
Systematic Method ◽  
Longshore Transport

A channel dredged at the mouth of a tidal inlet is subject to rapid shoaling because of longshore transport, but this shoaling is slower than would be computed from simple trapping of all the moving littoral drift. The reduction in shoaling rate is due to the bypassing of littoral drift which occurs simultaneously with shoaling. This report presents a systematic method for computing the rate of shoaling in channels subject to shoaling with bypassing. The method also permits estimates of the effect of the dredged channel on the downdrift beaches.

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