
	Where results make sense

Topic: Downdrift

In the News (Wed 25 Nov 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Coastal Systems International, Inc. \| Publications \| Miami Beach 32nd Street Hot Spot: Construction & Short - Term ...
		Due to the concern for downdrift impacts, the permit conditions for this project require that the shoreline response in t he vicinity of the structures be closely monitored for four years.
		The four profiles chosen present the updrift, within structures, and downdrift performance of the project, and the locations of the profiles are identified in Figure 6.
		This area is most susceptible to downdrift impacts as it is in the shadow zone of the last structure.
	www.coastalsystemsint.com /media/pop_32nd_conststruction.htm (2237 words)

	COAST PROTECTION. The Columbia Encyclopedia: Sixth Edition. 2000 (Site not responding. Last check: 2007-10-14)
		They act as a partial barrier to littoral drift, trapping sand on the updrift side and causing erosion on the downdrift side.
		Jetties are often built at river mouths and harbor entrances, projecting out into the ocean to direct and confine littoral currents and to prevent silting of the harbor entrance.
		Since beaches themselves are effective in dissipating wave energy, one remedy to the lack of a sand supply is to pump sand directly onto the beach from interior or offshore zones.
	www.bartleby.com /aol/65/co/coastpro.html (469 words)

	Beach Nourishment - Coastal Geology
		At those inlets where "training structures" (for example jetties) are particularly effective in disrupting the flow of sand to downdrift shorelines, appropriate inlet management may include mechanical bypassing of sand to downdrift shorelines.
		Severe erosion is often evident on the downdrift side of the inlet at the location where the flow, and thus the sediment transport, diverge.
		Adjacent shorelines are deprived of the sand thus accumulated, and the implied erosion rate of the "downdrift" shoreline is the same as the impoundment rate at the "updrift" jetty and within the ebb and flood shoals.
	www.csc.noaa.gov /beachnourishment/html/geo/channels.htm (3083 words)

	Downdrift, downstep, and declination
		The terminology arose largely through impressionistic work, and consequently use of these terms as found in the literature, especially downstep and downdrift is rather inconsistent: one author’s downstep may be another’s downdrift, and vice versa.
		The recent introduction of the concept of declination into studies of African tone systems brought in an additional element of terminological complexity; declination is may be taken to be the same as downdrift, though it is not, it seems, confused with automatic downstep.
		The confusion, or overlap, in their usage stems partly from the simple fact that until recently an insufficiently large range of languages to demonstrate the different phenomena had been examined; but also perhaps to some extent it can be attributed to an uncritical acceptance of the status quo.
	www.spectrum.uni-bielefeld.de /TAPS/bruce.html (540 words)

	Beach Nourishment - Coastal Geology
		At first, a groin field interrupts the longshore movement of sand in the littoral zone, but when a well-designed groin field fills to capacity with sand, longshore transport resumes at about the same rate as before the groins were built, and a stable beach is maintained (CSC 1997).
		Sand bypassing is the hydraulic or mechanical movement of sand from an accreting area updrift of a barrier to a downdrift eroding area.
		Dredged or mechanically moved material is placed on a beach immediately downdrift from the obstruction that then serves as a feeder beach to nourish beaches further downdrift.
	www.csc.noaa.gov /beachnourishment/html/geo/shorelin.htm (2429 words)

	fitzgerald (Site not responding. Last check: 2007-10-14)
		In the growth phase, large intertidal bar complexes are formed on both sides of the main ebb channel by the coalescence of landwardmigrating swash bars.
		When the inlet has a downdrift, offset configuration, the ebbtidal delta is skewed along the updrift shoreline.
		This causes a clockwise rotation of the main ebb channel and a shift in the ebb delta to a position along the downdrift shoreline.
	geology.uprm.edu /Morelock/GEOLOCN_/abstract/fitzgerald.htm (424 words)

	Western Orange Beach (Site not responding. Last check: 2007-10-14)
		Long-term erosion due to jetties typically is displaced some distance downdrift of the jetties, as it is in Orange Beach, due to the fillet formation as described in the section on Alabama Point.
		At other jettied inlets of comparable size, the downdrift erosion begins to show up 1 to 4 miles from the jetty.
		Essentially, the beaches of western Orange Beach (roughly all those west of the Cotton Bayou area access) are being starved for beach sand by the trapping at Perdido Pass.
	www.southalabama.edu /usa/cesrp/western_orange_beach2002.htm (214 words)

	Coastal Dynamics
		Erosion of downdrift beaches and dune-bluffs supplies sand to the littoral drift to make up for the sand trapped on the updrift side and to replace sand that is lost to deeper water offshore during intense storm events.
		On the downdrift side of man-made structures, if sand (littoral drift) is not abundant enough to maintain wide beaches and broad off-shore sand bars at a particular location, erosion rates may be higher there compared to other parts of the coast, even though the same wave energy and lake levels are present at both sites.
		Erosion rates usually increase dramatically on the downdrift side of a new structure as a result of severe sand-starved conditions created by sand being retained on the opposite (updrift) side of the littoral barrier.
	www.in.gov /nrc_dnr/lakemichigan/coadyn/coadynb.html (737 words)

	Surfrider Foundation USA - Coastal A-Z page template
		If the current direction is constant all year long, a groin "steals" sand that would normally be deposited on the downdrift end of the beach.
		As soon as one groin is built, property owners downdrift of it may start clamoring for the government to build groins to save "their" beach.
		A breakwater is a large pile of rocks built parallel to the shore.
	www.surfrider.org /srui.aspx?uiq=structures/erosion (880 words)

	Environment and Science (Site not responding. Last check: 2007-10-14)
		In Florida, the general flow of longshore currents is north to south, so the sand generally moves from north to south, flowing across inlets from one barrier island to another.
		This process is called "sand sharing." Barrier islands constantly lose sand to downdrift islands, but they constantly gain sand from updrift islands.
		But jetties prevent sand from flowing to the next island, which is losing sand naturally in the longshore current, and the downdrift island erodes.
	www.floridacapitalnews.com /erosion/stories/science1.htm (1379 words)

	Beneficial Use
		(maintenance dredging) is clamshelled onto a barge and off-loaded downdrift of the harbor for beach nourishment.
		, Indiana, approximately 85,000 cubic yards of sandy material from the outer harbor was dredged in 2000 by hydraulic dredge and pumped onto the beach west (downdrift) of the harbor.
		Indiana, approximately 142,000 cubic yards of material from the harbor was dredged in 2000 by hydraulic dredge and pumped to the beach west (downdrift) of the harbor.
	www.glc.org /dredging/benuse/beach.html (1057 words)

	The Delaware Coast October 2003
		However, this is often accompanied by accelerated erosion of the downdrift beach, which receives little or no sand via longshore transport.
		Because jetties interrupt longshore sand transport, the effect of jetties on adjacent beaches is similar to the effect of groins: accretion occurs on the updrift side, and erosion occurs downdrift.
		The offset is generally more extreme at jettied inlets, due to the length and relative impermeability of the jetties and the presence of strong tidal flow in the inlet channel.
	www.ocean.udel.edu /mas/wcarey/monthlyquestions/april04.html (591 words)

	ENHANCEMENT OF T-GROIN'S DESIGN TO IMPROVE DOWNDRIFT SHORELINE RESPONSE (Site not responding. Last check: 2007-10-14)
		Downdrift effects represent a major challenge to successful design of coastal structures.
		Previous attempts to reduce downdrift impacts focused on gradually reducing the size of erosion control structures to increase sand bypassing to the downdrift.
		The submerged extension to the T-head is intended to smooth the transition between the wave patterns in the shadow zone and the oblique wave angle further downdrift.
	eproceedings.worldscinet.com /9812562982/98125699520016.html (256 words)

	Transferring a coastal erosion problem: is this a wise practice? / Lagos-Nigeria. (via CobWeb/3.1 planetlab2.cs.unc.edu) (Site not responding. Last check: 2007-10-14)
		Due to continual erosion on the downdrift side of the school building, another shore parallel breakwater was constructed between April and June 1999 to protect the eastern part (downdrift side) of the school.
		The construction of the two stone moles (east and west moles) between 1904 and 1912 sparked off a high rate of erosion on the downdrift side of the east mole, causing high rates of erosion on the Victoria Beach.
		However, there is need to modify this methodology to accommodate the downdrift side, and also ensure that the project becomes a wp.
	www.csiwisepractices.org.cob-web.org:8888 /?read=43 (1198 words)

	houstonJ2
		In addition, beach nourishment avoids possible problems of downdrift erosion produced by structures.
		As a beach fill erodes, it provides material to downdrift beaches, providing additional benefits.
		Downdrift benefits are the source of the Dutch observation' that:
	geology.uprm.edu /Morelock/abstract/houstonJ2.htm (398 words)

	www.NuShore.com - Previous Studies (via CobWeb/3.1 planetlab2.cs.unc.edu) (Site not responding. Last check: 2007-10-14)
		The University of Florida laboratory experiments determined the major influence of permeable wood groins on the littoral system is the reduction of the longshore current velocity and sediment transport capacity within their reach.
		The beach profile responses to pile cluster groins included updrift and downdrift deposition, bar formation and seaward translation, and shoreline advance.
		Although erosion would be expected downdrift, it is not immediately obvious.
	www.nushore.com.cob-web.org:8888 /html/previous_studies.html (189 words)

	UCLA WPL 4 - Papers in Phonology 4
		In this paper, I attempt to characterize the domain of downdrift in Bole based on pitch tracks of utterances which vary in the syntactic structure, the length of phrase, focus, and speech rate.
		Results show that the downdrift is sensitive to the phonological length, focus, and speech rate; downdrift can be blocked in a sentence of the same syntactic structure when the constituent is long or when uttered at fast rate.
		That is, the domain of downdrift is sometimes smaller than the domain of a process of Low Tone Raising (LTR) (Gimba 1998), which applies within a Phonological Phrase.
	www.linguistics.ucla.edu /faciliti/wpl/issues/wpl4.htm (1146 words)

	Longshore Drift (Site not responding. Last check: 2007-10-14)
		These weak currents, known as longshore currents, carry water and sediment parallel to the shoreline toward the downdrift end of the beach.
		Spits are hooked-shaped lobes of sand extending downdrift from the barrier island.
		The action of southerly-directed longshore currents, wave refraction, and tidal currents, large reservoirs of sand in the form of sand bars tend to drift downward and inward toward the upper parts of islands that are south of coastal inlets.
	www.cofc.edu /CGOinquiry/longshoredrift.htm (314 words)

	Coastal Dynamics
		When a coastal structure traps sand on one side, creating erosion problems on the downdrift side, the trapped sand can be dredged and moved (by-passed) around the structure.
		This mechanical by-passing of sand places the same sand on the downdrift shoreline that would have arrived there naturally if the structure was not present.
		The other was mitigation for downdrift erosion from the Michigan City Harbor breakwater constructed by the federal government in 1836.
	www.in.gov /nrc_dnr/lakemichigan/coadyn/coadynf.html (1026 words)

	Four tones and downtrend - -
		Moreover, it would not be the first reported case of a downtrend applying differentially to different tones: Connell and Ladd (1990) suggest this with respect to Yoruba, and Clements (1981) observes a tendency for the two (phonetic) mid tones of Anlo-Ewe to demonstrate greater downdrift (though L does show downdrift as well).
		It appears from this work that declination (automatic downstep, downdrift) in a higher tone implies declination (automatic downstep, downdrift) in a lower tone; if the downtrend in T4 is analyzed as final lowering it would consequently provide some evidence that T2 and T3 are also subject to final lowering (i.e.
		Clements, N. (1981) Downdrift in a tone language with four tone levels: a report on some preliminary measurements.
	lucy.ukc.ac.uk /dz/connell/downtrend/downtrend.html (5173 words)

	Amazon.com: "downdrift beaches": Key Phrase page (Site not responding. Last check: 2007-10-14)
		This starves the downdrift beaches of the sand that is their very lifeblood.
		Unlike groins or detached breakwaters which may trap sand to the disadvantage of the downdrift beaches, beach nourishment adds sand to the adjacent beaches.
		inlets and efforts to ensure actions used to "deter erosion on updrift beaches do not result in the starvation of downdrift beaches of the sand that is vital to the protection of other private and public property.
	www.amazon.com /phrase/downdrift-beaches (566 words)

	Shoreline Signature and Grain Size East and West of Two Inlets: Mattituck Inlet and Goldsmith Inlet, Long Island , New ... (Site not responding. Last check: 2007-10-14)
		Jetties are shore-normal structures built to stabilize the location of an inlet, maintain depth in the inlet channel, and afford wave protection to vessels.
		Interruption of longshore sediment transport by jetties and sediment bypassing to the downdrift beaches are issues of concern at most inlets.
		Lag deposits then tend to remain on the downdrift sides of the jetties, where the existing sediment is winnowed by longshore transport under wave action.
	pbisotopes.ess.sunysb.edu /lig/Conferences/abstracts-04/morgan.htm (186 words)

	Beach Stabilization Alternatives (Site not responding. Last check: 2007-10-14)
		Traditional methods of stabilization - seawalls, groins and breakwaters - are increasingly being identified as leading to the erosion of fronting and downdrift beaches.
		Erosion of downdrift beaches : Devices that restrict transport of sand, either cross-shore or alongshore will lead to erosion elsewhere.
		No guarantees or warranties, including (but not limited to) any express or implied warranties or merchantability or fitness for a particular use or purpose, are made by Duke PSDS with respect to such information.
	www.env.duke.edu /psds/stabilization.htm (635 words)

	Sandy Coasts - Sediment Budget - An Overview of Coastal Land Loss: With Emphasis on the Southeastern United States
		Erosion along one stretch of sandy beach may be responsible for accretion or reduced erosion of a nearby beach in a downdrift direction if the sediment volume is sufficient and the available material is compatible with downdrift beaches.
		On the other hand, depletion of an updrift sediment source will initiate or accelerate retreat of downdrift beaches.
		For example, erosion of sandy beaches provides a ready source of sand for nourishment of downdrift beaches, whereas erosion of marshes and other muddy deposits usually does not contribute to the sand budget of adjacent beaches.
	pubs.usgs.gov /of/2003/of03-337/sandy.html (315 words)

	Solving beach erosion?
		The result is that sand is deposited on the updrift side, depriving the downdrift side of sand.
		Predictably, the groins caused erosion on the downdrift side, and, according to Rogers, "you'd have to say" it was a classic case of a groin field robbing sand from the downdrift side.)
		Another possible solution is building offshore breakwaters to reduce wave energy before it reaches the beach.
	whyfiles.org /091beach/4.html (935 words)

	Rutgers Marine Sciences Class - Class Notes 12/6
		Downdrift deflection of channel erodes tip of next barrier island downdrift
		Previous channel shoals and sediment is driven onshore to downdrift barrier
		Former (downdrift) channel shoals; sand driven onshore by waves to downdrift island
	marine.rutgers.edu /dmcs/ms200/coastal_geo.html (1739 words)

	Physical Geology Slides - Coastal Processes (via CobWeb/3.1 planetlab2.cs.unc.edu) (Site not responding. Last check: 2007-10-14)
		Breakwaters catch sand but also prevent it from replenishing the beach further downdrift.
		Erosion downdrift accelerates, requiring the next property owner to build a breakwater until the entire shoreline is dotted with them, as on this beach in New Jersey.
		Tidal marshes like this along the shore of Chesapeake Bay look fragile but comparison of very old and modern charts sometimes shows that channels have not changed in centuries.
	www.uwgb.edu.cob-web.org:8888 /dutchs/EarthSC202Slides/coasslid.htm (353 words)

	Case 4
		edge has eroded inland on the downdrift side.
		Groynes may be built singly, or in groups known as
		(See Figure 19.) However, as with groynes, downdrift beaches may suffer erosion if they are deprived of their sand supply.
	www.unesco.org /csi/pub/source/ero18.htm (2179 words)

	Intellectual downdrift - an issue for women (and men)
		There must be a lot more we can do.
		One thing is clear, we need to address the 'intellectual downdrift' issue in a way that is fair to all and enables society to benefit fully from the brightest of its women.
		We need to utilise the intellectual resource while also ensuring that our best genes are preserved and nurtured.
	www.daveslater.telinco.co.uk /women.htm (988 words)

	Meteo 22 lecture 26
		So the beach "downdrift" of the pass vanishes
		Pump it downdrift in a pipeline OR barge it downdrift
		Expect to move 100,000 or more cubic meters of sand per year
	www.ems.psu.edu /~young/meteo22/lecture_26.htm (211 words)

Try your search on: Qwika (all wikis)