Outline
Recent Field Observations of Cohesive and Mixed Sediment
Particle Properties in Estuarine and Coastal Environments
Carl Friedrichs, Virginia Institute of Marine Science
10
1 meter
30
2 hours
100 mg/l
Time-series of suspended sediment concentration in York River estuary, Virginia
Outline
Recent Field Observations of Cohesive and Mixed Sediment
Particle Properties in Estuarine and Coastal Environments
Carl Friedrichs, Virginia Institute of Marine Science
Review of Specific Set of New Articles:
10
• “Recent” = Publication date 2011, 2012 or 2013 (~since last INTERCOH).
• “Field Observations” = Not controlled lab experiments or theory alone.
• “Cohesive & Mixed Sediment Particle Properties” = Mostly flocculating
sediment, but also can be mixed with sand, pellets, etc. (but not fluid mud).
• “Estuarine & Coastal” = Mainly estuaries, but a few coastal examples.
• Also must contain interesting figures.
1 meter
30
2 hours
100 mg/l
Time-series of suspended sediment concentration in York River estuary, Virginia
Outline
Recent Field Observations of Cohesive and Mixed Sediment
Particle Properties in Estuarine and Coastal Environments
Carl Friedrichs, Virginia Institute of Marine Science
Review of Specific Set of New Articles:
10
• “Recent” = Publication date 2011, 2012 or 2013 (~since last INTERCOH).
• “Field Observations” = Not controlled lab experiments or theory alone.
• “Cohesive & Mixed Sediment Particle Properties” = Mostly flocculating
sediment, but also can be mixed with sand, pellets, etc. (but not fluid mud).
• “Estuarine & Coastal” = Mainly estuaries, but a few coastal examples.
• Also must contain interesting figures.
1 meter
30
2 hours
100 mg/l
Apologies to lab and theory focused work!
Apologies to great publications from 2010 and earlier!
Apologies for my innate biases!
Time-series of suspended sediment concentration in York River estuary, Virginia
Classic texts
“Stand on the Shoulders of Giants” – Isaac Newton
[Mehta 2013]
[Winterwerp, van Kesteren 2004]
[Mehta, McAnally 2008]
Classic texts
[Winterwerp 2004]
Google Scholar
“Stand on the Shoulders of Giants” – Also the official motto of Google Scholar (Seriously!)
Bainbridge, Wolanski, Álvarez-Romero, Lewis, Brodie (2012). Fine sediment and nutrient dynamics related to particle size and floc formation in a
Burdekin River flood plume, Australia. Marine Pollution Bulletin. http://dx.doi.org/10.1016/j.marpolbul.2012.01.043
Braithwaite, Bowers, Nimmo Smith, Graham (2012). Controls on floc growth in an energetic tidal channel. Journal of Geophysical Research.
http://dx.doi.org/10.1029/2011JC007094
Cartwright, Friedrichs, Sanford (2011). In situ characterization of estuarine suspended sediment in the presence of muddy flocs and pellets. In: P.
Wang, J.D. Rosati, and T.M. Roberts (eds.), Coastal Sediments 2011, http://www.vims.edu/~cfried/cv/2011/Cartwright_etal_2011_Coastal_Seds.pdf
Fall, Friedrichs, Cartwright (2013). Relationships among fine sediment settling and suspension, bed erodibility, and particle type in the York River
estuary Virginia. In prep from M.S. Thesis, Virginia Institute of Marine Science. http://www.vims.edu/~cfried/cv/2012/Fall_2012_MS_Thesis.pdf
Fettweis, Baeye, Lee, Chen, Jason (2012). Hydro-meteorological influences and multimodal suspended particle size distributions in the Belgian
nearshore area (southern North Sea). Geo-Marine Letters. http://dx.doi.org/10.1007/s00367-011-0266-7
Hill, Newgard, Law, Milligan (2013). Flocculation on a muddy intertidal flat in Willapa Bay, Washington, Part II: Observations of suspended particle
size in a secondary channel and adjacent flat. Continental Shelf Research. http://dx.doi.org/10.1016/j.csr.2012.06.006
Lee, Fettweis, Toorman, Molz (2012). Multimodality of a particle size distribution of cohesive suspended particulate matters in a coastal zone.
Journal of Geophysical Research. http://dx.doi.org/10.1029/2011JC007552
Lefebvre, Ouillon, Vinh, Arfi, Panché, Mari, Thuoc, Torréton (2012). Seasonal variability of cohesive sediment aggregation in the Bach Dang–Cam
Estuary, Haiphong (Vietnam). Geo-Marine Letters. http://dx.doi.org/10.1007/s00367-011-0273-8
Malpezzi, Sanford, Crump (2013). Abundance and distribution of transparent exopolymer particles in the estuarine turbidity maximum of
Chesapeake Bay. Marine Ecology Progress Series. http://dx.doi.org/10.3354/meps10362
Manning, Baugh, Soulsby, Spearman, Whitehouse (2011). Cohesive Sediment Flocculation and the Application to Settling Flux Modelling. In:
(Ginsberg, S. S., ed.) Sediment Transport. http://cdn.intechweb.org/pdfs/15517.pdf
Manning, Schoellhamer (2013). Factors controlling floc settling velocity along a longitudinal estuarine transect. Marine Geology.
http://dx.doi.org/10.1016/j.margeo.2013.06.018
Papenmeier, Schrottke, Bartholomä (2013). Over time and space changing characteristics of estuarine suspended particles in the German Weser
and Elbe estuaries. Journal of Sea Research. http://dx.doi.org/10.1016/j.seares.2013.03.010
Safak, Allison, Sheremet (2012). Floc variability under changing turbulent stresses and sediment availability on a wave energetic muddy shelf.
Continental Shelf Research. http://dx.doi.org/10.1016/j.csr.2012.11.015
Schindler, Bass, Manning (2013). Effects of non-cohesive particles on suspended particle characteristics in a partially flocculated estuary during
spring tides. Journal of Coastal Research. http://ics2013.org/papers/Paper3997_rev.pdf
Smith, Friedrichs (2011). Size and settling velocities of cohesive flocs and suspended sediment aggregates in a trailing suction hopper dredge
plume. http://dx.doi.org/10.1016/j.csr.2010.04.002
Soulsby, Manning, Spearman, Whitehouse (2013). Settling velocity and mass settling flux of flocculated estuarine sediments. Marine Geology.
http://dx.doi.org/10.1016/j.margeo.2013.04.006
van Leussen (2011). Macroflocs, fine-grained sediment transports, and their longitudinal variations in the Ems Estuary. Ocean Dynamics.
http://dx.doi.org/10.1007/s10236-011-0384-9
Outline
Recent Field Observations of Cohesive and Mixed Sediment
Particle Properties in Estuarine and Coastal Environments
Carl Friedrichs, Virginia Institute of Marine Science
Outline of Presentation:
• 1) Subpopulations in flocculated sediment suspensions
• 2) Response of floc subpopulations to strong shear
• 3) Floc resuspension and settling at low shear
• 4) Spatial variability in floc properties
• 5) Mixtures of flocs and other particle populations
10
1 meter
30
2 hours
100 mg/l
Time-series of suspended sediment concentration in York River estuary, Virginia
Outline
Recent Field Observations of Cohesive and Mixed Sediment
Particle Properties in Estuarine and Coastal Environments
Carl Friedrichs, Virginia Institute of Marine Science
Outline of Presentation:
• 1) Subpopulations in flocculated sediment suspensions
• 2) Response of floc subpopulations to strong shear
• 3) Floc resuspension and settling at low shear
• 4) Spatial variability in floc properties
• 5) Mixtures of flocs and other particle populations
10
1 meter
30
2 hours
100 mg/l
Time-series of suspended sediment concentration in York River estuary, Virginia
Outline
Recent Field Observations of Cohesive and Mixed Sediment
Particle Properties in Estuarine and Coastal Environments
Carl Friedrichs, Virginia Institute of Marine Science
Outline of Presentation:
• 1) Subpopulations in flocculated sediment suspensions
• 2) Response of floc subpopulations to strong shear
• 3) Floc resuspension and settling at low shear
• 4) Spatial variability in floc properties
• 5) Mixtures of flocs and other particle populations
10
1 meter
30
2 hours
100 mg/l
Time-series of suspended sediment concentration in York River estuary, Virginia
Average SPM (mg/L)
1) SUBPOPULATIONS Fettweis et al., Lee et al.
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
[Fettweis, Baeye, Lee, Chen, Yu 2012]
-- Tripod deployed Jan-Feb & April 2008.
-- ADV 0.2 mab, LISST 2 mab, OBS 0.2 & 2 mab.
-- CTD, ADP
-- Curve-fitted multi-modal particle size distribution
applied to LISST data.
-- Primary particles, flocculi, microflocs, macroflocs.
Vol. Conc. (mL/mm)
Tripod “Bla” at 6-m
depth, 1 km offshore
[Lee, Fettweis, Toorman, Molz 2012]
Vol. Conc. (mL/mm)
Vol. Conc. (mL/mm)
1) SUBPOPULATIONS Lee et al.
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
Vol. Conc. (mL/mm)
Vol. Conc. (mL/mm)
[Lee, Fettweis, Toorman, Molz 2012]
-- There is not a single peak in the PSD. -- Different components have distinct fractal dimensions.
-- Sediment mass moves from one distinct subpopulation to another. -- Single peak model inadequate for this case.
1) SUSPOPULATIONS Lefebvre et al. 2012
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
Example LISST data from profile in
7-m deep tidal estuary channel
[Lefebvre et al. 2012]
-- Cruises in July 2008 and March 2009.
-- Ship-based ADCP, LISST & CTD profiling.
-- Four subpopulations seen here like off
Belgium.
-- Turbulence estimated from ADCP shear
along with salinity stratification.
-- Turbulence changed relative importance of
subpopulations, but did not strongly shift
the modal position of each subpopulation.
1) SUBPOPULATIONS Soulsby Manning 2013
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
Example Tamar
INSEV data
[Manning et al. 2011]
-- Compiled from several past field
campaigns which utilized the INSSEV
video settling camera system.
-- There were often separate
clusterings of flocs in the micro- and
macrofloc ranges.
-- Compilations of previously collected
data from several estuaries show
distinctly different response to shear
stress, different excess density
patterns, and inconsistency in fractal
dimension for micro- versus
macroflocs.
[Soulsby, Manning, Spearman, Whitehouse 2013]
Compilation of INSEV floc settling camera
data from Tamar, Gironde and Dollard
Outline
Recent Field Observations of Cohesive and Mixed Sediment
Particle Properties in Estuarine and Coastal Environments
Carl Friedrichs, Virginia Institute of Marine Science
Outline of Presentation:
• 1) Subpopulations in flocculated sediment suspensions
• 2) Response of floc subpopulations to strong shear
• 3) Floc resuspension and settling at low shear
• 4) Spatial variability in floc properties
• 5) Mixtures of flocs and other particle populations
10
1 meter
30
2 hours
100 mg/l
Time-series of suspended sediment concentration in York River estuary, Virginia
2) HIGH SHEAR Panenmeier 2013
[Papenmeier, Schrottke, Bartholoma 2013]
-- Cruises along Elbe River estuary in August
and November 2011.
-- LISST profiles and water samples.
-- ADCP for tidal velocity.
-- Suspended sediment samples also
disaggregated and sized.
-- Little relationship found between changes
in disaggregated components and changes in
floc modes.
-- In late fall, higher tidal velocities rapidly
broke macroflocs down to microflocs.
-- In summer, higher tidal velocities changed
the size of macroflocs but did not break
macroflocs into microflocs.
-- Biology influences strength of macroflocs.
-- Microflocs are strong and do not
breakdown in fall or summer.
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
November
August
2) HIGH SHEAR Lee 2012
-- Seasonal trends also seen off of Belgium – biology is important.
-- In winter, moderately high stress readily breaks down macroflocs – all the way to flocculi
and also down to primary particles to some degree.
-- In late spring, flocs are stronger. Macroflocs are not completely destroyed by stress, and
microflocs are not broken into flocculi.
6-m depth off Belgium.
[Lee, Fettweis, Toorman, Molz 2012]
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
2) HIGH Shear Safak
-- Tripod at 4 m depth, LISST, PC-ADP
-- Macroflocs broken up under strong waves.
-- Otherwise little relation between stress and floc size.
-- Macroflocs broken into microflocs, mode of
macroflocs did not dramatically change.
-- Mean floc size is approximation of micro vs. macrofloc
abundance.
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
Sea
Swell
[Safak, Allison, Shemeret 2013]
Outline
Recent Field Observations of Cohesive and Mixed Sediment
Particle Properties in Estuarine and Coastal Environments
Carl Friedrichs, Virginia Institute of Marine Science
Outline of Presentation:
• 1) Subpopulations in flocculated sediment suspensions
• 2) Response of floc subpopulations to strong shear
• 3) Floc resuspension and settling at low shear
• 4) Spatial variability in floc properties
• 5) Mixtures of flocs and other particle populations
10
1 meter
30
2 hours
100 mg/l
Time-series of suspended sediment concentration in York River estuary, Virginia
3) SUSPENSION Manning_Schoellhamer 2013
-- Ship-based sampling on 17 June 2008.
-- INSSEV-FL version of setting velocity camera.
-- Cruise from -2 hr LW through +2 hr HW
-- The best single predictor of settling velocity was water
velocity 39 min prior to sampling, not sediment
concentration or salinity.
-- Resuspension and settling lag largely influence Ws.
Stn 36
[Manning, Schoellhamer 2013]
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
3) SUSPENSION Hill 2013 – floc suspension without breakup
Peak Velocity
-- 2 weeks, Feb/Mar 2010.
-- LISST, 0.5 mab.
-- Digital Floc Camera.
-- ADP/ADCP.
-- Channel 2-m deep
at LW.
-- Macroflocs survived
resuspension.
[Hill, Newgard, Law, Milligan 2013]
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
(a)
3) SUSPENSION Fall 2012 – low stress
(d)
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
-- ADV at 0.4 mab in 6-m, May – Aug 2007.
-- Backscatter calibrated by pump samples.
-- 40 strongest tides in June (vs. July) phase
averaged for Regime 1 (vs. Regime 2).
-- Regime 1 separated into “washload” and
(micro) “flocs”.
-- (Micro) flocs resuspended without
change in Ws.
(b)
(e)
(c)
(f)
[Fall, Friedrichs, Cartwright 2013]
3) TEP Malpezzi Sanford 2013
Fresh
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
Fraction of TSS with
Ws > 0.06 mm/s
Stn #
ETM
1-3
Salt
4-9
10-11
Transparent
Exopolymer
Particle (TEP)
concentration
Chl-a
(volt)
-- 8 cruises in 2007
to 2008 in ETM
region.
-- CTD, water
samples, lab
analysis for TEP.
Owen tube for Ws.
-- In relatively low
turbulence systems,
(e.g., Chesapeake
Bay), TEP is more
important than
shear in driving
flocculation and
settling.
[Malpezzi, Sanford, Crump 2013]
ETM
ETM
ETM
Outline
Recent Field Observations of Cohesive and Mixed Sediment
Particle Properties in Estuarine and Coastal Environments
Carl Friedrichs, Virginia Institute of Marine Science
Outline of Presentation:
• 1) Subpopulations in flocculated sediment suspensions
• 2) Response of floc subpopulations to strong shear
• 3) Floc resuspension and settling at low shear
• 4) Spatial variability in floc properties
• 5) Mixtures of flocs and other particle populations
10
1 meter
30
2 hours
100 mg/l
Time-series of suspended sediment concentration in York River estuary, Virginia
4) SPATIAL Bainbridge 2012
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
-- Transects along river plume, 12/2010 & 01/2011.
-- Near surface samples shown below for
18 January 2011.
-- Particle properties function of distance/time,
but not turbulence (for this cruise).
-- Dominant floc size increases strongly offshore.
-- Organic fraction increases offshore.
-- Settling velocity decreases offshore.
100 microns
[Bainbridge, Wolanski, Alvarez-Romero, Lewis, Brodie 2012]
4) SPATIAL Manning_Schoellhamer 2013 – location, velocity, NOT fractal dimension
-- Strong spatial variation in fractal dimension for both
microflocs and macroflocs.
-- Ws macrofloc / Ws microfloc also changes spatially.
-- Wide variability in physical, biological and chemical
processes which contribute to flocculation within SFB.
-- Spatial floc data is required in order to accurately
represent the diverse floc dynamics present in the Bay
system.
Stn 36
[Manning, Schoellhamer 2013]
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
4) SPATIAL Van Leussen 2011
A
10
mm
C
100
mm
B
100
mm
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
D
100
mm
[van Leussen 2011]
-- Water samples collected by boats following tide of entire tidal cycles in 1990s(?).
-- Suspended sediment collected 2.8-m surface at maximum tidal flow, each homogenized, concentrated to 1 g/L, and
placed in a settling column. Strong spatial variation was seen in resulting mean Ws.
-- Ws was found to vary spatially in a manner similar to electrophoretic mobility measured by Malvern Zeta-sizer II.
-- Electrophoretic mobility (related to zeta-potential) is governed by organic coatings along with cations in water.
4) SPATIAL Braithwaite 2012
[Braithwaite, Bowers, Nimmo Smith, Graham 2012]
10 km
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
-- 20-m of water, upward-looking 1200 KHz, ADCP, LISST on frame
0.5 mab, two weeks in September 2008.
-- ADCP used to calculated turbulence via “structure function
method”
-- With no time lags, a poor correlation was seen between
median particle size and the size of the smallest turbulent eddies.
-- Once horizontal advection of a longitudinal gradient of
8 micron/km was accounted for, median particle size agreed well
with reasonable parameters applied to the Winterwerp (1998)
floc model.
-- Message: Winterwerp model works here, but don’t forget
advection!
Winterwerp model + advection term
Observations
Outline
Recent Field Observations of Cohesive and Mixed Sediment
Particle Properties in Estuarine and Coastal Environments
Carl Friedrichs, Virginia Institute of Marine Science
Outline of Presentation:
• 1) Subpopulations in flocculated sediment suspensions
• 2) Response of floc subpopulations to strong shear
• 3) Floc resuspension and settling at low shear
• 4) Spatial variability in flocculated sediment properties
• 5) Mixtures of flocs and other particle populations
10
1 meter
30
2 hours
100 mg/l
Time-series of suspended sediment concentration in York River estuary, Virginia
5) MIXED Smith 2011
[Smith, Friedrichs 2011]
-- Vessel-based spatial survey of dredge plume in ~ 14 m.
-- Profiler sampled throughout water column for 2 hours,
10 June 2006.
-- Ws, size distribution, density via PICS video settling
camera sampling in situ.
-- PIV/PTV corrects for PICS motion, ~2000 particles sized
by software in 30 sec., new sample every 2 min.
-- Profiler also includes LISST, ADV, CTD, pump intake.
-- Flocs, bed aggregates, primary grains defined by density.
-- Science message: A full spectrum of densities can be
present at any one diameter in mixed cohesive cases.
-- 30 micron primary grains may settle faster than 300
micron macro flocs.
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
5) MIXED Schindler 2013
-- At high stress (4), microflocs strongly
influenced by sand suspension.
-- At lower stress (8), larger particles
strongly influenced by muddy macroflocs.
-- ADV frame, moored vessel sampled at 0.5 mab
in ~ 4 m, samples passed through LabSFLOC
settling video camera, 10 June 2009.
-- Settling velocity of denser microflocs can be
greater than that of less dense macroflocs.
[Schindler, Bass, Manning 2013]
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
5) MIXED Cartwright 2011
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
ADV-based
LISST
LISST particle size
(log10 microns)
-- LISST and ADV on benthic tripod, ~ 40 cmab at 6-m depth.
-- Particles dominated by flocs at times of low velocity.
-- At higher velocities flocs break up, but then bulk Ws is
dominated by resuspension of resilient fecal pellets.
Ws = <w’C’>/<C>
63 mm – 125 mm sieve, York River 1/2013
[Cartwright, Friedrichs, Sanford 2011]
[microscopy images Schaffner Lab, VIMS]
5) MIXED Wang 2013
ADCP, 3 ADVs on tripod (.2,.6,1 mab), LISST on
profiler, 2 weeks in spring 2010.
Flocs at low velocity shear.
Influence of suspended fine sand on bulk
particle properties at high velocity shear.
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
LISST-based D50 vs. ADV-based turbulent shear
ADV-based WS vs. ADV-based turbulent shear
[Wang, Voulgaris, Li, Yang, Gao, Chen, Gao 2013]
(a)
5) MIXED Fall 2012 – pellets
1) Floc subpopulations
2) High shear break-up
3) Low shear resuspen.
4) Spatial variability
5) Mixed populations
(d)
-- Pellets present during Regime 2.
-- Ws separated into flocs + pellets.
WsDEP = fFWsFLOCS + fFWsPELLETS
= ~ 1.5 mm/s at peak tb
Assume: fF = 5/8, fP = 3/8
This gives:
(b)
WsPELLETS = ~ 2 mm/s
(e)
(c)
(f)
[Fall, Friedrichs, Cartwright 2013]
Outline
Recent Field Observations of Cohesive and Mixed Sediment
Particle Properties in Estuarine and Coastal Environments
Carl Friedrichs, Virginia Institute of Marine Science
Conclusions:
• 1) Subpopulations in flocculated sediment suspensions
• 2) Response of floc subpopulations to strong shear
• 3) Floc resuspension and settling at low shear
• 4) Spatial variability in floc properties
• 5) Mixtures of flocs and other particle populations
10
1 meter
30
2 hours
100 mg/l
Time-series of suspended sediment concentration in York River estuary, Virginia
Outline
Recent Field Observations of Cohesive and Mixed Sediment
Particle Properties in Estuarine and Coastal Environments
Carl Friedrichs, Virginia Institute of Marine Science
Conclusions:
• 1) Subpopulations in flocculated sediment suspensions
• 2) Response of floc subpopulations to strong shear
• 3) Floc resuspension and settling at low shear
• 4) Spatial variability in floc properties
• 5) Mixtures of flocs and other particle populations
10
1 meter
30
2 hours
100 mg/l [Lee,
Time-series
of suspended
sediment concentration in York River estuary, Virginia
Fettweis, Toorman,
Molz 2012]
Outline
Recent Field Observations of Cohesive and Mixed Sediment
Particle Properties in Estuarine and Coastal Environments
Carl Friedrichs, Virginia Institute of Marine Science
Conclusions:
• 1) Subpopulations in flocculated sediment suspensions
• 2) Response of floc subpopulations to strong shear
• 3) Floc resuspension and settling at low shear
• 4) Spatial variability in floc properties
• 5) Mixtures of flocs and other particle populations
10
1 meter
30
2 hours
100 mg/l
Time-series of suspended sediment concentration in York River estuary, Virginia
[Papenmeier, Schrottke, Bartholoma 2013]
Outline
Recent Field Observations of Cohesive and Mixed Sediment
Particle Properties in Estuarine and Coastal Environments
Carl Friedrichs, Virginia Institute of Marine Science
Outline of Presentation:
10
• 1) Subpopulations in flocculated sediment suspensions
Time (hours)
[Hill, Newgard,
Milligan 2013]
• 2)Law,
Response
of floc subpopulations
to strong shear
• 3) Floc resuspension and settling at low shear
• 4) Spatial variability in floc properties
• 5) Mixtures of flocs and other particle populations
1 meter
30
2 hours
100 mg/l
Time-series of suspended sediment concentration in York River estuary, Virginia
Outline
Recent Field Observations of Cohesive and Mixed Sediment
Particle Properties in Estuarine and Coastal Environments
Carl Friedrichs, Virginia Institute of Marine Science
Outline of Presentation:
10
• 1) Subpopulations in flocculated sediment suspensions
• 2) Response of floc subpopulations to strong shear
[Manning, Schoellhamer 2013]
• 3) Floc resuspension and settling at low shear
• 4) Spatial variability in floc properties
• 5) Mixtures of flocs and other particle populations
1 meter
30
2 hours
100 mg/l
Time-series of suspended sediment concentration in York River estuary, Virginia
Outline
Recent Field Observations of Cohesive and Mixed Sediment
LISST
Particle Properties in Estuarine and Coastal Environments
Carl Friedrichs, Virginia Institute of Marine Science
ADV-based
Outline of Presentation:
Ws = <w’C’>/<C>
63 mm – 125 mm sieve, York River 1/2013
• 1) Subpopulations in flocculated sediment
suspensions
• 2) Response of floc subpopulations to strong shear
• 3) Floc resuspension and settling at low shear
[Cartwright, Friedrichs, Sanford 2011]
• 4) Spatial variability in flocculated sediment
properties
• 5) Mixtures of flocs and other particle populations
10
1 meter
30
2 hours
100 mg/l
Time-series of suspended sediment concentration in York River estuary, Virginia
Outline
Recent Field Observations of Cohesive and Mixed Sediment
Particle Properties in Estuarine and Coastal Environments
Carl Friedrichs, Virginia Institute of Marine Science
Conclusions:
• 1) Subpopulations in flocculated sediment suspensions
• 2) Response of floc subpopulations to strong shear
• 3) Floc resuspension and settling at low shear
• 4) Spatial variability in floc properties
• 5) Mixtures of flocs and other particle populations
10
1 meter
THANKS! -- QUESTIONS?
30
2 hours
100 mg/l
Time-series of suspended sediment concentration in York River estuary, Virginia