Development of a Sediment Transport Model
Download
1 / 26

Development of a Sediment Transport Model for the Chesapeake Bay: - PowerPoint PPT Presentation


  • 95 Views
  • Uploaded on

Development of a Sediment Transport Model for the Chesapeake Bay: Supporting Physical Data from VIMS Potomac River Intensive Surveys with Emphasis on Suspended Particle Populations and Bed Properties Carl T. Friedrichs and Grace M. Cartwright Virginia Institute of Marine Science.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Development of a Sediment Transport Model for the Chesapeake Bay:' - teague


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Development of a Sediment Transport Model

for the Chesapeake Bay:

Supporting Physical Data from VIMS Potomac River Intensive Surveys with

Emphasis on Suspended Particle Populations and Bed Properties

Carl T. Friedrichs and Grace M. Cartwright

Virginia Institute of Marine Science



Station locations
Station locations

General station locations along Potomac




Adcp proflier
ADCP, Proflier

ADCP

LISST

2 OBS

CTD

ADV

Pump


Bottom sampling
Bottom sampling

Bed grab with

1 cm interval

subsamples

of top 5 cm:

% water

organic matter

sand/silt/clay

Eh profile


Lisst 1
LISST 1

LISST:

Laser In-Situ Scattering

Transmissometer

Parts

Per

Million

5 m

500 m

Log10 particle size (micron)


Lisst 2
LISST 2

LISST:

Laser In-Situ Scattering

Transmissometer

Upper water column:

Larger size particles, presumably low density, biologically influenced flocs.

Parts

Per

Million

Near the bed:

Intermediate size particles, presumably higher density and suspended from bed.

5 m

500 m

Log10 particle size (micron)


Transects 1
Transects 1

ADCP

velocity

transect

ADCP

mass

conc

transect

LISST

D50

profiles

CTD

salinity

profiles


Transects 2
Transects 2

ADCP

velocity

transect

ADCP

mass

conc

transect

ADCP shows mass conc minimum at 2-3 m depth, but LISST shows size maximum

LISST

D50

profiles

CTD

salinity

profiles


Tss vs speed
TSS vs. speed

TSS vs. Speed

Pump

TSS

(mg/l)

Current speed (cm/s) (o 2004, x 2005)


Tss vs speed1
TSS vs. speed

TSS vs. Speed

Red = height above

bed < 1 m

Resuspension influence

Pump

TSS

(mg/l)

Biology/floc influence

Current speed (cm/s) (o 2004, x 2005)


Along axis
Along axis

UMCES Data: D50 depends on location, elevation and TSS.


Along axis1
Along axis

Positively correlated in z

Inversely correlated in z

UMCES Data: D50 depends on location, elevation and TSS.

Two distinct populations indicated: (i) suspended, (ii) biology/flocs


Shell at

km 35

Mud at

km 90

Sand at

km 20


August 2004

September 2005


August 2004

September 2005


August 2004

September 2005


August 2004

September 2005






Conclusions:

-- Two suspended populations exist: (1) inorganic, resuspended, denser with size positively correlated to mass concentration; (2) organic, advected, less dense with size negatively correlated to mass concentration and associated with stratification.

-- Bed types are regionally and locally diverse, dominated by shells, sand or mud. Fraction of mud content drives other properties like water and organic content. Eh is a useful indicator of “fresh”, easily resuspended mud.

-- Data is available to others and has already been passed on to other groups.


ad