Environmental Engineering Reference
In-Depth Information
Digital optic
imaging
Pressure
difference
Technology
Turbidity (bulk optics)
Laser
Hydroacoustic
Region of
measurement
Fixed point
Fixed point
Fixed point; device
may be used in
profi ling mode
by cable
suspension
Point, vertical,
or multiple
verticals by
cable
suspension
Fixed point
Single fi xed
vertical, mean
SSC value
Conic beam with
data available at
selected distances
from the sensor
Conic beam with
data available at
selected distances
from the sensor
Accuracy for
derivation of
suspended-
sediment data
When within
measurement
range has been
used to develop
reliable
SSC-turbidity
regression
relations
When within
measurement
range has been
used to develop
reliable
SSC-turbidity
regression
relations
Deemed reliable in
some fi eld
applications
Lab sedimento-
logical tests
completed
2008; fi eld
sedimento-
logical and
isokinetic
tests in 2009
Unresolved.
Preliminary
tests show
accurate
PSD results
for silt and
fi ne sand,
additional
testing is
planned
Unresolved
based on two
fi eld tests;
additional
evaluation
required
Shown useful in
fi eld applications
where PSD does
not change
dramatically
Shown to provide
accurate silt-clay
versus sand-size
fractions in one
fi eld deployment
Potential for
meeting U.S.
Geological
Survey
accuracy
criteria
High for mass SSC
depending on
nature of the
turbidity-SSC
relation
High for mass SSC
depending on
nature of the
turbidity-SSC
relation
High for volume
SSC and for PSD
High for
volume SSC
and for PSD
High for PSD;
accuracy is
still not
determined
for SSC
Low for mass
SSC
Moderate for mass
SSC
High for mass SSC;
moderate for
silt-clay versus
sand-size
fractions
Potential for
application in
suspended-
sediment
monitoring
programs
Endorsed by the
USGS, given
appropriate
in-stream
sedimentological
conditions,
calibrations, and
ability to
maintain
instruments
Endorsed by the
USGS, given
appropriate
in-stream
sedimentological
conditions,
calibrations, and
ability to
maintain
instruments
High (given
appropriate
in-stream
sedimentological
conditions,
known density,
and ability to
maintain
instruments)
High (among
potential
uses,
perform
calibrations
for
in situ
instruments)
High for
laboratory
SSC and
PSD;
moderate
for fi eld
applications
Unknown
pending
additional
testing using
modifi cations
of the
physical
system and
algorithms
Moderate (given
appropriate
in-stream
sediment-ological
conditions, and
calibration)
High for SSC;
moderate for
silt-clay versus
sand-size
fractions
