Data Quality and Metadata Elements of QAQC plan for streamflow analysis

1
Data Quality and MetadataElements of QA/QC plan
for streamflow analysis

• Mark Mastin
• US Geological SurveyWashington Water Science
  Center
• May 23, 2008

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Overview

• Quality assurance for stream discharge
  measurements as applied to the Baseflow
  Monitoring Project
• Velocity Meters
• Wading Discharge Measurements
• Auxillary DataYou can never write too
  much on your notes!

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Velocity Meters/ Discharge Meas.

• FlowTrackers
• Pygmy/Price
• Marsh Mc Birney
• Swoffer
• Portable Flumes
• Bucket Method

Methods or meters used by the USGS
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Meter comparisons made by the USGS at the
Hydrologic Instrumentation Facility (HIF)

• Price AA and Pygmy most accurate over the range
  of velocities tested
• Marsh McBirney 2000 usually measured within its
  accuracy specification
• Swoffer 2100 did not meet its stringent accuracy
  limits, but OK with individually calibrated
  rating were used.

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HIF Testing continued
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HIF Testing continued
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Meter Testlast summer
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Making a Discharge Measurement Some General
Considerations slide1 of 3

• 1st question-- is it safe or not to wade the
  stream?
• What meter should I use? (Price AA or Pygmy?)
• Do a spin test (Price AA or Pygmy) Record in
  notes and in log.
• Correct standing position45 degrees to meter
• First click is counted as zero

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Making a Discharge Measurement slide 2
of 3
Discharge

• Aim for 25 or more verticals
• Adjust width to amount of flow
• No more than 10 of flow in one vertical

Velocity (ft3/s)
Depth (ft)
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Making a Discharge Measurement slide 3 of
3

• Compute horizontal angle
• coefficient, except FlowTracker
• Read depth on wading rod as water surface and not
  pile up on leading edge
• Know when to use .6 depths and when to use .2 and
  .8 depths and how to use the top-setting wading
  rod.
• Compute vertical widths correctlyfor a
  particular measurement, the widths for the first
  and last verticals are ½ the width between the
  edge station and the next station otherwise it
  is ½ the width between the previous station and
  the following station.

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Do I need to measure the stream again?

• Originally, it was stated that for this baseflow
  study, all sites should be measured twice on the
  same day
• I suggest the following
• If this is the first time measuring the site, a
  repeat measurement is recommended.
• If there is any doubt in a measurement, measure
  it again
• If the measurement is more than 5 off the
  current rating, measure again (need rating and
  gage height)

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Auxilary Information

• Name of Hydrographers, Date, Start/End Times
• Width, Ave. Velocity, Area, Gage Height
• Number of Sections (verticals)
• Water Temperature
• Weather
• Meter Type and serial number
• Spin test (if appropriate)
• Measurement Rating
• Streambed Material
• Locationdescriptive, Lat/Long w/ Datum
• Bankfull Width?
• Photo?

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Check Measurements
All measurements should be checked.

• Excel files for Pygmy and Price AA meas. are
  available on the CDentering the data qualifies
  as a check if the results match.
• Automated calculations (ex. FlowTracker,
  AquaCalc) need to be checked for reasonableness.

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Sources of More Information

• See my Word document file, Discharge_meas_notes.d
  oc on the CD of reference material for this
  workshop.
• An online, USGS course on streamgaging can be
  found at http//wwwrcamnl.wr.usgs.gov/sws/SWTrai
  ning/FlashFandR/Index.html see modules Discharge
  Measurements I, Discharge Measurements II, and
  Miscellaneous Measurements
• USGS bible on streamgaging Measurement and
  Computation of Streamflow Vol. 1 and 2., USGS
  Water Supply Paper 2175 by S.E. Rantz and others
  http//pubs.usgs.gov/wsp/wsp2175
• Washington Water Science Center Surface-Water
  Quality-Assurance Plan http//pubs.er.usgs.gov/us
  gspubs/ofr/ofr03490