Sediment Monitoring: What good is it anyway

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Sediment Monitoring What good is it anyway??!?!

• USGS Water Resources Discipline
• Gary P. Johnson
• Hydrologic Data Section Chief
• Urbana, IL

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• It is a capital mistake to theorize before one
  has data. Insensibly, one begins to twist facts
  to suit theories, instead of theories to suit
  facts.--Sir Arthur Conan Doyle (1859-1930)
• As a general rule, the most successful man in
  life is the man who has the best information.
  --Benjamin Disraeli (1804-1881)

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Topics Ill cover--

• Fundamentals of how USGS sediment stations
  operate
• Some applications of USGS sediment data

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Sediment concentration varies by time
Flow
Hydrograph during an event
t(0)
t(x)
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Computed Sediment Discharge X tons/day
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Computed Sediment Discharge 1000X tons/day
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Fundamentals of how our sediment stations operate

• Local Observer
• Collects samples twice/wk during low flow
• Collects at least one per day during floods
• USGS Cross-sections
• Used to mathematically adjust observer samples
• 8 per year
• Samples to USGS Kentucky Lab

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Local observer box sampler
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Auto-Sampler Station

• Uses stage sensing device to trigger samples
• Very reliable
• Great for very flashy streams

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Computation/publication of sediment record
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PROVISIONAL DATA
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Locations of Gaging Stations in Judys Branch
Watershed
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PROVISIONAL DATA
Why so high??!!
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Bed and bank instability!
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Any questions?
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Thanks!!