what does it all mean siletz river near siletz, or may 20-23, 2013

What Does It All Mean

Siletz River near Siletz, OR

May 20-23, 2013

What we learned this week• Why & where we might collect sediment data

• How sediment is transported by water (fluvial)

• How the samplers work, (the 0.4 rule, isokinetic)

• Sed conc (mg/l) and discharge (tons/day)

• Under what conditions each sampler can be used (high vs low flow, Q vs sed peak)

• Sed sizes can vary in X-sec– pebbles,sand,silt,clay– In vertical and width

What we learned this week (cont)

• How to collect – Suspended-Sediment Samples– Bed Material (pebble counts with MacKenzie)

• Equal-Width-Increment (EWI) sampling• Equal-Discharge-Increment (EDI) sampling• Sampling sets A & B for QA/QC• Analyze individual or composite• Representative sample

What we learned this week (cont)

• Wading versus bridge sampling• Use of 4-wheel crane & bridgeboard with D-74 &

DH-76 --- Quart jars, green and red nozzles• Use of hand-line with DH-59 (pint jars)• Suspended load vs bedload (ewi & unequal-wi)

– (Qb (tons/day/ft) = K (grams/sec/ft to tons/day/ft) * drymass (grams) / time (sec)

• We need more collaborative discussions

What’s Next• Take this information and apply to your

situations in your work

• Determine what the problem is (define objectives)

• Determine how to collect the best data

• Estimate and reduce the errors

• Contact us with any questions

THIS MEANS THAT YOU WILL HAVE TO THINK

ABOUT WHAT YOU ARE DOING IN THE FIELD.

IF THIS IS YOUR PROBLEM

DO YOU COLLECT SAMPLES WITH THIS?

THINK ABOUT THESE SITUATIONS

• NON-MIXED STREAMS

• BRAIDED CHANNELS

• REVERSE FLOW

• URBAN vs RURAL STREAMS

• DEPTHS OVER 15’

• PARTICLE SIZE OF SEDIMENT

• BEDLOAD vs SUSPENDED LOAD

That’s it- you folks were great

The Siletz CallTutuni, Chinook and Kalapuyawe hear your callHigh from the treetopsthe eagle is tall

The Siletz rolls and rumblesthrough terrain ancient and wildYet peaceful enoughfor even a child

We thank you mighty oneFor this lookand hope we give backMore than we took