Mechanisms and Measurement of Fluvial-Coal Transport
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Transcript of Mechanisms and Measurement of Fluvial-Coal Transport
Mechanisms and Measurement of
Fluvial-Coal TransportCoal Mining and the Aquatic Environment
Abingdon, VA, Sept. 6-7, 2007
John R. Gray ([email protected])
USGS Office of Surface Water
Reston, Virginia
COAL MINING & THE AQUATIC ENVIRONMENT
?Fluvial Coal Transport/Fate?
• “Coal…is observed in the riverbed for months…but seems to disappear for a long time”
• “How and where coal moves in river systems?”
• “How to know where coal moves?”
(Braven Beaty, 5/2007 email)
• Overview of mechanisms, fluvial-sediment transport
• Coal movement and storage in streams as a special case of fluvial-sediment transport
• Suspended-sediment and bedload measurement – equipment and techniques
• USGS-BLM Coal-Hydrology Program, 1974-1984
COAL MINING & THE AQUATIC ENVIRONMENT
Ergo, My Overview:
NICKEL PRIMER ON FLUVIAL
SEDIMENTOLOGY
• Density (mass per unit volume).– wood <1– water 1.0 (pure, 4° C)– coal 0.9-1.4 (~1.3, eastern U.S. coal – W. Orem)– quartz & feldspar ~2.65 (prevalent minerals in nature)– iron 7.9– lead 11.4– mercury 13.5– gold 19.3
PHYSICAL CHARACTERISTICS OF SEDIMENT
Categories of Sediment Transport
0.062 mm2 mm 0.002 mmSands Silts
Clays
Cmean = ~930 mg/l
BC=1.03
BC=~1
Box Coefficient (BC) = Cmean/Cpoint
BC=~1.1
BC=~1.1
Culbertson et al., 1964
Cmean = ~1,360 mg/l
BC=~1.7
Box Coefficient (BC) = Cmean/Cpoint
BC=~5BC=~4
BC=~1.5
Mean Values
Culbertson et al., 1964
Measuring Coal TransportUsing FISP Sediment Samplers
► Suspended Sediment: - Isokinetic samplers deployed by flow-weighting techniques
of the Federal Interagency Sedimentation Project- Pumping samplers- Turbidity and other surrogate techniques might work*.
► Bedload: US BLH-84 or US BL-84 bedload samplers deployed
by Equal-Width or Unequal-Width Techniques
► Bottom Material: US BM or US BMH bottom-material samplers, or if material larger than medium gravel, Cooper Scooper, pipe dredge, or another ‘bulk-sampling’ technique
Sampled & Unsampled Zoneswith an Isokinetic Sampler
FISPFISPFISPFISPTMTM
US D-74US D-74
FISPFISPFISPFISPTMTM
US D-96US D-96
US BL-84
FISPFISPFISPFISPTMTM
U.S. BMH-80
U.S. BM-54
(Singer, Cepello, Henderson, 2006, 8FISC, p 328)
The Cooper Scooper36 x 23 x 28 cm16 kg dry weight
Contact Michael Singer, [email protected]
(Singer, Cepello, Henderson, 2006, 8FISC, p 328)
The Cooper Scooper
Analyzing Coal Samples
►USGS Kentucky Science Center Sediment Laboratory Libby Shreve ([email protected]), Chief
Standard sediment-lab services, plus
- % coal in bed material, loss-on-ignition
►See next plot from Bill Orem, USGS, on % organics in bed
material of eastern coal region rivers.
Coal Mussel StudyTN/VA/WV RiversFrom Bill Orem, USGS, on % organics in bed
material of eastern coal region rivers.
Mean value excluding 14.8% outlier
Predicting Coal Transport ► For bedload, empirical equations such as Meyer-Peter Mueller, Smith-Wiberg, Yalin, Parker, etc. work.
Requires sediment density -- OK
►For suspended load, coal-settling velocity must be known. That can be derived for eastern coal -- OK
►Both cases, the size distribution of coal bed material must be known. USGS Louisville, Kentucky, Laboratory performs such analyses -- OK
“If gravel-size material, should be pretty easy to predict mobility using USGS_MD SWMS Interface – J. Nelson, USGS, Golden, CO” http://pubs.usgs.gov/fs/2005/3078/
USGS-BLM Coal-Hydrology Program, 1974-1984
►Collect information and study hydrologic processes related to development and mining of coal.
►More than 500 reports produced.
►West Virginia: “A mined basin sediment yield was 240X > unmined (Parker, PP 1464, p. 157). Statistics also for VA, TN, KY that show as mined area increases, sediment yields increase.
USGS-BLM Coal-Hydrology Program, 1974-1984
USGS-BLM Coal-Hydrology Program, 1974-1984
Parker, USGS ProfessionalPaper 1464, p. 159
COAL MINING & THE AQUATIC ENVIRONMENT
Good News!: Measuring and estimating coal transport
• Wealth of historical information from the USGS-BLM Coal-Hydrology Program that might be ‘mined’ before considering more data collection.
• Wealth of capabilities for monitoring sediment transport; specific coal-monitoring protocols needed.
• Modeling capabilities appear to be up-to-the-task.
Thanks for loaning me your ears and eyes…
The END?