sediment source tracking in midwest
DESCRIPTION
69th SWCS International Annual Conference "Making Waves in Conservation: Our Life on Land and Its Impact on Water" July 27-30, 2014 Lombard, ILTRANSCRIPT
Sediment source tracking in mid-west agricultural basin 30 years after implementation of
conservation resource management
Tanja Williamson
Vicki Christensen
Bill Richardson
Jeff Frey
Allen Gellis
Kristen Kieta
Faith Fitzpatrick
July 23, 2014 SWCS U.S. Department of the Interior U.S. Geological Survey
WHY West Fork Beaver Creek?
Mea
n c
on
cen
trat
ion
(m
g L
-1)
Percen
tage of R
etired Lan
d
Low
High
Christensen V.G. and others. 2009. Water-quality and biological characteristics and responses to agricultural land retirement in three streams of the Minnesota River Basin, water years 2006-08, U.S. Geological Survey Scientific Investigations Report 2009-5215. pp. 52. http://pubs.usgs.gov/sir/2009/5215/
Hypotheses
1) Fine-grained sediment (<0.063 mm) source would be discernible based on a combination of stable isotopes and elemental concentrations
- including land retired from agricultural production 1-10 years before study began
2) Source contribution would vary in association with land retirement
Study Design
Sediment Sources Active Cropland (38) Retired Cropland (17) Streambanks (15) Roads (5)
Study Design
control
control
bu
ffer
ed
mixed
wetland NW SE
WFB
Fluvial Target Samples Suspended Sediment (SS) Channel Bed Sediment (B)
integrators
Do the fluvial targets differ?
NW SE WFB
Organic Carbon (mg g-1)
Median grain size (D50; mm) p = 0.00059
60
30
0.006
0.003
SS – Suspended sediment B – Channel bed sediment
Stable
Isotopes
Carbon
Forms
Macro-
elements Micro-elements
‰ mg g-1 mg g-1 mg kg-1
d13C CO3 C As In Sb
d15N Organic-C N Ba La Sc
C:N Al Be Li Sn
Ca Bi Mn Sr
Fe Cd Mo Th
K Ce Nb Tl
Mg Co Ni U
46 Na Cr P V
S Cu Pb W
Ti Ga Rb Y
Zn
Geochemical Fingerprint
Linear Discriminant Analysis
Gellis A.C., Noe G.B., Clune J.B., Myers M.K., Hupp C.R., Schenk E., Schwarz G. 2013. Sources of Fine-Grained Sediment in Linganore Creek watershed, Maryland: 2008 to 2010, Scientific Investigations Report 2013-xxxx, U.S. Geological Survey.
Element Discriminant Tracer For Adjusted For
NW SE WFB D50 OC
Indium Y Y Y St, Cr, Rd Cr, Rd
Phosphorus Y Y Y St, Cr St, Cr, Ret
Total Carbon Y Y Y St, Cr
Beryllium Y St, Cr Cr
Thallium Y St, Cr, Ret Cr
Thorium Y Y St, Rd Cr, Ret
Titanium Y St St, Cr, Ret
NW SE
WFB St – streambank Cr – cropland Rd – road Ret – retired land
Separation of Sediment Sources
Suspended sediment Channel bed sediment
Proportion of sediment attributed to each source
Where more retired buffer:
• Lower % CROPLAND sediment
• Lower % STREAMBANK sediment
RETIRED LAND
• Present in channel bed
• NOT in suspended sediment during high flow
SS – suspended B – channel bed
CONTROL
BUFFERED
MIXED
INTEGRATOR
Road + Cropland + Retired Land + Streambank = 100%
SS – Suspended sediment B – Channel bed sediment c – control b – buffered m – mixed i – integrator
* - significant difference SS vs. B
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Questions? https://dl.sciencesocieties.org/publications/jeq/
abstracts/0/0/jeq2013.12.0521