solute transport into shark river slough poinciana... · 13 conclusions • wrtds is a promising...
TRANSCRIPT
Solute transport into Shark River Slough
Troy D. Hill1, Kevin Kotun2
1National Park Service, Department of the Interior2United States Geological Survey, Department of the Interior
2
1. Application of WRTDS to stations at ENP northern boundary, 1992 - 2017
2. Trends in nutrients (TP, TKN) and geogenic solutes (Ca, Mg, Na)
Outline
3
> 5000 sampling locations
4
S151
S333
S12A S12BS12D
S12C
5
Why model concentrations?
Sampling events may not be representative
6
C-Q relationships are not uniform
WRTDS – WTF?• Weighted Regression on Time, Discharge, and Season (EGRET)
• Allows time and discharge relationships to vary• Estimates raw and flow-normalized concentrations
• What are the trends? How confident are we?• Do trends differ by season? By discharge magnitude?
7Hirsch et al. 2010; Hirsch et al. 2015
8
TP time series for S333
- estimated· observed
TP (m
g·L-1
)
9
· annual mean conc- flow-normalized conc (FNc)
TP a
t S33
3 (m
g·L-1
)Bootstrapped trend in FNc 1992-2017
Dens
ityComparison
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Water quality trends: 1992-2017
11
TP at different flows (S333)1987 - 1991 2015 - 2019
TP (m
g·L-1
)
12
Ca+Mg at different flows (S333)1987 - 1991 2015 - 2019
Hard
ness
as C
aCO
3(m
g·L-1
)
13
Conclusions
• WRTDS is a promising tool
• Water quality gains more dramatic for nutrient concentrations vs. fluxes
• Concentrations of geogenic solutes are also declining – less groundwater
• Nutrient reductions more dramatic at low flows
DataForEver data requests: [email protected]
S151 S333 S12A
S12B S12C S12D
TP (m
g·L-1
)