slide1
Download
Skip this Video
Download Presentation
The Confounding Effect of River Discharge on Estuarine Response to Nutrient Loading

Loading in 2 Seconds...

play fullscreen
1 / 20

The Confounding Effect of River Discharge on Estuarine Response to Nutrient Loading - PowerPoint PPT Presentation


  • 74 Views
  • Uploaded on

The Confounding Effect of River Discharge on Estuarine Response to Nutrient Loading. Craig A. Stow NOAA Great Lakes Environmental Research Laboratory Ann Arbor, MI.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' The Confounding Effect of River Discharge on Estuarine Response to Nutrient Loading' - ferdinand-dotson


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

The Confounding Effect of River Discharge on Estuarine Response to Nutrient Loading

Craig A. Stow

NOAA Great Lakes Environmental Research Laboratory

Ann Arbor, MI

Borsuk, M. E., C. A. Stow, and K. H. Reckhow. 2004. Confounding effect of flow on estuarine response to nitrogen loading. Journal of Environmental Engineering, 130: 605-614.

Additional Insights and Inputs provided by Conrad Lamon and Song Qian

slide4

Vollenweider Cross-Sectional Lake Nutrient Loading Model

  • Single Lake Relationship:
  • Positive
  • Negative
  • Nonlinear

Brazenly stolen from:

Vollenweider, R.A. 1976. Advances in defining critical loading levels for phosphorus in lake eutrophication. Mem. Ist. Ital. Idrobiol., 33:53-83.

slide5

Residence Time

Turbidity

Salinity

Temperature

River Flow

Nutrient

Concentration

Eutrophication

Nutrient Loading

Estimated

Nutrient Loading

Estimated

Concentration=

f(Flow)

slide6

River discharge highly variable – even on relatively long time-scales

Drives Nutrient Load Variability at this scale

slide7

Concentration:Flow relationships idiosyncratic: positive, negative, or non-monotonic

In the Neuse the relationship was negative

Log concentration

Log flow

  • High load = low concentrations

Data Provided by:

NC DENR DWQ – nutrient concentrations

USGS – daily flow

slide8

0

10

20

Upper

30

New

Bern

40

50

Middle

180

60

170

l

70

Bend

80

160

l

90

150

100

140

l

110

Water Quality Station

Hydrographic Station

l

130

120

l

l

l

l

N

10 miles

10 kilometers

Model Sections

River

Upper

Middle

Lower

Bend

slide9

Chlorophyll a Model

(Bayesian multilevel piecewise lognormal model)

slide10

Estuarine N Concentrations vs. Annual N Load

Ft. Barnwell

Swift Creek

New Bern

Broad Creek

Oriental

Pamlico

slide11

Estuarine P Concentrations vs. Annual P Load

Ft. Barnwell

Swift Creek

New Bern

Broad Creek

Oriental

Pamlico

slide12

Summary

Nonlinear chlorophyll, flow (~ load) relationship on short time-scales

Relationship differs systematically along spatial gradient

Maximum differs systematically along spatial gradient

No relationship between nutrient load, concentration on medium time-scales

This may differ among systems

slide13

TMDLs

Nutrient Loading

Nutrient Loading

Eutrophication

Eutrophication

Hypoxia

Hypoxia

slide14

Nutrient load targets appropriate on longer (multi-year) time scales

  • Short-term (yearly or less) misleading
  • Assuming stationary flow (long-term)
slide16

April 2006 - U.S. Court of Appeals District of Columbia Circuit ruled that EPA-approved plan to limit pollution into Anacostia River contrary to Clean Water Act requirements to set "total maximum daily loads" of pollutants.

January 2007 -- United States Supreme Court let stand lower court ruling requiring limits on pollution allowed in Anacostia River each day. 

slide17

River Flow

Nutrient

Concentration

Eutrophication

Nutrient Loading

?

Hypoxia

Upper Trophic Level

Effects

slide19

River Flow

Hypoxia

Nutrient Loading

Estimated

Nutrient Loading

ad