Transcript SE GSA Presentation_Vesely (6)x

Urbanization Impact on the Nature of
Dissolved Organic Carbon
William C. Vesely, Timothy J. Callahan, and Vijay M. Vulava
Overview
Introduction
• Objective: estimate the role
of urbanization on dissolved
organic carbon (DOC) in tidal
creeks
• Hypothesis: urbanized DOC is
different than a less
developed similar system
– DOC: concentration vs. form
Methods
Sampling Areas
What is Dissolved Organic Carbon?
Group of over a million molecules
including simple amino acids to
complex humic acids
Organic carbon that can pass through a
0.20 to 0.70 micron filter
(Wikipedia)
Can serve as an indicator of land-based
runoff
(Wikipedia)
Why should we be concerned?
Carbon Cycle
http://earthobser
vatory.nasa.gov/
Features/
Mobility of Pollutants
http://sofia.usgs.gov/sfrs
f/rooms/acme_sics/acme
/how.html
Water Cycle
http://water.epa.gov/
polwaste/nps/urban_f
acts.cfm
Natural Sources
Detritus
Soil Organic Matter
Urban Sources
SUVA254: Hydrocarbons from Human Activities
aromaticity
Pesticides
of DOC
Kerogen
Pet Waste
Plankton and Algae
Waste Water Treatment Effluent
http://www.tinyterrafe
rma.com/leaf-litter/
Field Methods
Samples collected with ashed
1L amber bottles
Environmental parameters
were measured using a YSI 556
MPS
Precipitation data collected
from NOAA database
Water Sample Preparation & Analysis
Filtered using a 0.70 µm filtration
system and then acidified
Carbon analysis on a Total Organic
Carbon Analyzer
Analyzed for aromaticity properties
using the SUVA254 method
Aromatic: humic load of organic C
Sampling Areas
Samples taken
from May 2015 to
March 2016
Developed sites
taken during
falling tide
#
Site ID
Site Name
1
BBC
Big Bay Creek
2
BC
Bull Creek
3
FC
Filbin Creek
4
FC_HP FC_ Hendricks Park
5
HBC
Horlbeck Creek
6
NC
Noisette Creek
7
WC
Wimbee Creek
Analyzing Urbanization Impact
DOC quality (SUVA254 values)
GIS: geospatial analysis (land
use: percent developed vs. DOC
and percent wetlands vs. DOC)
Impact of precipitation on DOC
mobilization
Big Bay Creek Watershed
DOC Levels Results
2500
#
Site ID
Site Name
1
BBC
Big Bay Creek
2
BC
Bull Creek
3
FC
Filbin Creek
4
DOC (µM)
2000
Undeveloped
FC_HP FC_ Hendricks Park
5
HBC
Horlbeck Creek
6
NC
Noisette Creek
7
WC
Wimbee Creek
Developed
1500
DOC  land cover,
not land use
1000
500
0
WC
BBC
HBC
BC
FC
FC_HP
NC
SUVA254 Results
4.5
4.0
SUVA (L*mgC-1*m-1)
3.5
3.0
Developed
2.5
2.0
1.5
1.0
0.5
0.0
BBC
HBC
Site ID
Site Name
1
BBC
Big Bay Creek
2
BC
Bull Creek
3
FC
Filbin Creek
4
Undeveloped
WC
#
BC
FC
FC_HP
NC
FC_HP FC_ Hendricks Park
5
HBC
Horlbeck Creek
6
NC
Noisette Creek
7
WC
Wimbee Creek
Urbanization Impact
100
Developed
Less land cover causing
reduced aromatic
properties
Percent Developed
80
60
40
R2=0.49
Should see urbanization
impact on functional
groups
20
Undeveloped
0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
SUVA (L*mgC-1*m-1)
3.5
4.0
4.5
Wetland Impact
70
60
Terrestrial input from wetland
likely causing high SUVA values
Undeveloped
Percent Wetland
50
R2=0.65
40
Need to determine controlling
factors on DOC levels
30
20
Developed
10
0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
SUVA (L*mgC-1*m-1)
3.5
4.0
4.5
Five Days Prior Rainfall for Surface Water
Filbin and Noisette Creek
50
50
40
40
Developed
30
20
R2=0.32
10
0
0.0
Precipitation (mm)
Precipitation (mm)
All Sites
1.0
1.5
2.0
2.5
Developed
20
R2=0.51
10
Undeveloped
0.5
30
3.0
3.5
4.0
4.5
0
0
500
SUVA (L*mgC-1*m-1)
1000
1500
DOC (µM)
Winter months
Developed sites
Precipitation diluting SUVA (?)
• Impervious cover a major factor
Summary
Terrestrial sources of carbon causing high levels of DOC at
Wimbee and Bull Creek
Hypothesis was inconclusive due to insufficient data
Wetlands showing to be a major source of
aromatic DOC  plant based
Future Work
Digitize watersheds: impact
of development, impervious
surfaces, and manipulated
streams
Watershed basin area and
slope, and watershed
hydrology
Analyze chemical
functionality of DOC using
13C-NMR
Acknowledgments
• Project supported by the College of Charleston’s URCA
by SURF grant SU 2015-032 and the CofC geology
department
• The work is indebted to assistance by Dr. Barbara
Beckingham, Cheryl Carmack of CWK, South Carolina
DNR, Katie Ellis, Austin Morrison, and Lea Richter
Questions?