Transcript Document 7553792

Seminar:
Snowmelt and Storm Events:
Biogeochemical and
Hydrological Responses
Why study: Snowmelt and Storm
Events
• Provide information on physical and
chemical attributes of catchments
• Important contributor to discharge and
biogeochemical fluxes
• Events can have a major influence on
physical, chemical and biological attributes
of surface waters.
Storm Event Example
Inamdar, S., P., S. F. Christopher, and M. J.
Mitchell. 2003. Export mechanisms for dissolved
organic carbon and nitrate during summer storm
events in a glaciated forested catchment in New
York, USA. Hydrological Processes (In Press).
748 m
X
S
1
G14
630 m
S
2
570 m
N
634 m
X 634
580 m X
Scale
0
H-Flume
540
0.5 km
Contour interval 30 m
Wetlands/Peatlands
Streams
Arbutus
Lake
Peatland with
groundwater
elevation well
Instrumented hillslope
with lysimeters &
throughfall collectors
Groundwater
sampling well
The Archer Creek catchment and instrumentation
Arbutus Watershed
(a)
0.5
8
discharge
precip
0.45
discharge (mm/hr)
0.4
6
0.35
0.3
5
0.25
4
0.2
3
0.15
2
0.1
1
0.05
0
9/16/99
9/18/99
(c)
0.45
0.4
80
0.4
0.35
70
0.3
60
0.25
50
magnesium
250
200
0.25
0.2
150
0.15
100
40
30
0.1
20
0.1
0.05
10
0.05
9/22
0
9/24
9/18
9/20
Date
9/22
0
9/24
(e)
0.4
30
0.4
0.3
20
0.25
15
0.2
0.15
10
0.1
5
0.05
9/18
9/20
Date
9/22
0
9/24
nitrate (ueq/L)
25
0.35
1800
discharge
doc
0.45
discharge (mm/hr)
discharge
nitrate
0.5
1600
1400
0.35
1200
0.3
1000
0.25
800
0.2
600
0.15
0.1
400
0.05
200
0
9/16
9/18
9/20
Date
9/22
0
9/24
DOC (umol/L)
35
0.45
discharge (mm/hr)
50
0
9/16
(d)
0.5
0
9/16
300
0.3
0.2
9/20
Date
calcium
0.35
0.15
9/18
350
discharge
calcium (ueq/L)
90
discharge
discharge (mm/hr)
0.5
0
9/16
0
9/24/99
9/22/99
100
magnesium (ueq/L)
discharge (mm/hr)
9/20/99
date
0.5
0.45
7
precip (mm/hr)
Precipitation,
streamflow, and
solute
concentrations for
the Floyd storm
events.
(b)
STAGE 1
Perceptual model for NO3and DOC evolution
considering water and
solute contributions from
deep and near-surface flow
paths and spatial
connectedness of saturated
areas. Note: Arrow on the
hydrograph (inset)
indicates position of the
stage during the event.
STAGE 2
discharge
DOC
nitrate
soil reservoir
till reservoir
STAGE 3
STAGE 4
Snowmelt Example
Piatek, K.B., M.J. Mitchell, S.R. Silva and
C. Kendall. 2003. Sources of nitrate in
Adirondack surface water during dissimilar
snowmelt events. (In review).
Snow Depth (cm) Discharge (mm day-1)
35
30
2001
2002
25
20
15
10
5
0
120
100
80
60
40
20
0
50
2001
-1
Precipitation (mm day )
40
30
20
10
0
50
2002
40
30
20
10
0
Jan
Feb
Mar
Apr
Time
May
Jun
Jul
Discharge (mm day-1)
-1
DOC (mol C L )
-1
Total Al (mol L )
-1
NO3 (mol L )
80
60
40
20
0
10
8
6
4
2
0
1500
1000
500
0
30
20
10
0
Jan
Feb
Mar
Apr
2001
May
Jun
Jul
Discharge (mm day-1)
-1
DOC (mol C L )
-1
Total Al (mol L )
-1
NO3 (mol L )
80
60
40
20
0
10
8
6
4
2
0
1500
1000
500
0
30
20
10
0
Jan
Feb
Mar
Apr
2002
May
Jun
Jul
Terminology
• Changes in isotopic abundance are expressed as
ratios of 15N/14N of sample to air or 18O/16O of
sample to ocean water.
δ15Nx = {[(15N/14N)x / (15N/14N)]air –1} * 1000
δ18Ox = {[(18O/16O)x / (18O/16O)]std –1} * 1000
• Units: per mil (o/oo)
Separation of nitrate sources using stable
isotopes of nitrogen and oxygen
• Nitrate has different stable isotopic values.
• Atmospheric N-nitrate has 18-O values than
N-nitrate derived from soil and ground
waters.
70
60
precipitation
O (o /oo )
40
18
30
Delta
50
20
Soil + groundwater
10
0
-10
-10
0
10
Delta N (o /oo )
15
20
30
General trends of 18-O and 15-N values of nitrate
Results of nitrate samples taken during snowmelt a
90
Archer Creek Catchment, Huntington Forest
Delta 18O (o/oo)
70
2001
50
2002
precipitation
groundwater
30
10
-10
-10
-8
-6
-4
-2
Delta 15N (o/oo)
0
2
4
6
Episodic Acidification
Mitchell, M.J. Episodic Acidification.
In: Jay H. Lehr (ed). Encyclopedia of
Water. John Wiley and Sons Publishing
(In Press).
Biscuit
Brook
Catskill
Mountains
New York
Goals of Seminar
• Increase understanding of biogeochemical and
hydrological responses of snowmelt and storm
events
• Exploration of literature on hydrology and
biogeochemistry
• Develop skills for oral presentations and
discussions
• Prepare for workshop to be held on Feb. 27, 2003
on “Snowmelt and Storm Events: Biogeochemical
and Hydrological Responses”