seminar: snowmelt and storm events: biogeochemical and hydrological responses
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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).
540
634
Arbutus Lake
H-Flume
X580 m
Scale
0 0.5 km
Contour interval 30 m
X
X
570 m
630 m
748 m
634 m
G14S1
Peatland with groundwaterelevation well
Wetlands/Peatlands
StreamsGroundwater sampling well
S2
Instrumented hillslope with lysimeters & throughfall collectors
N
The Archer Creek catchment and instrumentation
Arbutus Watershed
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
9/16 9/18 9/20 9/22 9/24
Date
dis
cha
rge
(m
m/h
r)
0
50
100
150
200
250
300
350
calc
ium
(u
eq
/L)
discharge calcium
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
9/16 9/18 9/20 9/22 9/24
Date
dis
cha
rge
(m
m/h
r)
0
10
20
30
40
50
60
70
80
90
100
ma
gn
esi
um
(u
eq
/L)
discharge magnesium
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
9/16 9/18 9/20 9/22 9/24
Date
dis
cha
rge
(m
m/h
r)
0
5
10
15
20
25
30
35
nitr
ate
(u
eq
/L)
dischargenitrate
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
9/16 9/18 9/20 9/22 9/24
Date
dis
cha
rge
(m
m/h
r)
0
200
400
600
800
1000
1200
1400
1600
1800
DO
C (
um
ol/L
)
dischargedoc
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
9/16/99 9/18/99 9/20/99 9/22/99 9/24/99
date
dis
cha
rge
(m
m/h
r)
0
1
2
3
4
5
6
7
8
pre
cip
(m
m/h
r)
dischargeprecip
(a)
(b) (c)
(d) (e)
Precipitation, streamflow, and solute concentrations for the Floyd storm events.
soil reservoir
till reservoir
STAGE 1 STAGE 2
STAGE 3 STAGE 4
DOC
nitrate
discharge
soil reservoir
till reservoir
STAGE 1 STAGE 2
STAGE 3 STAGE 4
DOC
nitrate
discharge
DOC
nitrate
discharge
Perceptual model for NO3-
and 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.
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).
Pre
cip
itat
ion
(m
m d
ay-1
)
0
10
20
30
40
50
Time
Jan Feb Mar Apr May Jun Jul
0
10
20
30
40
50 2002
2001
Dis
char
ge
(mm
day
-1)
0
5
10
15
20
25
30
35
2001 2002
Sn
ow
Dep
th (
cm)
0
20
40
60
80
100
120
NO
3- (
mo
l L-1
)0
20
40
60
80
To
tal
Al (
mo
l L-1
)
02468
10D
OC
(m
ol C
L-1
)
0
500
1000
1500
2001
Jan Feb Mar Apr May Jun Jul
Dis
char
ge
(mm
day
-1)
0
10
20
30
NO
3- (
mo
l L-1
)0
20
40
60
80
To
tal A
l (m
ol L
-1)
02468
10
DO
C (
mo
l C L
-1)
0
500
1000
1500
2002
Jan Feb Mar Apr May Jun Jul
Dis
cha
rge
(mm
day
-1)
0
10
20
30
Terminology
• Changes in isotopic abundance are expressed as ratios of 15N/14N of sample to air or 18O/16O of sample to ocean water.
• Units: per mil (o/oo)
δδ1515NNxx = {[( = {[(1515N/N/1414N)N)xx / ( / (1515N/N/1414N)]N)]airair –1} * 1000 –1} * 1000
δδ1818OOxx = {[( = {[(1818O/O/1616O)O)xx / ( / (1818O/O/1616O)]O)]stdstd –1} * 1000 –1} * 1000
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.
-10
0
10
20
30
40
50
60
70
-10 0 10 20 30Delta 15N (o/oo)
De
lta
18O
(o/ o
o)
precipitation
Soil + groundwater
General trends of 18-O and 15-N values of nitrate
-10
10
30
50
70
90
-10 -8 -6 -4 -2 0 2 4 6
Delta 15N (o/oo)
De
lta
18O
(o/ o
o)
2001
2002
precipitation
groundwater
Results of nitrate samples taken during snowmelt at Archer Creek Catchment, Huntington Forest
Episodic Acidification
Mitchell, M.J. Episodic Acidification. In: Jay H. Lehr (ed). Encyclopedia of Water. John Wiley and Sons Publishing (In Press).
Biscuit BrookCatskill MountainsNew 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”
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