0.0075 [N2O yield measurement]
NO3-(+)
(0.001 - 0.002) [N2O-N : NO3-N]
(0.0004 - 0.0038)
[N2O emission : N input]
NO3-(+)
DIN(+), NH4+(+)
NH4+(+), DO(-)
This study
Yan et al., 2012
NO3-(+), DO(+)
0.01 (0.005 - 0.0148) [N2O-N : NO3-N]
Toyoda et al., 2009
NH4+(+), NO3-(+)
Outram and Hiscock, 2012
(0.009 – 0.053)
[N2O emission : N input]
NO3-(+), NH4+(+)
Stow et al., 2005
Reay et al., 2003
(0.0002 - 0.0003) [N2O-N : NO3-N]
NO3-(+)
NO3-(+), DOC(+), water temperature(+)
McMahon and Dennehy,
1999
DIN(+), water temperature(+)
Rosamond et al., 2012
McElroy et al., 1978
DO(-)
DO(-)
Laurson and Seitzinger, 2004
NO3-(+)
Hinshaw et al., 2013
Hemond and Duran, 1989
water temperature(+), DO(-)
water temperature(+), NO3(+)
Hasegawa et al., 2000
Harrison and Matson, 2003
Cole and Caraco, 2001
NO3-(+)
0.0028 (0.0012-0.0069) [N2O-N : NO3-N]
Clough et al., 2006
0.0005 [N2O-N : NO3-N]
NO3-(+)
Clough et al., 2011
Beaulieu et al., 2010b
water temperature(+)
Beaulieu et al., 2010a
Beaulieu et al., 2008
0.002 [N2O-N : NO3-N]
NO3-(+)
reference
Baulch et al., 2011
EF5-r [method]
NO3-(+), NO3-+ NO2-(+)
predictors on N2O fluxb
1
Supporting Information accompanying the paper “Nitrous oxide emissions in the Shanghai river
2
network: implications for the effects of urban sewage and IPCC methodology” by Z. Yu, H.
3
Deng, D. Wang, M. Ye, Y. Tan, Y. Li, Z. Chen and S. Xu
4
Table S1. Mean (range) of N2O saturation and N2O flux, predictors on N2O flux, and EF5-r value
5
from streams and rivers.
6
a: Streams and rivers that affected by WWTPs effluents reported in original papers are noted by
7
“*”.
8
b: “+” and “-” in brackets denote positive and negative relationship between predictor and N2O
9
flux respectively.
10
11
Reference:
12
Clough TJ, Bertram JE, Sherlock RR, Leonard RL, Nowicki BL (2006) Comparison of measured
13
and EF5‐r‐derived N2O fluxes from a spring‐fed river. Global Change Biology, 12(2), 352-
14
363.
171 (110 - 241)
(201 - 404)
114
185 (125 - 385)
LII River, New Zealand
Ashburton River, New Zealand
Hudson River, USA
7440 (240 - 56580)
159.1 (54.1 - 1591)
3475 (380 - 18364)
362 (186 - 729)
(102 - 209)
2550 (100 - 5000)
Agricultural drains, Japan
Assabet River, USA*
San Joaquin River, USA
Small agricultural rivers, USA
Potomac River, USA*
770 (103 - 21172)
Shanghai river network, China*
80 (0.5 - 2170)
(1.87 - 40.8)
12.9 (-9.21 - 64.9)
Neuse River, USA
212 (116 - 339)
(-40.83 - 4900)
Grand River, Canada*
Changjiang River, China
(900 – 8100)
Agricultural drains, rivers, and broads, UK
1051 (93 - 6756)
(100 - 1000)
Agricultural drains, UK
Tama River, Japan*
62 (0.38 - 1360)
South Platte River, USA*
(11.2 - 1680)
(26.2 - 207)
165 (50 - 2450)
Agricultural/urban canals, Mexico*
6.4 (2.33 - 22.2)
(16 - 30)
(12.2 - 623)
Ohio River, USA*
35.2 (-8.9 - 266.8)
(-3.7 - 905.3)
N2O flux
(μg N2O-N•m-2•h-1)
53.2 (-14.5 - 541.4 )
236 (45 - 1358)
N2O saturation
(%)
Headwater streams, USA
Low order streams in Kalamazoo River basin, USA
Low order streams in southern Ontario, Canada
Sitea
15
Clough TJ, Buckthought LE, Casciotti KL, Kelliher FM, Jones PK (2011) Nitrous oxide
16
dynamics in a braided river system, New Zealand. Journal of Environmental Quality, 40(5),
17
1532-1541.
18
19
20
21
Cole JJ and Caraco NF (2001) Emissions of nitrous oxide (N2O) from a tidal, freshwater river,
the Hudson River, New York. Environmental science & technology, 35(6), 991-996.
Baulch HM, Schiff SL, Maranger R, Dillon PJ (2011) Nitrogen enrichment and the emission of
nitrous oxide from streams. Global Biogeochemical Cycles, 25, GB4013.
22
Beaulieu JJ, Arango CP, Hamiltion SK, Tank JL (2008) The production and emission of nitrous
23
oxide from headwater streams in the Midwestern United States. Global Change Biology,
24
14,878-894.
25
26
27
28
29
30
Beaulieu JJ, Tank JL, Hamilton SK et al. (2010a) Nitrous oxide emission from denitrification in
stream and river networks. PNAS, 108, 214-219.
Beaulieu JJ, Shuster WD, Rebholz JA (2010b) Nitrous oxide emissions from a large, impounded
river: The Ohio River. Environmental science & technology, 44(19), 7527-7533.
Harrison J and Matson P (2003) Patterns and controls of nitrous oxide emissions from waters
draining a subtropical agricultural valley. Global Biogeochemical Cycles, 17, 1080.
31
Hasegawa K, Hanaki K, Matsuo T, Hidaka S (2000) Nitrous oxide from the agricultural water
32
system contaminated with high nitrogen. Chemosphere-Global Change Science, 2(3), 335-
33
345.
34
35
36
37
Hemond HF and Duran AP (1989) Fluxes of N2O at the sediment-water and water-atmosphere
boundaries of a nitrogen-rich river. Water Resources Research, 25(5), 839-846.
Hinshaw S and Dahlgren R (2012) Dissolved nitrous oxide concentrations and fluxes from the
eutrophic San Joaquin River, California. Environmental Science & Technology, in press.
38
Laursen AE and Seitzinger SP (2004) Diurnal patterns of denitrification, oxygen consumption
39
and nitrous oxide production in rivers measured at the whole‐reach scale. Freshwater
40
Biology, 49(11), 1448-1458.
41
42
43
44
45
McElroy MB, Elkins JW, Wofsy SC, Kolb CE, Duran, AP, Kaplan WA (1978) Production and
release of N2O from the Potomac Estuary. Limnology and Oceanography, 1168-1182.
McMahon PB and Dennehy KF (1999) N2O emissions from a nitrogen-enriched
river. Environmental science & technology, 33(1), 21-25.
Outram FN and Hiscock K (2012) Indirect nitrous oxide emissions from surface waterbodies in a
46
lowland arable catchment: a significant contribution to agricultural greenhouse gas
47
budgets?. Environmental Science & Technology.
48
49
50
51
Reay D, Smith KA, Edwards AC (2003) Nitrous oxide emission from agricultural drainage
waters. Global Change Biology., 9, 195-203.
Rosamond MS, Thuss SJ, Schiff SL (2012) Dependence of riverine nitrous oxide emissions on
dissolved oxygen levels. Nature Geosciences, 5, 715-718.
52
Stow CA, Walker JT, Cardoch L, Spence P, Geron C (2005) N2O emissions from streams in the
53
Neuse River watershed, North Carolina. Environmental science & technology, 39(18), 6999-
54
7004.
55
Toyoda S, Iwai H, Koba K, Yoshida N (2009) Isotopomeric analysis of N2O dissolved in a river
56
in the Tokyo metropolitan area. Rapid Communications in Mass Spectrometry, 23, 809-821.
57
Yan W, Yang L, Wang F, Wang J, Ma P (2012) Riverine N2O concentrations, exports to estuary
58
and emissions to atmosphere from the Changjing River in response to increasing nitrogen
59
loads. Global Biogeochemical cycles, 26(4).
60
61
Table S2. Agricultural land area and N input from leaching and runoffa
62
N input through
leaching and runoff
(Gg N•yr-1)
rural
CM
1185
80
948
9.93
SP
289
1
3
0.03
MH
371
33
122
1.28
urban
BS
271
39
106
1.11
JD
464
44
204
2.14
PD
1210
45
545
5.71
SJ
606
54
327
3.43
suburban
JS
586
66
387
4.05
QP
670
53
355
3.72
FX
687
64
440
4.61
total
36.00
8
3
a: Multi-year averaged annual discharge of CM rivers are 33.79×10 m (Shanghai Chongming
63
Hydrologic Station, 2007); annual averaged NH4+-N and NO3--N concentrations for CM rivers
64
are 1.25 mg•L-1 and 1.69 mg•L-1, respectively; total area for each district are from Shanghai
65
Statistical Yearbook 2011.
total area
(km2)
agricultural land
percentage (%)
agricultural land
area (km2)
66
67
Reference:
68
Shanghai Chongming Hydrologic Station, 2007. http://file.lw23.com/5/5b/5b1/5b1f8210-a1c2-
69
4c6a-b668-73c55e306c6b.pdf
70
Shanghai Statistical Yearbook 2011. http://www.stats-sh.gov.cn/ (May 24, 2012)
71
72
73
74
75
76
77
Table S3. Sewage discharge and N input from sewage effluentsa
total sewage
discharge
(108 m3)
total capacity of
WWTPs
(108 m3)
untreated sewage
to the rivers
(108 m3)
Sewage
effluents to
the rivers
(108 m3)
N input from
untreated
sewage
(Gg N•yr-1)
N input from
treated sewage
(Gg N•yr-1)
2009
23.05
17.16
5.89
2.19
21.14
4.37
2010
24.82
18.97
5.85
3.50
21.02
7.00
average
23.94
18.06
5.87
2.84
21.08
5.69
78
a: total sewage discharge and total capacity of WWPTs were collected from Shanghai Statistical
79
Yearbook 2011; sewage effluents to the river network is the difference between total capacity of
80
WWTPs and treated sewage being released to open sea (14.98×108 t and 15.46×108 t for 2009
81
and 2010 respectively; data from Shanghai Water Bureau).
82
83
Reference:
84
Shanghai Water Bureau. http://www.shanghaiwater.gov.cn/swEng/index.jsp (Feburary 10, 2012)
85
Shanghai Statistical Yearbook 2011. http://www.stats-sh.gov.cn/ (May 24, 2012)