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PANGAEA.
Data Publisher for Earth & Environmental Science

Begum, Most Shirina; Bogard, Matthew J; Butman, David; Chea, Eliyan; Kumar, S; Lu, Xixi; Nayna, Omme K; Ran, Lishan; Richey, J E; Tareq, Shafi M; Xuan, Do Thi; Yu, Ruihong; Park, Ji-Hyung (2021): Spatiotemporal variation in pCO₂, CH₄, N₂O, DOM, and ancillary water quality measured in the Ganges, Mekong, and Yellow River during 2016 to 2019. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.926582 (dataset in review)

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Abstract:
Despite growing research on greenhouse gas (GHG) emissions from inland waters, few systematic efforts have been made to assess the regional-scale GHG emissions from Asian rivers under increasing anthropogenic stress. We examined factors controlling longitudinal and seasonal variations in the partial pressure of CO₂ (pCO₂), and CH₄ and N₂O concentrations in the Ganges, Mekong, and Yellow River (Huang He) by simultaneously measuring gas concentrations and stable C isotopes, and optical properties of dissolved organic matter (DOM) from 2016 to 2019. The levels of pCO₂ and CH₄ were distinctively higher in polluted tributaries and affected reaches of the Ganges and Mekong than in the Yellow River. The highest levels of N₂O were found in the Ganges, followed by Yellow River and Mekong. Across these basins, dry-season mean concentrations of CO₂, CH₄, and N₂O were 1.6, 2, and 7 times higher than those measured in the monsoon season, respectively. This seasonality was consistent with that of δ¹³C-CO₂, while δ¹³C-CH₄ showed an opposite pattern. The overall results suggest that neglecting localized pollution impacts on GHG emissions from increasingly urbanized river basins can result in inaccurate estimates of global riverine GHG emissions.
Keyword(s):
Greenhouse gases; organic matter; water pollution; δ13C
Related to:
Begum, Most Shirina; Bogard, Matthew J; Butman, David; Chea, Eliyan; Kumar, S; Lu, Xixi; Nayna, Omme K; Ran, Lishan; Richey, J E; Tareq, Shafi M; Xuan, Do Thi; Yu, Ruihong; Park, Ji-Hyung (submitted): Localized pollution impacts on greenhouse gas dynamics in three anthropogenically modified Asian river systems. Journal of Geophysical Research: Biogeosciences
Further details:
Lauerwald, Ronny; Laruelle, Goulven G; Hartmann, Jens; Ciais, Philippe; Regnier, P A (2015): Spatial patterns in CO2 evasion from the global river network. Global Biogeochemical Cycles, 29(5), 534-554, https://doi.org/10.1002/2014GB004941
Raymond, P A; Zappa, Christopher J; Butman, David; Bott, Thomas L; Potter, Jody; Mulholland, Patrick; Laursen, Andrew E; McDowell, William H; Newbold, Denis (2012): Scaling the gas transfer velocity and hydraulic geometry in streams and small rivers. Limnology and Oceanography: Fluids and Environments, 2(1), 41-53, https://doi.org/10.1215/21573689-1597669
Coverage:
Median Latitude: 21.679672 * Median Longitude: 96.205701 * South-bound Latitude: 9.948056 * West-bound Longitude: 77.253333 * North-bound Latitude: 40.519444 * East-bound Longitude: 116.983889
Date/Time Start: 2016-08-08T00:00:00 * Date/Time End: 2019-07-03T00:00:00
Event(s):
Ganges_G1 * Latitude: 30.993889 * Longitude: 78.944167 * Date/Time: 2017-07-24T00:00:00 * Method/Device: Sampling by hand (HAND)
Ganges_G10 * Latitude: 24.461667 * Longitude: 88.620000 * Date/Time: 2019-02-05T00:00:00 * Method/Device: Sampling by hand (HAND)
Ganges_G11 * Latitude: 24.041389 * Longitude: 89.028056 * Date/Time: 2017-08-14T00:00:00 * Method/Device: Sampling by hand (HAND)
Comment:
The air-water gas flux (F) of CO₂, CH₄, and N₂O was calculated according to the equation F = k ΔC, where k is the gas transfer velocity and ΔC is the air-water gas concentration gradient (Lauerwald et al., 2015). To estimate k, we used a range of k normalized to a Schmidt number of 600 (k600) estimated for global small and large rivers by Lauerwald et al. (2015): 6.61-8.64 m/day for the tributaries and wastewater drains; 3.49-4.41 m/day for the river mainstems.
The actual gas transfer velocity kactual was estimated from k600 and the measured water temperature (Raymond et al., 2012). The fluxes of CO₂, CH₄, and N₂O (mg/m²day) were calculated from the estimated kactual and measured ΔC values.
FCO₂-min, FCH₄-min, and FN2O-min were calculated using the lower range of k values
k = 3.49 for mainstem river (i.e., upper, middle, and lower reaches)
k = 6.61 for tributary and wastewater
FCO₂-max, FCH₄-max, and FN₂O-max were calculated with upper range of k values
k = 4.41 for mainstem river (i.e., upper, middle, and lower reaches)
k = 8.64 for tributary and wastewater
The three fluorescent dissolved organic matter (FDOM) components from parallel factor (PARAFAC) analysis with 126 samples are defined as C1 (humic like), C2 (microbial humic like), and C3 (protein like).
Parameter(s):
#NameShort NameUnitPrincipal InvestigatorMethod/DeviceComment
1Event labelEventPark, Ji-Hyung
2Latitude of eventLatitudePark, Ji-Hyung
3Longitude of eventLongitudePark, Ji-Hyung
4Date/Time of eventDate/TimePark, Ji-Hyung
5RiverRiverPark, Ji-Hyung
6Sample commentSample commentPark, Ji-Hyungreach
7Sample IDSample IDPark, Ji-Hyung
8SeasonSeasonPark, Ji-Hyung
9DistanceDistancekmPark, Ji-Hyungfrom river mouth
10Carbon dioxide (water) partial pressurepCO2(aq)µatmPark, Ji-Hyung
11MethaneCH4µmol/lPark, Ji-Hyung
12Nitrous oxide, dissolvedN2Onmol/lPark, Ji-Hyung
13δ13C, carbon dioxide, dissolvedδ13C CO2‰ PDBPark, Ji-Hyung
14δ13C, methane, dissolvedδ13C CH4‰ PDBPark, Ji-Hyung
15Carbon dioxide flux, in mass carbonCO2 fluxmg/m2/dayPark, Ji-HyungAir-water gas flux, river, Lauerwald et al. (2015)min
16Carbon dioxide flux, in mass carbonCO2 fluxmg/m2/dayPark, Ji-HyungAir-water gas flux, river, Lauerwald et al. (2015)max
17Methane flux, in mass carbonCH4 fluxmg/m2/dayPark, Ji-HyungAir-water gas flux, river, Lauerwald et al. (2015)min
18Methane flux, in mass carbonCH4 fluxmg/m2/dayPark, Ji-HyungAir-water gas flux, river, Lauerwald et al. (2015)max
19Nitrous oxide flux, in mass nitrogenN2O fluxmg/m2/dayPark, Ji-HyungAir-water gas flux, river, Lauerwald et al. (2015)min
20Nitrous oxide flux, in mass nitrogenN2O fluxmg/m2/dayPark, Ji-HyungAir-water gas flux, river, Lauerwald et al. (2015)max
21Temperature, waterTemp°CPark, Ji-Hyung
22pHpHPark, Ji-Hyung
23Oxygen, dissolvedDOmg/lPark, Ji-Hyung
24Conductivity, electrolyticECµS/cmPark, Ji-Hyung
25Suspended matter, totalTSSmg/lPark, Ji-Hyung
26Nitrogen in ammoniumN-[NH4]+mg/lPark, Ji-HyungIon chromatography
27Nitrogen in nitrateN-[NO3]-mg/lPark, Ji-HyungIon chromatography
28Nitrogen, inorganic, dissolvedDINmg/lPark, Ji-Hyung
29Phosphorus in orthophosphateP-[PO4]3-µg/lPark, Ji-HyungIon chromatography
30Carbon, organic, particulatePOCmg/lPark, Ji-Hyung
31Nitrogen, organic, particulatePONmg/lPark, Ji-Hyung
32Carbon, organic, dissolvedDOCmg/lPark, Ji-Hyung
33Fluorescence indexFIPark, Ji-HyungFluorescence index, McKnight et al. (2001)
34Biological indexBIXPark, Ji-Hyungaccording to Huguet et al. (2009)
35Humification indexHIXPark, Ji-Hyungaccording to Zsolnay et al. (1999)
36Specific ultraviolet absorbance normalized to DOC, 254 nm, per mass carbonSUVA254l/mg/mPark, Ji-HyungSpecific UV absorbance 254nm, DOC normalised, Weishaar et al. (2003)
37Fluorescence, dissolved organic matterfDOM%Park, Ji-HyungParallel factor analysis (PARAFAC)component C1 (humic)
38Fluorescence, dissolved organic matterfDOM%Park, Ji-HyungParallel factor analysis (PARAFAC)component C2 (microbial humic)
39Fluorescence, dissolved organic matterfDOM%Park, Ji-HyungParallel factor analysis (PARAFAC)component C3 (protein)
Size:
3479 data points

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