Weathering rates and origin of inorganic carbon as influenced by river regulation in the boreal sub-arctic region of Sweden
International audience Major environmental stressors of boreal and sub-arctic rivers are hydrological changes and global warming and both factors will significantly influence the future evolution of the river chemistry in high latitudes. We tested the hypothesis whether lower concentrations of disso...
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ftinsu:oai:HAL:hal-00298820v1 2023-11-12T04:11:58+01:00 Weathering rates and origin of inorganic carbon as influenced by river regulation in the boreal sub-arctic region of Sweden Brink, J. Humborg, C. Sahlberg, J. Rahm, L. Mörth, C.-M. Dept. of Geology and Geochemistry Dept. of Environmental assessment Swedish Meteorological and Hydrological Institute (SMHI) Dept. of Water and Environmental Studies 2007-03-13 https://hal.science/hal-00298820 https://hal.science/hal-00298820/document https://hal.science/hal-00298820/file/hessd-4-555-2007.pdf en eng HAL CCSD European Geosciences Union hal-00298820 https://hal.science/hal-00298820 https://hal.science/hal-00298820/document https://hal.science/hal-00298820/file/hessd-4-555-2007.pdf info:eu-repo/semantics/OpenAccess ISSN: 1812-2108 EISSN: 1812-2116 Hydrology and Earth System Sciences Discussions https://hal.science/hal-00298820 Hydrology and Earth System Sciences Discussions, 2007, 4 (2), pp.555-588 [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2007 ftinsu 2023-10-25T16:27:44Z International audience Major environmental stressors of boreal and sub-arctic rivers are hydrological changes and global warming and both factors will significantly influence the future evolution of the river chemistry in high latitudes. We tested the hypothesis whether lower concentrations of dissolved constituents observed in regulated rivers come along with lower weathering rates, though specific discharge as a major force for physical erosion and weathering is often higher in regulated river systems. In this study the river chemistry, weathering rates and related carbon dioxide consumption in two large watersheds in the sub arctic region of Sweden, one regulated river (Lule River) and one unregulated river (Kalix River), was investigated. Weathering rates of silicates in the two watersheds are shown to be different; the silicate weathering rate in Kalix River catchment is almost 30% higher than in the Lule River catchment. This is most likely a result of constructing large reservoirs in the former river valleys inundating the alluvial deposits and thus decreasing soil/water contact resulting in lower weathering rates. Furthermore, the difference observed in weathering rates between lowland regions and headwaters suggests that weathering in sub arctic boreal climates is controlled by the residence time for soil water rock interactions followed by lithology. The chemistry in the two rivers shows weathering of silicates as the origin for 68% of the inorganic carbon in the Lule River and 74% for Kalix River. The study clearly shows that river regulation significantly decreases alkalinity export to the sea because lower weathering rates gives less carbon dioxide ending up as DIC. By considering sources for inorganic carbon we here report that the inorganic carbon load that originates from respiration of organic matter in soils makes up of 30% and 35% of the total C export for the watersheds of the Kalix River and Lule River, respectively. Therefore, both the inorganic (i.e. the origin of carbon in DIC) and ... Article in Journal/Newspaper Arctic Global warming Institut national des sciences de l'Univers: HAL-INSU Arctic Kalix ENVELOPE(23.156,23.156,65.853,65.853) |
institution |
Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Brink, J. Humborg, C. Sahlberg, J. Rahm, L. Mörth, C.-M. Weathering rates and origin of inorganic carbon as influenced by river regulation in the boreal sub-arctic region of Sweden |
topic_facet |
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience Major environmental stressors of boreal and sub-arctic rivers are hydrological changes and global warming and both factors will significantly influence the future evolution of the river chemistry in high latitudes. We tested the hypothesis whether lower concentrations of dissolved constituents observed in regulated rivers come along with lower weathering rates, though specific discharge as a major force for physical erosion and weathering is often higher in regulated river systems. In this study the river chemistry, weathering rates and related carbon dioxide consumption in two large watersheds in the sub arctic region of Sweden, one regulated river (Lule River) and one unregulated river (Kalix River), was investigated. Weathering rates of silicates in the two watersheds are shown to be different; the silicate weathering rate in Kalix River catchment is almost 30% higher than in the Lule River catchment. This is most likely a result of constructing large reservoirs in the former river valleys inundating the alluvial deposits and thus decreasing soil/water contact resulting in lower weathering rates. Furthermore, the difference observed in weathering rates between lowland regions and headwaters suggests that weathering in sub arctic boreal climates is controlled by the residence time for soil water rock interactions followed by lithology. The chemistry in the two rivers shows weathering of silicates as the origin for 68% of the inorganic carbon in the Lule River and 74% for Kalix River. The study clearly shows that river regulation significantly decreases alkalinity export to the sea because lower weathering rates gives less carbon dioxide ending up as DIC. By considering sources for inorganic carbon we here report that the inorganic carbon load that originates from respiration of organic matter in soils makes up of 30% and 35% of the total C export for the watersheds of the Kalix River and Lule River, respectively. Therefore, both the inorganic (i.e. the origin of carbon in DIC) and ... |
author2 |
Dept. of Geology and Geochemistry Dept. of Environmental assessment Swedish Meteorological and Hydrological Institute (SMHI) Dept. of Water and Environmental Studies |
format |
Article in Journal/Newspaper |
author |
Brink, J. Humborg, C. Sahlberg, J. Rahm, L. Mörth, C.-M. |
author_facet |
Brink, J. Humborg, C. Sahlberg, J. Rahm, L. Mörth, C.-M. |
author_sort |
Brink, J. |
title |
Weathering rates and origin of inorganic carbon as influenced by river regulation in the boreal sub-arctic region of Sweden |
title_short |
Weathering rates and origin of inorganic carbon as influenced by river regulation in the boreal sub-arctic region of Sweden |
title_full |
Weathering rates and origin of inorganic carbon as influenced by river regulation in the boreal sub-arctic region of Sweden |
title_fullStr |
Weathering rates and origin of inorganic carbon as influenced by river regulation in the boreal sub-arctic region of Sweden |
title_full_unstemmed |
Weathering rates and origin of inorganic carbon as influenced by river regulation in the boreal sub-arctic region of Sweden |
title_sort |
weathering rates and origin of inorganic carbon as influenced by river regulation in the boreal sub-arctic region of sweden |
publisher |
HAL CCSD |
publishDate |
2007 |
url |
https://hal.science/hal-00298820 https://hal.science/hal-00298820/document https://hal.science/hal-00298820/file/hessd-4-555-2007.pdf |
long_lat |
ENVELOPE(23.156,23.156,65.853,65.853) |
geographic |
Arctic Kalix |
geographic_facet |
Arctic Kalix |
genre |
Arctic Global warming |
genre_facet |
Arctic Global warming |
op_source |
ISSN: 1812-2108 EISSN: 1812-2116 Hydrology and Earth System Sciences Discussions https://hal.science/hal-00298820 Hydrology and Earth System Sciences Discussions, 2007, 4 (2), pp.555-588 |
op_relation |
hal-00298820 https://hal.science/hal-00298820 https://hal.science/hal-00298820/document https://hal.science/hal-00298820/file/hessd-4-555-2007.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1782330792661221376 |