Water yield and sediment export in small, partially glaciated Alpine watersheds in a warming climate

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Serval ID
serval:BIB_3D0CB5AF71E8
Type
Article: article from journal or magazin.
Collection
Publications
Title
Water yield and sediment export in small, partially glaciated Alpine watersheds in a warming climate
Journal
Water Resources Research
Author(s)
Micheletti  Natan, Lane  Stuart N.
Publication state
Published
Issued date
2016
Peer-reviewed
Oui
Volume
52
Number
6
Pages
4924-4943
Language
english
Abstract
Climate change is expected to modify the hydrological and geomorphological dynamics of mountain watersheds significantly, so impacting on downstream water yield and sediment supply. However, such watersheds are often poorly instrumented, making it difficult to link recent and rapid climate change to landscape response. Here we combine unique records of river flow and sediment export, with historical archival imagery to test the hypothesis that climate warming has substantially increased both water yield and sediment export from small Alpine watersheds (<3 km2) characterized by small (<0.5 km2 surface) glaciers. To examine ice and landform response to climate change, we apply archival digital photogrammetry to historical aerial imagery available from 1967 to present. We use the resulting data on ice loss, in combination with reliable records of stream flow from hydroelectric power intakes and climate data to approximate a water budget and to determine the evolution of different contributions to river flow. We use the stream flow records to estimate volumetric sediment transport capacity and compare this with the volumes of sand and gravel exported from the watersheds, quantified from records of intake flushing. The data show clearly that climate forcing since the early 1980s has been accompanied by a net increase in both water yield and sediment transport capacity, and we attribute these as signals of reduced snow accumulation and glacier recession. However, sediment export has not responded in the same way and we attribute this to limits on sediment delivery to streams because of poor rockwall-hillslope-channel connectivity. However, we do find that extreme climate conditions can be seen in sediment export data suggesting that these, rather than mean climate warming, may dominate watershed response.
Web of science
Open Access
Yes
Create date
29/08/2016 13:45
Last modification date
20/08/2019 14:33
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