Utilisation des caractéristiques de l'écoulement superficiel pour explorer la fonte du pergélisol sur des bassins versants de la Suède du Nord

TY - JOUR

T1 - Utilisation des caractéristiques de l'écoulement superficiel pour explorer la fonte du pergélisol sur des bassins versants de la Suède du Nord

AU - Sjöberg, Ylva

AU - Frampton, Andrew

AU - Lyon, Steve W.

PY - 2013/2

Y1 - 2013/2

N2 - The recent and rapid warming of the Arctic leads to thawing of permafrost, which influences and changes subsurface water-flow systems in such landscapes. This study explores the utility of catchments as "sentinels of change" by considering long-term discharge data from 17 stations on unregulated rivers in northern Sweden and analyzing trends in annual minimum discharge and recession flow characteristics. For the catchments considered, the annual minimum discharge has increased significantly (based on the Mann Kendall test at a 95 % confidence level) in nine of the catchments and decreased significantly in one catchment. Considering changes in recession-flow characteristics, seven catchments showed significant trends consistent with permafrost thawing while two catchments showed significant trends in the opposite direction. These results are mechanistically consistent with generic physically based modeling studies and the geological setting, as the catchments considered span the spatial limit of permafrost extent. This study illuminates the potential for using hydrologic observations to monitor changes in catchment-scale permafrost. Further, this opens the door for research to isolate the mechanisms behind the different trends observed and to gauge their ability to reflect actual permafrost conditions at the catchment scale.

AB - The recent and rapid warming of the Arctic leads to thawing of permafrost, which influences and changes subsurface water-flow systems in such landscapes. This study explores the utility of catchments as "sentinels of change" by considering long-term discharge data from 17 stations on unregulated rivers in northern Sweden and analyzing trends in annual minimum discharge and recession flow characteristics. For the catchments considered, the annual minimum discharge has increased significantly (based on the Mann Kendall test at a 95 % confidence level) in nine of the catchments and decreased significantly in one catchment. Considering changes in recession-flow characteristics, seven catchments showed significant trends consistent with permafrost thawing while two catchments showed significant trends in the opposite direction. These results are mechanistically consistent with generic physically based modeling studies and the geological setting, as the catchments considered span the spatial limit of permafrost extent. This study illuminates the potential for using hydrologic observations to monitor changes in catchment-scale permafrost. Further, this opens the door for research to isolate the mechanisms behind the different trends observed and to gauge their ability to reflect actual permafrost conditions at the catchment scale.

KW - Climate change

KW - Groundwater-permafrost interactions

KW - Groundwater/surface-water relations

KW - Streamflow trends

KW - Sweden

U2 - 10.1007/s10040-012-0932-5

DO - 10.1007/s10040-012-0932-5

M3 - Tidsskriftartikel

AN - SCOPUS:84873520310

SN - 1431-2174

VL - 21

SP - 121

EP - 131

JO - Hydrogeology Journal

JF - Hydrogeology Journal

IS - 1

ER -