Groundwater recharge and capillary rise in a clayey catchment: modulation by topography and the Arctic Oscillation

International audience The signature left by capillary rise in the water balance is investigated for a 16 km 2 clayey till catchment in Denmark. Integrated modelling for 1981?99 substantiates a 30% uphill increase in average net recharge, caused by the reduction in capillary rise when the water tabl...

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Bibliographic Details
Main Authors: Schrøder, T. M., Rosbjerg, D.
Other Authors: Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Environment & Resources DTU
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2004
Subjects:
[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
Arctic
North Atlantic
North Atlantic oscillation
Online Access:https://hal.science/hal-00304984
https://hal.science/hal-00304984/document
https://hal.science/hal-00304984/file/hess-8-1090-2004.pdf
Description
Summary:International audience The signature left by capillary rise in the water balance is investigated for a 16 km 2 clayey till catchment in Denmark. Integrated modelling for 1981?99 substantiates a 30% uphill increase in average net recharge, caused by the reduction in capillary rise when the water table declines. Calibration of the groundwater module is constrained by stream flow separation and water table wells. Net recharge and a priori parameterisation has been estimated from those same data, an automatic rain gauge and electrical sounding. Evaluation of snow storage and compensation for a simplified formulation of unsaturated hydraulic conductivity contribute to a modelling of the precipitation-runoff relation that compares well with measurements in other underdrained clayey catchments. The capillary rise is assumed to be responsible for a 30% correlation between annual evapotranspiration and the North Atlantic Oscillation. The observed correlation, and the hypothesis of a hemispherical Arctic Oscillation linking atmospheric pressure with surface temperature, suggests that modelled evapotranspiration from clayey areas is better than precipitation records for identifying the region influenced by oscillation. Keywords: catchment modelling, MIKE SHE, capillary rise, degree-day model, climate

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