Subpermafrost groundwater modelling in Ny-Alesund, Svalbard

Svalbard is a high arctic archipelago where the permafrost thickness is 150-450 m and almost continuous in ice-free areas. The model work was carried out in Ny-Alesund, where the subpermafrost aquifers are recharged by water from the bottom of the Vestre Lovenbreen glacier. One main discharge spring is found at the entrance of an old coal mine. The computer code SUTRA has been used to simulate two-dimensional fluid movement and energy transport in the ground under steady state conditions. For the simulation, a cross section with unit thickness parallel to groundwater flow has been chosen. With the resulting output of SUTRA, contour maps of the pressure, hydraulic head, temperature and velocity have been made. Residence times for different situations have been determined to be 15 years as a minimum. In general there is a good agreement between the physical reality and the simulation results.