Hydrogeological Model of the Forefield Drainage System of Werenskioldbreen, Svalbard

Abstract

The significant recession of Arctic glaciers caused by climate warming is expanding their proglacial zones. Thus, their importance for the hydrology of glacierised basins is growing. In contrast to the surface waters in such areas, the role of groundwater in the hydrological balance of Svalbard catchments is poorly known. This paper presents the hydrogeological conditions and groundwater flow within the permafrost active layer in the forefield of the Werenskioldbreen glacier basin (44.1 km1 2), 61% of which is glacierised. Based on field studies of groundwater in the 2017 ablation season and laboratory analyses of the hydrogeological properties of proglacial sediments, a three-dimensional groundwater flow model (FEFLOW) for part of the glacier forefield (4.8 km2) was developed. The main results show the components and characteristics of the groundwater balance and indicate the preferential groundwater flow paths. The volume of water retained in the sediments of the marginal zone is 1.0073 mln m3. The maximum potential free pore space that could be filled by water is 2.0689 mln m3. The calculated groundwater discharge for average conditions is 6076.9 m3 d-1, which is about 2% of the total seasonal catchment runoff from the main glacial river. The results of the spatial analysis for the groundwater depth and the groundwater flow directions are also presented. There need to be further detailed studies of hydrogeological processes in glacial basins in Svalbard in order to develop existing knowledge.