Changing groundwater discharge dynamics in permafrost regions

Abstract

Permafrost thaw due to climate warming modifies hydrological processes by increasing hydrological connectivity between aquifers and surface water bodies and increasing groundwater storage. While previous studies have documented arctic river baseflow increases and changing wetland and lake distributions, the hydrogeological processes leading to these changes remain poorly understood. This study uses a coupled heat and groundwater flow numerical model with dynamic freezing and thawing processes and an improved set of boundary conditions to simulate the impacts of climate warming on permafrost distribution and groundwater discharge to surface water bodies. We show a spatial shift in groundwater discharge from upslope to downslope and a temporal shift with increasing groundwater discharge during the winter season due to the formation of a lateral supra-permafrost talik underlying the active layer. These insights into changing patterns of groundwater discharge help explain observed changes in arctic baseflow and wetland patterns and are important for northern water resources and ecosystem management.

Seasonal Subsurface Thaw Dynamics of an Aufeis Feature Inferred From Geophysical Methods

“…Results indicated a large lateral talik (~5 km 2 ) apparently connected throughout the south‐central portion of the ice field near the spring source (Figure c). The apparent connectivity of this lateral talik is likely a critical control on local subsurface hydrology (Lamontagne‐Hallé et al, ). This contrasts with other geophysical imaging studies of river taliks which are local to the river channel and do not exhibit such widespread subsurface connectivity (e.g., Arcone et al, , ).…”

Impact of heat advection on the thermal regime of roads built on permafrost

“…The larger heat exchange rate can explain the relatively faster permafrost warming rate (0.08°C year −1 ) and thawing rate (0.2 m year −1 ) at our study site. The measured increasing rates of ground temperature and active layer thickness linked with subsurface water flow are consistent with observation in Arctic gully system (Fortier et al, ) and support fast permafrost thawing rate caused by water flow, based on the hydrological modelling of conceptual hillslopes in permafrost regions (Bense, Ferguson, & Kooi, ; Chiasson‐Poirier, Franssen, Lafreniere, Fortier, & Lamoureux, ; Ge, McKenzie, Voss, & Wu, ; Kurylyk et al, ; Lamontagne‐Hallé, McKenzie, Kurylyk, & Zipper, ).…”

The impact of land surface temperatures on suprapermafrost groundwater on the central Qinghai‐Tibet Plateau

“…Under a warming climate, for suprapermafrost groundwater, the completely frozen period disappears (Figure ). Meanwhile the formations of both vertical and lateral taliks increase the hydrogeologic connectivity, (Hiyama, Asai, Kolesnikov, Gagarin, & Shepelev, ; Lamontagne‐Hallé et al, ; Walvoord & Striegl, ), through which the unfrozen suprapermafrost groundwater could discharge into the river even, result in increasing in baseflow in winter (Evans et al, ; Frampton et al, ; Ge et al, ; Lamontagne‐Hallé et al, ). However, this finding is based on the assumption that the right and left sides are both fixed hydraulic head, which means sufficient water supply.…”

“…However, most of suprapermafrost groundwater models hypothesized that the surface temperature as an isothermal boundary or the same as air temperature. Though some studies have employed simulated surface temperature as the upper boundary (Kurylyk et al, ; Lamontagne‐Hallé et al, ), slope aspects influence was still not considered. Therefore, it is necessary to conduct a more detailed study of the suprapermafrost groundwater system in the active layer to clarify its spatial and temporal variability with topography changes.…”