Contrasting hydrogeologic responses to warming in permafrost and seasonally frozen ground hillslopes. Issue 4 (27th February 2017)

• Record Type: Journal Article
• Authors: Evans, Sarah G.; Ge, Shemin
• Is Part Of: Geophysical research letters. Volume 44:Issue 4(2017)
• Page Start: 1803
• Page End: 1813
• Publication Date: 2017-02-27
• Subjects: groundwater -- permafrost -- seasonally frozen ground -- climate warming -- coupled modeling; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2016GL072009
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Seasonally frozen ground (SFG) and permafrost underlay approximately half of the land surface in the Northern Hemisphere. It is anticipated that climate warming will degrade both types of frozen ground, altering groundwater discharge to streams. While the effects of permafrost degradation on groundwater discharge have been analyzed, quantification of how groundwater discharge in degrading permafrost differs from that in SFG is lacking. This study simulates coupled groundwater and heat transport under freeze‐thaw conditions for four representative hillslopes underlain by either continuous permafrost or SFG and compares groundwater discharge outputs under projected warming scenarios over decadal scales. Model results show that without warming there is more groundwater discharge in hillslopes with SFG than permafrost. After a century of warming, groundwater discharge increases for both kinds of frozen ground, but permafrost experiences a larger increase than SFG. These findings have implications for aquatic ecosystems and prioritizing water resource planning. Key Points: A coupled groundwater and heat transport model is used to compare discharge in hillslopes with seasonally frozen ground and permafrost Without warming groundwater discharge is greater in hillslopes with seasonally frozen ground than permafrost Warming may increase groundwater discharge for both hillslopes with a larger increase for permafrost