Understanding Surface Water--Groundwater Connectivity and Discharge in Arctic Deltas

• Main Author: Aman, Lindsey N
• Format: Text
• Language: unknown
• Published: The Research Repository @ WVU 2022
• Subjects: Arctic; Talik; Surface Water > Groundwater Connectivity; Groundwater Discharge; Geology; Hydrology; Thermokarst
• Online Access: https://researchrepository.wvu.edu/etd/11415; https://researchrepository.wvu.edu/cgi/viewcontent.cgi?article=12287&context=etd

Increased warming is driving unprecedented hydrologic changes within arctic deltas with implications for water storage, solute processing, and terrestrial and marine ecology. Thermokarst lakes within Arctic deltas store flood waters and filter solutes and sediments, thus moderating the impact of flood water discharge to arctic seas. However, this moderating influence is diminishing as lakes shrink on annual and seasonal time scales, especially close to active channels where lakes are shrinking most rapidly. This study investigates surface water-groundwater connectivity in arctic delta plains with coupled flow and heat transport models to provide a mechanistic understanding of how lake-channel proximity will impact aquifer connectivity and associated groundwater discharge to downgradient channels. Results show near-channel lakes have increased lake-to-channel advective heat transport and perennial connectivity and discharge to downgradient channel. However, connectivity and discharge from far-channel lakes is seasonal, where near-zero discharge occurs when lake and channel taliks are isolated. Near-channel lakes are perennially draining through taliks contributing to observed increases in Arctic channel baseflow. Lake drainage highlights the importance that lakes – especially near-channel lakes most vulnerable to loss – will have changing roles in moderating flood waters and nutrient processing before discharging to the arctic seas.