Hydrogeology of Reclaimed Floodplain in A Permafrost Area, Yakutsk, Russia

Abstract

A study was performed to evaluate the current permafrost and groundwater conditions in the reclaimed floodplain of the Lena, one of the largest rivers in the permafrost zone. Data from ongoing hydrogeological monitoring were compared with earlier observations conducted during the reclamation process. The results demonstrate that the placement of dredged fill led to the development of suprapermafrost thaw zones (taliks). The anthropogenic taliks vary in thickness from 10 to 15 m in areas of buried bars to 20 m or more in the former locations of oxbow lakes. There is similarity in seasonal groundwater fluctuation patterns and response to river stage variations across the study area suggesting that a continuous aquifer connected to surface water. The connection with the river is most evident during the spring flood period. Two mechanisms of ground saturation are identified during this time. One is lateral seepage flow from the Lena River into the fill mass. The zone of its influence is limited to 150–170 m from the stream. The second is hydraulic pressure transmission from the river through the subchannel flow connected with the anthropogenic suprapermafrost aquifer. Its influence extends across the entire fill area. Continuous water movement at the base of the fill prevents permafrost aggradation from below. The study results should be taken into account when developing and implementing design and construction standards for engineering structures in the reclaimed floodplains of the permafrost zone.

Permafrost and groundwater interaction: current state and future perspective

“…Groundwater recharge capacities vary spatially, and the importance and significant role of water exchange between surface and groundwater resources via local connections such as taliks was already observed in the 1990s (Scheidegger, 2013). Studies along the reclaimed floodplain in the continuous permafrost area of Yakutia Yakutsk (Russia), showed that the open taliks were an active exchange channel for the Lena River and suprapermafrost groundwater (Pavlova et al, 2020). The exchange mechanism relies on lateral seepage from the Lena River into suprapermafrost groundwater and the magnitude of recharge probably depends on the volume of water in the river (Pavlova et al, 2020).…”

“…Studies along the reclaimed floodplain in the continuous permafrost area of Yakutia Yakutsk (Russia), showed that the open taliks were an active exchange channel for the Lena River and suprapermafrost groundwater (Pavlova et al, 2020). The exchange mechanism relies on lateral seepage from the Lena River into suprapermafrost groundwater and the magnitude of recharge probably depends on the volume of water in the river (Pavlova et al, 2020). Malov.…”

Review: Urban groundwater issues and resource management, and their roles in the resilience of cities

“…Notwithstanding the general low recharge capacity and the difficulties in reaching productive aquifers, the presence of taliks (areas of unfrozen ground surrounded by permafrost) allows considerable recharge and connection between unfrozen aquifers (Pavlova et al 2020). In such conditions, there is thus the possibility to reach groundwater for local community supply, even if dealing with technical difficulties sometimes, especially during the past, as reported (e.g.)…”

Fluorine in surface and suprapermafrost waters in Central Yakutia

“…Химический состав подземных вод аллювиального водоносного горизонта схо-ден с составом воды р. Лена. Минерализация подрусловых вод зимой 0,6-0,8, а летом она уменьшается до 0,4-0,5 г/л [45]. Их химический состав гидрокарбонатный или хлоридно-гидрокарбонатный смешанный по катионам.…”