Using Ensemble Data Assimilation to Estimate Transient Hydrologic Exchange Flow Under Highly Dynamic Flow Conditions

Abstract

Hydrologic exchange flows (HEFs), including the vertical flow through the riverbed and the lateral flow through bank sediments, have significant impacts on biogeochemical processes, such as carbon and nutrient cycling, in the river corridor systems (

A multi-scale temperature-based strategy to map hydrologic exchange flows in highly dynamic systems

“…The VTP-based flux estimates (Figure 2C, Figure 3) show rapid changes and reversals in flux consistent with findings of past studies in the Hanford Reach of the Columbia River (Arntzen et al, 2006;Fritz and Arntzen, 2007;Johnson et al, 2012;Chen et al, 2022;Johnson et al, 2022). Comparing flux estimates between studies is difficult because of permeability heterogeneity between study sites and temporal variability in hydraulic conditions; however, the range and annual pattern of our flux estimates compare favourably with previous work nearby (Fritz and Arntzen, 2007;Chen et al, 2022).…”

“…Characterizing and quantifying hydrologic exchange flows (HEFs) is important to understanding and addressing fate and transport of contaminants at the Hanford Site in eastern WA, United States. HEFs between the aquifer system and the Columbia River vary substantially in space and time due to geomorphologic and river-stage controls, respectively (e.g., Arntzen et al, 2006;Fritz and Arntzen, 2007;Slater et al, 2010;Johnson et al, 2012;Shuai et al, 2019;Chen et al, 2022;Johnson et al, 2022). HEFs comprise bidirectional water exchange through both the bank and bed, and thus include nested hyporheic and groundwater flow paths.…”

Vertical hydrologic exchange flows control methane emissions from riverbed sediments

“…The effect of VHEFs is illustrated by temperature at the intermediate depth of 53 cm (P2), which fluctuates between the river temperature and the deeper temperature at the depth of 113 cm (P1), indicating strong mixing of river water and groundwater under dynamic flow conditions. When the river stage is high (around the end of May and early June), fluid flow is downwelling-dominated and sediment temperature at P1 is closer to the river temperature 29 .…”

“…A variety of secondary redox reactions associated with reoxidation of reduced species were included in the model (19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33) in Supplementary Table 3 and Table 4). Inclusion of such reactions (e.g.…”

Drought Conditions Enhance Groundwater Table Fluctuations Caused by Hydropower Plant Management

“…Wavelet analysis is a powerful tool to investigate non‐stationary periodicities in hydrological time series. It has been applied to study time series in different (hydro)geological systems (Lu et al., 2015; Song et al., 2020; Tenorio‐Fernandez et al., 2019; Wright et al., 2015), and more recently in the context of surface water‐groundwater interaction to study hyporheic exchange flows (Chen et al., 2022). In this study, we apply the continuous wavelet transform (Torrence & Compo, 1998) and the wavelet coherence analysis (Grinsted et al., 2004) for three river discharge time series of the Adige catchment with different degrees of alteration under the same climatic and geologic conditions.…”