Numerical modelling of stream–aquifer interaction: Quantifying the impact of transient streambed permeability and aquifer heterogeneity

Abstract

Stream-aquifer interaction plays a vital role in the water cycle, and a proper study of this interaction is needed for understanding groundwater recharge, contaminants migration, and for managing surface water and groundwater resources. A modelbased investigation of a field experiment in a riparian zone of the Schwarzbach river, a tributary of the Rhine River in Germany, was conducted to understand stream-aquifer interaction under alternative gaining and losing streamflow conditions. An equivalent streambed permeability, estimated by inverting aquifer responses to flood waves, shows that streambed permeability increased during infiltration of stream water to aquifer and decreased during exfiltration. Aquifer permeability realizations generated by multiple-point geostatistics exhibit a high degree of heterogeneity and anisotropy. A coupled surface water groundwater flow model was developed incorporating the time-varying streambed permeability and heterogeneous aquifer permeability realizations. The model was able to reproduce varying pressure heads at two observation wells near the stream over a period of 55 days. A Monte Carlo analysis was also carried out to simulate groundwater flow, its age distribution, and the release of a hypothetical wastewater plume into the aquifer from the stream. Results of this uncertainty analysis suggest (a) stream-aquifer exchange flux during the infiltration periods was constrained by aquifer permeability; (b) during exfiltration, this flux was constrained by the reduced streambed permeability; (c) the effect of temporally variable streambed permeability and aquifer heterogeneity were found important to improve the accurate capture of the uncertainty; and (d) probabilistic infiltration paths in the aquifer reveal that such pathways and the associated prediction of the extent of the contaminant plume are highly dependent on aquifer heterogeneity.

Uncertainty Analysis and Identification of Key Parameters Controlling Bacteria Transport Within a Riverbank Filtration Scenario

“…Permeability of the colmation layer (Z6) can vary over orders of magnitude over a hydrological year due to variability of precipitation, stream discharge, sediment loads, or biogeochemical activity (Hatch et al., 2010; Schubert, 2002; Zhou et al., 2018). To include this feature in our model, we subdivide the temporal window of our simulations into five time periods.…”

Modelling the impact of lining and covering irrigation canals on underlying groundwater stores in the Nile Delta, Egypt

“…Excessive groundwater pumping reduced the lateral inflows depth of the recharge boundary and stream seepage contribution ranged from 14% to 75% along its length, a significant aspect of the regional water budget. Zhou et al (2018) developed a numerical model simulation for the banks of the Schwarzbach River (a tributary of the Rhine River, Germany) based on results of a field experiment that was conducted to understand the interaction between canals and the aquifer at various streamflow. When stream seepage to the aquifer occurred, the effective streambed permeability increased.…”

An Explicit Scheme to Represent the Bidirectional Hydrologic Exchanges Between the Vadose Zone, Phreatic Aquifer, and River

“…Richards equation on the Z coordinate, Boussinesq equation on the X coordinate, and Saint-Venant equation on the Y coordinate. however, the contribution of rivers and streams to groundwater storage (e.g., river leakage) has not been thoroughly studied even though the impact of the dynamic river on the variability of groundwater level could be significant (Basha, 2013;Govindaraju & Koelliker, 1994;Zhou et al, 2018). This gap calls for incorporating the bidirectional flow processes between the river reaches and local aquifer into groundwater modeling (i.e., gaining and losing streams), especially in the semiarid/arid regions where a little groundwater recharge occurs.…”

“…In catchment hydrology, a variety of studies have been conducted to estimate groundwater recharge with the assumption that recharge from soils is the primary source for available groundwater storage (Healy & Cook, 2002;Henry et al, 2011;Paniconi et al, 2003;Rushton & Ward, 1979;Sharda et al, 2006). In these studies, Water Resources Research however, the contribution of rivers and streams to groundwater storage (e.g., river leakage) has not been thoroughly studied even though the impact of the dynamic river on the variability of groundwater level could be significant (Basha, 2013;Govindaraju & Koelliker, 1994;Zhou et al, 2018). This gap calls for incorporating the bidirectional flow processes between the river reaches and local aquifer into groundwater modeling (i.e., gaining and losing streams), especially in the semiarid/arid regions where a little groundwater recharge occurs.…”