Continental hydrosystem modelling: the concept of nested stream–aquifer interfaces

Abstract

Abstract. Recent developments in hydrological modelling are based on a view of the interface being a single continuum through which water flows. These coupled hydrological-hydrogeological models, emphasising the importance of the stream–aquifer interface, are more and more used in hydrological sciences for pluri-disciplinary studies aiming at investigating environmental issues. This notion of a single continuum, which is accepted by the hydrological modellers, originates in the historical modelling of hydrosystems based on the hypothesis of a homogeneous media that led to the Darcy law. There is then a need to first bridge the gap between hydrological and eco-hydrological views of the stream–aquifer interfaces, and, secondly, to rationalise the modelling of stream–aquifer interface within a consistent framework that fully takes into account the multi-dimensionality of the stream–aquifer interfaces. We first define the concept of nested stream–aquifer interfaces as a key transitional component of continental hydrosystem. Based on a literature review, we then demonstrate the usefulness of the concept for the multi-dimensional study of the stream–aquifer interface, with a special emphasis on the stream network, which is identified as the key component for scaling hydrological processes occurring at the interface. Finally we focus on the stream–aquifer interface modelling at different scales, with up-to-date methodologies and give some guidances for the multi-dimensional modelling of the interface using the innovative methodology MIM (Measurements-Interpolation-Modelling), which is graphically developed, scaling in space the three pools of methods needed to fully understand stream–aquifer interfaces at various scales. The outcome of MIM is the localisation in space of the stream–aquifer interface types that can be studied by a given approach. The efficiency of the method is demonstrated with two approaches from the local (~1 m) to the continental (<10 M km2) scale.

Chemical weathering and CO2 consumption rate in a multilayered‐aquifer dominated watershed under intensive farming: The Orgeval Critical Zone Observatory, France

“…This input may be due to the discharge of springs directly to the river system or may be caused by diffuse contributions at the stream‐aquifer interface, called the hyporheic zone. The hyporheic zone is a particularly important locus of exchanges between the groundwaters and the river at the Orgeval CZO, as shown by hydrogeophysical surveys and drilling investigations (Flipo et al, ; Mouhri et al, ) and is suspected to have an important biogeochemical role, for example, in denitrification processes (Flipo, Even, Poulin, Théry, & Ledoux, ).…”

“…This catchment is one of the most instrumented in France and has been extensively investigated for nutrient cycling (Garnier et al, , ; Vilain, Garnier, Tallec, & Cellier, ; Vilain, Garnier, Tallec, & Tournebize, ), soil moisture (Carreau, Naveau, & Sauquet, ; Lauzon et al, ; Zribi et al, ; Zribi & Dechambre, ), and geophysical methods development and geophysical modelling (Flipo et al, ; Mouhri et al, ; Pasquet et al, ) and erosion (Le Cloarec et al, ). Agricultural inputs and land use are also monitored, making the study area an ideal setting to test the response of the CZ to intensive agricultural activity.…”

“…The Orgeval CZO has been studied over the past decades for subsurface flow characterization (Flipo et al, ; Mouhri et al, ; Pasquet et al, ), nutrient cycling (Billy et al, ; Garnier et al, ; Vilain, Garnier, Passy, Silvestre, & Billen, ), soil moisture monitoring (Lauzon, Anctil, & Petrinovic, ; Zribi, Baghdadi, Holah, Fafin, & Guérin, ), hydrology, and erosion (Le Cloarec, Bonté, Lefèvre, Mouchel, & Colbert, ). Despite this extensive body of work, stream and groundwater geochemistry have not been examined so far.…”

Approximate analysis of three-dimensional groundwater flow toward a radial collector well in a finite-extent unconfined aquifer

“…Well pumping in aquifers near streams may cause groundwater-surface water interactions (e.g., Rodriguez et al, 2013;Chen et al, 2013;Zhou et al, 2013;ExnerKittridge et al, 2014;Flipo et al, 2014;Unland et al, 2014). The stream depletion rate (SDR), commonly used to quantify stream water filtration into the adjacent aquifer, is defined as the ratio of the filtration rate to a pumping rate.…”

Impact of river water levels on the simulation of stream–aquifer exchanges over the Upper Rhine alluvial aquifer (France/Germany)

“…In general, a two-dimensional (2D) hydrogeological model is coupled to a hydrological model or a hydraulic model. Stream-aquifer exchanges can be represented either through a physically based approach considering the hyporheic zone as a continuum interface, or by using a conductance model (Kollet and Maxwell 2006;Rushton 2007;Flipo et al 2014). A conductance model computes the flux as the product between a transfer coefficient, depending on the riverbed characteristics, with the hydraulic head gradient between the river and the aquifer-for example, Sun et al (2016) used the Soil and Water Assessment Tool (SWAT) semi-distributed model to study river water and groundwater exchange in an alluvial plain by using a new module based on conductance.…”