Transient recharge as a driver of water table and baseflow dynamics: Reconciling the Hubbert-Toth conceptual models
Abstract
Half-a-century ago, J. Tóth proposed a seminal conceptualization, alternative to M.K. Hubbert's, to describe the nested nature of regional groundwater flow systems. To date, this conceptualization plays a fundamental role in our understanding of subsurface flow and transport and how we interrogate natural systems both numerically and observationally. However, discussions by various authors support the need for a paradigm shift and a path forward by changing the conceptualization of the aquifer processes and their drivers. These changes require a transient, recharge-based view of the aquifer systems and surface water-groundwater interactions. In this work, we present a new model that explicitly considers groundwater recharge, delineating the dynamics of moving water table, surface water-groundwater interactions, and baseflow; this model extends and reconciles the recharge-driven and topography-driven models by Hubbert and Toth, respectively. As a proof-of-concept, we present a cross-sectional, two-dimensional model that utilizes the transient groundwater flow equation with spatial and temporal recharge rate distribution on the moving water table boundary. The conceptual model can be extended to account for different spatio-temporal recharge patterns, three-dimensional systems, groundwater withdrawals, and explicit surface water-groundwater connections.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.H23K2071G
- Keywords:
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- 0408 Benthic processes;
- BIOGEOSCIENCESDE: 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCESDE: 1806 Chemistry of fresh water;
- HYDROLOGYDE: 1830 Groundwater/surface water interaction;
- HYDROLOGY