Abstract

An attempt is made here to summarize the history and to highlight the major constituting concepts, properties and applications of the Tóthian Theory of Regional Groundwater Flow from its conception [1,2] to the mid 2010s.

Regional, or basinal, groundwater flow is defined here as “the gravity-driven cross-formational motion of groundwater at spatial and temporal scales that are commensurate with dimensions of the natural topographic relief and with the human and geologic time spans, respectively. The general “umbrella” theory is made up of two component sub-theories, namely: 1) "The Hydraulics of Basin-Scale Groundwater Flow" and 2) "The Geologic Agency of Basin-Scale Groundwater Flow".

The subject matter of “Sub-Theory-1” is the spatial pattern and dynamic intensity of groundwater flow in topographically defined drainage basins. This flow is organized into cross-formational flow systems driven by elevation differences in the water table through a hydraulically continuous rock framework. Owing to the flow domain’s hydraulic continuity flow systems develop ubiquitously and simultaneously throughout the entire porous portion of the Earth’s upper crust. “Sub-Theory-2”, on the other hand, deals with the processes, products and manifestations of the interaction between moving groundwater and its natural environment at and beneath the land surface.

The theory has resulted in a paradigm shift in hydrogeology. The paradigm of basinal groundwater hydraulics has changed from the classical perception of "confined, or artesian, aquifers" to the modern understanding of “regionally unconfined cross-formational flow systems". Or, in other words, form “pipe flow from outcrops to outcrops” in highly permeable strata between impermeable boundaries, to “regionally unconfined cross-formational flow systems" from recharge areas to discharge areas”. As a consequence, regional groundwater flow has been recognized as a unique and general geologic agent in the subsurface.