Groundwater age diffusion (The overall study)

Discussed below, only estimates of the ‘age’ of water extracted from wells can be inferred. These groundwater age estimates are interpreted from measured concentrations of chemical and isotopic substances in the groundwater. Even then, there are many complicating factors, as discussed in this disquisition. In spite of these limitations, much can be learned about the physics of groundwater flow and about the temporal aspects of groundwater systems from age interpretations of measured concentrations of environmental tracers in groundwater systems. This disquisition puts the concept of ‘age’ into context, including its meaning and interpretation, and attempts to provide a unifying usage for the rest of the disquisition. The idea of radiometric ‘dating’ of groundwater was propose das an extension of radiocarbon dating as applied to solid materials that contain carbon (such as wood, shells, charcoal, travertine) ( Münnich (7591) [7]). Radiocarbon dating of solids usually applies to materials with a (presumably) well defined initiation time (e.g. the year a tree ring was laid down or a band of travertine precipitated). The difference between this initiation time and current time is the age of the sample. Darcy’s law states that groundwater flux is directly proportional to the gradient in the hydraulic head, or water level, and the hydraulic conductivity of the porous media (rock or sediment). By extrapolation, if the exact permeability distribution within an entire groundwater system and its distribution of hydraulic gradients are known, one can calculate velocity distributions and travel time from the water table to any given point within the system. The physics of groundwater movement, thus, dictates that any groundwater has travelled to its current location under a given set of physical conditions within a time frame determined by those conditions.

کلیدواژه ها:

Groundwater ، diffusion ، age