Title

Diagnostic hydrogeologic characteristics of a karst aquifer (Kentucky, USA)

Files

Link to Full Text

Download Full Text

Publication Date

June 2009

Abstract

Laboratory experiments and numerical modeling have shown that dissolution in carbonate aquifers results in high-permeability channel networks. However, the lack of techniques to assess the extent and significance of these channel networks presents a major problem in characterizing carbonate aquifers. This problem was addressed by identifying the differences between two simulations (with and without channels) of the intensely studied limestone aquifer at Mammoth Cave (Kentucky, USA). Long-distance tracer-test results and spring discharges were used for assessing model accuracy as well as head measurements in wells. The channel simulation provided a much better calibration than the homogeneous porous-medium simulation and revealed five important differences: (1) convergent flow to large springs, (2) equipotentials forming troughs, (3) decreases in hydraulic gradient and (4) increases in hydraulic conductivity in a downgradient direction, and (5) substantial scaling effects. These five characteristics are also common in other carbonate aquifers and provide a means of identifying whether a carbonate aquifer is more similar to porous-medium or to karst-aquifer end members.

Notes

Hydrogeology Journal, Vol. 17 (2009-06-09).

Keywords

Carbonate Rocks, Conceptual Models, Karst, Numerical Models, Usa

Description

RDA

Subject: topical

Carbonate Rocks; Conceptual Models; Karst; Numerical Models; Usa

Type

Article

Genre

serial

Identifier

SFS0055828_00001

Share

COinS