The use of simulation and multiple environmental tracers to quantify groundwater flow in a shallow aquifer
Article first published online: 9 JUL 2010
This paper is not subject to U.S. copyright. Published in 1994 by the American Geophysical Union.
Water Resources Research
Volume 30, Issue 2, pages 421–433, February 1994
How to Cite
1994), The use of simulation and multiple environmental tracers to quantify groundwater flow in a shallow aquifer, Water Resour. Res., 30(2), 421–433, doi:10.1029/93WR02655., , , and (
- Issue published online: 9 JUL 2010
- Article first published online: 9 JUL 2010
- Manuscript Accepted: 17 SEP 1993
- Manuscript Received: 13 JAN 1993
Measurements of the concentrations of chlorofluorocarbons (CFCs), tritium, and other environmental tracers can be used to calculate recharge ages of shallow groundwater and estimate rates of groundwater movement. Numerical simulation also provides quantitative estimates of flow rates, flow paths, and mixing properties of the groundwater system. The environmental tracer techniques and the hydraulic analyses each contribute to the understanding and quantification of the flow of shallow groundwater. However, when combined, the two methods provide feedback that improves the quantification of the flow system and provides insight into the processes that are the most uncertain. A case study near Locust Grove, Maryland, is used to investigate the utility of combining groundwater age dating, based on CFCs and tritium, and hydraulic analyses using numerical simulation techniques. The results of the feedback between an advective transport model and the estimates of groundwater ages determined by the CFCs improve a quantitative description of the system by refining the system conceptualization and estimating system parameters. The plausible system developed with this feedback between the advective flow model and the CFC ages is further tested using a solute transport simulation to reproduce the observed tritium distribution in the groundwater. The solute transport simulation corroborates the plausible system developed and also indicates that, for the system under investigation with the data obtained from 0.9-m-long (3-foot-long) well screens, the hydrodynamic dispersion is negligible. Together the two methods enable a coherent explanation of the flow paths and rates of movement while indicating weaknesses in the understanding of the system that will require future data collection and conceptual refinement of the groundwater system.