AUTHORS: Wade Shirley C., and Marshall Reiter
February 1994
ABSTRACT
The vertical component of specific discharge was estimated across several depth zones in the aquifer system at Canutillo, Texas. The specific discharge was estimated with temperature and thermal conductivity data from four observation wells bottoming near the base of the aquifer system.
Specific discharge was first calculated (using a steady-state model) from slopes of conductive heat flow versus temperature. The heat-flow plots for all four wells suggested a zone of downward groundwater flow from ~ 70 to ~ 220 feet depth and one or two zones of upward flow from ~ 800 to ~ 220 feet depth. Head data from the observation wells supported the conclusion of an upper zone of downflow indicated by the temperature data; however, the head data suggested that groundwater should be currently moving downward from ~220 to ~ 800 feet.
We developed a computer model to determine if the temperatures may be remanent and therefore reflect prepumping groundwater flow, particularly in the deep flow zone. Estimates were made of both minimum original and during-pumping groundwater flow and maximum original and during-pumping flow. The computer model estimates and steady-state vertical specific discharge estimates were similar for the upper zone having downward flow. In the deep zone, specific discharge estimates modeled on the computer for minimum (prepumping) upflow agreed with steady-state heat-flow specific discharge estimates. Hence current temperature data may demonstrate a significant remanent groundwater flow component.
Keywords: heat flow, temperature, groundwater, thermal conductivity, flow, aquifer
Account Number: 01345698
Hardcopy of report available from: New Mexico Water Resources Research Institute, NMSU, Box 30001, MSC 3167, Las Cruces, NM 88003 http://wrri.nmsu.edu/publish/order.html