Premium
ESTIMATING AQUIFER PARAMETERS FROM A HORIZONTAL WELL PUMPING TEST IN AN UNCONFINED AQUIFER 1
Author(s) -
Edwards Kenneth B.
Publication year - 1991
Publication title -
jawra journal of the american water resources association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.957
H-Index - 105
eISSN - 1752-1688
pISSN - 1093-474X
DOI - 10.1111/j.1752-1688.1991.tb01481.x
Subject(s) - aquifer , hydraulic conductivity , phreatic , slug test , hydraulic head , yield (engineering) , geology , aquifer test , head (geology) , soil science , geotechnical engineering , aquifer properties , hydraulics , hydrology (agriculture) , flow (mathematics) , groundwater , mechanics , geomorphology , materials science , groundwater recharge , soil water , thermodynamics , physics , metallurgy
ABSTRACT: A pumping test on a phreatic glacial till aquifer was performed near Ames, Iowa, in November 1990. The head in a horizontal well was pumped down rapidly and then held constant for the duration of the 30‐hour test. Throughout the test, the flow rate at the pumped well and the head at an adjacent vertical observation well were recorded. The pumping test data were used to determine the hydraulic conductivity and specific yield of the aquifer. The results indicate a hydraulic conductivity of 2.23 × 10 −5 cm/s and a representative specific yield of 0.03. Hydraulic conductivity was calculated by a simple integration of Darcy's Law after extrapolating the data to steady state. Specific yield was determined by use of several methods from the literature and a new method proposed by the author. The results show that specific yield increases with time, and that each method is within an order of magnitude of the others.