Results 81 to 90 of about 817 (127)

Identification of aquifer and well parameters from step-drawdown tests

Hydrogeology Journal, 2010
A new analysis technique has been proposed for interpreting transient step-drawdown test data. The proposed method is based on taking the derivative of the drawdown with respect to time for the entire pumping test period to eliminate the time-independent well-loss terms.
Cem B. Avci, Emin Ciftci, A. Ufuk Sahin
openaire   +1 more source

Type‐Curve Solution of Step‐Drawdown Test

Groundwater, 1971
Abstract A set of type‐curves is presented which simplifies and quickens the solution of the Rorabaugh equation for drawdown in a pumping well by eliminating the trial‐and‐error computations. Type‐curve analysis of test data in the field, before pumping is discontinued, provides an indication of the accuracy and adequacy of test data ...
openaire   +1 more source

An approach to interpretation of step drawdown tests

Hydrogeology Journal, 2006
To understand the behaviour of drawdown with discharge under site-specific conditions, a step drawdown test (SDT) was conducted on a tubewell in alluvium near Delhi, India, and the data were analyzed to find the value of well efficiency. The entrance velocity of groundwater into the well screen was computed to see if it exceeded the safety limit of 0 ...
openaire   +1 more source

Numerical analysis of step-drawdown tests: Parameter identification and uncertainty

Journal of Hydrology, 2010
An inverse, numerical model is presented as an interpretation method for step-drawdown tests. The model consists of an axi-symmetric model to simulate radial flow in a horizontally stratified aquifer, and a nonlinear regression analysis to identify hydraulic parameters and quantify parameter uncertainty.
A. Louwyck, A. Vandenbohede, L. Lebbe
openaire   +1 more source

Analysis and Application of Step-Drawdown Test

Journal of the Hydraulics Division, 1966
A review of the theory behind the step-drawdown test shows that the analytical method developed by Rorabaugh should be routinely used to discriminate among various types of flow and to determine more accurately flow parameters. The usual analysis for one selected time after the beginning of each step should be supplemented by a consideration of test ...
openaire   +1 more source

The analysis and planning of step drawdown tests

Quarterly Journal of Engineering Geology, 1977
Summary A step drawdown test is a pumping test in which the drawdown in a well is observed while the discharge rate from the well is increased in steps. The methods of analysis and the criteria for planning step drawdown tests are discussed and evaluated in order to produce an optimum test programme and a comprehensive test analysis.
openaire   +1 more source

New Insight Into The Step-Drawdown Test In Fractured-Rock Aquifers

Hydrogeology Journal, 1994
Review of the historical development of the step-drawdown pumping test and interpretations of well test data using the step-drawdown method indicates considerable differences in the importance attributed to head losses in the artificial environment (e.g., the gravel pack and screen) in the immediate vicinity of the wellbore and the losses resulting ...
Lee C. Atkinson, John E. Gale, Collin R. Dudgeon   +2 more
openaire   +1 more source

A General Solution to the Step‐Drawdown Test

Groundwater, 1994
Abstract A more general solution to the step‐drawdown test, called the General Well Function, GWF, is proposed to replace the classic Jacob's step‐drawdown equation for situations when the time that wells are continuously pumped varies greatly. Jacob's equation requires a preselected discharge duration and does not incorporate time as
openaire   +1 more source

EDNHAZ: a program for analyzing step drawdown tests

Computers & Geosciences, 1989
Abstract This paper presents a FORTRAN program for analyzing step drawdown tests which has some advantages over traditional graphically based methods. A more flexible approach to the planning and execution of stepped pumping tests is possible by using the method of analysis adopted in the program and outlined in the text.
openaire   +1 more source

Well Loss Estimation: Variable Pumping Replacing Step Drawdown Test

Journal of Hydraulic Engineering, 2002
An optimization method is presented for simultaneous estimation of aquifer parameters and well loss parameters utilizing all the drawdowns observed during a variable rate pumping or multiple step pumping test. The proposed method does not require any graphical analysis.
openaire   +1 more source