DRAWDOWN AT TIME‐DEPENDENT FLOWRATE¹

Abstract

The exact solution for the drawdown in and around a well in a homogeneous, isotropic, and confined aquifer is presented if the well discharge is a function of time. The effect of the storage capacity of the well is also taken into consideration. Two types of flowrate functions are studied, namely linear and exponential functions, and the results are plotted in graphs.(KEY TERMS: groundwater; unsteady flow; wells; well hydraulics)

On Simulation and Analysis of Variable‐Rate Pumping Tests

“…Abu‐Zeid and Scott (1963), Abu‐Zeid et al (1964) and Hantush (1964) proposed analytical solutions for variable‐rate pumping tests assuming exponentially decreasing pumping rates. Lai et al (1973) and Lai and Su (1974) extended the solution of Papadopulos and Cooper (1967) to include leakage from the semi‐confining layers when the pumping rates are exponentially and linearly varying. Black and Kipp (1981) provided a solution to an aquifer borehole test for sinusoidal perturbation in a confined non‐leaky aquifer.…”

Type curve and numerical solutions for estimation of Transmissivity and Storage coefficient with variable discharge condition

“…Sternberg (1968) considered of the recovery data at an observation well, and presented an approximate solution for the decreasing discharge conditions. Lai et al (1973) presented the exact solution for the drawdown in and around a well with variable discharge, namely linear and exponential, respectively. And in his paper, the effect of the storage capacity of the well is also taken into consideration.…”

Evaluation of Analytical Methods to Study Aquifer Properties with Pumping Tests in Coastal Aquifers with Numerical Modelling (Motril-Salobreña Aquifer)

“…However, Sternberg (1967) presents an approximate solution for decreasing discharge. Lai et al (1973) consider a variable discharge that is both linear and exponential. Sen and Altunkaynak (2004) compare the T and S values obtained considering steady and variable discharge, respectively.…”