Lecture 30: Theis Equation and example of superposition for solution

This lecture focuses on the Theis equation, which was developed by C. V. Theis in 1935 to analyze groundwater drawdown under nonsteady conditions. Unlike the earlier Thiem equation, which is limited to steady-state conditions and is challenging for distant observations, the Theis equation is applicable for varying pumping conditions and allows for the calculation of transmissibility and storage coefficients. Theis introduced a graphical method using a type curve to solve the equation, which involves plotting drawdown data and superimposing it on the type curve to determine hydraulic parameters. An example illustrates this method by using actual pumping test data to determine the transmissibility and storage of a confined aquifer.