Lecture 32: Theis Equation Theis Equation Assumptions and Applications 02

This lecture expands the previous discussion by introducing the Cooper-Jacob method for solving the Theis equation. Cooper and Jacob (1946) simplified the Theis equation for small values of u and large t, leading to a linear relationship between drawdown and the logarithm of time. The method allows for easier calculation of transmissibility T and storativity S from pump test data by plotting drawdown against the log of time and finding the slope. Additionally, the lecture covers recovery tests, which measure how groundwater levels return to normal after pumping ceases, using residual drawdowns to verify transmissibility. The Cooper-Jacob method is particularly useful for small uuu values to minimize errors, and example calculations illustrate its application.