C.V. THEIS CONTRIBUTIONS TO QUANTITATIVE HYDROGEOLOGY

Prior to 1935, the method for testing the hydraulic properties of aquifers was the steady state or equilibrium method (Theim method). In 1935, Theis published a paper in which he derived an equation (the nonequilibrium formula) to describe nonsteady flow to a pumping well. The formula was from the analogy between hydrologic conditions in an aquifer and heat flow in solids. He was the first to introduce the concept of time to the mathematics of groundwater hydraulics and the importance of aquifer storage. This work is considered the greatest single contribution to the science of groundwater hydraulics in the 20th Century and opened the door to modern quantitative investigations. In 1940, he followed this work with a paper on the source of water derived from wells, the significance of the cone of depression created by pumping, and the key factors that control the response of an aquifer to development. In 1941, he presented a method to estimate the effects on a stream from pumping of a nearby well.

Charles Theis was born in Newport Kentucky on March 27, 1900. He was awarded a Ph.D in Geology from the University of Cincinnati in 1929. He joined the USGS IN 1930 and was assigned to a group of geologists who were investigating the diminishing artesian flow in the Roswell Basin in New Mexico. During the war years he worked for the Atomic Energy Commission during WW2. He adopted New Mexico as home and lived in Albuquerque until he retired in 1985 and died in 1987.