Dupuit

Jules Dupuit (1804–1866) was a French civil engineer and economist whose work spanned hydraulics, hydrology, and welfare economics. In hydrology, he is celebrated for pioneering the quantitative study of groundwater and for introducing concepts that shaped early groundwater science. His work laid the groundwork for treating aquifer flow with simplified, testable assumptions, bridging engineering practice and physical theory.

In particular, Dupuit formulated an assumption that groundwater flow in unconfined aquifers is primarily horizontal and that vertical gradients and the storage term can be neglected when estimating discharge to streams or wells. This Dupuit assumption enabled researchers to relate groundwater discharge to the slope of the water table and to the saturated thickness, offering a practical framework for analyzing groundwater systems with limited data. The resulting methods influenced subsequent developments in hydrogeology and aquifer testing.

The Dupuit-Forchheimer equation, associated with his ideas and later extended by German hydrologist Forchheimer, provides a practical approach to estimating groundwater discharge in unconfined aquifers under steady conditions. Although refined by later researchers, the underlying principle remains a staple in introductory groundwater hydrology and in teaching the behavior of public-supply wells and seepage to drains.

In economics, Dupuit is remembered for early work on welfare economics, notably the concept of consumer surplus and analyses of pricing and taxation. His interdisciplinary pursuits contributed to the 19th-century development of both hydraulic engineering and economic theory, and his name persists in foundational ideas across multiple fields.