Water on the Land: Eight Hydrologists From Evaporation to Floods

Brutsaert is known within hydrology as Mr. Evaporation for decades spent quantifying how water moves from the land surface into the atmosphere. He spent fifty years at Cornell developing methods to estimate that evaporation, work that underpins both remote sensing and ground based measurement of the global water cycle. His 1982 book Evaporation into the Atmosphere and his 2005 textbook Hydrology: An Introduction became standard references.

Theis turns the path underground. Working on High Plains aquifers between 1932 and 1934, he developed equations for nonequilibrium groundwater flow toward a pumped well, a result known as the Theis solution that is still a foundational tool in aquifer analysis. His later research showed that the share of pumping drawn from stream capture grows over time while the share drawn from storage depletion shrinks, and he received the Robert E. Horton Medal in 1984.

Leopold brings the path to the river channel. He is widely known for fluvial geomorphology, including the book Fluvial Processes in Geomorphology written with Gordon Wolman and John Miller. He also argued that water resource management must rest on geologic, geographic and climatic factors, not on economic and political considerations alone.

Wolman worked with Luna Leopold at the United States Geological Survey and helped move geomorphology from a descriptive to a quantitative discipline. He developed methods for measuring river depth, velocity and the size of streambed pebbles, a technique now called the Wolman pebble count that remains standard practice. The 1964 textbook he co-authored with Leopold is considered a seminal work in the field.

Chow was a hydrologist and hydraulic engineer, born in Hangzhou, China, in 1919, who is acclaimed for contributions to hydrology and to water resources development. After earning degrees in China, at Pennsylvania State University and at the University of Illinois, he taught as a professor of civil and hydrosystems engineering. His stop connects the science of streams to the engineering of water supply.

White is called the father of floodplain management. His 1942 doctoral research at the University of Chicago argued that flood losses are largely the product of human decisions to build and farm on flood-prone land, in his words that floods are an act of God but flood losses are largely an act of man. His research reshaped federal flood policy away from dams and levees toward floodplain zoning, insurance and other non-structural adjustments.

Yevjevich is known as the father of stochastic hydrology. After directing the Hydroenergetic Institute in Belgrade he emigrated to the United States and joined Colorado State University, where he applied probability and statistics to river flows, droughts and reservoir design. His 1972 book Stochastic Processes in Hydrology became a foundational text.

Klemes closes the path as a critic of the statistical methods the previous stop pioneered. Working largely with Environment Canada, he wrote roughly 150 papers on the statistical foundations of hydrology, including influential critiques of how hydrologists apply probability theory to design floods and reservoir storage. He served as president of the International Association of Hydrological Sciences in 1987 and received the International Hydrology Prize.