Gilbert White, a geographer whose studies of human-water interaction are an important influence on flood-plain management around the world, died of dehydration October 5 at his home in Boulder, Colo. He was 94.

While studying recurrent Mississippi River floods in the late 1930s, he challenged the then-pervasive notion that natural hazards were best controlled by engineers and construction. His point of view was radical at the time, but land-use planners, scientists and government officials around the world today look at the landscape the way White did: balancing a range of alternatives that includes upstream watershed treatment, flood-proofing of buildings, emergency evacuation procedures and dams. He is known as the “father of flood-plain management.”

“Floods are ‘acts of God,’ but flood losses are largely acts of man,” he said in his 1942 doctoral dissertation. Natural hazards are best avoided rather than “managed” by building dams, levees and walls, which often do more harm than good, he showed. His research laid the foundation for the federal flood insurance program.

White, who won the National Medal of Science in 2000, helped forge international cooperation on water systems in the Middle East, Southeast Asia and Africa, fought the spread of deserts and warned in the 1970s about the impact of human behavior on the global climate.

He led an international scientific body that concluded that an all-out nuclear war would cut off sunlight sufficiently to produce a “nuclear winter.” The 1985 report, which he drafted, said the danger was real.

White, a native of Chicago, received a bachelor’s degree in 1932 and a master’s degree in 1934 in geography from the University of Chicago. He interrupted his doctoral studies at Chicago to be part of the New Deal in Washington.

In 1946, White became the youngest college president in the nation when he joined Haverford College in Pennsylvania at age 34. Nine years later, he returned to the University of Chicago. He moved to the University of Colorado in 1970, where he was director of the Institute of Behavioral Science and founded the Natural Hazards Research Center.

Late in the 1970s, he issued a declaration with Mostafa Tolba, head of the United Nations Environment Programme, suggesting human activity might cause a change in global climate. White was then the president of the Scientific Committee on Problems of the Environment, which published the first serious book on the subject and sponsored a 1985 conference mobilizing concern about greenhouse gases.

White chaired the American Friends Service Committee from 1963 to 1969.