Walter B. Langbein, 75, a retired research hydrologist and senior staff adviser with the U.S. Geological Survey, died of a lung ailment Dec. 10 at his home in Arlington.

Mr. Langbein spent 33 years with the survey before retiring in 1968. He was an authority in hydrology and geomorphology. His work included research in floods, soil temperature, lake and river sedimentation and reservoir storage. The results of his work helped the insurance industry devise its national flood insurance program.

For his contributions in promoting the International Hydrologic Decade, beginning in the mid-1960s, Mr. Langbein was awarded the International Prize in Hydrology by the International Association of Hydrological Sciences. He also received the Interior Department's Distinguished Service Award and citations from American Society of Civil Engineers, the American Water Resources Association, the National Academy of Sciences and the American Geophysical Union.

Mr. Langbein was a founder and editor of the Journal of Water Resources Research. He had been a consultant to presidential and congressional committees, UNESCO and the World Meteorological Organization.

He was born in Newark, N.J. He graduated from Cooper Union College in 1935 with a degree in civil engineering. Later that year, he joined the Geological Survey's water resources divison in Albany, N.Y. He transferred to this area in the late 1930s.

Survivors include his wife, Rose, of Arlington; a son, John, of Menlo Park, Calif.; a daughter, Laura, of Bethesda, and one grandchild.