Luna B. Leopold, an ecologist and author whose studies of American rivers provided new insights into their depth, velocity and movement patterns that proved to be fundamental to all rivers, died on Feb. 23 at his home in Berkeley, Calif. He was 90.His death was announced by the University of California, Berkeley, where he was a professor of geology and geophysics.
A versatile scientist, Dr. Leopold trained as an engineer, meteorologist and geologist before combining the fields, to embark on his principal work on rivers, as a hydrologist. From 1956 to 1966, he was the chief hydrologist for the United States Geological Survey.
Dr. Leopold tried to sharpen earlier observations of rivers by measuring their characteristics. He and others studied river depths and velocity, vegetation and sediments, and the way water carries particles along riverbeds. With colleagues in the Geological Survey, he also studied rivers in their landscapes, as well as the effects of hills and slopes and the geology underpinning them.
The research resulted in a seminal book, "Fluvial Processes in Geomorphology" (1964), which Dr. Leopold wrote with M. Gordon Wolman and John P. Miller.
The book refines an important observation made in the 1950's by Dr. Leopold and Thomas Maddock Jr., concluding that "river depth and velocity increase at a predictable rate going downstream" and that the increase was similar for all rivers, regardless of their scale, said William W. Emmett, a former research hydrologist with the Geological Survey.
Previously, Dr. Emmett said, it was widely held that rivers slowed as they reached their end and met the sea, as when the Mississippi River widens and appears to come to a muddy standstill near New Orleans. Through their measurements, Dr. Leopold and his co-authors were able to prove that the reverse was true.
In 1969, Dr. Leopold attracted national attention in the course of an early environmental debate in Florida, when he headed a study of the Everglades by the Geological Survey. Officials of the Dade County Port Authority proposed the construction of an airport on 39 square miles of mostly wetlands near the northern fringes of Everglades National Park. Dr. Leopold's role was to determine possible effects from pollution and development on the park's ecosystem.
Findings from the study, known as the Leopold report, were scathing and heightened public awareness about the fragility of the Everglades. A small airstrip was allowed to operate, despite objections in the report, but the larger airport project was scuttled as a result of the findings.
The son of the conservationist Aldo Leopold, author of "A Sand County Almanac and Sketches Here and There" (1949), Luna Leopold held interests that were similarly broad. He edited and published his father's journals and rafted rivers in Alaska, Idaho and other states to measure their depths and flows.
In 1965, he and others floated 300 miles on the Colorado River through the Grand Canyon to chart the forces that formed the river and canyon surrounding it. In his travels, Dr. Leopold took detailed notes and recorded all measurements to allow for future comparisons.
Luna Bergere Leopold was born in Albuquerque. He received an undergraduate degree in civil engineering from the University of Wisconsin and a master's degree in meteorology from the University of California, Los Angeles. In 1950, he earned his doctorate in geology from Harvard.
He joined the Geological Survey that year and retired as a senior research hydrologist in 1972. Dr. Leopold then began his teaching career at Berkeley. He was named a professor emeritus there in 1987, but continued to publish books and papers on hydrology and environmental subjects until last year. He also wrote "Water: A Primer" (1974) and "A View of the River" (1994).
Dr. Leopold was a member of the National Academy of Sciences and the American Academy of Arts and Sciences. In 1991, he was awarded the National Medal of Science. He lived in Berkeley and Pinedale, Wyoming.
by Jeremy Pearce
New York Times
No comments:
Post a Comment