Science - USA (2020-08-21)

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pioneering studies never quite persuaded
scientists that some waterways had been
utterly transformed.
Much of our understanding of how riv-
ers behave and evolve comes from two geo-
morphologists, Luna Leopold and Gordon
“Reds” Wolman. While working together
at the U.S. Geological Survey (USGS) in the
1950s, they studied streams in Virginia,
Maryland, and Pennsylvania—all easily ac-
cessible from USGS headquarters in Reston,
Virginia. Using quantitative techniques rare
at the time, they developed an influential
explanation for how rivers form stable,
braided, meandering channels and sculpt

the land around them. As part of their

work, they showed the importance of rivers

frequently spilling over their banks during

floods and depositing sediment on adjacent

floodplains; such overbank deposition, they

found, was a fundamental part of a natural,

healthy waterway.

Merritts, 62, says she grew up wanting

to tell her own stories about the landscape.

Raised in central Pennsylvania, she spent

her childhood outdoors, climbing and hik-

ing with packs of kids. Her grandfather, a

conductor on the Pennsylvania Railroad,

told her of the wonders he saw in the state’s

valleys. “That’s what I wanted to do,” she

recalls. “I wanted to be able to understand

everywhere around me.”

After earning a doctorate in geomorpho-

logy from the University of Arizona in 1987,

Merritts joined the F&M faculty. She became

a field junkie, spending much of her career

deciphering how plate tectonics had reshaped

landscapes around the Pacific Rim by looking

at how rivers had shifted over time. The work

often took her to hazardous spots, including

East Timor, where she needed a bodyguard

because of a civil war, and Humboldt county

in California, where she was threatened at

gunpoint by cannabis growers. Until recently,

Merritts carried two life insurance policies.

As the result of a restoration project that

removed 22,000 tons of colonial-era

sediment, Big Spring Run in Pennsylvania

now snakes through lush wetlands.

21 AUGUST 2020 • VOL 369 ISSUE 6506 899

Published by AAAS