David Montgomery started out his geological career studying landslides in Northern California and playing guitar for bands with names like Flat Earth or Reckless Pedestrians.

Now, as a University of Washington professor of "geomorphology" and lead guitarist for the perhaps still-to-be-discovered Seattle basement band known as Big Dirt, he's officially become a genius. Montgomery, 47, is one of this year's winners of a $500,000 "genius" award from the John D. and Catherine T. MacArthur Foundation.

"I still have a hard time believing it," Montgomery said. He just began a sabbatical last week to work on a book and had been pondering how to cut back on expenses to make ends meet. Now, as a MacArthur genius, he'll be getting $100,000 every year for the next five years to spend in whatever way he sees fit.

"When he told me, I said 'No (expletive) way!' " laughed Anne Bikle, his wife of more than two decades. "It's really great. I don't totally buy this whole genius thing, however. We're going to keep a lid on that, I think. ... I mean, he still gets confused about the difference between garbage and what's recyclable."

The MacArthur Foundation, which today will officially announce its 25 award winners for 2008 (technically known as MacArthur Fellows but popularly known as the "genius awards"), said Montgomery was selected for his groundbreaking scientific contributions to understanding how landscapes form -- on Mars as well as here on Earth -- along with his ongoing effort to communicate the significance of these findings to the public.

"With a scientist's rigor, a historian's curiosity and an environmentalist's passion, Montgomery is leading investigations into the ecological consequences of a wide range of Earth surface processes," the philanthropy said in its statement announcing the award.

Take Montgomery's most recent popular book, "Dirt: The Erosion of Civilizations." In it, the UW geologist makes the case that modern agricultural practices are now stripping the planet of its relatively thin skin of topsoil at such an alarming rate we should be looking at erosion and soil loss as a comprehensive threat on par with climate change.

"It's a serious but still mostly neglected problem," Montgomery said. In his earlier book on salmon called "King of Fish," he similarly warned how our business-as-usual approach to fishing, forestry and land use will doom the Pacific Northwest salmon runs to the same tragic decline as happened in Europe, New England and elsewhere. He's now working on the story of the planet's history of catastrophic -- biblical, you might even say -- flooding.

Despite his interest in studying such massive eco-disasters and sometimes even challenging the powers-that-be in Seattle over disastrous land-use policies, Montgomery typically talks with a smile and an easy laugh. He clearly loves his work. So what exactly is it that a "geomorphologist" does?

"I wanted to be a theoretical ecologist," he said, adding that a high school biology teacher got him hooked on science by explaining things like how tall trees move water up hundreds of feet against the force of gravity. His father was a business professor at Stanford University, but Montgomery shied away from the practical ways of business.

"I always loved maps," he said. At Stanford, most of the biology majors were hypercompetitive premed types, and so he drifted into geology. "Everybody there just worked together on the science."

After two years, Montgomery dropped out and got a geology job working in mines in Queensland, Australia. Hard labor Down Under persuaded him to return to academics and pursue a graduate degree in geology. At the University of California-Berkeley, he got his doctorate, met Bikle and learned the joys of geomorphology from Professor William Dietrich.

"Geomorphology is basically the science of the surface of the Earth, how it works," said Montgomery. His doctoral thesis sought to answer the deceptively simple question of why mountain streams form where they do. The interplay of water and land has remained a focus of his work ever since.

Montgomery is an expert on such matters as the science of how, and why, landslides take place or a river creates a landscape. His studies now take him all over the globe, from examining sediment deposition on the Skokomish River in the Olympic Mountains to examining the riverine geology of the Himalayas or the Andes -- or even Mars.

"At the moment, I'm working on Martian topology," said the UW's new genius.

He also needs to work on his recycling, added Bikle, regional education director for the National Wildlife Federation.