A Utah girl won a prestigious science competition Tuesday for analyzing how to protect water quality by improving environmental buffers and changing daily behavior.

Shannon Babb of Highland, Utah, earned a $100,000 college scholarship in the 2006 Intel Science Talent Search. Babb, who attends American Fork High School, spent six months studying the Spanish Fork River drainage system to assess the effects of human and animal behavior.

The 18-year-old concluded that pollution runoff can be reduced by fortifying and replanting the banks along the river, reducing animal grazing in those areas, directing runoff into settling ponds, and educating people about how to discard household chemicals.

Over the competition's 65-year history, winners have gone on to earn more than 100 of the world's most coveted honors, including six Nobel Prizes. Intel has sponsored the event since 1998.

Yi Sun, 17, of The Harker School in San Jose, Calif., took second place and a $75,000 scholarship. Yuan "Chelsea" Zhang, also 17, of Montgomery Blair High School in Rockville, Md., won the $50,000 third-place scholarship.

Another three dozen students won scholarships ranging from $5,000 to $25,000. Almost 1,600 students entered the competition.