CORVALLIS, Ore. – Rivers have long captured the imagination of poets, essayists and other writers, who have used them to tell iconic stories like “Huckleberry Finn,” “The Heart of Darkness,” and “Wind and the Willows.”
Oregon State University geophysicist and author Sean Fleming explores rivers from different angles – where they come from, why they may flood one year and dry up the next, and how almost every aspect of our lives revolves around water.
In his new book “Where the River Flows,” published by the Princeton University Press, Fleming explains that mathematics and physics give us a fresh way to look at rivers. Not to worry, though – it is a book aimed at the lay public and presented in a unique style. He asks questions such as “how do rivers remember?” and “how do clouds talk to fish?” as a way to introduce new topics.
“Ultimately, almost everything revolves around water, from the food we eat and the beer we drink, to hydroelectric power and recreation,” Fleming said. “Rivers are essential to civilization and even life itself, but people rarely delve into what makes them work. And in an interesting way, mathematical ideas underlie the science of rivers and underscore the importance of interconnectedness.”
Fleming uses debris flows as an example. This flood and landslide hybrid, which poses threats around the world, can be explained using a computer simulation called “cellular automata,” which originally was created to explore artificial life.
“It also reveals something about the origins of fractal patterns, which occur in everything from tree branches, to galaxies to the stock market,” Fleming said. “Recognizing that ideas from one field can be so powerful in another is important for pushing science forward.”
In his book, Fleming also points out some oddities about rivers across the world. For example, most rivers have seasonal “heart-beats,” he pointed out, with one peak per year – like the Columbia River’s springtime snowmelt freshet. Across the globe, however, Africa’s Congo River is so big and covers so much territory on either side of the equator that it has two peaks and two troughs because when it is summer in one part of the river it is winter in the other.
The Colorado River provides another oddity. In the upper Colorado, the water flow is impressive, attracting white water rafters for its massive rapids and thrills. But the river doesn’t even end up flowing into the Pacific Ocean any longer because of the demand of people living along its path. That is well-documented. The backdrop to the water usage, however, is not as widely known, Fleming noted.
“The allocations for water from the Colorado River were made in the early 1900s,” he said. “They were based on the observed weather and stream flow at the time, which were expected to remain roughly the same. But little did they know that it turned out to be one of the wettest periods in the basin’s history.
“So the allotments then – and today – were made on the assumption that the river’s flow would be much greater than it actually is.”
Fleming also explores issues of water security and the increasing demand worldwide for fresh water.
“That demand is expected to increase 55 percent by the year 2050, so we may be looking at increased opportunities for cooperation, but also conflict,” he said. “Some people have even predicted water wars. To better manage the resource, we need to make a quantum leap forward in understanding how rivers work and that means looking at them from all angles.”
“Where the River Flows: Scientific Reflections on Earth’s Waterways” is available through the Princeton University Press at: http://press.princeton.edu/titles/10978.html and at Amazon at: http://amzn.to/2r3eOR4
Fleming is a courtesy faculty member in Oregon State’s College of Earth, Ocean, and Atmospheric Sciences.