Meandering Rivers Keep Themselves in Check
All rivers follow a gently winding path, regardless of the terrain. Now Physicists at the University of Cambridge have produced a mathematical model that explain a river’s winding, or meandering, habits.
The group of physicists has successes in modeling certain meanders from their beginning using “an equation of model.†This equation describes the river in terms of both time and space. Competing processes keep the river from making unusual paths through the terrain. Some of these processes include the erosion of material at the outside of a bend where the water’s speed is fastest and the deposition of sediment on the inside of the bend, where the water travels more slowly. The formation of oxbow lakes is a powerful competing factor. An oxbow lake is formed when a river bends so far out that it makes a complete loop. Eventually, the river pinches off the bend and flows straight through, isolating the water in the bend. Rivers naturally seek a steady state in which the two processes of forming bends and pinching off the bends to flow straight through again exactly cancel each other out. Terrain variations cause a river to reshape the terrain. Rivers always follow natural, scale invariant paths.
The forces which shape a river’s course may be predictors of oil deposits. Rivers have the force to compress organic sediments into oil over the course of thousands of years. By understanding the behavior of meandering rivers, it may someday be possible to explore for oil using far fewer test drills.
