Performance of bare-earth and vegetated steep channels under long-duration flows

摘要

Thousands of dams built in the U.S. have a potential to be overtopped by flood flows. It is therefore necessary to understand the mechanics of embankment erosion in order to evaluate the potential erosion damage to an embankment and the safety risk that overtopping represents. This article describes tests conducted at the USDA-ARS Hydraulic Engineering Research Laboratory in Stillwater, Oklahoma, using an embankment 3 in high and 37 in long with 3:1 slopes. Measured water surface, bed, and velocity profiles and predicted hydraulic stress for four 1-m wide trapezoidal channels, two vegetated and two non-vegetated, are compared. The tests were conducted at discharges of 0.2 m(3)/s and 0.6 m(3)/s. The tests in the vegetated condition were run for 75 hours, and the tests in the non-vegetated condition for 73 hours and 52 hours, respectively.