Development and testing of a surface roughness measurement device based on aerial ultrasonic reflections

Repairs of concrete irrigation channels in Japan are guided to a large extent by the degree to which their walls have degraded over decades of use. Current methods of estimating Manning roughness coefficients from the roughness of the channel wall are based on linear profiles of arithmetic mean roughness. This study developed a method to estimate Manning roughness coefficients for a planar region directly from the peak-to-peak value of a...