Evaluating the Effects of the Rill Longitudinal Profile on Flow Resistance Law

In this paper, for the first time, effect of longitudinal profile shape rill (uniform, concave, and convex) on flow resistance law was studied. The part paper is based a theoretical equation to estimate Darcy–Weisbach friction factor f, deduced from power velocity distribution measurements performed plot. At first, Γ parameter calibrated using all available measurements. Then an analysis hydraulic characteristics at reach scale, comparable values discharge, carried out, comparing different shapes. To assess influence law, calibration also out data categorized by profile. second scour depth eroded volume developed four rills each configuration. results showed that accurate f can be obtained calibrating shape. component due varied 0.68 14.6% overall concave profile, 3.4 26.9% convex that, concentrated downstream slope change, while uniform profiles, it uniformly distributed. Furthermore, measured in correspondence thalweg had generally increasing trend, with discharge investigated Total lower than those detected profiles characterized reduction 57.9%, as compared