Flow resistance dynamics in step‐pool stream channels: 1. Large woody debris and controls on total resistance

摘要: [1] Flow resistance dynamics in step-pool channels were investigated through physical modeling using a laboratory flume. Variables contributing to flow manipulated order measure the effects of various large woody debris (LWD) configurations, steps, grains, discharge, and slope on total resistance. This entailed nearly 400 flume runs, organized into series factorial experiments. Factorial analyses variance indicated significant two-way three-way interaction between LWD, illustrating complexity these channels. Interactions steps LWD resulted substantially greater for with than lacking LWD. position contributed interactions, whereby pieces located near lip analogous step-forming natural channels, increased effective height created higher farther upstream step treads. Step geometry density orientation also had highly Flow effect bed roughness configurations strongly discharge-dependent; discharge both main interactions all other variables.