Robust prediction of hydraulic roughness

摘要: Abstract : OVERVIEW: The National River Restoration Science Synthesis (NRRSS) demonstrated that, in 2007, river and stream restoration projects funding were at an all time high increasing exponentially (Bernhardt et al. 2007). Increasingly, these rely on soft engineering techniques involving planting riparian vegetation to alter channel floodplain hydraulics or geomorphology. ability quantify the influence of hydraulics, particular hydraulic roughness, is critical for flood control concerns; however, diversity type behavior makes this parameter very difficult repeatedly accurately. A fundamental concept theory context boundary conditions flow through natural environments. This technical note presents a tool estimating roughness from rivers. Hydraulic resistance, herein defined as primary factor influencing retarding resisting forces exerted by boundaries flow. Calculation resistance not trivial matter due multitude factors (e.g., bed material, forms, crosssectional planform variability, vegetation, etc.). document will present estimation, synthesis many estimation into spreadsheet model, application said model Ham Branch, tributary Trinity River. methods applied allow users isolate effects diverse contributions grain v. vegetative) create weight-of-evidence roughness.