Scouring Processes for Extreme Hydrological Events: Review

Heavy rainfall/snow events due to climate change can cause strong flooding, damaging existing infrastructure. The potential erosive action of runoff flow produces considerable local scouring at hydraulic structures, compromising their stability. This study is a synthesis of the research on scouring processes conducted by the hydraulic group of the Department of Civil, Environmental, Land, Building Engineering and Chemistry of the Polytechnic University of Bari (Italy). Results of a wide range of laboratory experiments performed on scouring around Grade-control structures (GCSs) in alluvial channels with noncohesive sediment beds were considered. In addition to a number of innovative scouring predictors achieved by the researcher group, i.e., the maximum scour depth and its location and the scour length, some results of the hydrodynamic flow structures in scour holes, obtained experimentally and numerically, are illustrated and discussed in this study. The high uncertainty in predicting scour characteristic lengths is due to the difficulty of considering all the physical parameters that can influence the scour development. It is strongly recommended to consider the flow turbulence properties in the design of GCSs.