Spatial patterns of exposure to sediment-laden flows on an experimental alluvial fan

Sediment-laden flows with significant amounts of large wood can impact alluvial fans and seriously damage infrastructure property which makes a profound knowledge exposure an essential requisite for risk mitigation. To investigate its spatial variability, we executed experiments on simplified physical model assessed the observed process patterns by quantifying synthetic indexes geostatistically analysing probabilities. We systematically varied loading conditions, i.e. total flow volume, solid fraction tank opening controlling water release, repeated each experimental configuration eight times. Two fan layouts were considered, one equipped guiding channel bridge only. First, tested hypothesis, that released though fully opened outflow valve induces sediment-laden is associated higher lower uncertainty if compared to generated half-opened valve. Second, whether volume uncertainty. It turned out neither aforementioned hypotheses verified whole set conditions. The first hypothesis rejected in majority considered second prevailingly corroborated when exposed areas due both sediment considered. Instead, only deposition are this featuring presence bridge. provided probability maps all conditions presented variability standard deviation ellipses. Although solely indicative adopted layouts, variation parameters led remarkable changes Our results urge decision makers acknowledge potential geomorphic responses their management practices as avoid underestimating impacts built environment.