Flash Floods

Flash floods are a particular kind of flood event during which the run-off of heavy precipitation can, over a short period of time, coalesce into torrent-like, dangerous streams. The flow characteristics are driven both by free-surface controls as well as by the porosity and saturation detail of the surface ground layers, and can be highly three dimensional and closely tied to complex topographies. All of these dynamics tie in to FLOW-3D‘s modeling strengths, in particular:

  • FLOW-3D‘s advanced porosity models predict the drainage of water through porous, saturated or non-saturated soil
  • Its precipitation model captures the temporal and spatial accumulation of rain water over the surface layers
  • FLOW-3D‘s Volume of Fluid (TruVOF) approach to free-surface flow dynamics captures transient waves and run-ups
  • An advanced sediment and deposition model ties in seamlessly to these simulations when needed
Flash flood simulation
A surface layer gradually reaching saturation during a precipitation event. The formation of surface waters accelerates sharply thereafter, quickly forming both torrents in the central canyon and strong outflows into the adjacent water reservoir to the left of the domain.