The River Mechanics models and tools were originally developed by Dr. Danny Fread and Janice Sylvestre at the National Weather Service (NWS) from 1974 through 2005. Although they are no longer supported by NWS, the RiverMechanics Group is committed to enhancing and maintaining the following: BREACH, SMPDBK, FLDWAV, FLDAT, and FLDVIEW.
Featured Application: FLDWAVE
FLDWAVE, an enhanced version of the NWS FLDWAV model, is a generalized flood routing model applicable to natural river systems with hydraulic complexities. It is based on an implicit finite-difference solution of the complete one-dimensional Saint-Venant equations coupled with an assortment of internal boundary conditions for simulating unsteady flows controlled by a wide spectrum of hydraulic structures. The flow may occur in a single channel or a system of interconnected channels in which sinuosity effects are considered. The flow, which can range from Newtonian (water) to non-Newtonian (mud/debris, mine tailings) may freely change with time and location from subcritical to supercritical or vice versa, and from free-surface to pressurized flow. Special modeling features include time-dependent dam breaches, multiple levees overtopping and crevasse, time-dependent gate controlled flows, assorted spillway flows, bridge/embankments, tidal flap gates, and user-specified multiple routing techniques throughout the river system. Input/Output may be in English or metric units.
FLDWAVE is generalized for wide applicability to rivers of varying physical features, such as irregular channel geometry, varying roughness, lateral inflows, flow diversions, off-channel storage, local head losses such as bridge contractions and expansions, lock and dam operations, and wind effects. It is suited for efficient application to dendritic river/floodplain systems or to channel networks consisting of bifurcations with weir-type flow into the bifurcated channel.
FLDWAVE can be used by hydrologists/engineers for a wide range of unsteady flow applications including real-time flood forecasting in a dendritic system of rivers, dam-breach analysis for sunny-day piping or overtopping failures associated with a Probable Maximum Flood, design of waterway improvements, floodplain inundation mapping, irrigation system design, and storm sewer analysis/design.
Although FLDWAVE can model complex river systems very accurately, it can also be used as an emergency management tool to produce fairly accurate results (discharge, elevation, and velocity hydrographs and profiles) when limited data is available.
NWS FLDWAV replaced the NWS DAMBRK (1977-1988) and NWS DWOPER (1974-1988) models which were developed by Dr. Danny Fread and Janice Sylvestre. The last version of NWS FLDWAV was released in 2000. Although NWS ceased support for the model in 2005, Janice Sylvestre has continued the development, maintenance, and support of the FLDWAVE model. The name of the model has been changed to FLDWAVE since the continued work is not affiliated with NWS.
Application: FLDWAVE was applied to Hurricane Frances (2004) on the St. Johns River System in Florida to showcase its applicability to coastal rivers. The presentation below gives an overview of how to model coastal rivers and the results of the St. Johns River System simulation.
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