PLUME1.1 - DEPOSITION OF SEDIMENT FROM A FLUVIAL PLUME

An ANSI-standard Fortran 77 program solves the steady, two-dimensional advection-diffusion equation describing a turbid hypopycnal plume ema nating from a river mouth. The model solves for the extent of the plum e as a non-dimensioned inventory of sediment mass on an axial-lateral grid. The basis for the model is a derivation by Albertson for a two-d imensional momentum-driven submerged jet. Particle settling is based o n the scavenging model of Syvitski. PLUME is robust but fast enough to handle the sedimentation beneath a river plume flowing into a coastal sea on a daily basis. Designed for speed, the model may be run with d aily-changing river input characteristics (flow velocity, river mouth dimensions, sediment concentrations of up to ten grain sizes) for many (up to thousands of) years. PLUME1.1 works with input from long-term field observations or from climate-hydrologic simulations. The model p rovides for an improved geological simulator of land-sea interaction a nd the delivery of sediment onto continental margins. The model can be used to simulate flow into both open-coast and semi-enclosed basins. Open-coast plume simulations include the hood-dominated Eel River marg in, Northern California, where a three-day flood event could supply mo re sediment than the previous seven years combined. A semi-enclosed ba sin example is from a fjord-basin from British Columbia, where model s imulations agree well with sediment concentration observations. (C) 19 98 Elsevier Science Ltd. All rights reserved.