Modeling Evolution Of A Large Mining Pit In The Lower Mississippi River

Excavation of sediment from alluvial channel beds are common for the purpose of navigation maintenance, flood control, civil construction, etc. The post-dredge evolution of the mining-pit as well as the continuous changing of local flow and sediment transport, however, are poorly understood. The study simulates the morphological change of a large (1.46 million m(3)) borrow pit mined on a lateral sandbar in the lower Mississippi River using a depth-averaged two-dimensional hydrodynamic and sediment transport model. The model is calibrated and verified against 2.5 year time-series of multibeam bathymetric surveys. Besides, the study examined the sensitivity of mining-pit evolution simulation to the variation of the non-equilibrium adaptation parameters. Study results provide an insight into appropriate selection of the adaptation parameters in order to close the non-equilibrium sediment transport formulas when modeling large anthropogenic disturbance within the geomorphic processes.