Three Dimensional Numerical Modeling of Flow and Pollutant Transport in a Flooding Area of 2008 US Midwest Flood

This paper presents the development and application of a three-dimensional numerical model for simulating the flow field and pollutant transport in a flood zone near the confluence of the Mississippi River and Iowa River during the US Midwest Flood in 2008. Due to a prolonged precipitation event, a levee along the Iowa River just upstream of Oakville, Iowa broke, and the small town was completely flooded for a couple of weeks. During this period, the high water level in the flood zone reached about 2.5 meters above the ground, and wind was the major force for the flow circulation. It was observed that some pollutants were leaked from the residential and farming facilities and transported into the flood zone. Leaking of pollutants from these facilities was reported by different news media during the flood and was identified using high resolution satellite imagery. The developed 3D numerical model was first validated using experimental measurements, and then applied to the flood inundated zone in Oakville for simulating the unsteady hydrodynamics and pollutant transport. The simulated pollutant distributions were generally in good agreement with the observed data obtained from satellite imagery.