Overview
This study developed a three-dimensional Environmental Fluid Dynamics Code model for a 17-km segment of the Mobile River, Alabama, USA, to simulate flow dynamics under various upstream hydrologic conditions.
Model Setup
The model’s external forcing factors include river inflows from upstream, tides from downstream, and atmospheric conditions. It was calibrated against measured water levels, velocities, and temperatures from 26 April to 29 August 2011, achieving Nash-Sutcliffe coefficients greater than 0.94 for water levels and ranging from 0.88 to 0.99 for water temperatures. The calibrated model was then extended approximately 13 km upstream to simulate unsteady flow, dye, and temperature distributions under different upstream inflows and downstream harmonic tides.
Key Findings
Velocity profiles and distributions of flow, dye, and temperature at various locations show that flow recirculation could only occur under small inflow (50 m³/s), when downstream tides control the flow pattern in the Mobile River. The model results reveal complex interactions among discharges from a power plant, upstream inflows, and tides.