1. A method for creating simulated river data for a prediction model comprising: generating river coastline segments based on river imagery, the river imagery having water location points and river boundaries, the river boundaries including coastline location points; generating river cross sections from the river coastline segments; generating synthetic bathymetry from the river cross sections; correcting gaps in the river coastline segments; creating a finite element mesh based on the river cross sections, the corrected portions, the corrected gaps, the river coastline segments, and the river extension; and generating model parameters and input data files based on the synthetic bathymetry, the finite element mesh, the boundary nodes, and the boundary parameters.