Floodplain Simulation Using Sub-Grid Bathymetry: Case Study of Broken River Basin, Australia

Flood modeling is a critical subject to provide reliable information about runoff data of a region and risk management. In this research, Victoria state floods of 2012 have been modeled by implementing a sub-grid bathymetry method not only to reduce heavy computations but also to prevent oversimplification. Using elevation models and Broken River basin along with precipitation data from the mentioned disaster, a 2-dimensional model has been generated to depict the runoff movement toward downstream of the basin. With sub-grid method discretization, mass and momentum conservation equations are implemented inside each cell, resulting in the direction, speed, and volume of fluid moving from each cell to another in 1-Hour time intervals. The model generated for simulating 7- days of flood in the region and the validation of each day has been done with confusion matrix and Kappa coefficient, which showed a total rate of 81.2% in the generated model. The calculated Kappa index expresses high reliability and accuracy in the performed model for further flood modeling in the region based on current land-cover and weather conditions. Therefore, it can be used for future risk maps and disaster management.

Floodplain Simulation Using Sub-Grid Bathymetry: Case Study of Broken River Basin, Australia Keywords:

Runoff Modeling , Sub-grid Bathymetry , Flood , Confusion Matrix