Defining Appropriate Boundary Conditions of Hydrodynamic Model from Time Series Data

Abstract

This study illustrates a procedure of defining precise boundary conditions for the hydrodynamic model from time series data for a particular event. As a test case, the flood event of different return periods was selected for the Brahmaputra-Jamuna River, Bangladesh. Here, the magnitude of different return period flood was chosen by best-fitted frequency distribution. This study suggests that prior to do any frequency distribution the data series should be checked for the outlier, homogeneity, randomness, dependency, and trend. The magnitude of flood obtained from the best-fitted frequency distribution should be considered as the maximum flooding level of different return period flood and river's regular discharge hydrograph of the identical peak should be adjusted to fit the different return period floods and can be used as the upstream boundary condition of the hydrodynamic model. From the stage-discharge relationship of that particular year, the adjustment of downstream boundary condition can be estimated and implemented as the downstream boundary condition in the hydrodynamic model.