Stage-discharge curve is a graph of discharge versus stage for a given point on a stream, usually at gauging stations, where the stream discharge is measured across the stream channel. The rating curve is a very important tool in surface hydrology bec...
Stage-discharge curve is a graph of discharge versus stage for a given point on a stream, usually at gauging stations, where the stream discharge is measured across the stream channel. The rating curve is a very important tool in surface hydrology because the reliability of discharge data values is highly dependent on a satisfactory stage-discharge relationship at the gauging station. It has been acknowledged that a one-segmented stage-discharge curve is insufficient due to the change in geometry and/or channel resistance. This study investigates Hierarchical Bayesian methods to better derive complex stage-discharge relationship. Parameter estimation and associated uncertainty analysis is performed using Markov Chain Monte Carlo Simulation (MCMC). The multi-segmented stage-discharge curve is formulated as a piecewise regression problem where the number of change points are assumed unknown. It was found that the proposed procedure gave the improved results in terms of reducing error propagation due to change points. Also, the results demonstrated that the proposed model procedure provided the better estimates of extrapolated part of the stage-discharge curve.