LAUSR

This study proposes a framework for uncertainty analysis by incorporating explicit numerical solutions of governing equations for flood wave propagation with the expectation operator. It aims at effectively evaluating the effect of variations in initial and boundary conditions on the estimation of flood waves. Spatiotemporal semi-variogram models are employed to quantify the correlation of the variables in time and space. The 1-D nonlinear kinematic wave equation for the overland flow (named EVO_NS_KWE) is applied in the model development. Model validation is made by comparison with the Monte Carlo simulation (MCS) model in the calculation of statistical properties of model outputs (i.e. flow depths), that is, the mean, standard deviation and coefficient of variation (CV). The results from the model validation show that the EVO_NS_KWE model can produce excellent approximations of the mean and less satisfactory approximations of the standard deviation and CV compared with those obtained using the MCS model. It concludes that the uncertainties of flow depths in the domain are significantly affected by variations in the boundary condition. Future, application of the EVO_NS_KWE model enable the evaluation of uncertainty in model outputs induced by the initial and boundary condition subject to uncertainty, and will also provide corresponding probabilistic information for risk quantification method.