Abstract
Evaluation and quantification of possible sources of uncertainty and
their influence on water resource planning and extreme management is
very important for risk modeling and extreme hydrological management.
The main objective of this research work is to combine statistical
climate ensembles, multiple parameter sets for three conceptual
hydrological model structure and five flood frequency distribution
models to investigate the interplay among the associated uncertainty in
flood and low flow modelling. Uncertainty in the modeling of extreme
high flow frequency mainly comes from the quality of the input data,
while in the modeling of low flow frequency, the main contributor to the
total uncertainty is from model parameterization. This result is also
confirmed by using the Analysis Of Variance Analysis (ANOVA) that
considers additional information about the interaction impact of the
main factors. The total uncertainty of QT90 (extreme peak flow quantile
at 90-year return period) quantile shows the interaction of input data
and extreme frequency models has significant influence on the total
uncertainty. In contrast, in the QT10 (extreme low flow quantile at
10-year return period) estimation, the hydrological models and
hydrological parameters have significant impact on the total
uncertainty. This implies that the four factors and their interactions
may cause significant risk in water resource management and flood and
drought risk management, and neglecting of these four factors and their
interaction in disaster risk management, water resource planning and
evaluation of environmental impact assessment is not feasible and may
lead to big risk.