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Major issues: Question (1): P6 L19 ‘...and can be regarded to be the error-free data.’ Weather radar data could have significant errors. Your study is about radar data error propagation. If you assume the radar data are error free, explain how this assumption will affect your study results. P7 L20 ‘Consequently, all the model errors are assumed to be free’, again, this assumption is quite wrong. Again, explain how this assumption will affect your study results. Reply: The aim of this work is to analyse the error propagation of radar rainfall in the context of hydrological models. And the analysed error in this study was assumed to be derived from the proposed error model only, instead of the errors contained in the raw radar rainfall and hydrological models. In order to achieve that, the raw radar rainfall data in this study was extracted from Nimrod data, which can be considered to be error-free with the state-of-the-art processes by Met Office, while the hydrological models were assume to be error-free as the surrogate of the study catchment, after the selected criteria for model calibration and validation have been met. The reason for those assumptions is to set up a conditional environment to trace the error in the rainfall through the hydrological models, without the interference of internal error from the raw radar rainfall data and hydrological models.