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The default values adopted for MUSIC are based on calibration of the model to typical urban catchments (further guidance is available in the Appendices). It should be noted that the volume of runoff generated and the stormwater runoff time series from an urban catchment are not very sensitive to variation in the parameters defining the pervious area response to rainfall, except where directly connected imperviousness percentages are low, and the model is significantly more sensitive to the accurate definition of the fraction imperviousness and the selection of simulation time-step.
Figure 1. Conceptual Rainfall-Runoff Model adopted for MUSIC (after Chiew & McMahon, 1997)
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