Abstract
In the runoff analysis, not much attention has been paid to the process of flowing down the channeling system embedded in a basin. The existence of the channeling system in any basin all the way up to the basin divide indicates, however, this process to be an important part in the runoff analysis. The objective of this paper is to show how this process governs the concentration process of the basin runoff. A distributed rainfall-runoff model is used for this purpose in which the longitudinal distributions of channel geometry and flow resistance can be taken into account. Firstly, the sensitivity analysis of the parameters governing the channel geometry and the flow resistance showed that the runoff model is quite stable to some of the change of the parameters. Secondly, the effects of both spatial and temporal distribution of rainfall within a basin have been investigated with this model. Finally, the propagation of flood flow along channeling system is investegated to obtain the relationship of the time of peak flow, drainage area at each channel and the rainfall intensity.
