| Volumes and Issues Contents of Issue 4 Special Issue |
www.hydrol-earth-syst-sci.net/11/1515/2007/
© Author(s) 2007. This work is licensed
under a Creative Commons License.
Threshold effects in catchment storm response and the occurrence and magnitude of flood events: implications for flood frequency
1School of Environmental Systems Engineering, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
2Centre for Water Research, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
*now at: Departments of Geography & Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 220 Davenport Hall, 607 S. Matthews Avenue, Urbana, Illinois 61801, USA
Abstract. The aim of this paper is to illustrate the effects of selected catchment storage thresholds upon runoff behaviour, and specifically their impact upon flood frequency. The analysis is carried out with the use of a stochastic rainfall model, incorporating rainfall variability at intra-event, inter-event and seasonal timescales, as well as infrequent summer tropical cyclones, coupled with deterministic rainfall-runoff models that incorporate runoff generation by both saturation excess and subsurface stormflow mechanisms. Changing runoff generation mechanisms (i.e. from subsurface flow to surface runoff) associated with a given threshold (i.e. saturation storage capacity) is shown to be manifested in the flood frequency curve as a break in slope. It is observed that the inclusion of infrequent summer storm events increases the temporal frequency occurrence and magnitude of surface runoff events, in this way contributing to steeper flood frequency curves, and an additional break in the slope of the flood frequency curve. The results of this study highlight the importance of thresholds on flood frequency, and provide insights into the complex interactions between rainfall variability and threshold nonlinearities in the rainfall-runoff process, which are shown to have a significant impact on the resulting flood frequency curves.
Final Revised Paper (PDF, 1039 KB) Discussion Paper (HESSD)
Citation: Kusumastuti, D. I., Struthers, I., Sivapalan, M., and Reynolds, D. A.: Threshold effects in catchment storm response and the occurrence and magnitude of flood events: implications for flood frequency, Hydrol. Earth Syst. Sci., 11, 1515-1528, 2007. Bibtex EndNote Reference Manager
