HR: 1340h
AN: H33E-1426    [Abstracts]
TI: Temporal Scales and Hydrological Regimes: The Impact of Climate Change and Variability Upon Flood Response
AU: * Struthers, I
EM: struther@cwr.uwa.edu.au
AF: Centre for Water Research, M015, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 Australia
AU: Sivapalan, M
EM: sivapala@uiuc.edu
AF: Centre for Water as a Complex Environmental System (CWACES), Departments of Geography and of Civil & Environmental Engineering, University of Illinois at Urbana-Champaign, 220 Davenport Hall, MC-150, 607 South Mathews Avenue, Urbana, IL 61801 United States
AB: As with many other natural processes, the transformation of precipitation into runoff is highly non-linear and is impacted by threshold-activated processes. The purpose of this work is to conceptually examine which aspects of temporal variability in precipitation are `filtered out', and which aspects are retained or even enhanced, during the transformation into runoff. The work of Robinson and Sivapalan [1] employed a stochastic rainfall model and a spatially-lumped linear rainfall-runoff model to address these questions, and found that the nature of that transformation is governed by the interaction between climatic and catchment response timescales. This work is extended here to consider (a) a variety of mechanisms for runoff generation, including the threshold processes of infiltration excess overland flow and preferential subsurface flow, and (b) inter-annual variability in precipitation behaviour associated with climate states such as El Niño/La Niña, as well as scenarios for systematic changes in precipitation behaviour associated with climate change. The aim is to understand which aspects of precipitation variability impact runoff generation by different mechanisms, and to understand how long-term multi-scale climate variability (and change) can alter the predominance of competing flow generation processes in a given catchment. This research represents the first step in a larger conceptual examination of how climate variability, subject to threshold and non-threshold filtering by the catchment, is manifested in temporal and spatial patterns in hydrological response. [1] Robinson JS, Sivapalan M. Temporal scales and hydrological regimes: implications for flood frequency scaling. Water Resour Res 1997; 33(12): 2981-2999.
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1807 Climate impacts
DE: 1847 Modeling
SC: Hydrology [H]
MN: Fall Meeting 2005