HR: 09:00h
AN: H11G-04    [Abstracts]
TI: Consistency between hydrological models and field observations: Linking processes at the hillslope scale to hydrological responses at the watershed scale.
AU: Woods, R
EM: r.woods@niwa.co.nz
AF: NIWA, 10 Kyle Street, Christchurch, 8004, New Zealand
AU: * Clark, M
EM: mp.clark@niwa.co.nz
AF: NIWA, 10 Kyle Street, Christchurch, 8004, New Zealand
AU: Rupp, D
EM: d.rupp@niwa.co.nz
AF: NIWA, 10 Kyle Street, Christchurch, 8004, New Zealand
AU: Tromp van Meerveld, I
EM: ilja@sfu.ca
AF: Department of Geography, Simon Fraser University, Burnaby, BC V5A1S6, Canada
AU: Peters, J
EM: nepeters@usgs.gov
AF: USGS Water Science Center, 3039 Amwiler Road, Suite 130, Atlanta, GA 30360, United States
AU: Freer, J
EM: j.freer@lancaster.ac.uk
AF: Environmental Science Department, Lancaster University, Lancaster, LA14YQ, United Kingdom
AB: The purpose of this paper is to identify simple connections between observations of hydrological processes at the hillslope scale and observations of the response of watersheds following rainfall. We focus on the well- studied Panola Mountain Research Watershed (PMRW), Georgia, USA. Recession analysis of discharge Q shows that while the relationship between dQ/dt and Q is approximately consistent with a linear reservoir for the hillslope, there is a deviation from linearity that becomes progressively larger with increasing spatial scale. To account for these scale differences we define conceptual models of streamflow recession at both the hillslope scale and the watershed scale, and assess how models at the hillslope scale can be aggregated to be consistent with models at the watershed scale. Results show that it is possible to reproduce the non-linear behaviour of the watershed following rainfall by adding flow from a small set of linear reservoirs. Indeed, the non-linear recession behavior at the 41-ha Panola watershed can be reproduced by combining linear time constants from the 0.1-ha hillslope and the 10-ha upper catchment with a linear time constant that reflects a slowly draining aquifer. These simple links between linear processes at the hillslope scale and non-linear watershed scale should be considered carefully when calibrating distributed hydrological models, especially in cases when the transmissibility varies considerably between different hydrological response units.
DE: 1805 Computational hydrology
DE: 1839 Hydrologic scaling
DE: 1847 Modeling
DE: 1848 Monitoring networks
DE: 1860 Streamflow
SC: Hydrology [H]
MN: 2007 Fall Meeting