HR: 0800h
AN: H51B-1120    [Abstracts]
TI: A multi-basin analysis of runoff generation in a temperate forested watershed
AU: * James, A L
EM: april.james@mail.mcgill.ca
AF: McGill University, Rm 705 Burnside Hall, 805 Sherbrooke St West, Montreal, QC H3A 2K6 Canada
AU: Roulet, N T
EM: nigel.roulet@mcgill.ca
AF: McGill University, Rm 705 Burnside Hall, 805 Sherbrooke St West, Montreal, QC H3A 2K6 Canada
AU: Roulet, N T
EM: nigel.roulet@mcgill.ca
AF: McGill School of Environment, McGill University, 3534 University Avenue, Montreal, QC H3A 2A7 Canada
AB: Recent hydrologic and biogeochemical studies emphasise the importance of spatial, in addition to temporal, testing of process models. In doing so, they re-assert the influence of both the spatial and temporal variability in process that lead to difficulties in modelling storm response, contaminant transport and nutrient fluxes. Detailed empirical studies of runoff generation were traditionally confined to temporal aspects of meso-scale, trench and plot scales. More recently, empirical work has moved towards collecting more extensive spatial datasets within and among multiple basins as invaluable tools to seek better understanding of the controls on basin scale runoff processes. In our research our objectives are i) to estimate runoff generation across 8 nested basins in a pristine forested watershed in Eastern Quebec and ii) to examine the influence of antecedent moisture conditions (connectivity) and basin morphology on runoff generation. The 8 nested basins studied range in size from 7 to 147 ha and have considerable relief. Morphological characteristics for each basin are derived from a high-resolution digital elevation model ($<$1m spacing), a product of a 50 KHz LIDAR dataset. Isotopic hydrograph separation and geochemical end-member-mixing-analysis provide estimates of runoff generation for 5 storms of varying in size, intensity and antecedent moisture conditions. In two catchments antecedent moisture conditions and connectivity are evaluated using pre-storm spatial surveys of shallow soil moisture and transects of water table elevations. With an extended spatial dataset, we attempt to separate out how the controls on runoff generation change in space and time, in and across basins.
DE: 1806 Chemistry of fresh water
DE: 1829 Groundwater hydrology
DE: 1860 Runoff and streamflow
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting