HR: 0800h
AN: H41D-0429    [Abstracts]
TI: Investigating the Influences of Climatic Variability and Land Cover Change on the Land Surface Hydrology of Northern Wisconsin, USA
AU: * Vano, J A
EM: jvano@wisc.edu
AF: Center for Sustainability and the Global Environment, U of Wisconsin, Madison, 1710 University Avenue, Madison, WI 53726 United States
AU: Foley, J A
EM: jfoley@wisc.edu
AF: Center for Sustainability and the Global Environment, U of Wisconsin, Madison, 1710 University Avenue, Madison, WI 53726 United States
AU: Kucharik, C J
EM: kucharik@wisc.edu
AF: Center for Sustainability and the Global Environment, U of Wisconsin, Madison, 1710 University Avenue, Madison, WI 53726 United States
AU: Coe, M T
EM: mtcoe@wisc.edu
AF: Woods Hole Research Center, 149 Woods Hole Road, Woods Hole, MA` 02540 United States
AB: Ecosystem processes depend on water. As such, our understanding of biogeochemical and ecological processes is enhanced when our ability to track the flow and storage of water within ecosystems is improved. In this study, we focus on the climate and ecological controls of the land surface water balance within the Northern Highlands Lake District of northern Wisconsin, USA. To better understand the region's water resources and how the magnitude, timing, and variability in water flow could be altered by future human development and climate change, we investigate the balance between precipitation, evapotranspiration to the atmosphere, surface runoff, and groundwater recharge from 1951-2000. For this study, we use the Integrated BIosphere Simulator (IBIS), a land surface / ecosystem model, along with a diverse range of observations including eddy-covariance fluxes, stream gauge data, groundwater recharge rates, soil temperature, and snow cover measurements. We investigate the biophysical and hydrological processes specific to cold temperate climates, which requires special attention to complexity of the soil freeze-thaw cycle and the snow mass and energy balance. We also examine how the land cover impacts the flow and storage of water by comparing both seasonal and interannual variations over various land covers including grasslands, shrublands, coniferous and deciduous forests, as well as soil types ranging from sand to clay. Results show 1) snow cover and a soil surface organic layer (i.e. decomposing litter fall) play a key role in wintertime soil temperatures and the timing of spring thaw and 2) both land cover and climate variability affect the regional hydrology, but these mechanisms impart change expressed at different timescales. Climate variability has an obvious signal from one year to the next, but does not persist for long. In contrast, land cover change affects the hydrology in subtler, but consistent ways, which may have larger cumulative effects in the long term.
DE: 1843 Land/atmosphere interactions (1218, 1631, 3322)
DE: 1847 Modeling
DE: 1863 Snow and ice (0736, 0738, 0776, 1827)
DE: 1876 Water budgets
DE: 1878 Water/energy interactions (0495)
SC: Hydrology [H]
MN: Fall Meeting 2005