HR: 16:45h
AN: H34D-04    [Abstracts]
TI: Integrated snow, soil and water-balance measurement strategy for multi-scale environmental observations in mountain areas
AU: * Bales, R C
EM: rbales@ucmerced.edu
AF: University of California, Merced, PO Box 2039, Merced, CA 95344 United States
AU: Molotch, N P
EM: molotch@cires.colorado.edu
AF: University of Colorado, CIRES 216 UCB, Boulder, CO 80309 United States
AU: Marks, D G
EM: danny@nwrc.ars.usda.gov
AF: USDA Agriculture Research Service, NW Watershad Reseach Ctr 800 Park Blvd Ste 105, Boise, ID 83712 United States
AU: Small, E E
EM: Eric.Small@colorado.edu
AF: University of Colorado, Dept Geological Sciences Box 399, Boulder, CO 80309 United States
AB: The building of multiscale environmental observatory networks is a critical step in addressing the woefully inadequate observational infrastructure and understanding of mountain water balances. These networks will support science questions that need estimates of water reservoirs and fluxes at the point, hillslope, headwater catchment and basin scales. This strategy will necessarily integrate both ground- and space-based data, using a coherent approach to measure fluxes of water and nutrients from bedrock to boundary layer. At the point scale multiple strategies can provide accurate estimates of rainfall, snow depth and soil moisture; though snow water equivalent and snowmelt remain challenges, in part due to the spatial heterogeneity of the energy balance, topography, and interactions between vegetation, snow and soil. The spatial distribution of snow is perhaps the best understood, measurable quantity at hillslope to headwater catchment (<1 km²) and at basin scales (>100 km²) using a blended satellite and ground-based measurement strategy, though significant measurement challenges remain at intermediate scales. Comparable understanding for soil moisture, rainfall and water use by vegetation have yet to emerge, however we are testing approaches that build on what we have learned from prototype snow, soil moisture and sap-flow arrays. For example, the gap between the scale of a ground-based array and that of visible/infrared satellite data (0.25-1.0 km²) is one that is amenable to various interpolation methods in complex terrain; however satellite-based information on soil moisture is generally available only at a much coarser resolution (>100 km²). A coherent, integrated measurement system with carefully placed instrument clusters that measure atmospheric fluxes, snow depth, energy, and melt, soil moisture, and groundwater fluxes will provide information on how these processes are coupled, and how they vary with topography, vegetation, and soil characteristics. Extending these sites across a range of elevations in transects will provide information on how to scale snow and hydrologic processes from hillslope to larger scales. Within each cluster, randomly placed nodes to measure these properties at the same point provide an indication of how these quantities vary with slope, aspect, location in canopy, and soil characteristics. At larger scales, measurement sites should include end-member conditions to capture the heterogeneities that can lead to hydrologic extremes.
DE: 1836 Hydrological cycles and budgets (1218, 1655)
DE: 1866 Soil moisture
SC: Hydrology [H]
MN: Fall Meeting 2005