Untitled DocumentSWE distribution and snowmelt processes
Macro Theme Area:
Basin Scale Water Balance [Project ID: B01]
PI:
Paul Brooks
CO-PI(s):
Roger Bales, Enrique Vivoni, Noah Molotch
Basin focus:
Regional SW, Colorado, Rio Grande
Specific area in
basin /
field sites:
Rio Grande
VCNP
Signature data: Kings River Basin CA, Salt-Verde River Basin, AZ
Summary/Goals: Examines the spatial and temporal distribution of snow water equivalent (SWE) and snowmelt that force the energy balance variables, with the goal of improving inputs into hydrologic models.
Activities and outcomes during past year:
Three scientific questions have been addressed during the current reporting period aimed at improving estimates of hydrologic fluxes in and out of mountainous watersheds. First, process level controls on snow accumulation and ablation were investigated in the VCNP ecohydrology obseratory in NM. Second, uncertainty in spatially distributed snow water equivalence estimates arising from changes in radiation associate with vegetation strucutre was evaluated using both field observations and models. The results showed that snow distribution and ablation is extremely sensitive to the shading and scattering of incident radiation by vegetation.
Third, processes controlling stream flow generation and the fate of snowmelt were investigated using isotopic and geochemical tracers at two streams draining from Redondo Peak, Redondo Creek and La Jara Creek. Contribution of "old" waters to stream flow was 80% to 90% on average and its percentage gradually increased from spring to summer with increase in discharge. Infiltration-excess overland flow of snowmelt did not appear to occur at both catchments. This information will improve our understanding of how changes in hydrologic and biogeochemical cycles in response to climate variability and change in these catchments affect water availability for terrestrial and aquatic ecosystems.
The results from these projects were published in one paper in the Journal Hydrologic Processes and four papers in the Journal Ecohydrology.
Plans for the upcoming year:
For the next reporting period we will refine our spatial models of snow accumulation using RS products and link them with process models of snow melt and partitioning into vegetation water use, runoff, and recharge.
