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Watershed Modeling and Tree Rings
Multi-century streamflow derived from watershed
modeling and tree-ring data
Franco Biondi (PI); Laurel Saito (Co-PI);
Jose Salas (Co-PI)
Student: Jasmine Vittori
Funded by:
National Science Foundation
* 2009 -2012*
Insight on long-term changes of streamflow is critical for addressing
implications of global warming on sustainable water management, especially in
the semi-arid western USA. A widely
used approach for extending the relatively brief instrumental record of
streamflow, and obtaining a paleo perspective on recent hydrological changes, is
by means of tree-ring records. To date,
dendrohydrologists have employed sophisticated regression techniques to extend
runoff records, but this empirical approach cannot directly test the influence
of watershed factors that alter streamflow independently of climate. We are
applying a transformative approach for quantifying the effect of watershed
topography, vegetation dynamics, natural disturbance (such as wildfire), and
land use changes on proxy-augmented streamflow records. This approach can better
define uncertainty of paleo reconstructions, since it employs tree-ring records
to generate long time series of precipitation (and possibly temperature), which
then become inputs to a mechanistic watershed model that calculates streamflow
while at the same time determining the influence of landscape changes.
Hydrological parameters will first be generated directly from tree-ring records
using several statistical approaches to distinguish uncertainties in the
reconstructions due to noise, parameters of
record extension models, and/or regional versus local scales. A mechanistic
watershed model that was specifically designed to calculate streamflows at
seasonal and annual time scales will then be applied using the most reliable
precipitation and air temperature reconstructions. Through model experiments, we
will determine the influence of factors that can change the streamflow measured
at a certain point even when upstream climate remains the same, such as
vegetation cover (affected by plant species dynamics, wildfire, landslides,
etc.) and land use (due to human activities, such as cattle or sheep grazing,
clearcutting, crop production, urban development, etc.).The study will be
conducted in the upper reaches of the Walker River, which straddles the boundary
between the Sierra Nevada of California and the Great Basin of Nevada, and for
which we already have generated a 2300-year tree-ring record of water-year
precipitation.
Publications:
Related
publications:
For further
information contact Dr. Saito,
lsaito@cabnr.unr.edu
Research
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