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[Geophysical Research Letters]
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Supporting Information For:
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[Placing the 2012-2015 California-Nevada drought into a paleoclimatic context: Insights
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from Walker Lake, California-Nevada, USA]
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[Benjamin J. Hatchett1*, Douglas P. Boyle1, Aaron E. Putnam2, 3, and Scott D. Bassett1]
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[1. Department of Geography, University of Nevada, Reno, Reno, Nevada
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2. School of Earth and Climate Sciences and Climate Change Institute, University of
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Maine, Orono, Maine
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3. Lamont-Doherty Earth Observatory, Columbia University, New York City, New York]
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Contents: Figures S1 to S2 and captions.
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Figure S1: a) Schematic of the water balance model components. The total runoff
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produced by each of the model units is summed and used as input (inflow) to the lake
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model. b) Schematic of the lake evaporation model components. A United States
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Geological Survey 10 m digital elevation map (DEM) was used to produce the rating
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curve (volume-elevation-surface area relationships). A monthly time step is used for both
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models. Calibrated parameter values are shown in bold italics and fixed parameter values
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are shown in italics. The water balance model was manually calibrated using a multi-step
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method aimed at fitting observed West Walker River streamflow, snow water equivalent,
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and potential evapotranspiration. Observed streamflow from the United States Geological
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Survey Gauge 10296500 near Coleville, CA (see Figure 1a) between A.D. 1993-2011
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was used in the water balance model calibration procedure. This gauge represents the
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naturalized flow regime of the West Walker River. Potential evapotranspiration estimates
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from the Farnsworth et al. [1982] atlas and SNODAS [NORSCH, 2004] estimates of
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snow water equivalent between A.D. 2003-2011 were also used in the calibration
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procedure.
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References:
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Farnsworth, R.K., E.S. Thompson, and E.L. Peck (1982), Evaporation atlas for the
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contiguous 48 United States, NOAA Tech. Rep. NWS 33, U.S. Department of
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Commerce, Washington D.C.
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National Operational Hydrologic Remote Sensing Center (2004), Snow Data Assimilation
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System (SNODAS) Data Products at NSIDC, 2003-2013, Boulder, Colorado USA:
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National Snow and Ice Data Center, doi:10.7265/N5TB14TC.
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Figure S2: PRISM-estimated basin average precipitation for the Walker Lake Watershed
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showing water years 1895-2015 (through June) used for the transient simulation (the
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simulation used monthly data from this period). Key periods are shown by bar coloring,
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including the 1987-1992 drought for comparison to the current drought. Note that the
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period chosen as the baseline has the greatest variability of all modeled periods and
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includes the wettest year (water year 1983) and the driest year (water year 1977) that
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exists in the PRISM timeseries, as well as the 1987-1992 drought and 1995-1998 wet
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interval. The two recent droughts of the last 30 years are shown and it can be seen that
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the current 2012-2015 drought is of greater severity from a negative precipitation
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anomaly that than 1987-1992 drought.