Modeling transport of nutrients & sediment loads into Lake Tahoe under climate change
The outputs from two General Circulation Models (GCMs) with two emissions scenarios were downscaled and bias-corrected to develop regional climate change projections for the Tahoe Basin. For one model—the Geophysical Fluid Dynamics Laboratory or GFDL model—the daily model results were used to drive a distributed hydrologic model. The watershed model used an energy balance approach for computing evapotranspiration and snowpack dynamics so that the processes remain a function of the climate change projections. For this study, all other aspects of the model (i.e. land use distribution, routing configuration, and parameterization) were held constant to isolate impacts of climate change projections. The results indicate that (1) precipitation falling as rain rather than snow will increase, starting at the current mean snowline, and moving towards higher elevations over time; (2) annual accumulated snowpack will be reduced; (3) snowpack accumulation will start later; and (4) snowmelt will start earlier in the year. Certain changes were masked (or counter-balanced) when summarized as basin-wide averages; however, spatial evaluation added notable resolution. While rainfall runoff increased at higher elevations, a drop in total precipitation volume decreased runoff and fine sediment load from the lower elevation meadow areas and also decreased baseflow and nitrogen loads basin-wide. This finding also highlights the important role that the meadow areas could play as high-flow buffers under climatic change. Because the watershed model accounts for elevation change and variable meteorological patterns, it provided a robust platform for evaluating the impacts of projected climate change on hydrology and water quality.
Citation Information
Publication Year | 2013 |
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Title | Modeling transport of nutrients & sediment loads into Lake Tahoe under climate change |
DOI | 10.1007/s10584-012-0629-8 |
Authors | John Riverson, Robert Coats, Mariza Costa-Cabral, Mike Dettinger, John Reuter, Goloka Sahoo, Geoffrey Schladow |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Climatic Change |
Index ID | 70040562 |
Record Source | USGS Publications Warehouse |
USGS Organization | Branch of Regional Research-Western Region |