Geochemical maps of the North Fork of the American River Wilderness Study Area, California

1982 ◽  
Keyword(s):  
The North ◽  
American River ◽  
North Fork

scholarly journals Intercomparison of Meteorological Forcing Data from Empirical and Mesoscale Model Sources in the North Fork American River Basin in Northern Sierra Nevada, California*

2013 ◽  
Vol 14 (3) ◽  
pp. 677-699 ◽  
Author(s):  
Nicholas E. Wayand ◽  
Alan F. Hamlet ◽  
Mimi Hughes ◽  
Shara I. Feld ◽  
Jessica D. Lundquist
Keyword(s):  
River Basin ◽  
Sierra Nevada ◽  
Mesoscale Model ◽  
Wrf Model ◽  
High Elevation ◽  
Meteorological Forcing ◽  
The North ◽  
Single Station ◽  
American River ◽  
North Fork

Abstract The data required to drive distributed hydrological models are significantly limited within mountainous terrain because of a scarcity of observations. This study evaluated three common configurations of forcing data: 1) one low-elevation station, combined with empirical techniques; 2) gridded output from the Weather Research and Forecasting Model (WRF); and 3) a combination of the two. Each configuration was evaluated within the heavily instrumented North Fork American River basin in California during October–June 2000–10. Simulations of streamflow and snowpack using the Distributed Hydrology Soil and Vegetation Model (DHSVM) highlighted precipitation and radiation as variables whose sources resulted in significant differences. The best source of precipitation data varied between years. On average, the WRF performed as well as the single station distributed using the Parameter Regression on Independent Slopes Model (PRISM). The average percent biases in simulated streamflow were 3% and 1%, for configurations 1 and 2, respectively, even though precipitation compared directly with gauge measurements was biased high by 6% and 17%, suggesting that gauge undercatch may explain part of the bias. Simulations of snowpack using empirically estimated longwave irradiance resulted in melt rates lower than those observed at high-elevation sites, while at lower elevations the same forcing caused significant midwinter melt that was not observed. These results highlight the complexity of how forcing data sources impact hydrology over different areas (high- versus low-elevation snow) and different time periods. Overall, results support the use of output from the WRF model over empirical techniques in regions with limited station data.

Evidence for a Prehistoric Petroglyph Trail Map in the Sierra Nevada

1988 ◽  
Vol 9 (2) ◽  
pp. 147-154 ◽  
Author(s):  
Willis A. Gortner
Keyword(s):  
Sierra Nevada ◽  
Topographic Map ◽  
North Central ◽  
The North ◽  
Map Interpretation ◽  
American River ◽  
North Fork

A single petroglyph site in the North-Central Sierra Nevada in the upper watershed of the North Fork of the American River has a unique glyph with meandering and connecting wavy lines that are now proposed as trail maps. A tracing of this glyph was made from a photograph, and this was then placed with the same compass alignment on a topographic map showing all petrographic sites along the North Fork watershed. The ability to superimpose and accurately orient the glyph tracing over a map of these petroglyph sites, and the presence of petroglyphs on seventy-seven individual rock outcroppings mostly within 50 m of the presumed trails, support the trail map interpretation of this rock carving. It is suggested that a hunt shaman may have incised this glyph for ritualistic use.

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