Poster Number 51
Statistical methods involved general summary statistics, and time series cross-correlation with prior smoothing through the use of a 24-hour averaging filter. Numerical modeling was completed using VS2DH software, a 2-D heat transport model developed by the USGS.
Initial findings indicate that analysis by statistical methods may provide a clearer mode of comparison between sites than numerical modeling methods. Numerical modeling attempts appear severely restricted by the use of a 2-D model, by low data resolution across each site, and by the likely presence of a high degree of subsurface heterogeneity.
Descriptive statistics reveal that the gravel site features a higher degree of hyporheic thermal heterogeneity, resulting from greatly varying degrees of stream-hyporheic connectivity. Stream-hyporheic connectivity at the sand site appears more consistent throughout, resulting in less thermal heterogeneities. Ultimately, our results suggest that physical heterogeneities such as a greater range in sediment size or a less even stream channel are reflected as thermal heterogeneities in the subsurface.