Spatial And Temporal Variation Of SWE In An Upper Montane Forest Catchment In The Front Range Of Colorado
Coate, Jacob 1 ; Anderson, Suzanne P 2
1 INSTAAR
2 INSTAAR
Gordon Gulch is a headwater catchment for Boulder Creek in Boulder, CO, which helps supply water to the Mississippi and many of the populations in the South East of the United States. Gordon Gulch experiences maximum precipitation and stream discharge in late April and early May (Rock, 2008). Due to its relatively high elevation and subalpine mountainous terrain, Gordon Gulch catchment receives much of its precipitation as snow. Peak discharge occurs near the timing of maximum snow depth, when snowmelt it at its peak. A major difference between Gordon Gulch and other high elevation sites is that Gordon Gulch does not retain all of its snowfall is one seasonal snowpack (Rock, 2008). Instead, stream discharge increases greatly as temperatures rise above freezing after each snow event. This leads to a much more variable seasonal snow depth trend than many other high elevation sites. This has significant hydrologic implications, as snowmelt produces as much as 80% of streamflow in the Front Range of Colorado (Caine, 1995). The most important variable for hydrologic forecasting in snowmelt dominated watersheds is the total water volume contained in the snowpack (Elder et al. 1998). Here, we examine spatial and temporal variations of snow water equivalent (SWE) through three snow seasons (2009, 2010, 2011) in Gordon Gulch. Field observations, remote sensing, and GIS analysis were used to gain insight into factors influencing the distribution of SWE in a snowmelt dominated hydrologic system. By assuming little spatial variability in snow density, we primarily utilize snow depth measurements to derive SWE. By observing trends in SWE between two transects in Gordon Gulch on different aspects and slope angles, we can gain insight into factors affecting SWE in this subalpine snow-dominated ecosystem.
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Nathan Rock, SP Anderson. Analysis of spatial and temporal variability of snowpack in an Upper Montane Forest Catchment in the Front Range of Colorado. Unpublished p. 1-39