TY - Generic T1 - Understanding the Spatial Distribution of Snow Water Equivalent in Paired Basins in Southwest Montana, USA T2 - 83rd Annual Western Snow Conference Y1 - 2015 A1 - Jason Welz A1 - Jordy Hendrikx A1 - Stuart Challender A1 - Paul Stoy KW - avalanche KW - binary regression tree KW - paired basin KW - Snow water equivalent KW - spatial distribution AB -

The goal of this research, which was the focus of a master’s thesis, was to build upon previous investigations of the processes controlling the spatial distribution of snow water equivalent (SWE) in alpine environments. This involved taking a comprehensive look at the widely accepted physiographic variables of: elevation, slope, aspect, solar radiation, and wind exposure, but also avalanche activity, which has been given limited explicit inclusion. The paired basin design adopted in this study, between hypothesized avalanche-prone and avalanche-free basins, has been previously used to correlate avalanche activity with snowmelt runoff. However, it has not been used in an attempt to parse out which variables have the dominant influence on SWE distribution between adjacent areas of very similar physiographic character. While most previous studies have focused on the period of peak SWE to study its distribution, this current research considered the evolution of the controlling variables throughout snowpack development, and subsequent melt-out. A robust dataset of snow depth and SWE measurements were collected January 31 - July 10, 2013 on Cedar Mountain near Big Sky, MT. Physiographic variable values were extracted from a 10 m resolution digital elevation model (DEM) at snow sample points and input as predictors of observed SWE in multiple linear regression (MLR) and binary regression tree (BRT) models to spatially distribute SWE across the study area. Optimal models were selected by various measures of goodness of fit and cross-validation criteria. Calculated R2 values for MLR models (0.17-0.57) and BRT models (0.33-0.66) were comparable to previous studies indicating a relative level of success in predictive performance. Subsequent analysis of each optimal model’s variable selection and predicted SWE distributions revealed differences in the spatial and temporal patterns of this metric between the paired basins, confirming some well-understood processes as well as offering new insights.

 

Presentation in PDF

JF - 83rd Annual Western Snow Conference T3 - Proceedings of the Western Snow Conference CY - Grass Valley, California UR - /files/PDFs/2015Welz.pdf ER - TY - Generic T1 - Understanding the Spatial Distribution of Snow Water Equivalent and Subsequent Snowmelt Runoff Patterns of Paired Basins in Southwest Montana T2 - 82nd Annual Western Snow Conference Y1 - 2014 A1 - Jason Welz A1 - Jordy Hendrikx A1 - Stuart Challender A1 - Paul Stoy KW - avalanche KW - mountain hydrology KW - runoff KW - Snow water equivalent KW - snowmelt AB -

This paper presents the initial results of a research project with the primary goal of investigating the hydrologic role of avalanche activity alongside the physiographic variables (i.e. elevation, slope, aspect, wind shelter/exposure, landcover, and solar radiation) that the snow hydrology community widely consider to be the dominant controls on the spatial distribution of snow water equivalent (SWE) and subsequent snowmelt runoff in alpine basins. An extensive field campaign was conducted in two adjacent alpine basins in southwest Montana from January 31 to August 21, 2013, consisting of three survey periods to capture snowpack metrics during the phases of (1) accumulation; (2) peak SWE, and (3) ablation/snowmelt runoff. During each period, the same stratified random sampling methods were used to measure snow depth and SWE at transects along elevation contours. Transects were spatially distributed with the goal of acquiring a representative sample of the aforementioned physiographic variables as well as the components of avalanche paths. After quantifying the contribution of each of these variables to the distribution of SWE, we will also consider their impact on the timing and magnitude of snowmelt runoff. This will be determined by correlation to stream discharge measurements that were collected throughout the 2012- 2013 water year. The initial results are discussed as are the future steps.

JF - 82nd Annual Western Snow Conference T3 - Proceedings of the Western Snow Conference CY - Durango, Colorado UR - sites/westernsnowconference.org/PDFs/2014Welz.pdf ER -