Four-dimensional snowmelt distribution in the Sierra Nevada imaged with ground-based Tripod LiDAR
Abstract
Studies involving the modeling of snow pack and snowmelt distribution under current conditions and potential climate change conditions often use MODIS snow cover maps for the snow cover extent (satellite imagery product with 500 m pixel postings), point data from snow pillows that provide snow water equivalent (SWE), and snow course data that provide estimates of SWE from composite measurements over a site. Systematic measurements of spatially varying snow depth as it relates to the distribution of SWE as scales 30-100 m are needed to adequately parameterize hydrologic-process models, such as the Basin Characterization Model. Repeat ground-based LiDAR (Terrestrial Laser Scanning-TLS) was used to develop sub-decimeter (3-5 cm) 3D time-series of snow melt distribution at four study sites in the Sierra Nevada: 1) the U.C. Berkeley Central Sierra Snow Lab, 2) the Castle Creek snow course, 3) an site west of Conway summit (Highway 395 north of Lee Vining), and 4) the Mammoth Mountain Snow Science Lab. Baseline TLS data at site were collected during Fall 2007 with periodic surveys during the snow accumulation and snowmelt periods through Spring 2008. The spatially dense TLS imagery (3-5 cm spot spacing) were aligned for each epoch and were used to calculate spatially varied snow surfaces, the snow volume, and snow volume change. Snow-core derived SWE measurements were used to compute the spatially varying water volume for each site. Ground-based LiDAR proved to be an excellent tool for measuring sub-decimeter scale snow surfaces and the resulting snow and equivalent water volumes for targets roughly the size of one to four MODIS pixel cells.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFM.G41D..05B
- Keywords:
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- 0740 Snowmelt;
- 0758 Remote sensing;
- 0794 Instruments and techniques;
- 1294 Instruments and techniques;
- 1876 Water budgets