| Abstract: | Recharge into granitic bedrock under a melting snowpack is being investigated as part of a study designed to understand hydrologic processes involving snow at Yosemite National Park in the Sierra Nevada Mountains of California. Snowpack measurements, accompanied by water content and matric potential measurements of the soil under the snowpack, allowed for estimates of infiltration into the soil during snowmelt and percolation into the bedrock. During portions of the snowmelt period, infiltration rates into the soil exceeded the permeability of the bedrock and caused ponding to be sustained at the soil-bedrock interface. During a 5-d period with little measured snowmelt, drainage of the ponded water into the underlying fractured granitic bedrock was estimated to be 1.6 cm d?1, which is used as an estimate of bedrock permeability. The numerical simulator TOUGH2 was used to reproduce the field data and evaluate the potential for vertical flow into the fractured bedrock or lateral flow at the bedrock-soil interface. During most of the snowmelt season, the snowmelt rates were near or below the bedrock permeability. The field data and model results support the notion that snowmelt on the shallow soil overlying low permeability bedrock becomes direct infiltration unless the snowmelt rate greatly exceeds the bedrock permeability. Late in the season, melt rates are double that of the bedrock permeability (although only for a few days) and may tend to move laterally at the soil-bedrock interface downgradient and contribute directly to streamflow. ?? Soil Science Society of America. |
| Genre: | Conference Paper |
| ProdID: | 70033294 |
| Citation Author: | Flint, A. L.; Flint, L. E.; Dettinger, M. D. |
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| Citation End Page: | 357 |
| Citation Issue: | 1 |
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| Citation Language: | English |
| Citation Larger Work Title: | Vadose Zone Journal |
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| Citation Number Of Pages: | 8 |
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| Citation Search Results Text: | Modeling soil moisture processes and recharge under a melting snowpack; 2008; Conference Paper; Vadose Zone Journal; Flint, A. L.; Flint, L. E.; Dettinger, M. D. |
| Citation Start Page: | 350 |
| Citation Volume: | 7 |
| Citation Year: | 2008 |
| Type: | citation/reference |
| Text: | Modeling soil moisture processes and recharge under a melting snowpack; 2008; Conference Paper; Vadose Zone Journal; Flint, A. L.; Flint, L. E.; Dettinger, M. D. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.2136/vzj2006.0135 |
| Date Other: | Tue, 1 Jan 2008 00:00 -0600 |
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