Subsurface lateral flow generation in aspen and conifer-dominated hillslopes of a first order catchment in northern Utah
Article first published online: 3 DEC 2010
Copyright © 2010 John Wiley & Sons, Ltd.
Volume 25, Issue 9, pages 1407–1417, 30 April 2011
How to Cite
Burke, A. R. and Kasahara, T. (2011), Subsurface lateral flow generation in aspen and conifer-dominated hillslopes of a first order catchment in northern Utah. Hydrol. Process., 25: 1407–1417. doi: 10.1002/hyp.7906
- Issue published online: 13 APR 2011
- Article first published online: 3 DEC 2010
- Manuscript Accepted: 20 SEP 2010
- Manuscript Received: 19 FEB 2010
- Natural Resource Conservation Service
- Utah State University's Department of Watershed Sciences
- soil moisture;
- runoff generation;
- hillslope-stream connectivity;
Mountain headwater catchments in the semi-arid Intermountain West are important sources of surface water because these high elevations receive more precipitation than neighboring lowlands. This study examined subsurface runoff in two hillslopes, one aspen dominated, the other conifer dominated, adjacent to a first order stream in snow-driven northern Utah. Snow accumulation, soil moisture, trenchflow and streamflow were examined in hillslopes and their adjacent stream. Snow water equivalents (SWEs) were greater under aspen stands compared to conifer, the difference increasing with higher annual precipitation. Semi-variograms of shallow spatial soil moisture patterns and transects of continuous soil moisture showed no increase in soil moisture downslope, suggesting the absence of subsurface flow in shallow (∼12 cm) soil layers of either vegetation type. However, a clear threshold relationship between soil moisture and streamflow indicated hillslope–stream connectivity, deeper within the soil profile. Subsurface flow was detected at ∼50 cm depth, which was sustained for longer in the conifer hillslope. Soil profiles under the two vegetation types varied, with deep aspen soils having greater water storage capacity than shallow rocky conifer soils. Though SWEs were less under the conifers, the soil profile had less water storage capacity and produced more subsurface lateral flow during the spring snowmelt. Copyright © 2010 John Wiley & Sons, Ltd.