Surface-subsurface flow linkage in a snowmelt environment

Authors: Seyfried, Mark; Marks, Daniel; GRANT, LAURA - UCSB; Winstral, Adam

Submitted to: Trans American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: 9/30/2006
Publication Date: 12/20/2006
Citation: Seyfried, M., Marks, D., Grant, L., and Winstral, A. 2006. Surface-subsurface flow linkage in a snowmelt environment. EOS Transactions of the American Geophysical Union, 87(52) Fall Meeting Supplement, Abs H32B-01.

Interpretive Summary:

Technical Abstract: In much of the inter-mountain western USA streamflow and water resources are driven by snowmelt. Hydrologic objectives for addressing water issues have generally revolved around predicting the timing and amount of snowmelt input and assessing the impact on streamflow. Groundwater is generally overlooked. We provide evidence from the Reynolds Mountain Experimental Watershed (RCEW) located in southwestern Idaho that upland recharge processes are closely linked to groundwater-derived streamflow, so that neither can be understood independently. Two years of extensive soil water content data collected within indicate that water movement in the upper 1-3 m is largely vertical. These data, in combination with a separate snowmelt simulation, are the basis for a spatially distributed soil water balance model that shows how upland recharge is often limited to specific recharge sites some distance from the stream. At the same time, streamflow dynamics indicate that melt water inputs are rapidly expressed as streamflow, and groundwater levels are highly sensitive to these inputs. This has important implications on a local scale for issues regarding stream temperature impacting fisheries, and chemical exports. On a larger scale, it is directly related to mountain block recharge and water supply downstream.