ARS | Publication request: Hypothesized hydrological response to a prescribed fire on a small mountainous watershed

Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: September 6, 2003
Publication Date: November 18, 2003
Citation: Flerchinger, G.N., and Clark, P.E., 2003. Hypothesized hydrological response to a prescribed fire on a small mountainous watershed. Abstract H32C-0585 In: EOS Transactions, Vol. 84(46) supplement, American Geophysical Union, CD-ROM)

Technical Abstract: Prescribed fire is often used to control invasive weeds, improve habitat, and deter wildfire. The USDA-ARS Northwest Watershed Research Center plans to burn a small 26-ha ephemeral watershed where detailed measurements and a ten-year water balance had been conducted. This paper investigates the potential hydrological response to that prescribed fire. Changes in water repellency and infiltration capacity were assumed not to limit the low intensity snowmelt input to the basin. Percolation, subsurface flow and runoff during the first runoff season are influenced by the soil moisture deficit created by pre-burn vegetation conditions and will likely not be influenced greatly by the fire. A year of reduced evapotranspiration following the fire is necessary to significantly reduce the soil moisture deficit and increase percolation through the root zone and subsurface flow to the stream. Results indicate significant changes in streamflow in this subsurface-flow-dominated watershed may not be observed until the second snowmelt season following the fire and could increase by approximately 25%. These results are unlike watersheds dominated by overland flow and surface runoff where increased flows are more likely to occur during the first year following a fire.