Spatial And Temporal Variations In Stream Chemistry After Wildfire
Murphy, Sheila F 1 ; Writer, Jeff H 2
2 Presenting Author
1 U.S.G.S.
2 U.S.G.S. ; University of Colorado
Past studies of stream chemistry after wildfire are conflicting. Some studies show increases in pH, turbidity, nutrients, metals, and other constituents, while others report little impact. Many of these studies sampled water chemistry at monthly intervals; this frequency cannot capture the high temporal variability in stream discharge and chemistry of many mountain streams. Discharge, organic carbon, nutrients, major ions, and metals were measured at several sites along a stream affected by the September 2010 Fourmile Canyon Fire (within the Boulder Creek Watershed, Colorado) immediately after the wildfire and through the following winter. High-frequency sampling (daily and shorter periods) continues during snowmelt and summer convective storms. Runoff from burned north- and south-facing drainages will also be monitored to assess differences in hillslope contributions to the stream. This study will improve our knowledge of how upland hydrologic and biogeochemical processes affected by fire influence downstream water quality, both spatially and temporally.