USGS-Water Quality Partnership, Fixed Station: Hydrologic response to woodland restoration treatement

U.S. Geological Survey

Overland runoff and associated sediment production at Bandelier National Monument threaten the integrity of both a wilderness landscape and the thousands of pre-historic cultural resources it contains. Restoration studies conducted at multiple scales at Bandelier since 1992 have demonstrated the potential of slash-mulching restoration treatments in degraded woodland areas to promote herbaceous growth and stabilize eroding soils; in 1996 a paired, 40 ha watershed restoration study area was established to evaluate landscape scale effects of restoration treatment. Subsequently, two separate hydrologic assessments were initiated within the watershed study area to quantify and monitor the long term effects of the restoration treatment on runoff and sediment production. The first (2000-2001) was designed to quantify differences between the treated and untreated watersheds for bed-sediment production as measured in six 0.1 ha catchment areas in each 40 ha watershed. The second (2002-2004) was designed to quantify differences in runoff and suspended-sediment production between treated and untreated watersheds by instrumenting a 0.38 ha catchment in each watershed. The bed-sediment production study documented a two order magnitude difference between the two watersheds for the two years sampled; the runoff/ suspended sediment study however, has suffered from a relative absence of significant precipitation events since it was initiated in 2002. The current proposal is a request for funding to continue fixed station monitoring of runoff and suspended sediment for an additional three years, given the initial investment to instrument the two 0.38 ha catchment areas and the absence of significant results to date. Continued operation of the two stations would provide an opportunity to sample a sufficient number and range of runoff events necessary to properly quantify differences in hydrologic response between treated and untreated areas.