Caspar Creek Experimental Watersheds Phase 2 (1985-2017) data: 3rd edition

The Caspar Creek Experimental Watersheds are a long-term USDA Forest Service research site located near Fort Bragg, California in the Jackson Demonstration State Forest in a coast redwood and Douglas-fir dominated conifer forest. The site includes two experimental watersheds: the North Fork (479 hectares) and the South Fork (417 hectares). Measurements of precipitation, streamflow, and sediment transport began at Caspar Creek in 1962. Two timber harvesting experiments have been completed. The first experimental harvest (Phase 1) was a selection cut conducted in the South Fork watershed using tractor yarding in the early 1970s, prior to the implementation of the modern California Forest Practice Rules. Phase 1 of the project includes data from 1962 to 1985. Gaging stations were added in 12 subwatersheds of the North Fork by 1985 in preparation for the second experimental harvest (Phase 2, 1985-2017). From 1985 to 1992, roughly half of the North Fork watershed was logged, mainly using clearcutting and cable yarding, and following the newly-enacted Forest Practice Rules. Gaging stations were added in 10 subwatersheds of the South Fork in 2000 in preparation for a third harvesting experiment (Phase 3). Logging for the third harvest occurred in 2017-2019 in the South Fork watershed. This data publication contains the following Phase 2 data: 1) Water depth (stage) and volumetric discharge and turbidity data measured at the North Fork and South Fork weirs (1 August 1985 to 31 July 2017); the North Fork subwatersheds Henningson (1 August 1985 to 31 July 2017), XYZ (1 November 1999 to 31 July 2017), and X-ray (1 August 2001 to 31 July 2017); nine subwatersheds in the South Fork: Ogilvie, Porter, Richards, Sequoyah, Treat, Uqlidisi, Williams, Yocom, and Ziemer (1 August 2000 to 31 July 2017); and stage and turbidity data for Arfstein in the North Fork (1 August 1985 to July 2017) and Quetelet in the South Fork (1 August 2000 to 31 July 2017). 2) Annual deposition volumes for the collection ponds directly upstream of the North Fork and South Fork weirs from 1986 to 2017. 3) Suspended sediment concentrations collected at the North Fork and South Fork weirs (1985 to 2017); North Fork subwatersheds Arfstein (1985 to 2017), Henningson (1985 to 2017), X-ray (2001 to 2017), and XYZ (1999 to 2017); South Fork tributaries Quetelet, Ogilvie, Porter, Richards, Sequoyah, Treat, Uqlidisi, Williams, Yocom, and Ziemer (2000 to 2017). 4) Bedload transport rates measured during thirteen storms (stage > 2 feet at the North Fork weir) from 1988 to 1995 on the North Fork mainstem at the Arfstein gaging station. 5) Air temperature, relative humidity, wind speed and direction, incoming solar radiation, photosynthetically active radiation (PAR), heat index, and dew point at a meteorological station adjacent to the South Fork watershed (MET) (6 February 2009 to 31 July 2017). 6) Precipitation from five tipping bucket rain gages: N408 and N620 (1 August 1987 to 31 July 2017); S620 (1 August 1985 to 31 July 2017); S640 (1 August 2000 to 31 July 2017); S600 (1 August 2012 to 31 July 2017) and one weighing gage, MET (26 March 2009 to 31 July 2017). 6) Stable water isotope concentrations (δ18O and δ2H) from water samples obtained from precipitation, soil, vegetation, groundwater, and streams along transects in four subwatersheds of the South Fork (Treat, Uqlidisi, Williams, and Ziemer) from May 2016 through July 2017. 7) Size, condition, and mobility variables of tagged in-channel wood monitored along the North Fork and South Fork large wood (LW) study reaches (1998 to 2018). 8) Spatial files describing: a geodatabase and shapefiles containing study locations, harvest unit boundaries, stream lines, isotope sampling locations, and watershed boundaries for Phase 2; mapped wood and channel banks in the large wood study reaches (including photographs); raster files containing a digital elevation model and hillshade for Caspar Creek; and point cloud data for Caspar Creek derived from airborne LiDAR acquired in 2017.
The Caspar Creek Experimental Watersheds were established to determine the effects of timber harvesting on streamflow and sediment delivery in northern coastal California watersheds.
Additional metadata documents containing details specific to each dataset are also provided in this data package. The first edition of the Phase 2 data was published on 17 March 2020 (https://doi.org/10.2737/RDS-2020-0018). A second edition of these data was made available on 07 January 2021 (https://doi.org/10.2737/RDS-2020-0018-2) which included additional data, corrections, and geospatial files. The metadata for this third edition was published on 18 November 2022, with the data being under embargo. On 10 January 2024 the data embargo was lifted and this third edition now includes water depth, volumetric discharge, turbidity, and suspended sediment concentration data for the Henningson subwatershed, turbidity for all subwatersheds included in the second edition, precipitation at five locations, and in-channel large wood. General data changes made in this third edition are described in the process steps section. Minor errors in the early editions of these data were also corrected and noted in the metadata documents specific to each dataset. All of these data modifications resulted in substantial updates to the metadata documentation. On 03/22/2024, we updated the package to include all metadata documents as both XML and HTML. The Caspar Creek Phase 1 data (1962-1985) are also available (Richardson et al. 2021, https://doi.org/10.2737/RDS-2020-0017-2).