DOI: 10.5061/dryad.tb2rbp05h
title: Frying Pan avalanche data

description: The data here are large wood data collected in the Summer of 2022 in the
 Frying Pan River Basin in the Sawatch Mountains of Central Colorado. There
 are six datasets included or referenced here. The first is general
 geomorphic and watershed characteristics of the stream reaches surveyed.
  The second is data from field reports to the CAIC. The third is
 topographic data for the studied avalanche pathways. The fourth is summary
 data of the wood volumes within each surveyed reach. The fifth is the
 unprocessed raw data for all wood jams and individual pieces surveyed. The
 sixth is a table of literature-derived annual recruitment rates for
 mechanisms common to mountain streams. Data may also be accessed via the
 Dryad data repository as linked in the data accessibility statement. Raw
 data relate several wood jam and individual piece properties, including
 length, width, and depth of the former, and length and diameter of the
 latter. Data also indicate several other wood characteristics, such as
 piece orientation, stability and decay class, and the presence of a
 rootwad. Finally, data include information about the geomorphic impact of
 each surveyed piece and jam. Data were collected to examine research
 questions related to in-stream wood load volumes supplied by snow
 avalanches and the resultant geomorphic impacts. 
description: Raw data were collected in the field by two trained observers.
 Wood loads were measured in the field using a census approach for all wood
 jams and individual wood pieces within the bankfull channel. Jams were
 identified as accumulations with three or more contiguous pieces; jam
 volume was quantified by measuring the length, width, and height of a
 rectangular prism fit to the dimensions of the jam and visually estimating
 porosity. Porosity was consistently estimated by two independent observers
 to minimize systematic bias. For individual wood pieces, diameter and
 length were measured and then used to compute volume via the formula of a
 cylinder. All measurements were made for wood at least partially contained
 within the bankfull channel, which was visually estimated in the field
 using topography (e.g., slope breaks). For wood pieces or jams that
 extended laterally beyond the bankfull dimensions, those portions outside
 were excluded from measurements. Measured wood loads were normalized by
 stream surface area (in ha) for comparisons between reaches with varied
 bankfull widths and lengths. These data have not been processed other than
 the above related volume calculations, which were then summarized across
 sites and watersheds (which have yielded the wood_volume_summary.csv data
 also presented here).  Data regarding topographic and
 vegetation characteristics of the studied avalanche pathways were obtained
 via freely available remote datasets. These include a 1-m DEM for the
 study area available from USGS EarthExplorer (https://earthexplorer.usgs.gov/) and vegetation data from the LANDFIRE program (https://landfire.gov/). Canopy cover comes from the Existing Vegetation Cover raster in the LANDFIRE 2016 dataset. Planform curvature and slope angle were dervied from a 1-m DEM using the Curvature and Slope functions in ArcGIS Pro Version 2.8. Median was calculated for each pathway area using the Zonal Statistics function in ArcGIS Pro.  Avalanche report data was gathered from Colorado Avalanche Information Center field reports (https://avalanche.state.co.us/observations/view-field-reports), restricting the "area" field to Sawatch and Aspen and the dates from 2019-03-01 to 2019-03-15.  Literature data were gathered using a publication database/search engine (scholar.google.com) to find relevant sources via keyword sources. Data were then processed using the information in each publication to determine rates in units of m<sup>3</sup>/ha/yr.  NAs in all datasets mean that the measure in question was inapplicable to the parameter under consideration. An open-source R code is provided to re-create data processing and figure creation. 
description: CSV files can be opened by all software. 
description: # Frying Pan Avalanche Data --- The data here are large wood and
 geomorphic characteristic data collected in the Summer of 2022 in the
 Frying Pan River Basin in the Central Mountains of Central Colorado,
 avalanche report data collected from the Colorado Avalanche Information
 Center website (avalanche.state.co.us), topographic and vegetation summary
 data derived from USGS Elevation Products
 (apps.nationalmap.gov/downloader/) and LANDFIRE (landfire.gov), and data
 derived from a meta-analysis of the large wood literature. Data were
 collected to examine research questions related to in-stream wood load
 volumes supplied by snow avalanches and the resultant geomorphic impacts.
 There are nine datasets here. Below we detail the data formatting
 specifics for each file. Note that data in each file are formatted in
 "long" format for easy use with statistical software. NAs in all
 datasets mean that the measure in question was inapplicable to the
 parameter under consideration. ## Description of the data and file
 structure ### **Note:** Variable explanations below follow the formatting
 convention of *variable name: explanation* #### In the file
 stream\_characteristics.csv General geomorphic and watershed
 characteristics of the stream reaches surveyed. Columns are as follows: *
 River: Study catchments (SFFP = South Fork Frying Pan, MC = Marten Creek,
 MFFP = Main Fork Frying Pan) * Site: Surveyed reach in each watershed with
 site number and type (avalanche or control) * stream_length_m: Length of
 the surveyed reach in meters * stream_gradient: Gradient (slope) of the
 stream through a given study reach (in m/m) * stream_elevation_m:
 Elevation above sea level at the downstream end of a given reach (meters)
 * drainage_area_km2: Contributing drainage area as calculated at the
 downstream end of a given reach (via USGS StreamStats,
 ) (sq. km) * mean_bfw_m: Mean
 bankfull width as measured in a given study reach (meters) *
 damaged_forest_area_ha: Forest area damaged or destroyed by a given
 avalanche (hectares) * mean_pct_fines: The percentage of the surface bed
 sediment composed of fines (here defined as sand-sized or smaller
 sediment) as estimated via visual inspection (unitless) * ripar_veg: the
 dominant riparian vegetation as esimated via a visual estimation of
 prevalence by area (unitless) * latitude: Latitude for the downstream
 point of the study reach (Projection: WGS1984) * longitude: Longitudge for
 the downstream point of the study reach (Projection: WGS1984) #### In the
 file wood\_volume\_summary.csv Summarized data of the wood volumes within
 each surveyed reach. Columns are as follows: * River: Study catchments
 (SFFP = South Fork Frying Pan, MC = Marten Creek, MFFP = (Main Fork)
 Frying Pan) * Site: Surveyed reach in each watershed with site number and
 type (avalanche or control) * total_wood_volume: total wood volume as
 calculated by summing the volumes of jams and individual pieces for each
 reach (in m3) * total_wood_load_m3_per_100m: Total wood volume normalized
 by reach length and then multiplied by 100 (in m3/100 m) *
 total_wood_load_m3_per_ha: Total wood volume normalized by the area of the
 stream surface. Stream surface area calculated by multiplying the length
 of the reach and then multiplying by mean bankfull width (in m3/ha) *
 fraction_volume_jams: the fraction of the total wood volume per reach
 contained in log jams (unitless) * fraction_volume_pieces: the fraction of
 the total wood volume per reach that occurs as indiviudal wood pieces
 (unitless) * fraction_geomorph_impact: the fraction of the total wood
 observed that has a geomorphic impact (as defined in the text) (unitless)
 #### In the files jams\_and\_pieces\_avy.csv &
 jams\_and\_pieces\_control.csv The unprocessed raw data for all wood jams
 and individual pieces surveyed. These data include several wood jam and
 individual piece properties: length, width, depth, and porosity of the
 former, and length and diameter of the latter. These data also indicate
 several other wood characteristics, such as piece orientation, stability
 and decay class, and the presence of a rootwad. Finally, these data
 include information about the geomorphic impact of each surveyed piece and
 jam. Columns are as follows: * Metric: Whether it is an avy reach
 (avy_wood) or control reach (cp_wood) * River: Study catchments (SFFP =
 South Fork Frying Pan, MC = Marten Creek, MFFP = (Main Fork Frying Pan) *
 Site: Numbered avalanche or control reach within a catchment * \#: Number
 of the piece or jam number within a reach * Length_m: Length of jam or
 piece (in meters) * Width_m: Width of jam (in meters) * Depth_m: Vertical
 height of jam (in meters) * Porosity: Jam porosity (%) * Diameter_cm:
 Diameter of piece (in centimeters) * Orientation: Orientation of piece or
 jaw to flow (prl = parallel, trv = transverse, prp = perpendicular) * TB:
 Logistic value (Y/N) for whether a given piece or jam is touching the
 stream bed * RW: Logistic value (Y/N) for whether a given piece or jam
 contains a rootwad * Pool: Logistic value (Y/N) for whether a given piece
 or jam is forming a pool * LSP: Logistic value (Y/N) for whether a given
 piece or jam is forming a logstep * Stability: How the jam or piece is
 anchored (jam = jam with no other clear anchoring, bldr = pinned on
 boulder, brdg = bridged across channel, rmp = ramped (one end touching bed
 other touching the bank), bnk = pinned on bank, pin_wd = pinned on other
 wood (another jam, perhaps)) * Decay: Decay class (brk = bark present,
 brnch = branches (and bark) present, nb = no bark, rtn = rotten).
 Combinations of classes (e.g., brnch_brk) indicate multiple classes are
 contained within a jam * Function: Geomorphic function of the wood beyond
 the classes above (ss = storing sediment, vd = creating a vertical drop
 for the flow, mlti = creating multithread reach, fd = deflecting flow,
 bnkstb = stabilizing/protecting the stream bank) * Jam: Logistic (Y/N) as
 for whether it is a jam * Volume_m3: Volume of the piece or jam in m3 *
 type: jam or individual piece #### In the file caic\_field\_reports.csv
 Information from reports submitted to the Colorado Avalanche Information
 Center in the first half of March 2019 for the region in which the study
 area is located. Data are the type of avalanches observed and other
 information necessary to access the original copy of each report. *
 report_date: Date the report was filed to the Colorado Avalanche
 Information Center (CAIC) * observer: The person/organization who filed
 the report (CAIC - Colorado Avalanche Information Center staff member;
 Public - member of the general public; Colorado DNR - Colorado Department
 of Natural Resources staff member; CMC - Colorado Mountain College staff
 member) * avalanche_type: The type of avalanche failure observed (SS -
 Soft slab; HS - Hard Slab; NtSpc - Type not specified; WS - wet slab; WL -
 wet loose). For more information on the meaning behind these terms, see
 here: *
 report_approx_location_lat_long: Coordinates (lat,long in decimal degrees)
 of the approximate location the report refers to. Note that observers
 sometimes do not reliably indicate avalanche location, but instead use
 this to denote the location of a trailhead, a distal observation point,
 etc. * url: The url for the report #### In the file
 pathway\_topo\_and\_veg\_characteristics.csv Topographic & vegetation
 characteristics of avalanche pathways in study reaches. Canopy cover comes
 from the Existing Vegetation Cover raster in the Landfire 2016 Dataset
 (landfire.gov). Planform curvature and slope angle were derived from a 1-m
 DEM (acquired via (apps.nationalmap.gov/downloader/) using the Curvature
 and Slope functions in ArcGIS Pro Version 2.8. Median was calculated for
 each pathway using the Zonal Statistics function in ArcGIS Pro. *
 watershed: The watershed in which the pathway is located * reach: The
 corresponding study reach for the observed avalanche pathway (SFFP = South
 Fork Frying Pan, MC = Marten Creek, MFFP = (Main Fork Frying Pan) *
 median_plan_curv: The median curvature of the all cells in the avalanche
 pathway as measured perpendicular to the fall line using a 1-m DEM. A
 negative value indicates a concave slope, ~zero indicates planar, and
 greater than zero indicates a convex slope. For more information on how
 this was derived, see here:
 * median_slope_degree: The median angle (in degrees) of all cells in the avalanche pathway measured using a 1-m DEM. * median_canopy_cvr_pct: The median canopy cover (in percent) of all cells in the Existing Vegetation Cover raster contained within the avalanche pathway ### In the file ref\_recruitment\_rates\_by\_mechanism.csv These are literature-derived rates for recruitment from processes common to mountain watersheds. Columns are as follows: * recruiment_mechanism: The mechanism of recruitment examined * rate_m3_ha_yr: The annual recruitment rate as derived for each reach in the corresponding study * location: The location of the study * citation: The reference for the derived rate ### In the file ref\_wood\_loads\_landslides\_debris\_flows.csv These are literature-derived wood loads for reaches that have experienced landslides/debris flows. Columns are as follows: * wood_load_m3_ha: The derived wood load from the relevant reaches in the corresponding study * citation: The reference for the derived volume ### In the file ref\_wood\_loads\_northern\_dry\_conifer.csv These are literature-derived wood loads for unmanaged forests in the equivalent bioclimatic regime (northern dry conifer) as those in the Frying Pan examined in the publication accompanying this repository (Kemper and Scamardo, 2023). Columns are as follows: * citation: The reference for the derived volume * wood_load_m3_ha: The derived wood load from the relevant reaches in the corresponding study * study: A column indicating whether the value is from the literature (Other Studies), an avalanche reach in the present study of Kemper & Scamardo, 2023 (Avalanche), or a control reach in the present study ### Sharing/access Information Links to other publicly accessible locations of the data: See Journal Supplemental Files Was data derived from another source? No If yes, list source(s):