DOI: 10.5061/dryad.05qfttf2q
title: Data from: Watershed classification predicts streamflow regime and organic carbon dynamics in the Northeast Pacific Coastal Temperate Rainforest

description: Watershed classification has long been a key tool in the hydrological
 sciences, but few studies have been extended to biogeochemistry. We
 developed a combined hydro-biogeochemical classification for watersheds
 draining to the coastal margin of the Northeast Pacific coastal temperate
 rainforest (1,443,062 km2), including 2,695 small coastal rivers (SCR) and
 10 large continental watersheds. We used cluster analysis to group SCR
 watersheds into 12 types, based on watershed properties. The most
 important variables for distinguishing SCR watershed types were
 evapotranspiration, slope, snowfall, and total precipitation. We used both
 streamflow and dissolved organic carbon (DOC) measurements from rivers (n
 = 104 and 90 watersheds respectively) to validate the classification.
 Watershed types corresponded with broad differences in streamflow regime,
 mean annual runoff, DOC seasonality, and mean DOC concentration. These
 links between watershed type and river conditions enabled the first
 region-wide empirical characterization of river hydro-biogeochemistry at
 the land-sea margin, spanning extensive ungauged and unsampled areas. We
 found very high annual runoff (mean &gt; 3000 mm, n = 10) in three
 watershed types totaling 59,024 km2 and ranging from heavily glacierized
 mountain watersheds with high flow in summer to a rain-fed mountain
 watershed type with high flow in fall-winter. DOC hotspots (mean &gt;
 4 mg L-1, n = 14) were found in three other watershed types (48,557 km2)
 with perhumid rainforest climates and less-mountainous topography. We
 described four patterns of DOC seasonality linked to watershed hydrology,
 with fall-flushing being widespread. Hydro-biogeochemical watershed
 classification may be useful for other complex regions with sparse
 observation networks.
description: For a complete description of methods, please see the manuscript
 <em>Watershed classification predicts streamflow regime and organic
 carbon dynamics in the Northeast Pacific Coastal Temperate
 Rainforest</em>, in review at Global Biogeochemical Cycles
 (Giesbrecht et al., 2022). Watershed polygons were
 taken from Gonzalez Arriola et al. (2018) which can be accessed through
 the Related Works section below. Watershed properties
 were extracted from published geospatial datasets that were freely
 available, peer-reviewed, and spatially consistent across all three
 geopolitical regions with respect to variable definitions and estimation
 approaches. Source datasets are defined in the README file.
 We used two separate approaches to place all watersheds of the
 NPCTR margin into discrete groups or types. First, we set aside 10 large
 continental watersheds because we expected them to be fundamentally
 different from the SCR watersheds in terms of climate, terrain, landcover,
 and catchment controls on river hydro-biogeochemistry. Second, we grouped
 the remaining 2,695 SCR watersheds into 12 statistically similar clusters
 using k-means partitioning. The watershed types were subsequently assigned
 descriptive labels that reflect their defining characteristics.
 Discharge data were acquired for near-outlet gauging stations in
 104 independent watersheds. To achieve the maximum spatial coverage, we
 included all active and deactivated gauges that met
 basic quality criteria. We considered all gauges operated by the Water
 Survey of Canada (WSC) and the US Geological Survey (USGS).
 We compiled a dataset of 4,674 riverine DOC concentration
 (mgL<sup>-1</sup>) measurements at near-outlet stream
 locations in 90 watersheds. We omitted sites that were clearly
 unrepresentative of the watershed outlet (e.g., headwaters) and sites with
 obviously poor data quality or small sample size. The DOC dataset was
 derived from an exhaustive search of six different water-quality
 databases.
description: This data package contains several datasets corresponding with
 the manuscript <em>Watershed classification predicts streamflow
 regime and organic carbon dynamics in the Northeast Pacific Coastal
 Temperate Rainforest</em>, in review at Global Biogeochemical Cycles
 (Giesbrecht et al., 2022).  1. Watershed
 properties including the watershed type defined by cluster
 analysis 2. Metadata for streamflow gauging station
 assessment and selection 3. Streamflow data from
 gauging stations 4. Metadata for Dissolved Organic
 Carbon (DOC) site assessment and selection 5. DOC data
 from river observation sites 6. Streamflow hydrographs
 for individual watersheds 7. Monthly DOC concentration
 plots for individual watersheds All variables are
 defined in the README file. For full details, see the corresponding
 manuscript and the source datasets. These
 files include both primary data sources and processed data derived from
 other publicly accessible data sources. The source is named for each case
 of streamflow or DOC data.