All of the post-1952 sedimentation rates were divided by the background rate for conversion to a dimensionless index of sedimentation relative to the early 20th century. We standardized the spatial datasets of catchment topography and land use into a consistent GIS database structure, organized by individual catchment, in terms of layer and attribute definitions. The Spicer (1999) and Schiefer et al. (2001a) data were converted from an older ARC/INFO format to a more recent Shapefile layer format that matched the Schiefer and Immell (2012) data. Layers that were available selleck inhibitor for all catchments included: catchment boundary, rivers, lakes, coring location,

a DEM, roads (temporal, i.e. containing an attribute for known or estimated year of construction), and cuts (temporal). The Foothills-Alberta Plateau catchments also included seismic cutline and hydrocarbon well (primarily for natural gas) layers of land use (temporal). We developed

Selleck Y27632 GIS scripts to extract a suite of consistent variables for representing catchment morphometry and land use history, including: region (categorical), catchment area (km2), mean catchment slope (%), road density (km/km2), cut density (km2/km2), cutline density (km/km2), and well density (number of wells/km2). All of the land use density variables were extracted for the full catchment areas, as well as for four different buffer distances from rivers and lakes (10 m, 50 m, 250 m, and 500 m) to quantify land use densities at different proximities to water

courses. To assess potential relations between sedimentation trends and climate change, we generated temperature and precipitation data for each study catchment. Wang et al. (2012) combined regression and spatial smoothing techniques to produce interpolated climate data for western North America from the Parameter-elevation Regressions on Independent Slopes Model (PRISM) gridded data (Daly et al., 2002). An associated application (ClimateWNA, version 4.70) produces down-scaled, annual climate data from 1901 to 2009, including mean monthly temperature and precipitation, suitable for the variable terrain Morin Hydrate of the Canadian cordillera. The climate data generated for our analyses included mean monthly temperature (°C) and total precipitation (mm) for times of the year that represent open-water conditions (i.e. generally lacking ice cover) (Apr–Oct) and closed-water conditions (Nov–Mar). This climate data was added to our longitudinal dataset by using the centroid coordinate for each catchment polygon as a PRISM interpolation point. Given the degree of spatial interpolation of the climate data, we do not attempt to resolve climatic gradients within individual catchments. The land use and climate variables were both resampled to the same 5-year interval used for the sedimentation data (Table 1).