Canada1Water: Hydraulic parametrized integrated soil, bedrock and peatlands datasets

The Canada1Water (C1W) initiative is a national-scale effort to model Canada's hydrologic cycle, integrating groundwater, surface water, and climate influences across continental Canada and shared watersheds with the United States. Soil, bedrock, and peatlands critically connect atmospheric processes, vegetation, and hydrology. Infiltration and recharge are governed by the hydraulic properties and topographic and pressure gradients, making accurate representation of surficial substrates essential in hydrological modelling. For continental-scale groundwater-surface water modelling in Canada, a 7-layer hydrostratigraphic framework was developed, with the upper two soil layers being 0-0.5 m and 0.5-1.0 m below ground surface. National coverage of mineral soils was derived from the global OpenLandMap dataset at 250 m resolution, using soil texture, bulk density, and water content at 33 and 1500 kPa from six depth intervals. These inputs were vertically averaged into two soil layers and parameterized using Rosetta v3 pedotransfer function approaches to derive residual and saturated water content, van Genuchten parameters (α and n), and saturated hydraulic conductivity. Exposed bedrock was explicitly mapped using a combination of land cover classification (NALCMS v2015 barren land and snow/ice classes) and national-scale surficial geology datasets, with depth-dependent expansion of bedrock extent in the lower soil layer. Peatlands were delineated using peatland extent products and OpenLandMap soil organic carbon content, producing a three-dimensional peat model classified into moderately decomposed, decomposed, and well-decomposed peat, each assigned depth-dependent hydraulic properties based on published literature. The final product is an 18-band raster GeoTIFF, comprising OpenLandMap soil attributes, Rosetta-derived hydraulic parameters, and specific classifications for bedrock and peatlands. The dataset provides seamless 250 m resolution coverage across all Canadian provinces and territories and extends into transboundary watersheds with the United States. By integrating mineral soils, bedrock outcrops, and peatlands into its comprehensive hydraulic parameterization, this dataset is ideally suited for supra-regional hydrological modelling.