U.S. Department of the Interior U.S. Geological Survey Norman B. Bliss, ASRC Federal InuTeq Contractor to the USGS 6/4/2015 A continental view of soil properties: Linking scales from 1 cm to 4,000 km

Outline   Soil Geographic Databases in the USA  SSURGO: detailed mapping (e.g., 1:24,000 scale)  STATSGO : general mapping (e.g., 1:250,000 scale)   Data structure   Example maps   Future work

Soil Geographic Data Bases in USA   Origin: SSURGO and STATSGO  National Cooperative Soil Survey  Federal, State, University  Coordinated by Natural Resources Conservation Service (NRCS)   Distribution  Vector data, web mapping services  gSSURGO: raster data at 10 meter resolution  Attribute data: hierarchy of related tables

Data structure (SSURGO)   chorizon: soil profile horizons (3 million)   component: attributes not delineated (1 million)   mapunit: delineate (300,000)   Spatial data: digitized maps (10 m resolution)

Approach   Use hierarchical data structure to query attributes and make raster maps   Fill missing data in SSURGO with data from the General Soil Map (STATSGO2)   Deliver as 30 meter rasters

Recent work   Rock percentages, Sand, silt, clay percentages   Hydrologic group   Saturated Hydraulic Conductivity   Available Water Capacity & Available Water Storage   Soil organic carbon   Erosion factor (kffact)   Drainage class   Hydric soils   Depth of soil, depth to bedrock, to water table   Flooding frequency   Calcium Carbonate, pH, cation exchange capacity

Results: Rock percentage   Raster datasets for 6 depth zones (SSURGO only): 0-5, 5-20, 20-50, , , greater than 150cm   Rock percentage: 0-5 cm and cm

Results: Sand percentage   Raster datasets for 6 depth zones (SSURGO filled): 0-5, 5-20, 20-50, , , greater than 150cm   Sand percentage: 0-5 cm and cm

Results: Silt percentage   Silt percentage: 0-5 cm and cm

Results: Clay percentage   Clay percentage: 0-5 cm and cm

Results: Hydrologic group (infiltration)   Dominant condition and percentages of individual classes (as appropriate):   Hydrologic group: Dominant condition, Group A %

Results: Ksat   Saturated Hydraulic Conductivity 0-5 cm and cm

Results: Available Water Storage (mm)   Raster datasets for 6 depth zones (as appropriate): 0-5, 5-20, 20-50, , , greater than 150cm   Available Water Storage: 0-5 cm and cm

Results: Soil organic carbon (kgC m -2 )   Soil organic carbon : 0-5 cm and cm

Results: spatial metadata  Metadata rasters  Left: percentage area with components contributing to the dominant condition hydrologic group  Right: status map: pixels filled with STATSGO2 (blue)

Impact of results   EPA will incorporate into the EnviroAtlas  A state-of-the-art map viewing and analysis tool   Data are model-ready  Hydrologic models  Carbon cycle models  Climate change drivers  Climate change impacts  Modelers want defined depth zones

Future work   Digital soil mapping: link pedon data to maps  Data structure to support results of this conference  Make use of legacy soil data: SSURGO & STATSGO  Use Landsat and other images  GlobalSoilMap.net  New topographic derivatives  Multi-scale view of a landscape  Large features precisely defined  Slope and slope length simultaneously  Floodplain delineation

Acknowledgments   US Geological Survey: Climate and Land Use Change Program   US Environmental Protection Agency: EnviroAtlas   US Department of Agriculture: Natural Resources Conservation Service Thank you

Results   Soil Organic Carbon (SOC) Organic layer Mineral layer (up to 1-m) Red is low, blue is high Color scales are not comparable between these plots SOC is often higher in Organic than in Mineral

Results   Organic Layer Thickness  Probability that the organic layer is >= 40 cm thick Red is low, blue is high Maximum is 87%