Soil Types
Definition
Soil types categorize soils into classes based on genesis, horizon sequence, texture, mineralogy, and climate, as in USDA Soil Taxonomy or the World Reference Base. Each type implies behavior—drainage, fertility, swelling, salinity, acid sulfate potential. GIS maps encode dominant and associated types with confidence, often at multiple scales from reconnaissance to detailed surveys. Understanding types informs land‑use decisions and engineering design.
Application
Agronomy tailors crop rotations to types; construction selects foundations and treatments; conservation identifies wetlands and peatlands; and emergency management anticipates shrink‑swell or liquefaction zones. Education and citizen science use type maps to connect people to landscapes.
FAQ
How do taxonomic maps handle inclusions and mapping confidence?
Polygons include minor inclusions of other types; metadata should state typical inclusion percentages and provide a confidence or purity estimate so users understand variability.
What is the best way to link soil types with continuous properties like pH or organic carbon?
Use pedo‑transfer functions and associate distributions (mean, variance) per type, enabling stochastic simulations rather than a single deterministic value.
How can legacy hand‑drawn surveys be modernized?
Digitize with topology checks, reproject accurately, and enrich with terrain, climate, and new observations. Document lineage so future users can distinguish interpreted updates from the original survey.
Why do planners need both type maps and management zone maps?
Types reflect formation and horizons; management zones reflect present behavior under current use. Together they guide both long‑term suitability and near‑term operations.
SUPPORT
© 2025 GISCARTA