Soil Drainage Class Image
| Updated:
Author: Bradley Miller
This map displays the natural soil drainage classes across Iowa, categorized into seven standard classes: excessively drained, somewhat excessively drained, well drained, moderately well drained, somewhat poorly drained, poorly drained, and very poorly drained. The classifications reflect the frequency and duration of wet periods in each soil under natural conditions, based on morphology and landscape position. Color gradients correspond to the drainage classes and are overlaid on a hillshaded DEM to emphasize landscape variation.
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Source:
Produced by the Geospatial Laboratory for Soil Informatics (GLSI) at Iowa State University. Map authors: Meyer Bohn, Joshua McDanel, and Bradley Miller (January 2019).
Resolution:
10-meter raster resolution on hillshaded DEM; displayed as a statewide static image
Interpretation:
Drainage class reflects inherent hydrologic behavior and long-term water saturation patterns. It is based on redoximorphic features, depth to water table, and other soil profile indicators. This information supports wetland delineation, agricultural planning, and environmental modeling.
Suggested Use:
Ideal for use in hydrologic modeling, conservation planning, drainage design, and identifying areas requiring management for water retention or removal. It also supports regulatory compliance and land capability assessments.
References
Spatial and tabular data overlaid on hillshaded DEM courtesy of the National Cooperative Soil Survey (FY2018) and the National Elevation Dataset (2018).