Nitrate Leaching Classes for Illinois Soil Associations

Six qualitative classes rank soil associations across Illinois by their relative probability of nitrate movement through soil profiles. The dataset was created by SCIOPS for statewide evaluation of aquifer sensitivity to contamination, with a publication date in 1995. It is derived from a soil association map and database using an interpretive mapping model.

Use Cases

• Classify soil associations into one of six nitrate leaching classes (Excessive, High, Moderate, Somewhat Limited, Limited, Very Limited) for regional water quality risk assessment.
• Analyze the trimmed range values for leaching classes to understand variability within each soil association, excluding the upper and lower 10% of values.
• Identify disturbed land and surface water areas within the geospatial data to exclude them from agricultural leaching potential models.
• Combine the nitrate leaching class data with the related aquifer sensitivity and leaching class range datasets for a comprehensive statewide contamination analysis.
• Use the soil association map data, originally developed from 1:15,000 scale source data, to study factors relating to water movement characteristics of Illinois soils.

Strengths

• Provides six distinct nitrate leaching classes for qualitative ranking across the entire state of Illinois.
• Derived from source soil data mapped at a detailed scale of 1:15,000, though the final nominal scale is 1:250,000.
• Includes trimmed range values for each leaching class to reduce the impact of extreme values on variability estimates.

Limitations

• The classifications are qualitative and have not been validated by water quality sampling results.
• Data is temporally stale, with a last update date of 1995-12-31, limiting relevance to current conditions.
• The use of the aquifer sensitivity ratings as predictors of actual water quality has not been evaluated.

Provenance

Source

SCIOPS

Collection Method

Generated via an interpretive mapping model applied to a statewide soil association map and database, with source data digitized at 1:250,000 scale.

Geography

State of Illinois, USA