Nitrate Leaching Class RangesEntry ID: IGDNR_NO3LRANGE
Abstract: This is a statewide Arc/Info data set of nitrate leaching class ranges for
soils in Illinois. It was generated to aid in determining aquifer sensitivity
to nitrate leaching in Illinois. The source map was digitized at 1:250,000, but
was developed from source data mapped at 1:15,000. The publication of this map
was at 1:500,000. Nominal scale is 1:250,000.
This ... data set contains the four trimmed range values presented on the ISGS map
Nitrate Leaching Classes of Illinois. Range values were determined for the
nitrate leaching classes in each soil association to give an indication of the
variability within a specific leaching class. This data set is necessary
because each soil association (in data set *path_name_suppressed*/no3leach)
could have only a single leaching class value assigned to it. In this data set
the item NO3INDEX_RANGE contains a 10% trimmed range for the leaching class
characteristics of each association. This item was calculated by sorting the
component soil series in order of their leaching characteristic within the
association. The trimmed range is the domain of leaching characteristic values
between the 90th and 10th quantiles in the sorted list. The range was trimmed
(by 10% at either end) to reduce the significance of extreme values. These data
were used as an overprint on the published map. (see cross references).
Purpose: Two statewide data sets were identified as containing information that would be
useful for producing aquifer sensitivity maps: a soil association map (and
database) and a map of geologic materials to a depth of 50 feet (Stack-unit
map). The soil association map and database were used in an interpretive
mapping model that generated a map of nitrate leaching classes by ... examining
factors that could predict water movement in the soil (because the chemical
nature of nitrate allows it to move with water).
The result is six nitrate leaching classes that group soil associations based
on the relative probability of nitrate movement through the associated soil
profiles. The ranking is qualitative, and is based on the median leaching value
for a related group of soil associations. Nitrate leaching classes include:
Excessive, High, Moderate, Somewhat Limited, Limited, and Very Limited. See
ISGS EG 148 for the derivation of these classes.
This data set shows the ranges of leaching class values that occur within a
particular soil association. For example, a particular soil association may
have nitrate leaching values that range from "Excessive" to "Somewhat Limited",
with a median value of "Moderate". This soil association is assigned an overall
leaching value of "Moderate", with a range of 4 (being the values Excessive,
High, Moderate, and Somewhat Limited).
This data set was designed for statewide evaluation of agrichemical leaching
characteristics. It was created to classify soils and aquifer settings
according to predictions of leaching potential. The classifications have not
been validated by the results of water quality sampling.
These data are to be used in conjunction with ISGS Environmental Geology report
148. This data set is one of a suite of six related data sets (listed below).
Full citation details are available in the Cross References section.
Aquifer Sensitivity to Contamination by Nitrate Leaching in Illinois
Nitrate Leaching Classes of Illinois Soils
Nitrate Leaching Class Ranges (this data set)
Aquifer Sensitivity to Contamination by Pesticide Leaching in Illinois
Pesticide Leaching Classes of Illinois Soils
Pesticide Leaching Class Ranges
ISO Topic Category
Role: SERF AUTHOR
Phone: (301) 614-6898
Email: Tyler.B.Stevens at nasa.gov
NASA Goddard Space Flight Center Global Change Master Directory
Province or State: MD
Postal Code: 20771
Role: TECHNICAL CONTACT
Email: warmerdam at pobox.com
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City: Richmond Hill
Province or State: ON
Creation and Review Dates