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 Metrics > Soil / Landform > Metric Map (cgrvl), Natural Breaks, Methodology and Interpretation
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Methodology and Interpretation

CGRVL - Coarse gravel fraction ( wt % )
STATSGO weighted-average soil coarse gravel fraction (> 5-mm and < 75-mm diameter) using approximate EMAP physical habitat substrate criteria, expressed as percent by weight

Metric Map (cgrvl), Quantile Metric Map (cgrvl), Natural Breaks

Quantile: Each class contains an approximately equal number (count) of features. A quantile classification is well-suited to linearly distributed data. Because features are grouped by the number within each class, the resulting map can be misleading, in that similar features can be separated into adjacent classes, or features with widely different values can be lumped into the same class. This distortion can be minimized by increasing the number of classes.

Natural Breaks: Classes are based on natural groupings of data values. Natural break points are identified by looking for groupings and patterns inherent in the data. The features are divided into classes whose boundaries are set where there are relatively large jumps in the distribution of data values.

* EMAP-West Soil / Landform Metrics Metadata (FGDC)

 

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