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Methodology and Interpretation
RBAR30 - Percent barren within 30 meters of streams
The percentage of barren land cover 30 meters adjacent to streams is
calculated by summing the number of barren rock land cover cells underneath
stream segments in the 3 km grid cell reporting unit and within a one cell
buffer (30 meters) and dividing by the stream corridor's total land area (all
cells 30 meters adjacent to streams minus those classified as water). Cells
inside the buffer zone but outside of the grid cell boundary are ignored. This
metric can be used to identify areas near streams which may be more susceptible
to water run off which may in turn cause soil loss and stream and lake sedimentation.
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 Landscape Metrics Metadata (FGDC)
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