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 Metrics > Human Stressors > Metric Map (popdens), Quantile, Methodology and Interpretation
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Natural Breaks
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Methodology and Interpretation

POPDENS - Population density
Population density was calculated by summing number of people living in the 3 km grid cell reporting unit and dividing by the grid cell area. Where census units were not completely contained within the grid cell, population was apportioned by area. High population densities are generally well correlated with high amounts of human land uses, especially urban and residential development. Large areas of development often involve substantial modification of natural vegetation cover and may have significant effects on wildlife habitat, soil erosion and water quality.

Metric Map (popdens), Quantile Metric Map (popdens), 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 Landscape Metrics Metadata (FGDC)


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