Classification of Pennsylvania

• All maps on this page use 1/64 divisions of 1:24,000 DEMs of Pennsylvania.

• The folded ridges of the Appalachians are the most prominent feature on all maps.

• The Great Valley appears clearly on all maps.

• The Susquehanna River flows SE in the SE portion of the map; it appears on all the maps.

• The Allegheny Front appears in the NW corner of the map; it also appears on all the maps.

• These maps emphasize the importance of the terrain around Gettysburg, and why the pivotal battle of the American Civil War took place there.

There are 5 maps in 4 categories:

1. Steepness

2. Organization

3. Terrain classifications

4. Grain overlay

Steepness

Flatness (ln(S1/S2))

Organization

Organization (ln(S2/S3))

Terrain Classifications

Two parameter classification

This classification uses

• steepness, an inverted ln(S1/S2), to control the red color,

• organization, ln(S2/S3), to control the green color.

Three parameter classification

This classification uses

• steepness, an inverted ln(S1/S2), to control the red color

• organization, ln(S2/S3), to control the green color

• natural logarithm of elevation to control the blue color

Grain overlay

Grain overlay

The lines show the strength and orientation of the computed fabric, with the length and orientation of the lines.

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