GIS4930 Module 2 - Mountain Top Removal, Appalachia Coal Region (Analyze)

Assessing the impact of Mountain Top Removal (MTR) mining on an area requires comparing imagery of that area taken after a period of time has passed. The Analyze portion of this module helped develop the skills to do just that. Utilizing data from SkyTruth, 2005 Landsat imagery was used in ArcMap to select training samples in known MTR polygons as well as in nonMTR areas. After changing class names, values, and colors for the samples they were compared for overlaps, and a signature file was created to be used in Supervised Classification. The same data was used in Erdas with the "Grow" tool to select several samples to add to the Signature Editor table.

The class was split into several different work groups of 3-4 students to analyze the 2010 data for SkyTruth. Each group was responsible for 2 to 4 images. After the preliminary exercise, the 2010 imagery was prepared by first using the Composite Bands tool to consolidate the 7 bands of the Landsat file and then clipping the imagery to the group's study area in ArcMap. In Erdas the Unsupervised Classification tool was used to create a layer with 50 classes. Areas which seemed to be part of MTR were classed and symbolized by color accordingly. Distinguishing the MTR areas was difficult for me. The remaining areas were classed as NonMTR and symbolized by a different color. Because identical spectral signatures can be assigned to very different types of features, many objects which are not MTR areas are included in the MTR class. This will be accounted for at a later time.

Back in ArcMap, the classified image was reclassified with MTR being assigned a value of 1 and all other Class Names assigned blank values. The resulting image is shown here:

2010 Landsat Imagery Classified for MTR
(NOTE: This image includes some nonMTR features with the same spectral signature as MTR.)

From this information, the MTR raster will need to be converted to polygons and smaller MTR areas removed. Buffers will be created around roads and rivers, and MTR areas within the buffers will be removed. An accuracy assessment will be done as well as a comparison with the 2005 dataset. Each group member will submit packaged data to the group leader for compilation into one dataset for the study area. Finally a map service to present the group findings online will be created. Look for this next week!