Methodology

While working with maps and aerial photos at different scales it is hard to compare similar areas and features.  The first thing that needed to be done with the maps and photos was to resize them so they are all the same scale.  Using the 1:24,000 USGS Topographic maps from 1943 and 1982 as a base, the scale and orientation of the other maps and photos were set to match these.  The base maps were scanned at a resolution of 300 dots per inch.  By calculating the scale for the other maps and photos, it was possible to scan them at different resolutions to make them 1:24,000.  Once all of the maps and photos were at a scale of 1:24,000, Adobe Photoshop was used to orient and resize all of the sources to be the same size and cover the study area.

 To determine the changes in land-use/land cover on New Island, a modified version of Anderson’s Level I classification system was created and used to classify the study area. (Anderson, 1976) The five classes that were chosen represent the major land-use/land cover on New Island from 1937 to 1998.  These classes are: agriculture, urban or built up land, forest, scrub shrub/grasslands, and water bodies.  Using Adobe Photoshop, each air photo was divided into these five classes and colored to indicate the area of each of the types of land-use/land-cover on New Island.