Global Islands

A new 30-m spatial resolution global shoreline vector (GSV) was developed from annual composites of 2014 Landsat satellite imagery. The semi-automated classification of the imagery was accomplished by manual selection of training points representing water and non-water classes along the entire global coastline. Polygon topology was applied to the GSV, and the resulting polygons were mapped into four size classes of islands: Continental Mainlands, Big Islands (greater than 1 km2), Small Islands (less than or equal to 1 km2 and greater than or equal to 0.0036 km2), and Very Small Islands (less than 0.0036 km2).