Using High Resolution Change Data with Existing Spatial Information to Observe Trends in Coastal Development

High resolution 1-m aerial photo data has great potential to inform natural resource planning but is difficult to analyze in an automated way over large areas because of the need to replicate an analysts cognitive process on highly variable image data. The recent acquisition of high resolution color aerial digital photography covering all of Washington State offered us an opportunity to utilize recent software developments and develop new image analysis techniques to automate the process of detecting major changes in vegetation between 2006 and 2009 images. Major vegetative change includes transitions from mature shrub or forest cover to non forest landcover on parcels as small as 1/10 of a hectare.   We analyzed vegetation change immediately adjacent to and at varying distances from marine and fresh water shorelines in regions of Kitsap, Skagit and Thurston Counties. We estimate that the automated process can track changes about 20 times as fast as traditional methods of hand digitization. This process could be used to help assess changes in nearshore ecological function associated with loss of forest cover over long stretches of marine and fresh water systems.