The objective of this study was to provide an overview of the issues affecting the natural
resources on Koh Tao, Thailand, so a management plan could be developed. Remote sensed data was
combined with data from a questionnaire to create a model that assesses the condition of the reefs and
threats to the reefs. Remote sensed data were acquired from 4 y (1975, 1994, 2001 and 2005) to assess
changes in land usage and to determine the location of the reefs. With a geographical information system
(GIS) different models were created based on the available data.