The image overlay processing of multi-temporal images is a new processing method to extract small changes within different images, in which classification results of images and geographical information are overlaid using a piccell as a unit. The method was adopted in analyzing landcover of Toyonaka City, Osaka Prefecture, using LANDSAT MSS data of four seasons. The landcover was classified into five categories, of which areal ratios were calculated. Seasonal changes in landcover were recognized, such as a partial replacement of bare land by grass land from winter to summer. The result shows that the method proposed in this paper is effective for extraction of small changes within different images, and that the seasonal change should be considered in analyzing landcover. The method can be applied to update, landuse information by overlaying landuse maps previously prepared and landcover map derived from recent LANDSAT data, and to discriminate disaster dangerousness by overlaying classification results of LANDSAT images and geographical information.
