Integration of GIS and TM Data to Extract Early Rice Area in Longyou County

This paper introduces the methodology of integrating GIS and TM data for estimating the early rice planted area. It overcomes static disadvantage of GIS and enhance the classification results of TM image. Land use map and town boundary map were digitized then transferred to raster format and opened in ENVI image analysis system. TM image, land use map and town boundaries map were registered to the same projection. Utilizing of mask utility, the study area, every land using type and every town TM images were established. Supervised and unsupervised image classification were applied to the study area TM image and to the paddy field TM image. And the early rice areas were calculated by each method. Using the proposed methodology improved the quantitative accuracy of early rice area estimated up to 93.98%, whereas it was 82.83% when image classification was used only. The extracted information from the classification is belonging to the early rice and not to any other vegetation. Since the GIS database is available, the method is easily applicable to any new RS images.