Updating the landuse data by remote sensing images and GIS

Abstract

Updating the land use data timely by remote sensing image is very important for effectively managing and using land resources. A new method of updating the land use data by remote sensing and GIS is discussed here. The method includes several steps. Firstly, the prophase digital land use data and LANDSAT TM image were acquired, and the landsat TM image was geometrically and radiantly corrected. Secondly, the anaphase Landsat TM image was acquired and geometrically and radiantly corrected. Thirdly, the mean and standard deviation of each patch in each band of the LANDSAT TM and ETM images acquired in two periods were obtained by calculating and overlaying the Landsat TM and ETM images with the land use data. Fourthly, all patches were divided into two categories such as one without change in spatial data and the other with change in spatial data by analyzing the standard deviations of the two periods, and the patch with change in spatial data was divided into two or more new patches by identifying the border. Fifthly, the mean and standard deviation of the new patches were obtained by calculating and overlaying the landsat TM and ETM images with the new patches. Sixthly, the patches were divided into two categories such as one with the land use type change and the other without the land use type change by analyzing and comparing the means of the images in two periods for each patch.. Seventhly, the spectral knowledge of each land use type was discovered and obtained by calculating and analyzing the mean of prophase LANDSAT TM image for each land use type on basis of patch. Eighthly, the type of each patch with the land use type change was obtained by analyzing and applying the spectral knowledge of each land use type and its means of the anaphase LANDSAT TM images. Finally, the land use data without change in type or spatial border were updated by inheriting the original spatial and type data, and the land use data with changes in spatial border or type were updated with new type or new spatial border. The study shows that the land use data can be effectively updated by the method.