Evaluation of Shape Characteristics of Vegetation Distribution in the Central Part of Tokyo by Using High-resolution Satellite Images

The city environment in the central part of the capital of Japan, Tokyo has been investigated by using high-resolution satellite images. The accumulation of environmental information necessary to create a good quality, city environment has been advanced. Up to now, the environmental information has been examined for the amount of distribution and the distribution shape of small-scale vegetation in the city. However, when a small scale vegetation region in the city is extracted from the high-resolution satellite image, it is necessary to improve the extraction accuracy by decreasing the miss-extraction rate. Moreover, a quantitative evaluation technique of the city environment by the distribution shape of vegetation in the city has not been firmly established. In this study, the extraction accuracy improvement of the vegetation area in the city region was examined by using the high-resolution satellite image that had been observed by the Quickbird satellite. The extraction accuracy admittedly improved by uniting the extraction result by NDVI value with the extraction result by clustering method. Moreover, the shape factor calculated from the area of the vegetation region and the surroundings length of the area was calculated from the extraction result, and the vegetation ratio and the distribution shape were evaluated. As a result, even if the vegetation ratio was the same, the difference of the shape characteristic of distribution was able to be evaluated quantitatively by the place in the city.