Friday, August 8, 2008
Exhibit Hall CD, Midwest Airlines Center
Hideki Hashiba, Department of Civil Engineering, College of Science and Technology, Nihon University,, Tokyo, Japan
Background/Question/Methods The ecology of vegetation such as trees and greens is considered to greatly affect the urban environment and human physiology in large cities overcrowded according to a lot of artificial land use such as Tokyo. Currently, the vegetation area has been maintained and planed in nature parks, public green spaces, and along roadsides by central and local governments in Tokyo. Moreover, a great quantity of vegetation is arranged in gardens and green spaces by the private sector. The urban vegetation has a lot of characteristics in the distribution shape and conditions. Up to now, the urban vegetation has been examined for the amount of distribution in many cases. However, a quantitative evaluation technique of the city environment by the distribution shape of vegetation in the city has not been established enough. In this study, the characteristics of distribution shape of vegetation in Tokyo central area was evaluated by shape factor by using high resolution satellite Quickbird image data. The shape factor was calculated by the area of the vegetation and the surroundings length of the area in each grid. The Tokyo metropolitan area was divided into a grid of 1 km x 1 km, and the vegetation distribution of each grid square were evaluated. The vegetation distribution of Tokyo was extracted by the technique of land cover classification and using NDVI values using Quickbird image data.
Results/Conclusions Consequently, the ratio of vegetation cover in Tokyo central area is higher than that of the surrounding area. The high and low ratios are mixed in the outer area of the surrounding area. Moreover, even if the ratio of vegetation cover for each grid was the same, the difference which is distribution is continuous or non-continuous of the characteristics in distribution was shown with the value of shape factor and ground surveying. Shape factor indicated a large value in some grids in central area and the part in the surrounding. In other grids, a small value was comparatively indicated. From this, the vegetation cover were shown to be compactly distributed in the Tokyo central area and sparsely distributed in the surrounding area by using shape factor.
