抄録
This paper estimates the vegetation cover ratio in Tokyo metropolitan area. The research carried out to develop a practical technique for promoting efficiency constructing a vegetation cover map by using satellite remote sensing. Though previous studies have proposed to estimate vegetation cover ratio from normalized difference vegetation index (NDVI) based on empirical formulae, physical meaning of those methods are not clear. Besides, those methods are not necessarily practical, because the other vegetation cover ratio data are required to correspond with. Thus, this paper proposes a method to set up estimation formulae by applying linear combination model, which allows to express area ratio more directly. This method is based on the assumption that the radiance of a mixel is represented by linear combination of radiance of its components. To verify this method, vegetation cover ratio of the test site, selected in the City of Inagi, was estimated using JERS-1 OPS data and compared with verification data generated by interpretation of aerial photograph. We concluded that this method is a more practical method. Further, relationships between vegetation cover ratio estimated by the proposed formulae and NDVI of urban land surface, which is a mixed land cover, is shown. These relationships are explained by intervals of intersection points of segments between pure pixels and isoline of NDVI on Visible-Near infrared wavelength space (V-NIR space). Using land use data as substitution for land cover category and applying this method to JERS-1 OPS data, the vegetation cover map of Tokyo metropolitan area was constructed.
