The Integration of Satellite Data with Environmental Database

Abstract

The environmental database is becoming an indispensable source for various planning processes. However, it is a tough task to keep up the data with the ever changing environment. Especially factors like landuse are rapidly altered in Japan. On the other hand, constant renewal of such man-made data requires a lot of labor and time. Even if we have both, the precision of the data remains dubious because they have to depend on existing information such as maps, aerial photographs and occasional field trips.
The integration of LANDSAT TM data with existing enviromental database of Kobe area is tried, and the results are discussed. First, the TM data covering Kobe area is extracted from a scene of 1984. Then band 2, 3 and 4 of the TM data was agreed to the coordinates of exiting database using affine approximation based on 10 corresponding ground control points. Thus agreed TM data was classified into several categories using maximum likelihood method and shown on the display attached to an image processing system named FIVIS. Finally the data was compared with some factors in Kobe environmental database.
Strictly speaking, it is impossible to compare the two data because the TM data is based on an instantaneous view of the land surface, while man-made landuse and vegetation data is produced on various data of different stages. Satellite data can supply constant view of the area with reasonable cost though cloud-free data is rare. This is an advantage to follow the changing land surface. However, the view by satellite is often different from landuse we recongnize on vegetation-covered areas and mountain ranges. For instance, paddy fields are major agricultural landuse, but it is perceived as completely different landuses depending on the season by satellite. In addition, classifying landuse or vegetation is difficult due to shadows on the slope. For these reasons, both data should be supplemented each other to obtain more precise view of the area. Then satellite data will contribute a lot to improve current environmental and geographical databases.