ASSESSMENT OF RIVER ENVIRONMENT IN THE EAST TIAOXI BASIN, CHINA USING GPS-LOGGER, GOOGLE EARTH AND LANDSAT IMAGES

Abstract

In Taihu Lake Basin in China, due to the rapid development of economy and society, degradation of aquatic environment has been one of the most urgent issues. On the other hand, the region still holds a lot of rivers and lakes with good environmental condition, which Japan and other advanced countries have already lost. For the first step to conserve such remaining environments, the past and present environmental status of the East Tiaoxi River (one of the most significant rivers in Taihu Lake Basin) was surveyed using GPS-logger, Google Earth and Landsat images. At first, NDBI, NDVI, BA was calculated from the multi-temporal Landsat images. The past Landsat images showed that, since 2000, urban areas and open-cast mining have been drastically expanded in the region. Classification of bank type was conducted using high resolution satellite images of Google Earth and digital photographs taken at main stream of East Tiaoxi; As a result, it was suggested that the carrying vessels for mineral substance considerably disturb the river environment.