Analysis on evolutionary process of Liaohe Delta wetlands based on geographic information system (GIS) and remote sensing (RS)

With the interpretation and analysis of 1978, 1988, 1998 and 2008 remote sensing images, evolutionary process during different periods of Suaeda heteroptera and reed wetlands in Liaohe Delta was discussed. Results showed that, although areas of Suaeda heteroptera and reed wetlands during 1978-1988 were increased, their areas were abbreviated from 1978 to 2008 in the mass. The area degeneration of Suaeda heteroptera was mainly affected by human activities, such as aquaculture, exploitation of paddy field and sea level rise caused by climate change. Areas of reed wetlands were degenerated which had the evolutionary trend to paddy fields, built up areas (such as roads, oil wells and residential areas) and dry farmlands. Nonetheless, because of the artificial management and implement of protection policy, the degeneration of reed areas become less in recent years.