DYNAMIC CHANGE MONITORING OF COASTAL WETLANDS IN LIAOHE DELTA FROM 1995 TO 201S,CHINA

摘要

The coastal wetlands in Liaohe Delta are increasingly threatened. Monitoring their dynamic changes can provide scientific basis for the restoration and sustainable management of wetland ecosystem health. Landsat TM/OLI remote sensing images from 1995, 2000, 2005, 2009, 2014 and 2018 are used as data sources, and wetland distribution map was obtained by object-oriented classification method. The total accuracy of classification results was 93.67%, and the kappa coefficient was 0.91. The transformation of wetland types and nonwetland types was analysed. The results show that the total area of natural wetlands (including marsh, tidal flat, river and lake) decreased by 5.33% from 1995 to 2018, about 215.8 km2. Constructed wetlands (including paddy field, reservoir, salt pan and marine farm) decreased by 32.75%, about 111.36 km2, and increased first and then decreased. Most of the new paddy field area comes from marshes, and most of the new construction land area comes from paddy field, the area of tidal flat has been reduced most dramatically. Most wetlands are converted to non-wetlands, and the area of natural wetlands is severely reduced. The protection of existing wetlands should be strengthened to maintain a sustainable and good ecological environment.