Taking Yancheng coastal wetlands as an example

we analyzed the spatial and temporal evolution characteristics of coastal wetlands landscape about two periods based on the years of 1987

1997 and 2007 landscape images.We used two landscape ecology indicators: transition probability and centroid

with the technologies of RS and GIS.The results indicated that both the landscape structure and centroid changed from 1987 to 2007.Firstly

the percentage of natural wetland dropped from 42.45% to 21.44%

but the artificial wetland rose from 18.19% to 58.88%.During the former decade

45.40% of the natural wetlands were transferred to the artificial wetlands or the non-wetland;while in the later decade

additional 37.91% of the natural wetlands were transformed

leading to an increased and then decreased landscape heterogeneity over the time.Secondly

both the natural and the artificial Landscape centroid shifted to the southeast from 1987 to 2007.From 1987 to 1997

the artificial wetland centroid moved 58.17 km and the natural wetland centroid did 6.15 km

while from 1997 to 2007

they shifted additional 12.67 and 7.15 km

respectively.