Four phases of wetland thematic maps for 1980

1990

2000

and 2007 were mapped fromLandsat MSS/TM/ETM+ remote sensing images.The wetland landscape pattern changing

the regional climate changing

and the human activities’ impact were analyzed.We concluded that:（1） The shrinking trend of the natural wetlands is significant

with total area decreasing from 5360 km2 to 4331 km2 within the period from 1980 to 2007.The man-made wetland areas increasing from 3492 km2 to 5245 km2 within the period from 1980 to 1990

and then decreasing to 4499 km2 in 2007;（2） The plains wetlands spread firstly and then shrank along with the changes in agricultural wetlands.The mountain wetland areas have shrunk gradually mainly because of the decreasing of rivers and river flood plains;（3） In the Grade Ⅲ water resources regions

the rivers and agricultural wetlands of the downstream plains of the Ziyahe River and the Beisanhe River are the most dramatically changed wetland types in the natural and man-made wetlands in the plain area of the Basin.The rivers and river flood plains in the mountain areas of the Yongdinghe River

the Ziyahe River

the Daqinghe River are the mostly changed natural wetlands

and the reservoirs in the mountain areas of the Yongdinghe River

the Beisanhe River and the Daqinghe River are the mostly changed man-made wetlands;（4） Until 1980

the rivers wetlands have been found distributed

widely and afterwards reducing

comparing with the spreading of the other wetland types such as agricultural

reservoirs

marine aquaculture fields and brine pans as well as the shallow waters;（5） Influenced by the climate changes and human activities

the wetland landscape patches are becoming fragmented

and their spatial distribution is becoming homogenized and isolated.Among the influences mentioned above

temperature is the main natural factor that influences the wetland changes

and total population changes and food production are the main human activity factors.