��RS/GISΪ��Ҫ�ֶ�, �Ի���60���ĩ��Ƭ���Ƶ�������1: 10�����ͼ��1990��TMң�����ݡ�2000��ETMң�����ݺ�1��25��DEM����Ϊ��Ҫ����Դ, ����������¶ȡ���ˮ������, ��������ʪ�طֲ��������Ǩ�����������з���, �������: ������ʪ�ر�Ǩ����������20����70���������ή�����ơ��ռ�������Ϊ: ����������С�Ͷ��ݺ���ȵ������ʪ�������70�������һֱ����ή������, �������ϲ���ɽ��ȵ�������Դ��ʪ���Ծ���70��90������ź�, ��90������תΪή�������򲨶���Ƶ����������ʪ�ر�Ǩ��������, ʪ�صĵ��ʡ�ˮ�ĵȱ������صIJ�ͬ�����DZ�Ǩ�������Ҫԭ��

The wetland distribution, area change and driving force have been analyzed by means of RS/GIS, and take 1��100 000 topographic map s of Nakchu, based on aerial photographs in the late 1960 s, remote sensing images of Landsat TM in 1990, Landsat ETM in 2 000 and the 1��250 000 DEM data as main data sources, as well as combined with the temperature and precipitation data in Nakchu. The results indicate the wetland change in Nakchu presented degradation trend from 1970 s. The spatial differences show that the wetland acreage in small-sized faulted lake basin valley areas of western Nakchu was degenerated from 1970 s, while increased in high mountain-wide valley and river source areas of eastern and southern Nakchu during 1970��1990, and decreased after 1990 s. Climatic fluctuations and human activities are also the driving forces of wetland change, and the differences of wetland geological and hydrological factorsmaybe an important reason forwetland change.