Abstract: Taking Eryuan County, Dali Bai Autonomous Prefecture, Yunnan Province as the research object, ENVI and ArcGIS were used for data processing to construct a multi factor ecological sensitivity evaluation index system, and single factor and comprehensive sensitivity evaluations were carried out. The results showed that from 2000 to 2020, the proportion of non sensitive areas, mild sensitive areas, and moderate sensitive areas of vegetation coverage index, land use type, and comprehensive ecological sensitivity in Eryuan County showed a decreasing trend;the proportion of highly sensitive areas in vegetation coverage index, land use type, and comprehensive ecological sensitivity showed an increasing trend, increasing by 31.47, 21.85, and 20.76 percentage points, respectively;the highly sensitive areas of vegetation coverage index range from sporadic distribution to a “Chuan” shaped distribution;the highly sensitive areas of land use types were distributed in most areas except for the mountainous basins in Sanying Town and Dengchuan Town;the distribution range of non sensitive and lightly sensitive areas of comprehensive ecological sensitivity was gradually shrinking, mainly distributed in mountain basins, while highly sensitive areas were mainly distributed in Luoping Mountains in the eastern and central Eryuan County. The rapid increase in the area of highly sensitive areas in Eryuan County was fundamentally due to the implementation of ecological protection policies in the Erhai River Basin.

Key words: ecological sensitivity, spatiotemporal changes, Eryuan County,Dali Bai Autonomous Prefecture,Yunnan Province