Decadal variations of arid and semi-arid boundary in China
中国干旱和半干旱带的10年际演变特征

Decadal variations of arid and semi-arid boundary in China during last 100 years have been analyzed by using Thornthwaite's method. The results indicate that, during the last 50 years, there is a distinguished periodic variation of arid and semi-arid boundary in their locations in the middle part of northeast China and northern part of central northern China, and an obvious trend moving to east. In south part of Shannxi province and central northern China, the boundaries of arid and semi-arid areas have been moving to the south, and there is also a periodic variation in the locations, the boundary of semi-arid area reaches the largest extent to the south. During the last 100 years, there is a trend of the boundaries moving to the south or east, and in the south part of northern China and the central part of northeast China, the extent and intensity of arid and semi-arid area was the largest and severest in the 1920s. The location variation of arid and semi-arid boundaries is closely related to regional warming and precipitation reduction.