Abstract: Based on the meteorological data of 80 stations in the south and north areas of the Qingling Mountains over 1980-2009, and by applying spatial analysis method to analyze the boundaries’position variation between semiarid and humid areas, warm temperate and subtropical zones. Results indicate:(1) In the recent 30 a, the climate aridity index of the south and north areas of the Qinling Mountains showed an obvious latitudinal distribution, namely the humidity increased from the south to the north, and showed a linearly decreased tendency except the northeast of Shangluo City and the center of Xi’an City; the days of daily mean temperature ≥10 ℃ showed a latitudinal distribution, namely increased in turn from the north to the south, and showed a linearly increased tendency; the spatial distribution showed a concentric characteristic. (2) The position of semiarid and humid region’s boundary was at the northmost in the 1980s, and at the southmost in the 1990s, and in the middle position during the first decade of 21 st century; the position of warm temperate and subtropical zones’ boundary was at the southmost in the 1980s, and moved to the north in the 1990s, and at the northmost during the first decade of 21 st century. (3) The maximum position fluctuations of the boundaries between semiarid and humid areas, and warm temperate and subtropical zones were 1.2 degrees and 0.5 degree of latitude, respectively, in the study area; and the mean position of both boundaries was near the 34 °N. (4) In the recent 30 a, the warming and drying tendency was very prominent; the northward movement of the boundaries between semiarid and humid areas, and warm temperate and subtropical zones may have a great influence to the cropping system in the study area.

Key words: climate change, climatic zone, aridity, spatial analysis, Qinling Mountains