Changes in the arid climate over North China were investigated by applying the Koppen climate classification to Chinese station measurements and global grid data sets compiled over the period of 1951. 2000. The use of the Koppen scheme enables us to detect arid climate on a longer time-scale than is attainable through satellite remote sensing. A climatic shift toward a warmer and dryer condition is seen to be robust and substantial enough to cause conspicuous changes in the arid climate in North China from the decades 1951.1970 to the recent decades 1981.2000. The areas of semiarid (BS) and desert (BW) climate exhibit an overall expansion at the periphery of the existing arid zones in the studied period; a significance test shows that the increase in BS area is significant at the 99% confidence level, while that in BW area is relatively marginal. These results are indicative of the meteorological stress due to climatic transformation in North China, which is likely to be an impediment to sustainable re-greening in that region. Therefore, careful consideration of the effects of long-term climate change is required to support on-going and planned vegetation restoration in North China.
2008 by Meteorological Society of Japan