The Yunnan Plateau is situated in subtropical Southwest China and covers an area of about 394,000 km2 between 21.14-29.25°N and 97.52–106.19°E. It is a mountainous area with an average altitude of 1980 m. Its climate is influenced by the interaction of several circulation systems. Climatic changes in the area will have a strong impact not only on the position of the upper tree line and on the hydrological cycle, but also for geomorphological activity and the risk of flooding during the summer monsoon season.
Dr. FAN Zexin of Xishuangbanna Tropical Botanical Garden (XTBG) and his colleagues examined the spatial and temporal temperature variability over the Yunnan Plateau during the period 1961–2004. The study was carried out on the basis of an extensive dataset from 119 meteorological stations from Yunnan Province in southwestern China. The researchers investigated annual and seasonal temperatures (mean, minimum and maximum)for their spatial and seasonal trends and variability.
The study found that regional annual temperature has risen by 0.3 0C/decade during the past 44 years. The warming trends were found to be more pronounced during the winter season from November to February, whereas summer warming is mostly confined to the south part of the Yunnan Plateau. Regional warming trends in monthly minimum temperatures are more prominent than increase of maximum temperatures. Greater and more consistent warming was found in the south and northwest (high-elevation) area of the Yunnan Plateau, but less in the east. In contrast, the hot-dry valleys of the Great Asian Rivers experienced a cooling trend during the past decades.
Climate data used in the study were provided by theNational Meteorological Information Centre (NMIC) of China. The work was funded by the National Natural Science Foundation of China (Project No. 90302013).
The study entitled “Spatial and temporal temperature trends on the Yunnan Plateau (Southwest China) during 1961–2004” has been published in International Journal of Climatology, 31(14): 2078-2090, DOI: 10.1002/joc.2214