Spatial and temporal trends of temperature and precipitation during 1960–2008 at the Hengduan Mountains, China

Annual and seasonal changes of temperature and precipitation were analyzed based on climate data at 27 meteorological stations in the Hengduan Mountains region during 1960–2008. The average annual, spring, summer, autumn, and winter temperatures exhibited significantly increasing trends of 0.15, 0.589, 0.153, 0.167 and 0.347 °C/decade over the studied period, respectively. Temperature increases showed a relationship with increasing elevation. In contrast to the temperature, the significance of changes in precipitation during 1960–2008 was low. Regional precipitation for annual, spring, autumn, and winter showed nonsignificant increasing trends of 9.09, 8.62, 1.53, and 1.47 mm/decade. Summer precipitation exhibited a decreasing trend at a rate of −1.5 mm/decade. Under the influence of the longitudinal range-gorge, the regional trend in precipitation was on the decrease from the southwest to the northeast in Hengduan Mountains. During the summer monsoon period, the increase in temperature was 0.117 °C/decade, significant at the level of 0.001. Precipitation increased at 6.01 mm/decade, but also started to decrease and fluctuate after 2000. There was also a 0.25 °C/decade and 7.47 mm/decade increase of temperature and precipitation, significant at the 0.001 level, in the winter monsoon period. The climatic complexity in a mountainous region is reflected by the temporal and spatial differences of climate in the Hengduan Mountains. Compared with other regions in China, the climatic warming magnitude is relatively lower in the Hengduan Mountains.