Spatio-temporal characteristics of temperature and precipitation in Sichuan Province, Southwestern China, 1960–2009

Abstract

Annual and seasonal changes of temperature and precipitation were analyzed based on climate data at 37 meteorological stations in Sichuan Province (SP, Southwest China) by using trends detection and kriging spatial interpolation approaches during the period 1960–2009. The results showed that mean annual temperature (MAT) over the SP increased at a rate of 0.173 °C/decade in the most recent five decades, while a significant warming trend of 0.26 °C/decade was observed for winter. It is demonstrated statistically that MAT across the SP has a large spatial heterogeneity. A relatively great rising with a rate of 0.198 and 0.202 °C/decade occurred in Northwest Sichuan (NWS) and Southwest Sichuan (SWS), while a smaller increase at a rate of 0.12 °C/decade took place in the Sichuan Basin (SB) in the past 50 years. This means that mountainous regions are more sensitive and vulnerable to climate change than lowlands. In contrast to the temperature, the significance of changes in precipitation during 1960–2009 was low. Annual precipitation showed nonsignificant decreasing trends of −4.19 mm/decade, in which the decrease rate of −7.44 mm/decade in autumn is the most significant. In NWS and SWS, the precipitation exhibited insignificantly increasing trend of 1.41 and 9.69 mm/decade, respectively, whereas it decreased significantly at a rate of −23.70 mm/decade in SB from 1960 to 2009. In the spatial distribution, the magnitude of precipitation change exhibited a decreasing trend from the surrounding mountains to the central basin in the last five decades, which can be influenced strongly by the thermal difference between the Tibetan Plateau and the plain east of Plateau.