Abstract

This paper characterizes the spatial features and trends of temperature change during 1960 to 2009 using the daily temperature data of 48 stations in Sichuan-Chongqing and 47 stations close to Sichuan-Chongqing from 691 national meteorological stations adopting the GIS spatial analysis function and the linear trend method. The results showed that firstly, the annual mean temperature change of Sichuan-Chongqing presented different spatial unconventionally sensitive areas due to local complex terrain patterns. Typically, Sichuan basin was the cooling center and the Southwestern Sichuan became warming center. In the past 50 years, the change of annual mean temperature showed a U-pattern including the rapid cooling period of 1960s, the relative stability period of 1970s to 1980s and the obviously warming period of 1990s to 2000s. Secondly, the interdecadal change of seasonal temperature in Sichuan-Chongqing strongly fluctuated. The warming rate was more significant in spring and autumn than that in summer and winter. Specifically, in spring, the temperature change of inner Sichuan basin was generally stable, but fluctuated greatly in the boundary of Sichuan basin. In summer, the temperature change of Sichuan-Chongqing showed a weakened cooling trend, and a significantly warming trend in autumn and a gradually warming trend in winter. Thirdly, the temperature change of Sichuan-Chongqing was significantly controlled by the large temporal-scale. The trend of temperature change showed a remarkably difference among annual, decade, accumulated decade and season. The annual mean temperature did not change significantly (in a warming rate of 0.173°C/10a) in the past 50 years. However, the temperature change showed a fluctuant pattern, with a cooling trend, a stable trend, and a warming trend associating with time process, regardless of interdecades, accumulated interdecades and seasons. Fourthly, the mutation of annual mean temperature change in Sichuan-Chongqing occurred about 1974. The change of annual mean temperature presented an overall cooling trend before 1974 and a fluctuated warming trend with dentate-like patterns after 1974.

Key words: Sichuan-Chongqing, temperature change, spatial-temporal distribution, station statistics.