Spatio-temporal Variations of Temperature and Precipitation During 1951–2019 in Arid and Semiarid Region, China

Understanding the spatio-temporal variations of temperature and precipitation in the arid and semiarid region of China (ASRC) is of great significance for promoting regional eco-environmental protection and policy-making. In this study, the annual and seasonal spatio-temporal patterns of change in average temperature and precipitation and their influencing factors in the ASRC were analyzed using the Mann-Kendall test, linear tendency estimation, accumulative anomaly and the Pearson’s correlation coefficient. The results showed that both annual average temperature and average annual precipitation increased in the ASRC during 1951–2019. The temperature rose by about 1.93°C and precipitation increased by about 24 mm. The seasonal average temperature presented a significant increase trend, and the seasonal precipitation was conspicuous ascension in spring and winter. The spatio-temporal patterns of change in temperature and precipitation differed, with the southwest area showing the most obvious variation in each season. Abrupt changes in annual and seasonal average temperature and precipitation occurred mainly around the 1990s and after 2000, respectively. Atmospheric circulation had an important effect on the trends and abrupt changes in temperature and precipitation. The East Asian summer monsoon had the largest impact on the trend of average annual temperature, as well as on the abrupt changes of annual average temperature and precipitation. Temperature and precipitation changes in the ASRC were influenced by long-term and short-term as well as direct and indirect anthropogenic and natural factors. This study identifies the characteristics of spatio-temporal variations in temperature and precipitation in the ASRC and provides a scientific reference for the formulation of climate change responses.