Analysis on Temperature Variation over the Past 55 Years in Guyuan City, China

Global climate change has far-reaching effects on natural ecosystem and socio-economic system, and it is a hot issue that the governments and the scientific community as well as the general public pay attention to today. Meanwhile, climate change has strong regional characteristics. In the global context of climate warming, the climate change trends and intensity is not entirely consistent. Therefore, strengthening small regional climate change research plays an extremely important role on local agricultural production, livelihood and disaster prevention. On the basis of the monthly average temperature series in Guyuan meteorological station from 1957 to 2011, the temperature trends were analyzed with Mann-Kendall test and Pettitt jump test. The result with linear regression analysis showed that the annual average temperature in Guyuan City is in an increasing trend, and the average increase rate is 0.3071/10a. The annual highest temperature, the annual lowest temperature, and the annual average temperature in Guyuan City showed an upward trend with Mann-Kendall test. The biggest change is the annual lowest temperature, and the change rate is 0.60 /10a, and then is the annual average temperature and annual highest temperature. Pettitt jump test results showed that the annual lowest temperature in Guyuan City changed in the earliest year before 1984. The annual average temperature and annual highest temperature changed nearly the year of 1993. Multiple regression analysis showed that changes of temperature in Guyuan City mainly occurred after the 1980s, and there is a significant upward trend into the 21st, which is in accordance with Pettitt jump test results.