Climate Analysis in Recent 50 Years in Jinchang of Gansu Province

The monthly,seasonal and annual average temperature series,precipitation in Yongchang during 1959-2009 was analyzed using linear and polynomial regression methods. The results show that the average temperature presented increasing trend,the abrupt change occurred in 1996 for temperature. The annual precipitation also showed increase trend since 1983,and during 1992-2009 annual precipitation was 20. 6 mm more than climate average value,and abrupt change occurred in 1984 for precipitation. In the 1960s and the early of 1990s,it was relatively dry,the driest year in history occurred in this period,and during 1970-1978,1992-2009 it was relatively humid,the frost-free period prolonged since 1998,and it was gradually moving to the relatively warm and humid period.