Abstract:

Based on the daily temperature of Jingzhou from 1954 to 2008,authors analyzed the characteristics of accumulated temperature change of ≥10℃ and ≥20℃ by using the methods of linear trend estimates and MK test.The results indicated that,the annual temperature showed an increasing trend with the linear warming rate of 0.26℃/10 a during the past 55 years.In 1986 the annual temperature had abrupt change,especially after 1989,the warming trend increased significantly.The trend of initial date of ≥10℃ and ≥20℃ appeared ahead,while the terminal date was delayed,so the sustained days of ≥10℃ and ≥20℃ increased significantly.During the past 55 years,≥10℃ accumulated temperature showed an increasing trend significantly with the warming rate of 859℃/10 a.Mutation point of ≥10℃ accumulated temperature was appeared in 1990,and after 1994,≥10℃ accumulated temperature increased sharply.At the same time,the ≥20℃ accumulated temperature also appeared an increased trend with the warming rate of 756℃/10 a.The ≥20℃ accumulated temperature had abrupt change in 1995,especially after 2004,the warming trend increased sharply.In the past 55 years, the ahead of the initial date of ≥10℃ and ≥20℃ was greater than the delay of the terminal date,and the same situation occurred in  heat resources.The mutation point and the point of the significant increased year of ≥20℃ accumulated temperature appeared latter than that of ≥10℃ accumulated temperature.〖