Change Characteristics Analysis of Critical Temperature in the Farming Stage in Yingkou City during Recent 57 Years

The accumulated temperature and accumulated temperature days though 0 and 10 ℃ stably and the variation rate in Yingkou City from 1951 to 2007 were discussed.The accumulated temperature and accumulated temperature days though 0 and 10 ℃stably during recent 57 years showed the increasing trend and the increasing trend of the accumulated temperature and accumulated temperature days though 0 ℃ stably was stronger than that through 10 ℃ stably.The change trend of the accumulated temperature though 0 and 10 ℃stably was different in different stages.The increasing trend was weaker in the first and second 30 years and that was strong in the third and latest 30 years.The decreasing tend of accumulated temperature days through 10 ℃ stably in Yingkou City during 57 recent years was more significant than that through 0 ℃.During the latest 30 years,the increasing trend of accumulated temperature through 0 and 10 ℃stably was accordant with the global warming.