Characteristics of Climate Change in the North China Plain for Recent 45 Years

A statistical analysis of the temporal and spatial changes of mainly climatic elements over the North China Plain was conducted,based on the daily climatic data of 53 stations from 1961 to 2005 by using the trend analysis, and the jumping point of temperature was fixed by using the Mann-Kendall test method.It was found that the climate was warming up in the last 45 years,in particular in the 1990s.For annual precipitation,no significant trend was found on the basis of long-term change.Precipitation gradually decreased in the middle and later period of the 1980s.Thus,it was believed that climatic variation in the North China Plain over the 45 years experienced a course of humid-cold to dry-warm.And the sunshine duration was decreasing significantly.The climate change feature of each month was characterized by monthly linear inclination rates which showed that from January to April,the temperature increased most remarkably,the precipitation decreased most obviously in summer and April,and the sunshine duration decreased rapidly in summer,winter and spring.The results also showed that the temperature difference between the south part and the north part was getting smaller,but the precipitation and sunshine-duration were opposite.The heat resources were more abundant for the whole area as the result of the climate warming up.