Abstract: Based on the statistical data of disaster covered areas, disaster affected areas and disaster areas with no harvests of drought, flood, chilling damage, wind-hail, together with crop yield data, in North China Plain(NCP) from 1951 to 2010, the trends of strength and scope of these disasters covered was analyzed by using linear regression analysis, moving average, Mann-Kendall and fuzzy comprehensive evaluation methods, and the impacts of disasters on agriculture production and the crop loss risk were also analyzed. The results showed that the trends disaster covered area ratio existed abrupt change in 1970, 1988, and 1974 for flood, chilling damage and wind-hail respectively, except for drought which tendency variation was not obvious, while a very significant increasing trend for the strength (P<0.01). Flood disaster covered area ratio was a very significant decreasing trend (P<0.01), and the disaster intensity decreased significantly (P<0.05). Wind and hail showed a very significant increase in the trend of both disaster covered area ratio and intensity (P<0.01). Fuzzy comprehensive evaluation showed that drought was the main agro-meteorological disasters in the provinces and cities, the minimum extent of cold damage, during the whole 60 years, where had some differences at sort of the four kinds of disasters on the degree of influence of different provinces in each period. Crop loss quantity was increasing in NCP during the last 60 years. The high risk of crop loss caused by drought was moving towards to the north of NCP; the loss risk was increasing of wind-hail, and the increase speed in North was faster than that in South; its risk caused by flood and chilling damage always remained in the small or low degree.

Key words: North China Plain, Agro meteorological disaster, Disaster covered area ratio, Disaster intensity, Fuzzy comprehensive evaluation, Crop loss risk