中文摘要：

基于信息扩散理论提出直接估计低温冷害、干旱和洪涝的风险评估方法，以低温冷害为例，将计算结果与风险指数法和主观频率法做比较。直接估计灾害风险具有：（1）计算过程简单，所需资料少；（2）可对灾害不同级别进行风险评估，利于进行灾害风险评价和区划；（3）此方法可触类旁通，应用到其它自然灾害风险评估；（4）此方法需要的资料年限短等优点，对开展乡（镇）级小区域自然灾害风险评估有借鉴作用。

英文摘要：

This research raised the method in risk assessment of low temperature and cold damage, drought and flood disaster based on information diffusion theory. Taking low temperature and cold damage for example, through a comparison between the calculated results of risk index method and subjective frequency method, direct risk assessment, has obvious advantages： （ 1 ） it needs simple calculation process and less information; （2） it helps for risk assessment and zoning through different levels of risk assessment; （3） it can also used into other natural disaster risk assessment; （4） it can do the research of risk assessment in small county and town through information diffusion theory for less information.