春季低温连阴雨灾害对农作物产量影响评估

Method for Estimating Impact of Spring Low-Temperature and Continuous-Rain Disasters on Crop Yields

依据河南省春季低温连阴雨灾害标准,对信阳市1971—2007年春季达到低温连阴雨过程标准的气象资料,分别从3月低温上,4月低温、连阴雨以及低温连阴雨,5月连阴雨等不同的致灾因子持续时间长短、对农作物造成危害程度的大小,将其划分3成个不同的灾害等级。用拉格朗日插值法计算作物的期望产量,用分离法将春季低温连阴雨灾害对作物造成的损失分离出来。结果发现,不同时段的春季低温连阴雨对水稻、小麦、油菜和茶叶造成的危害程度是不同的,以4月低温连阴雨和5月连阴雨危害最大。定量评估春季低温连阴雨灾害损失对防灾减灾和政府决策具有十分重要意义。

A quantitative assessment is made of the economic loss of main crops,including rice,wheat,rape and tea,resulted from the spring low-temperature and continuous-rain disasters in Xinyang,Henan Province,according to the standard definition of the spring low-temperature and continuous-rain disaster,by means of the related meteorological data from 1971 to 2007.The spring low-temperature and continuous-rain disasters are divided into three levels,based on the durations and harmfulness of disaster inducing factors,such as low temperature in March,＂low temperature＋continuous rain＋low temperature-continuous-rain＂ in April,and continuousrain in May.The expected crop yields and the disaster loss rates are calculated with the separation method based on Lagrange interpolation theory.The results show that the spring low-temperature and continuous-rain disasters have different impacts during the different periods in spring on rice,wheat,rape,and tea,most harmful in April and May.It is of great significance to carry out the damage assessment of spring low-temperature and continuous-rain disasters for the disaster prevention/mitigation and decision-making of governments at all levels.