主要农业气象灾害风险评估技术及其应用研究

基于灾害风险分析的原理,论文提出了我国几种主要农业气象灾害风险评估的技术方法。包括一年生农作物、多年生果树减产率序列的构建技术,不同致灾因子、致灾指标序列的构建技术,灾害风险估算模型的构建技术;致灾损失(减产率)的风险评估技术,致灾指标的风险评估技术,减灾措施降低灾害风险的评估技术。通过对1961～2000年逐日气象资料与产量、灾情资料的相关分析研究,筛选出适用于北方地区冬小麦干旱、东北地区玉米和水稻冷害、江淮地区冬小麦和油菜涝渍、华南地区香蕉和荔枝寒害风险评估的主要致灾因子、致灾等级、致灾指标及其对应的减产率。以北方地区冬小麦干旱、华南地区香蕉和荔枝寒害风险评估为例,给出了针对一年生农作物、多年生果树不同承灾体类型的风险概率估算方法及其风险等级划分。结果表明:北方地区冬小麦干旱、华南地区香蕉和荔枝寒害风险概率分布有着很好的连片性和区域性。北方地区冬小麦全生育期内,自然水分亏缺的风险概率很高,随着灌溉次数的增加,缺水率的风险概率逐渐降低。一般在轻旱年灌水1～2次、中旱年灌水2～3次、重旱年灌水3次之后,大部分地区都能基本满足冬小麦的需水要求,缺水率出现的概率已经很小。

Study on the risk evaluation technologies of main agrometeorological disasters and their application

Basing on the theory of risk analysis of disasters,several kinds of risk evaluation tech-ology of main agrometeorological disasters in China are put forward,including establishment technology of the sequences of yield reduction rates of annual crops and perennial fruit trees,different factors causing disasters,index sequences causing disasters,risk estimate models;risk evaluation technology of loss(yield reduction rate)caused by disasters,indices and methods taken to reduce risk.By analyzing and studying the correlation between meteorological data day by day from1961to2000and yield and disasters,the main factors,grades and indices causing disasters and the corresponding yield reduction rates which are suitable for drought of winter wheat in North China,cool injury of corn and rice in Northeast China,waterlogging of winter wheat and cold in Jianghuai valley and cold damage of banana and litchi in South China are selected.Making the risk evaluation of drought of winter wheat in North China and cold damage of banana and litchi in South China as examples,the methods which can be used to calculate risk probability and divide risk grades aiming at annual crops and perennial fruit trees are given.The technologies and methods of risk evaluation of drought of winter wheat basing on actual yields,climatic productive potentialities,natural water deficiency rate and the methods taken to reduce disasters are studied,and the risk probabilities under different conditions of yield reduction rates,indices causing disasters and methods taken to reduce disasters are calculated.The results indicate:the risk probability distributions of drought of winter wheat in North China,cold damage of banana and litchi in South China have the character of juncture and regionalization.The risk probability of natural water deficiency is high in the whole growing period of winter wheat in North China,but it will decrease gradually with the increase in irrigation times.Generally,the irrigation times in the year of light drought is1-2,in the year of moderate drought is2-3and in the year of heavy drought is3,which can meet the water requirement of winter wheat in many areas,and the risk probability of water deficiency is low.The study can supply scientific evidences to government and production department to control the occurrence of agrome-teorological disasters,to take precautions against harm or reduce harm that disasters to agriculture,to make methods to reduce loss,to formulate insurance policies about agrome-teorological disasters and to transfer the risk.