中文摘要：

旱灾是影响我国农业最严重的自然灾害。近10多年来我国每年有170~200万hm2农田遭受不同程度的旱灾,造成了巨大的损失,威胁着国家的粮食安全。然而,农业旱灾对我国粮食产量影响的定量分析尚未见有人研究。提出了一个衡量旱灾强度的定量模型,建立了旱灾粮食损失的估算方法,并对全国及各省区近10多年来的旱灾粮食损失进行了评估,定量分析了农业旱灾对我国粮食安全的影响程度,建立了旱灾强度与灾害粮食损失之间的时空数量关系。结果表明,旱灾对我国粮食安全的影响较为显著,1990-2005年间我国平均旱灾强度达13.8%,平均每年因旱灾导致的粮食损失达到2600万t,对国家粮食安全的影响为8%左右;粮食损失量可满足6000万人,相当于一个大省如河北省人口的需要。因此,加强农业旱灾监测评价,积极进行农业抗旱减灾,是保障国家粮食安全的重要措施。

英文摘要：

Agro-drought in China is very severe.In recent decade China＇s cropping land under drought attacks at various levels was annually 1.7—2.0 million hm2.Economic loss as a result of drought was enormous.Drought had been listed as the most serious natural disaster threatening food security in China.However,quantitative analysis of the impact of agro-drought on national food security has not been reported.In this paper a model was developed for quantification of agro-drought intensity and its relationship with food security.Using the model we analysed the spatial and temporal variations of agro-drought impact on food security in recent decade in China.Our analysis indicates that the impact is very significant.Average intensity of agro-drought is high up to 13.8% during the period of 1990-2005.Annual loss of grain production due to drought is 26 million tons on the average.It could be concluded that drought brings about an impact of 8% on national food security in China.The drought-caused grain loss could satisfy the needs of 60 million people,which is equivalent to the population of a big province such as Hebei in China.Therefore,it is extremely important to strengthen agro-drought monitoring and evaluation,carry out drought disaster prevention and reduction and ensure national grain security.