中文摘要：

建立华南早稻干旱灾害定量评估模型,分析干旱灾害时空特征,为主动防旱减灾、制定气候变化适应政策提供参考。根据分县早稻产量及生育期资料,采用逐日气象干旱指数DI计算各生育期干旱指数,并由统计回归方法率定各生育期干旱指数对产量影响系数。华南近30年（1981—2010）早稻干旱年频率平均为10.4%,平均减产率为0.82%,以轻旱为主。早稻干旱主要发生在移栽-分蘖期。干旱频率及减产率均呈西高东低分布,旱年频率在20%-50%、减产率在1%-3%的区域集中在广西西南部至广东雷州半岛一带。近30年华南早稻最旱的3年为1991、2002、1998,早稻干旱总体趋于增强但不显著,增强趋势显著的站点约占10%,分布于华南北部和北部湾至粤西沿海地区。基于不同生育期干旱指数建立的评估模型,揭示早稻不同生育期对干旱敏感性差异,精细刻画早稻干旱时空特征,克服基于全生育期降水的干旱评估模型的局限性。

英文摘要：

The paper aims to establish a quantitative evaluation model of early rice drought m South China, to analyze temporal-spatial characteristics of the drought disaster, and to provide scientific reference for drought disaster mitigation and climate change adaptation policy making. Using county based yield and growth period data of early rice, drought index of each growth period was calculated by daily meteorological drought indicator （DI）, and coefficient in each growth stage was calibrated by statistical regression method. Average drought frequency of early rice in South China in recent 30 years （1981-2010） was 10.4%; mean yield reduction rate was 0.82%. Drought disaster mainly occurs in transplanting-tillering stage of early rice, and light drought day＇ s accounts for the main. Spatial distribution of early rice drought frequency and yield reduction rate was high in stations where drought disaster of early rice tended to increase significantly accountecl tot 10%, distributing m north and coastal region from Beibu Gulf to west Guangdong. Using drought evaluation model based on drought index of each growth period, the study revealed sensitivity difference between each growth stage of early rice, and temporal-spatial characteristics of the droght drough evaluation model presented in the paper t disaster was characterized in more detail, and therefore the overcame the limitations of those models based on rain of whole growth period of rice.