关键词: 关联度分析, 关联度分析

Abstract: The paper aims to establish a quantitative evaluation model of early rice drought in 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 west and low in east in South China. High incidence region of drought spreads in the area from southwest Guangxi to Leizhou Peninsula of Guangdong Province, where the drought frequency was 20%-50%, and yield reduction rate was 1%-3%. The driest 3 years in recent 30 years was 1991, 2002 and 1998. Drought disaster of early rice in South China tended to increase without statistical significance during recent 30 years. Those stations where drought disaster of early rice tended to increase significantly accounted for 10%, distributing in 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 drought disaster was characterized in more detail, and therefore the drought evaluation model presented in the paper overcame the limitations of those models based on rain of whole growth period of rice.