本文依据水稻气象灾害标准,提取了湖南省1981—2013年双季稻生育期内干旱、洪涝、高温热害和低温冷害,分别探讨致灾因子类型和灾次的时空分布与组合特征.结果表明,湖南省水稻灾害呈现鲜明的多致灾因子特征.单一生育期内,水稻致灾因子类型以2~3种为主,多致灾因子类型组合以干旱高温热害组合比例最高,达到22.87%.水稻致灾因子灾次以4~6次为主,湖南东部地区高于中西部地区.各站多致灾因子灾次的频率分布呈现出明显的泊松分布特征,泊松参数值自西向东逐渐增大,最大值为5.5次.根据多致灾因子类型和灾次的组合特征,最终将湖南省划分为8个多致灾因子区.洞庭湖区及湘中地区为双季稻主产区,水稻种植过程中应注意防范高温热害和干旱灾害.
Drought,flood,heat damage and cold injury in the growth period of double-season paddy rice in Hunan Province from 1981 to 2013were investigated.Temporal-spatial distribution and combination features of hazard type and frequency were examined.Two to three types of hazards were found to likely occur in a single growth period.Drought-heat combination held the highest frequency of 22.87%.In another growth period,4~6hazards were most likely to occur.High event frequency center was found to be in eastern Hunan Province.Multi-hazard frequency in a single growth period could be well fitted with Poisson distribution.Poisson parameters increased from west to east with a maximum value of 5.5times.Features of hazard type and frequency clearly indicated that Hunan Province could be regionalized into 8 multi-hazard regions.In the Dongting Lake area and central Hunan,the major production regions for paddy rice,rice cultivation was found to be vulnerable to drought and heat damage.