The quantitative evaluation and comparison of drought risks at each development stage and the whole growth period between transplanting rice and direct-sowing rice in Sichuan Basin can provide a scientific basis for the transformation and promotion of rice production technology in various regions. Based on the theory of natural disaster risk and the formation mechanism of rice drought risk, we evaluated and compared the drought risk in the whole growth period and the four development stages (sowing-jointing, jointing-booting, booting-full heading, full heading-maturity) between transplanting rice and direct-sowing rice, analyzed the vulnerability of disaster bodies, the sensitivity of disaster environment and the capacity of drought disaster prevention and reduction of rice drought in Sichuan Basin, using meteorological data in Sichuan Basin from 1961 to 2017, the observation data of rise production, agricultural statistics and the basic geographical information. The drought risk assessment model for Sichuan Basin was established, which was used to classify the results of evaluation. The results indicated that the drought risk of rice in Sichuan Basin was higher. The medium-risk areas in terms of the two planting methods were both the most widely distributed areas. The spatial-distribution characteristics of drought risk for the two kinds of rice were generally the same which was high in the middle and east of the basin, low in the southwest of the basin, and decreased from east to west and from the center to the surroundings. For the two planting methods, the greatest difference of rice drought risk appeared at the sowing-jointing stage. The drought risk of the direct-sowing rice at the sowing-jointing stage was significantly lower, and the distribution range was smaller than that of the transplanting rice. The distribution of the slight-low drought risk area of the direct-sowing rice was wider, but the high-risk area was slightly smaller.
定量评价和比较四川盆区移栽水稻与直播水稻各发育阶段及全生育期干旱灾害风险,能为各区域水稻防旱减灾生产技术转型和推广提供科学依据.基于自然灾害风险理论和水稻干旱灾害风险形成机理,利用四川盆区1961—2017年的气象资料、水稻生产观测资料、农业统计资料和基础地理信息,对移栽和直播水稻全生育期和播种-拔节、拔节-孕穗、孕穗-齐穗、齐穗-成熟4个发育阶段干旱危险性进行评价和比较,对四川盆区水稻干旱灾害承灾体易损性、成灾环境敏感性和防灾减灾能力进行分析,从而构建四川盆区水稻干旱风险评价模型,并对评价结果进行区划.结果表明: 四川盆区水稻旱灾风险整体较高,两种播栽方式下均为中等风险区分布面积最广;两种播栽方式下干旱风险空间分布特征总体一致,表现为中东部高、西南部低,从东向西、从中部向周围递减的趋势.两种播栽方式下,水稻干旱危险性差异最大的时期出现在播种-拔节阶段,直播水稻在播种-拔节阶段的干旱危险性明显低于移栽水稻,且分布范围也较移栽水稻小;直播水稻干旱灾害的轻-低风险区分布较移栽水稻广,高风险区分布面积较移栽水稻略小.
Keywords: Sichuan Basin; drought; rice; risk comparison..