基于热害累计指数的四川单季稻高温热害综合风险评价

高温热害是四川主要农业气象灾害之一,研究高温热害对水稻的风险区划,对保障水稻产量及农业可持续发展有重要意义。本文利用四川单季稻种植区1986-2015年气象观测资料、农业气象观测资料、社会统计资料以及基础地理信息资料,以单季稻生育敏感期（抽穗扬花期和灌浆结实期）为研究时段,选取热害累积指数、地形、产量变异度、农村经济等因子,分别构建了危险性、脆弱性、暴露性和防灾减灾能力4个风险因子,利用灰色关联度方法构建了四川单季稻高温热害"四因子"风险评价模型并对种植区进行风险区划。结果显示,高风险区主要分布在盆东平行岭谷区、盆中浅丘区、盆周边缘山地区的西部,以及盆南丘陵区的南部,该类型区域地势平缓,高温热害频繁。中等风险区主要集中在盆西平丘区和川西南中山山地区,该类型区域灌溉条件优越,社会经济水平发达,应对高温热害风险水平较高。低风险区主要集中在川西南中山宽谷区以及盆周边缘山地区,该类型区域地形较复杂,水稻种植较少,受高温热害影响偏小。四川盆地单季稻高温热害风险存在显著地区差异,应根据各自区域的风险特征选用适合的品种和方式提高防灾减灾能力。

Risk assessment of hot damages for single-cropping rice based on accumulation index of heat stress in Sichuan

Under global climate change, agricultural meteorological disasters have been increasing. Heat stress has been one of the most important agro-meteorological disasters in Sichuan Province, and the affected area and frequency and intensity of heat stress have significantly changed. Therefore, research on the effect of heat stress on rice is critical for sustainable agricultural development and safe production in Sichuan Province. Heat damage risk of single-cropping rice in Sichuan was studied using meteorological, agricultural meteorological, statistical, and geographic data during 1986-2015. Four factors, which were hazard, sensitivity, exposure, and disaster prevention and mitigation capacity, were created with the cumulative high temperature-induced damage index, topography, yield variation, and rural economy as the basic indexes to evaluate heat damage risk during the sensitive stages of heading, flowering, and filling. A "Four Factors" multi-risk assessment index system of heat injury for single-cropping rice in Sichuan Province was established by using the Grey Correlation method, and used in the risk regionalization of single-cropping rice of the study area. The results of the multi-risk assessment model were valuable for making decisions to relieve disaster risk. The assessment results showed that the parallel ridge-valley region of the eastern basin, the shallow hilly area of the central basin, the west part of mountain area around the basin, and the southern hilly area of the southern basin were divided into high-risk areas with gentle topography and frequent heat damage. Plain and hill areas of the western basin and mountain area of southwest Sichuan were roughly divided into medium risk areas with good irrigation conditions, higher socioeconomic developmental levels, and good coping abilities. The wide valley area of Southwest Sichuan and mountain area around the basin were roughly divided into low risk areas where the regional topography is complex, and less rice is planted. In summary, there were clear differences in heat damage risks on single-cropping rice in different regions in Sichuan. Reasonable varieties and cultivation modes should be chosen to raise prevention and reduction ability based on different regional risk characteristics.