中国冬小麦麦收期连阴雨灾害风险评价

论文基于中国839个国家气象站点逐日降水观测数据和778个农业气象站点农作物生长发育数据,提取并统计了中国冬麦区265个国家气象站点麦收期连阴雨频率、最长连阴雨日数和最大过程雨量。通过构建“灾害胁迫-暴露-适应”的麦收期连阴雨灾害风险评价体系,采用熵权灰色关联分析法对2014年中国166个地级市冬小麦麦收期连阴雨的灾害风险进行评价。在此基础上,针对不同灾害风险主导因子进行风险防范分区。结果表明：1）空间分布上连阴雨灾害胁迫的带状递减特征明显,秦岭—淮河以南地区的灾害胁迫等级整体高于秦岭—淮河以北地区;灾害暴露和适应等级呈现出高低交错的空间分布特征。其中,华北西部、黄淮西部和西南地区东南部的暴露等级相对较高,适应能力相对较强的地区主要分布在省会城市、直辖市及其周边区域。2）处于麦收期连阴雨灾害中等以上风险的区域占冬小麦播种地市的73%,2 226.23万hm²的冬小麦处于麦收期连阴雨的胁迫中。3）中国冬小麦麦收期连阴雨灾害风险热点区域以灾害胁迫-适应主导和适应能力主导为主,加强灾害监测预警及提升区域适应能力是降低冬小麦麦收期连阴雨风险的有效途径。

Disaster Risk Assessment of Continuous Rain during Harvest Period of Winter Wheat in China

Continuous rain is an extreme weather event relevant to climate change that has caused difficulties in the harvesting, drying, storage, and transportation of winter wheat. These issues generally degrade wheat quality, resulting in high yield but poor crop income. Based on daily precipitation observation data from 839 national meteorological stations in China and crop phenology data from 778 Chinese agrometeorological stations, the frequency, longest duration and maximum total precipitation during the harvesting period of winter wheat were extracted and calculated for 265 stations in winter wheat region of China. By constructing a “disaster stress-exposure-adaptation” risk evaluation system and using an entropy weight grey correlation model, we evaluated the continuous rain disaster risk for winter wheat in 166 cities in China. On this basis, areas with high risk of continuous rain disaster were partitioned for risk prevention according to different dominant risk factors. Results showed that: 1) Spatially, disaster stress decreased significantly from south of the Qinling-Huaihe to north in a banded pattern. Both exposure level and adaptation level of disaster showed the pattern interlaced with high and low levels. The high exposure areas were mainly concentrated in western part of North China, the western Huang-Huai region and the southeastern part of Southwest China. The high adaptability areas were concentrated in municipalities, provincial capitals and their neighboring cities. 2) The disaster risk level for continuous rain on winter wheat was determined on the basis of three factors: disaster stress, exposure and adaptability. The regions with the highest and higher risk levels were mainly concentrated in the western Huang-Huai region, the western Yangtze-Huaihe region, the southeastern part of Southwest China and Southwest China, while the lowest and low risk levels were mainly concentrated in municipalities, provincial capitals and their surrounding cities. The number of cities above the medium level of risk accounted for 73% of all cities, directly threatening the harvest of 22.262 3 million hectares of winter wheat. 3) Disaster stress and disaster adaptation factors were each divided into two grades, high and low, according to natural breaks method, and the two factors were combined to partition the prevention areas of winter wheat. Areas of high stress and high adaptability were named stress-dominated areas, areas of low stress and low adaptability were named adaptation-dominated areas, areas of high stress and low adaptability were named stress-adaptation-dominated areas, and areas of low stress and high adaptability were named exposure areas. The hotspots of disaster risk were mainly stress-adaptation-dominated areas and adaptation-dominated areas. Strengthening disaster monitoring and early warning and improving regional adaptability can serve as effective ways for reducing the risk of continuous rain disaster.