西南地区水稻洪涝灾害风险评估与区划

为全面评估水稻洪涝的综合风险,基于自然灾害系统理论和农业气象灾害风险评估方法,利用西南地区(重庆、四川、贵州和云南)193个气象站1961-2012年逐日降水资料、396个县(市)1981-2012年水稻产量、面积资料和17个农气站点水稻生育期数据,以及西南地区数字高程(DEM)数据,构建区域水稻洪涝灾害致灾因子危险性、承灾体暴露性、孕灾环境敏感性和区域抗灾能力指数,以及综合风险评价模型,对西南地区水稻洪涝进行风险分析与区划。结果表明:(1)水稻不同生育阶段洪涝等级风险概率分布存在明显的地区差异,洪涝危险性表现为移栽分蘖期拔节孕穗期抽穗成熟期;全生育期高、次高危险区主要分布于云南南部和东北部、贵州南部,以及四川的成都、眉山和德阳地区。(2)基于不同时间序列的水稻相对暴露率明显波动,水稻生产承灾体高、次高暴露区主要集中在四川东北部和重庆地区;孕灾环境高、次高敏感区主要位于云南北部、四川南部和贵州东南部地区;水稻洪涝低抗灾能力区主要位于贵州。(3)西南地区水稻洪涝综合风险呈由中部向四周递增的趋势,高、次高风险区主要位于贵州南部、云南南部和四川东北部地区,低风险区位于重庆南部和云南北部地区。

Flood Risk Assessment and Zoning for Rice in Southwest China

As the main crop in Southwest China (Sichuan, Chongqing, Guizhou and Yunnan province), rice is widely accepted to be seriously threatened by the flood disaster. Agro-flood risk analysis is helpful for improving the ability of regional disaster management and reducing potential flood risk. In this study, the rice flood risk was analyzed and then zoned using the integrated rice flood risk assessment model including hazard, exposure, sensitivity, and flood prevention and mitigation ability, and based on a data set of the daily rainfall data in 193 meteorological stations from 1961 to 2012, rice production data in 396 counties including plant and yield data from 1981 to 2012, the phenophase data of rice from 17 agrometeorological stations and geographic data in Southwest China. The results indicated that flood hazard risk probabilities variated with phenophase and hazard level. High flood hazard risk happened in transplanting-tillering stage, followed by jointing-booting and tasselling-maturity stages. High-risk areas of flood hazard in whole rice growth stage was detected to be located in south and northeast areas of Yunnan, southern Guizhou, and Chengdu, Meishan and Deyang in Sichuan province. High and sub high exposure zones were mainly located in northeast part of Sichuan province and Chongqing. Subsequently, high and sub high sensitive zones were mainly found in north Yunnan province, south Sichuan province and southeast Guizhou province. Low flood prevention and mitigation zones were located in parts of Guizhou. Finally, the high and sub high zones for integrated rice flood risk were detected in northeast Sichuan province, south Guizhou province and south part of Yunnan province, while south Chongqing and north Yunnan were recognized with low rice flood risk.