1961～2011年长江中下游地区一季稻洪涝灾害时空变化 及风险评估

为探究长江中下游地区一季稻洪涝灾害的变化规律和风险分布，本研究利用该地区1961～2011年气象观测资料和1980～2011年一季稻发育期资料、面积产量数据，以累积湿润指数为基础构建灾害辨识指标，分析了一季稻洪涝灾害的时空变化；综合考虑致灾因子危险性、孕灾环境脆弱性和承灾体暴露性建立风险评估模型，完成了风险度区划。结果表明：（1）近51年长江中下游一季稻洪涝灾害年际变化显著，除重度洪涝外均呈增加态势；大部分地区灾害发生频次为30～90次，高发区在湘鄂交界西部地区。（2）一季稻洪涝灾害发生概率高值区在长江沿岸地区和浙江东南沿海地区，达30%以上；灾损率为3.2%～5.2%，大致呈阶梯分布，从东到西逐渐减小；大部分地区种植比率低于10%，江苏省的种植比率明显高于其他省；风险度分布大致以长江为轴，由长江沿岸向外逐渐递减，最高值出现在湖南石门，达0.24。

Spatial-temporal Variation and Risk Assessment of Flood Disaster for Single-season Rice in Middle and Lower Yangtze River from 1961 to 2011

To explore the change rules and the risk distribution of flood disaster for single-season rice in Middle and Lower Yangtze River,based on the meteorological observation data from 1961 to 2011 and the rice growth period data as well as the area yield data from 1981 to 2011 in this area,the disaster identification index was built by accumulated humidity index,and the temporal and spatial changes of flood disaster for single-season rice were analyzed. The risk regionalization of flood disaster was achieved using the risk assessment model,which was constructed with the consideration of the dangerousness of disaster-causing?factors, the vulnerability and exposure of hazard-affected?bodies.The results showed that:(1)The annual variations of flood disaster for single-season rice in Middle and Lower Yangtze River was significant in recent 50 years,and the occurrence of flood showed an increasing trend except the heavy floods .The occurrence frequency was 30 to 90 in most areas, and the areas with high incidence was the western of the junction of Hubei and Hunan .(2)The probability of flood disaster for single-season rice was relatively high in the area along the Yangtze River and the southeast coast of Zhejiang,which reached more than 30%.The loss rate showed ladder-like distribution reducing from the east to the west gradually, range from 3.2% to 5.2%.The ratio of planting was under 10% in most areas,and the value in Jiangsu was significantly higher?compared to other provinces. The region of high risk degree distributed in the area along the Yangtze River.The value of risk degree decreased gradually from the Yangtze river,with a maximum of 0.24 in Shimen, Hunan.